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How to calculate IWA water balance
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You can download the free AWA manual, software, data sheets etc. here
Attached is a component analysis spreadsheet model with built-in instructions
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Hi,
I am looking for a spreadsheet-based water balance model for lake operation. Please don't refer me to papers. I am looking for an actual spreadsheet. Thanks
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Dear Hadi Hamaaziz Muhammed and dear Rafael Anleu I pm'ed you
Best,
Angelos
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Towards a holistic water vision for national water and food security The discussion focuses on the analysis of comprehensive national water balances: underground and surface water "Blue Water", soil water reserves "Green water", and the net "Virtual Water" flux related to foodstuffs imports/exports; in order to conciliate in a sustainable way water resource supply with the whole demand, including food demand.
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Dear Prof Jamel Chahed
Appreciated you, for Very vital and interesting discussion, as far as the all evidences have showed that climate change would have adverse impact on world water resources and food production!!!!!!!!!!!!!!!!!
Rising global food production has put pressure on freshwater resources, especially in countries with high growth rates of food demand.....
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Hello, honorable forum members. I have a question related to ponds, retention tanks, etc. in the SWAT model. What water balance parameters are affected by adding pond parameters in the .pnd file? I would also like to model an increase in the number of ponds in the catchment area. Is it enough to enter new parameters in the .pnd file for this purpose, or do you also need to draw the joints on the landuse layer? Best regards Damian
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Considering water balance, the quantity and timing of flow may be affected, and evaporation from the ponded water likely to increase. Shallow ponds would evaporate more than deep ones. Deep ponds hold or detain more water. Ponds may have variable leakage rates to groundwater, some of which may emerge downstream. Ponds may be used for irrigation, increasing evapotranspiration rates. Ponds may or may not have downstream discharges, so some sections of streams could dry up, affecting aquatic life. Deep ponds with near bottom discharges may have cooling effect on downstream section, but oxygenation sometimes a problem. Ponds capturing heavy sediment loading may loose capacity with time, and the clean water releases can contribute to downstream erosion. It’s best to evaluate on a case by case basis, and using models that have not been validated to specific area as compared to actually collecting water balance data can cause some major inadequacies in estimates.
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I am trying to determine the actual evapotranspiration using soil water balance method. But cannot determine deep percolation. Could you please let me know if there's any method, formulas to estimate the DP. Thank you.
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Please Help me. I can plot it on graph paper, but I am searching for software to reduce my time.
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In General, spreadsheets have powerful graphing capabilities Kajal Kumar Mandal
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Water Value: Shadow price of the reservoir water balance equation. Why is it a constant value?
In the book "Managing Energy Risk: An Integrated View on Power and Other Energy Markets" by Markus Burger, it is mentioned is mentioned on page 171 that "Water values stay constant over time unless the reservoir content reaches upper or lower limits".
Why is it that the shadow price of the reservoir water balance equation (water Value) stays constant over time? Why does it change to another constant value only after hitting the upper ot lower reservoir limit?
In comparison, whereas the shadow price of the load balance equation (marginal clear price or locational marginal price) varies from hour to hour, assuming the resolution of the optimization is by hour?
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I don't think it's reasonable for this value to be constant, because prices change from time to time, and the value is reflected in the price
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I´m trying to get an optimal reservoir operation rule  in a multireservoir system where some reservoirs have carryover storage. I had developed an operation  model based on Kritski and Menkel´s method and uses generalized Storage - Reliabiliy-Yield relashionship. This model has been tasted and implemented in single reservoirs but not in a multireservoir system. I want to know if there are other  carryover storage methods that have been implemented in a multireservoir system.
Thank you.
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That is a good question.
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I have 5 cm, 8 cm, 10 cm, 18 cm, 20 cm volumetric water content data from TDR sensor that records every 15min. I want to know ΔS at (0-30 cm) to calculate ET by water balance method.
I changed 15min data to 1-hour data by doing average and calculated soil water storage by this method:
theta 1= [{8am (TDR 5cm)- 9am(TDR 5cm)}*0.005cm] (0.005 is depth)
theta2 = [{8am( TDR 8cm)- 9 am(TDR 8cm)}*0.003]
same for 10cm = theta 3
theta 4 for 18 cm
theta 5 for 20 cm
At last, I added (theta 1+theta 2 +theta 3 +theta 4 +theta 5)= soil water storage, but my data is not showing drying trend in mid-summer and also not showing the wetting trend for fall. I couldn't figure out where I am wrong.
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Firstly, you could have to determine the root depth of your crop, and the respective bulk density of the soil profiles. And then, you can determine the available water content as; AW=(F.C-PWP)*Depth*Bulk density.[for each layers ]. F
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Good Morning. I would like to ask a question about finding an interval for Tanaka' model. I will add boundaries and for half-width of the fuzzy numbers cj and center of the fuzzy numbers aj should be in boudaries. An article says that:
After the data related to percentage error in estimating all components of the water balance equation had been obtained, the second step was to define the reasonable criteria for setting
the constraints’ boundaries. Therefore, the interval covering 68% of the data was considered for the center of the correction coefficient fuzzy numbers, and the interval covering 99% of the data
was considered for the minimum half-width of the fuzzy numbers. From a probabilistic point of view, the coverage of 68% and 99% indicate coverage of a mean plus one standard deviation and a mean plus three standard deviations, respectively. Table 3 shows the boundaries considered for the correction coefficient fuzzy numbers used as constraints in the fuzzy linear regression models.
I do not know how to find percentage error and also how to define the reasonable criteria for setting the constraints' boundaries. I 'll appreciate it if I can get an answer.
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Kindly read this book
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  1. How can I get the software ?
  2. do you expect the model better estimate soil moisture and other water balance components in small to large area ?
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I think Distributed Hydrology Soil Vegetation Model (DHSVM) may have batter soil moisture simulation in fine resolution. And DHSVM model is easy to get.
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The aim of the article is to apply a set of fuzzy coefficients in order to minimize existing error of the water balance equation. Fuzzy regression models based on possisbility theory and fuzzy regression models based on interval analysis were applied. But according to given datas I could not find the coefficients as in the article. I took the precipitation as independent variable (x) and evapotranspiration, surface water outflow and change of groundwater storage as dependent variables as(y) How should apply the variables?
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Hi Ecem, the image shows the target equation 16, which I guess is to minimize residuals? subject to two constraints. First of all, the information provided does not fully define the constraints e.g. what is ni, what is h?
Nonetheless, assuming that the coefficients you are getting are REASONABLE, I would guess that the reason you do not get the exact same results have to do with the fitting method. I suggest you take a look at this
Hope it helps
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1. Overall view on catchment during construction of Tunnel.
2. Quantity of water unbalance, recharge process blockage, water table effect on that location and their implication.
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Before the construction of tunnels, detailed geological and hydrogeological investigation is required. We need to determine the rock types in the area, nature of the topography, the water table, existing landforms and other buried materials such as oil pipeline, electric cables and water pipelines. The recharge and discharge mechanism of the aquifer systems, the inflow and outflow of water, the drainage systems, groundwater flow direction in area needs to be put into considerations.
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I need transfer function for the mathematical model of solute and fluid transport in human kidney for the simulation purpose.
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Mathematical Modeling of Kidney Transport
By: Anita T. Layton
Modeling transport in the kidney: investigating function and dysfunction
By: Aurélie Edwards
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Hi all, i'm trying to implement the SM2RAIN algorithm in python for estimating precipitation in USA based on soil moisture observations, i started by gathering data on county level.
I used " NASA_USDA/HSL/soil_moisture" for the SM observations, basically the SURFACE SOIL MOISTURE (ranges from 0 to 25mm), the temporal resolution is 3 days (the lowest available one)
For the precipitation, i used "IDAHO_EPSCOR/GRIDMET" for daily observation, i resamplead the data to 3 day accumulated values.
I implement the algorithm using this code freely available on github " https://github.com/IRPIhydrology/sm2rain/blob/master/sm2rain/algorithm.py ".
I normalized the surface soil moisture values and got started with on county (320 observation)
I used the pearson's correlation R and RMSE as metrics for evaluating the output of the model.
The calibration process was processed on the whole dataset
PROBLEM:
The issue is that i'm getting a low R value (below 50%), and the simulated precipitation always has the same pattern as the soil moisture.
the simulated precipitation cannot catch the hight values of observed precipitation as you see in the attached file (orange color: observed precipitation/ blue color simulated precipitation [only 30 points in the graph]
Questions:
Did i choose the correct soil moisture variable ?
it is normal that simulated precipitation has the same pattern as the soil moisture ?
Any tips or suggestions are appreciated.
Thanks in advance.
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Very late answer :)
I believe there's a temporal mismatch between soil moisture and precip data.
Two suggestions:
1) you can send us the SM and P data to have a quick check
2) please note that an updated version of SM2RAIN algorithm is available in GITHUB: https://github.com/IRPIhydrology/sm2rain
I am at disposal for any question
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Groundwater recharge, groundwater pumping and regional groundwater flow are the main components of groundwater water balance calculations of an area under study.
Although, there can be much variation in recharge, discharge and regional groundwater flows from place to place. Suppose, we are talking about an area having a square shape, so that lateral flow and vertical recharge/discharge areas are in proportion, i.e. in square shape, the size of the area will not affect the relative proportion of regional flow to vertical recharge/discharge from the aquifer.
My question is: what can be the relative (%) quantum of regional groundwater flow in overall water balance of the area under study, having a square shape.
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not more than 4%.
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I have a multipurpose dam with hydropower, irrigation and water supply. I need to optimize water balance budget for the various component. Can anyone help me with a software or excel based program to perform the optimisation analysis?
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A little bit outdated, but still good for estimating required reservoir volumes from monthly water budgets may be the sequent peak algorithm. A short summary of the sequent peak algorithm is in one of our public Python programming exercises:
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Hi
Would you please let me know if the following is accurate as an answer to the question:
Suppose we have sensors which measure the volumetric soil water content of a soil layer for a long period (more than 6 months) and also high temporal resolution (half-hourly). Could I assign the maximum in this dataset to the saturation point?
I understand that we do need to have a lengthy rainfall event, how long the event should be so that the above proposal works?
And if there is any other way that I can get to the saturation point of a soil layer from the volumetric soil water content data/sensors, please let me know.
Mostly focused on the topsoil and preferably only using the dataset.
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There are standard methods for testing soils to consider. Usually soil samples are taken and put into a container of water so the soil is saturated from the bottom, about 24 hours. Unless there is a water table to saturate soils in the field, ability in reaching saturation may vary with the conditions. I remember we had a dry period and wildfire, then a substantial rain, about 3-5 inches. Water was pounded on the surface the next day, but the soil scientist found the soil totally dry about 12-18 inches below the surface. I also learned that an upper clay layer needs to be saturated before the lower sandy layer can effectively gain water and this is related to the tension with which clay holds water as compared to sands. Some soil layers have difficulty becoming saturated, such as well developed forest soils seldom exhibit runoff due to high infiltration and macropores from roots, etc. other soils as hydric soils are saturated frequent enough to exhibit hydric soil indicators due to frequency of high water table. Sampling the soil depth or horizon is probably the most reliable using standard methods to saturate and measure.
I would not use just the high reading in 6 month period, unless at least I reviewed nearby stream gauging stations and the rainfall during the 6 month produced at least a bankfull streamflow event, which occurs generally about every year, and the stream channel is at a level where flooding begins for stable channels that have not aggraded or degraded. I would want to be pretty sure there was a reasonable likelihood of saturation based on evidence like the streams were near or at flooding. The other option might be to set up so the area with the data sensors can be irrigated for long enough so the detectors stabilize after reaching their approximate maximum. Saturating from the surface can apparently leave some air spaces unfilled, but unless the area periodically has a high water table, the air spaces may not be filled easily to saturation by rainfall anyway.
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Dear colleagues,
I am looking for observed water balance data for Roseires and Merowe dams during the period 2008 to 2012. I will appreciate for any help.
Thanks in advance
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Follow.
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I have seen that normally available river flows divided by the population of the country is taken as water availability (cubic meters per person per year) for the country. I feel that available rainfall below the measuring points for river flows should also be included towards water availability calculations.
I want to know the opinion of other colleagues in this regard.
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Hello, guys, I need resources for these types of questions. if anyone can help I would appreciate it.
Q: How much water resource is required for a person/year to keep better river quality?
Please calculate under following assumption; (2 significant figures)
- Water consumption per person per day: 250 L
- BOD value of treated water by biological wastewater treatment process: 20 mg/L
-BOD value for maintenance of biological ecosystem in the aquatic environment: 4 mg/L
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I am doing a research studying impact of climate on lake and want to make scenario i read alot of researches ,but don't know how to start , i will be grateful if someone help me
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I recommend the following article; You can use the WEAP water balance model.
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Our assumption:
We assume that data-driven models are superior to physically-based and conceptual models.
Our question:
Are data-driven approaches “a good/the best guess” to benchmark our model and the used input data, respectively?
Here is an example to illustrate the problem:
We have a physically based hydrological model which simulates the components of the water balance and whose parameters are physically meaningful and therefore are based on observations.
Our model simulates for an observed catchment the discharge. We are getting an NSE of 0.1 in validation. Normally this performance would be judged as very critical. Alternatively running a data-driven approach, with the same meteorological input results only in a slightly better NSE of 0.13.
Under our assumption of data-driven models superiority we than can concluded:
1. Our physical based model represents the processes quite well
2. The model parameters are carefully chosen/observed
3. The meteorological input data is not sufficient to achieve a proper discharge and vice versa
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I probably did not answer your questions. I have always preferred to use the USGS stream gauging data and along with local data I collected when needed. Being able to read the channel relative to bankful elevation is also helpful (more info at www.wildlandhydrology.com). I hope as professionals we can do better than a good guess, but I know with the past information that I have had access to (USGS, experimental hydrologic stations USFS, precip data network, well records, etc.) is likely more than most have to work with. Some of the earliest experimental watershed studies I believe were in Germany, since I saw your University location). In the USA, there are some unbelievably excellent works from many decades ago. In some ways, they seemed to invest more back then, than they do now. Many long term stations have been abandoned due to cost savings. I know very little about the Germany studies if that is the area of interest. Land use, soils, geology, topography, channel types, incipient conditions and hydrologic modifications are among the factors that need to be considered in hydrologic responses. I do note that the USGS flood frequency models typically have a 40% variation, so this level of uncertainty from data based models across physiographic areas or regions should be expected. By selecting the more localized stations to an area of interest, it is likely the variation can be reduced. Often the physiographic area or regional approach to prediction of flood frequency uses a regional skew, sometimes urban or land use adjustment coefficient, and does not normally make adjustment for rainfall intensity and frequency differences such as those in Technical Paper 40 (US Weather Bureau, NOAA). Based on my work in the Chattooga River, it appears that the high rainfall in this area has to be considered when applying regional or physiographic area equations for flood prediction. In the upper part of the Chattooga watershed, a 40% increase in the 100 year flood estimates appear to be justified, based on the rainfall frequency map when comparing this local area to the average rainfall of the many stations, and also based on storm response data actually collected and compared to other station data. In addition, past failure of road sections were due to culvert failure or erosion bipass. In some cases, leaf fall was also contributing to culvert plugging or diversion, and the engineers decides to just oversize replacement culverts. But in my response, I have not been very impressed with the few models I have tried. I have seen some results of individuals that suggest they have had good, even impressive results with Mike-She, SWAT, etc. I have not been very impressed in past trials from the SCS-CN method that I have tried or been exposed to. In a couple of instances, I found and somewhat impressed that the Rational Method was in the ballpark on small catchment estimates in comparing with results from the USGS equations. It seems important to validate model with data, or data based equations from vicinity of interest.
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The USGS has developed reference and potential evapotranspiration databases covering large land areas. This information would be helpful in developing water balances where direct measurements are sparse. However, accessing the data for use in simulations is not user friendly. Does anyone have a script or methodolgy that I can use or adapt for my research?
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Hi James R Chastain, Jr , As Mohammad said, please provide the data link. Best.
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Hi,
I have a question for all the soil scientists and geo-hydrologists around.
We want to model the runoff behaviour of a couple of watersheds where some soil and water conservation measures will be implemented (something like small trenches to retain runoff).
Our model is something simple and we are building it for an area with little data available (thus the need to stay simple). We want to roughly estimate how much additional water (runoff and direct rainfall) can be captured by the soil and water conservation structures. The model is a simple water balance for which we need infiltration values (measured with mini disk infiltrometer), which in turns is influenced by soil texture.
We have collected quite a number of samples at surface (0 to 20 cm) and subsurface (20-50 cm) for this. Here is my question for you:
When on a budget constrain, which depth would you prioritize to characterize texture - surface or sub-surface?
Our gut feeling is to prioritize the surface samples, but i would love the opinion of some scientists with hands on experience (possibly with some references to prove the point).
Any thought on this would be much appreciated!
Thanks a lot everyone,
Francesco
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The priority would be for the surface layers. If low hydraulic conductivity layers are expected in the subsurface layer, the importance of characterizing these strata would be increased.
With budget constraints, it might be a valid idea to prioritize field infiltration testing to calibrate empirical models, in addition to soil density and macroporosity.
An additional note: in certain oxisols, texture is not a determinant of infiltration capacity, but rather soil structure (granular), which results in high macroporosity. In these cases, even for clay soils but with granular texture, the infiltration capacity is high.
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Does anyone know how to calibrate a PR2/6 SOIL MOISTURE PROBE in the field?
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see my profile to get the publication related to the calibration.
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If we are consuming salty food?
Can we consume low TDS water to balance the salts of body at equilibrium?
Because most of the expert says Low TDS water is dangerous for consumption.
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Interesting........... Safe water and food both necessary for good health.
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Good Afternoon Everyone! I am working on the optimization of Irrigation supply. For that I need to develop water Balance. The area I am working on is water scarce so, the irrigation is dependent on Surface water as well as on Groundwater Abstraction. My question is how can I add the groundwater Portion in the water balance? As, I don't have any information regarding the volume being extracted. I am having the climatic data, and the Channel flows at head and tail. In addition to that there are also some data points available regarding Groundwater table pre. and post monsoon. Is there anyway to estimate the amount of Groundwater with the available data without using model i.e Swat?
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You can calculate the water budget base on storage capacity in aquifers as a specific yield of these aquifer, study infiltration, the relationship between rainfall and infiltration, surface runoff.....
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I found softwere (http://greenleaf.unl.edu/), but potential evapotranspiration is done by Thornthwaite method.
Also i can do it in excel but is very time consuming process. 
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Terrestrial water storage (TWS) changes are calculated using GRACE data given as TWS = Surface water + Soil water + Snow.
How to calculate TWS from CMIP data ? what parameters can i use from GCMs?
Is there any possibility to calculate TWS from water balance equation?
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You need to assess the water balance from the climate data that CMIP Models. I recommend using a hydrology model to use the temperature and precipitation data from CMIP. If it is a regional study, VIC model might be ideal. If you are studying a watershed, you can assess TWS using a simulation model. Simple water budgets at a unit scale can also be used to assess water storage using GIS. Without specifics of your research, it is difficult to be specific.
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WR=ETc
Soil water balance method
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The tool that is mainly used to estimate crop watre requirements is the Food and Arigultural Organization's CropWat. CropWat 8.0 is available to download from here: http://www.fao.org/land-water/databases-and-software/cropwat/en/
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Of the total amount of precipitation, some runs-off, some evaporates, some infiltrates. Run-off depends on multiple factors like
  1. Amount and intensity of precipitation
  2. Slope
  3. Permeability of underlying soil and rock
  4. Wetness of soil
  5. Temperature
  6. Vegetation cover
  7. Surface storage
What is the most accurate method to estimate run-off coefficient local to a village, which takes into account these factors? Are there any tables which tabulate run-off coefficients for different field situations?
I would like to explain the context of my question here.
We train villagers to manage water resources in the village. In the process, villagers prepare the water budget for their village. We are fortunate to be engaged with 4000 villages. Thus we need run-off and evapo-transpiration coefficients for 4000 villages. These coefficients should be accurate enough to represent their localities. But, the process has to be simple enough so that villagers are not discouraged. What should be the process to estimate run-off and evapo-transpiration coefficients?
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The Budyko Framework (Budyko,1974) constitutes the strong globally observed empirical relationship between the ratio of atmospheric water supply and demand (potential evaporation/precipitation) and evaporative ratio (evaporation/precipitation ~=1-runoff/precipitation) for multi-annual data at the catchment scale. The framework has a long history as it finds its origins in empirical findings of Schreiber (1904) and Ol'dekop (1911) and over the years many Equations have been developped that describe the empirical relationship E/P =F(Ep/P) (e.g. Turc, 1954, Fuh 1981, Zhang et al, 2001, Wang & Tang, 2014).
Over the past years it seems the framework is experiencing a Renaissance where the framework is used to understand and to predict water balance behavior, both for stationary and changing climate and landscape conditions.
This Renaissance mainly started with the work of Milly (1993, 1994a,b) who was the first to attempt to understand the role of several climate and landscape conditions that control long-term water balance. Milly's work lead to many studies applying the framework to understand the role of different climate and landscape properties on the water balance.
Although the framework was originally developed for multi annual mean values, Dooge (1992) introduced how the framework can be used to asses the impact of climate change and variability on the water balance, which has subsequently been extended to also quantify the impact of humans (eg. via water use and land over change (Roderick & Farquhar, 2011; Wang & Hejazi, 2011). The past couple of years this approach is now very frequently applied.
The strong empirical relationship between Ep,P and runoff ratio also brings up the interesting question how landscape properties evolve under climate conditions such that this strong empirical relationship is found. Some initial studies have been performed (e.g., Gentine et al., 2012; Troch et al., 2013) but it seems that such approaches are still in their infancy.
The question I now have is: what do you consider the future of the Budyko framework?
Will you consider this framework a valuable tool to guide hydrologic studies in the future? What questions regarding the framework are still unaddressed, but would provide valuable insight? How can we use new data sources to improve our understanding? What novel approaches (eg for more multidisciplinary research efforts) do you envision? How can we test some of the underlying assumptions of the framework when it's applied to changing climate and landscape conditions?
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I I think the Budyko framework should evolve to a smaller time scale to expand its applicability. We developed the Budyko framework to the annual time scale in a more concise way.
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I have an estuary having 5 rivers as its inlet and 3 outlet connected to sea. I wanted to water balance of estuary and how it is changing with drastic change in surrounding landuse/land cover change. Is there any model that computes water balance of estuary?
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For Vemband estuary cwrdm is already carried out water balance in collaboration with koyoto university japan
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Dear Researchers,
I would like to request that if anybody have Budyko Frame work in excel (Macro), or MATLAB code or any other userfriendly tool for water balance study induced by climate change. Please share.
OR
Any idea how to use Budyko Framework also appriciated.
Regards
Naveed.
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Dr Maryam Hafezparast , I have been using WEAP Model sice last 5 years and also delivered many lectures on it also workshops.
Pleas let me know, how I ca use WEAP for this purpose. Can you please further elaborate me so that I can follow your suggestions.
I did not how to use ANNs but over WEAP I have well command upto expert level.
Regards
Naveed.
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I’m working on impact of rainfall and temperature on crop productivity, so I want to assess the correlation between weekly water deficit in growth stages of crops and productivity of crop using ArcGIS 10. Can anyone suggest me how compute weekly water balance by Thornthwaite method using ArcGIS 10? Is there any tool for spatial analysis of water balance in ArcGIS?
If anyone workout on this topic, please, send me references.
Thanks
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Thanks Gabriel Vicente Gaona
I will try to apply toolbox suggest by you.
Thanks for your valuable guidance and links.
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Is there any new method for water balance calculation?
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Hi Arnab,
Have a look on the following paper to give you a clear idea about how to calculate water balance.
El Chami D, El Moujabber M and Scardigno A; (2009). Regional water balance and economic assessment as tools for water management in coastal Lebanon. Water Resource Management, 23 (11): 2361-2378. (DOI: 10.1007/s11269-008-9385-y)
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I want to calculate water deficit period for understanding impact of rainfall on crop productivity. Can I use 'Raster Calculator' for calculation of water balance of District using ArcGIS 10?
If anyone know the, please guide me.
Thank You
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Hi Sandip,
When you apply an interpolation based on whatever method on raster data, the raster pixel size of your water balance model has to be small enough to obtain enough pixels in your Region of Interest (ROI). If not, interpolation will give you biased vector information of your water balance variables.
It is by the way possible to estimate Soil Moisture Content (SMC) with remote sensing. I figger that SMC is a better proxy for crop productivity estimation than precipitation.
Cheers,
Frank Veroustraete
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Hi RGmate,
I have initiated an experiment focusing on crop evapotranspiration. I need to measure the crop evapotranspiration by water balance equation.
ETc = I + P + U – D – R – ΔS
In above equation, important thing is to find ΔS (change in soil moisture) and for ΔS I have two different values. Firstly, moisture contents were measured by gravimetric method (unit is gram/gram). After that I recorded moisture contents by EM50 logger and it gives values in volumetric water content (unit is m3/m3). I have three questions.
1: How can I convert the gravimetric method value into volumetric value?
2: What is exact formula to measure change in soil moisture? Either Current soil moisture – Previous soil moisture or Previous soil moisture – Current soil moisture?
3: Although irrigation, precipitation and others in above water balance equation are in mm. What is the unit of Change in soil moisture (gram/gram, m3/m3 or mm)? If the unit will be mm then How do I convert gram/gram or m3/m3 into mm?
Regards
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I am interested in simulating the effect of future climate change on groundwater resources in Nigeria using a spatially distributed monthly water balance model. Which of the global circulation models is the best suited for Nigeria? Secondly, I wish to know if there is a way to get already downscaled GCM that can be used for monthly water balance model in Nigeria?
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Hi Eniola,
Regarding your first question, I agree with Proloy Deb that some literature search on GCMs analysed for Africa or parts of Africa will be very useful. Alternatively, you can download GCM data and compare relevant climate statistics obtained from GCM data with observed statistics. Regarding your second question, besides Sim-Clim you might have a look at the CORDEX website (http://www.cordex.org), specifically at the availability of RCM data for Region 4: Africa.
Good luck,
Martijn
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I want to simulate potential future climate change scenario on groundwater resources in Nigeria, using a monthly spatially distributed water balance model. I wish to know which of the global circulation models is the best suited for Nigeria and can be used with monthly water balance model? Secondly, is there is anybody with information on already downscaled GCM I can use for such study in Nigeria. Thank you
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Dear Eniola, you may need to read up about the different models before deciding on what best suits your research aim and scenario. I have attached a document that may guide your decision. Best wishes.
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Hi RGmate,
I have initiated an experiment focusing on crop evapotranspiration. I need to measure the crop evapotranspiration by water balance equation.
ETc = I + P + U – D – R – ΔS
In above equation, important thing is to find ΔS (change in soil moisture) and for ΔS I have two different values. Firstly, moisture contents were measured by gravimetric method (unit is gram/gram). After that I recorded moisture contents by EM50 logger and it gives values in volumetric water content (unit is m3/m3). I have three questions.
1: How can I convert the gravimetric method value into volumetric value?
2: What is exact formula to measure change in soil moisture? Either Current soil moisture – Previous soil moisture or Previous soil moisture – Current soil moisture?
3: Although irrigation, precipitation and others in above water balance equation are in mm. What is the unit of Change in soil moisture (gram/gram, m3/m3 or mm)? If the unit will be mm then How do I convert gram/gram or m3/m3 into mm?
Regards
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Dear Muhammad,
Regarding your questions:
1: The gravimetric water content should be multiplied with the bulk relative density (the ratio of the bulk density of the soil to the density of water; dimensionless) to obtain the volumetric water content.
2: The general formula for change in storage dS = S(t+dt)-S(t), where S is storage, t is time and dt is the time step.
3: The volumetric water content should be multiplied with the soil depth to obtain the storage in mm and hence also the change in storage in mm.
Good luck,
Martijn
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In the T&M monthly water balance we can compute surplus as the difference between precipitation and potential evapotranspiration, once the soil water reserve has been filled. Is there a way to separate water surplus into infiltration and direct ruonff on a monthly time-scale?
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Some versions of Thornthwaite & Mather (TM) monthly water balance have included DRO (direct runoff) calculation - paper in attachment. Authors of this paper and software suggested using 5% of precipitation as direct runoff, later this DRO is added to runoff that is generated from the surplus S). In software it is possible to adjust this percentage. I tried this software but I was not happy with results, or perhaps I did not understand the method.
I am not sure who first introduced direct runoff calculation into TM, perhaps Mather in:
  1. Mather, J.R., 1978, The climatic water balance in environmental analysis: Lexington, Mass., D.C. Heath and Company, 239 p.
  2. Mather, J.R., 1979, Use of the climatic water budget to estimate streamflow, in Mather, J.R., ed., Use of the climatic water budget in selected environmental water problems: Elmer, N.J., C.W. Thornthwaite Associates, Laboratory of Climatology, Publications in Climatology, v. 32, no. 1, p. 1–52.
but these papers cannot be found on net, so i cannot be sure!
Version from 1948, 1955, 1957 dont have direct runoff (I have this papers). Same problem is with AWPL (accumulated water potential loss), it is there in 1955/57 version, and than as Dingman, S.L. presented in his book Physical Hydrology there is no AWPL even he is referring to 1955, 57 version...all these TM model versions (Thornthwaite, 1948; Thornthwaite & Mather 1955/57; Mather 1978/79; Dingman, 2002, McCabe, Markstrom 2007) give different results...
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I am trying to create a (very approximative) model of a territory, focusing on the water balance.
I have some different vegetation areas, taken from the Map of Natural Vegetation of Europe (by the Bundesamt für Naturschutz).
The data look like for example like this:
"Formation F.1 : Species-poor oak and mixed oak forests (Quercus robur, Q. petraea, Q. pyrenaica, Pinus sylvestris, Betula pendula, B. pubescens, B. pubescens subsp. celtiberica, Castanea sativa)".
Does anyone know where to find data about the root depth of particular species or of the kind of forest in average?
Thank you in advance for your help!
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The process will be dynamic with both preferential and chromatographic flow
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We are planning riyadh city as water sensitive urban city. We have developed urban water balance model. How we can get help in applying your model?
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ournal articles and conference papers (and links where available) are available under open access arrangements where possible. Otherwise please contact your institution’s library, the authors, or publishers to organise full access.
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We are in a head watershed with a sandstone fractured lithology covered with a shallow sandy loam soil, at some places there is no soil and the fresh fractured rock outctops, no deep-rooted trees.  The climate is semi-arid.  I need to estimate the evaporation (I expect no transpiration takes place at the groundwater table) only and to make use of it in a catchment water balance. Thank you.
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Suppose there is a method to estimate groundwater evaporation. What its importance?
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I just run the Hydrus model successfully, but now I want to extract or to know how much was infiltration, evaporation, recharge throughout the simulation. I am not sure which output file I must open in excel
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Thank you for valuable comments.
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The correction of evapotranspirative fluxes of eddy covariance by means of two different approaches (Oncely and Bowen ratio), showed that the difference between the two methods increases in wet area more than the dry ones. Does anyone have an explanation for this observation?
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We did not made researchs in this area
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I am working on surface water balance of marginal grabens in northern Ethiopia. Here marginal grabens (about 2,500 km2) are transitional zone between the lowland (arid area) and northern highland (semi-arid area). The major lithological units of the escarpments are basaltic rocks. The escarpments have the same aspect, all looking towards the east direction. They recharge the graben bottoms, agricultural potential area.
Part of the water budget components, the representative rivers have been monitored since the last three years. However, there are ungauged streams contributing to the graben bottoms. In fact, there are a number of approaches available for prediction of ungauged catchments based on the spatial proximity, catchment area ratio and catchment characteristics.
I want you guys to share me your best experience (read or worked) on how to estimate the discharge of the ungauged rivers under the data-scarce geographical region.
With bets regards,
Hailemariam Meaza
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Dear Hailemariam Meaza,
I agree with Dr. Keblouti. You should perform hydrological to your ungauged River basins. Indeed you are going to need a variety of data, amongst which data of soil characteristics, topographical data, morphological data, hydrological group of soil, hydraulic parameters for streams etc., depending on the hydrologic model-software you choose to use.
However, I would like to add that it is essential to perform some discharge measurements (preferably on rain days) to validate your model. Depending on the purpose of your research, they do not need to be too many; just enough to know that your model simulates your basin efficiently.
Individual discharge measurements can be carried out manually, by means of a propeller device, for the determination of the flow velocity, after determining the dimensions of the cross-section. You should always keep in mind that the measurement of water discharge, in such conventional manner, under flood conditions is practically not feasible.
Good luck with your research!
Kostas Kaffas
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I've only seen it for routing single-event hydrographs. I'm trying to model reservoir water levels and spillway flows using a 10-year inflow time-series, bathymetry (already calculated the stage-storage and stage-area relationships), ogee spillway rating equation, and prescribed minimum conservation flows through separate outlets. Using a basic spreadsheet water-balance for daily or hourly time-step, the head and flows over the spillway are unrealistically large. 15-minutes helped but is straining my computing resources. Can level-pool (storage indication) be applied here? Any special considerations/assumptions needed?
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Well, Supposing same condition of climate factors, you can use the application of Gumbel statistical method to predict the percentile success chance (%)of any variable used in water balance for future estimation.
thanks
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1. how to calculate the different components of energy budget using satellite data
2. Which satellite products may help in this regards
3. what are the different models that can be employed 
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EUMETSAT has products, where evapotranspiration (ET) is calculated. For example, I use one of these to integrate ET values at daly, 10-day or month periods. Example is on the pictures.
Drawback of the product is a fact, that algorithm does not take into account ice evaporation.
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I have installed different length of perforated pipe in both the plots (DSR and Transplanted Rice) and after decline all water from pipe I will irrigate.
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Please shed a bit more on the design, are the pipe vertical and perforated and to what depth, do you have water in the pipe? what devices do you have for soil water measurements. 
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The SPEI is a multiscalar drought index based on climatic data. It can be used for determining the onset, duration and magnitude of drought conditions with respect to normal conditions in a variety of natural and managed systems such as crops, ecosystems, rivers, water resources, etc. However, the calculation of the SPEI gives high frequency of 0 values for precipitation and water balances when performing sensitivity analysis. It make its calculation of sensitivity coefficient a problem. The non-dimensional relative sensitivity coefficients for T can be expressed as :  S= (∂SPEI/∂T)T/SPEI
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Dear Dr. Alvaro:
I have finished the calculation of the SPEI in one of my previous study. My question is the implement of the calculation of sensitivity coefficient of the SPEI in response to a meteorological factor (such as temperature). The non-dimensional relative sensitivity coefficients S for temperature(T) is S=(∂SPEI/∂T) T/SPEI.
But the calculation of the SPEI giving high frequency of 0 values for precipitation and water balances will extensively result in 1÷0 problems. This make the calculation of the sensitivity coefficient of SPEI impossible.
I would appreciate if anybody could help me with some advice.
Thanks!
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Dear Expert
I have monitored streamflow, rainfall with another meteorological variable. While trying to do water balance of the catchment (Himalayan) following the equation P-Q=ET, it is not fulfilling the above equation. ET is being calculated using the PM method.
I am not able to find out the reason behind it. Can you please let me know the things that can be done.
Is there any problem to use ET or else I have to use actual evaporation. Please suggest me the conversion factor if any from PET to actual evaporation.
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The water balance is often done on water year to keep soil moisture changes small when done at low flow, low water table season.  Many points already made are appropriate.  The equation as you prefer is P (input) = Q + ET + soil moisture change + deep seepage (all outputs).  As mentioned, just about every factor, even if measured to some degree, is an estimate.  If the geology is tight, soil moisture change is small or accounted for, then the ET estimate can be made, but also difficult as specific to vegetation types, etc.  In some conditions, even condensation on plant surfaces can be a difficult to measure or account for input.  In some ecosystems, ET is the greatest output.  In karst systems with underground springs entering, it is possible for water input  to come from outside of hydrologic boundary, or water outputs to appear elsewhere.  If you tend to have loosing streams, water is removed from stream to replenish groundwater or aquifer.  In some channel types with coarse substrates, hyporheic flow will often go unmeasured when measuring Streamflow Q.  So considering the conditions of each water balance period, recognizing geology, soils, location of raingauges with respect to watershed, elevation, quality of measurements or estimates, all enter into a water balance analysis and help to ensure that the uncertainties are considered and addressed when possible.  Besides the hydrology, consulting with geology, soils, climate and plant specialists or information will help, especially if P-Q does not equal or come close to ET estimate.  If you did a water balance from Oct 1 to Sept 31, for each year, check for possibility of differences in soil moisture, with streamflow and recent rainfall as surrogates or indicators that there is likely a difference in soil and water table storage.  
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I currently have monthly precipitation and potential evapotranspiration for each month in my 17-year study. I calculated the water balance for each month by subtracting PET from precipitation. I then summed the water balance in three month chunks since I want the 3-month SPEI.
From here, I'm confused about calculating the probability-weighted moments (PWM) of the water balance series, which is necessary to determine SPEI.
My question is: How do I calculate the 3-month SPEI across my entire 17-year time scale? I understand how to calculate the alpha, beta, and gamma coefficients, etc. I attached a picture of the PWM formula (from Wagan 2015 "Drought Trends and Temperature Influence in Zhanghe River Basin, China".) From what I understand, the Ws is computed at different orders of s, and these results are inputs to the formulas for alpha, beta, gamma coefficients, which are themselves inputs into the SPEI formula.
In terms of Di, how do I combine my time series into this formula? For instance, I have 17 files for the 3-month June water balance, which is the sum of the April, May and June water balance in a given year. In this PWM equation, I imagine I would include all 17 years for June (and then would run the equation again for all 17 data points for July, etc.) If I did that though, then how would I determine SPEI for a particular year? Do I use this equation twice, once for the whole time series, and then again for the particular 3 month span I'm interested in?
I know there is SPEI R code, but this code cannot handle NaNs and I have a lot of NaNs. These cannot be removed since the location of the data values is very important. Thanks for any feedback.
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Dear Dion: From your message I think that your calculations are ok. Answering to your question "how do I combine my time series into this formula?", the procedure is as follows:
1) You have time series of D, isn´t it?
2) You should calculate F(x) being the xi = Di, that is, apply the log-logistic distribution with your time series.
3) p (i) = 1 - F(x), then you will have the probability of exceedance for your D time series and following the log-logistic distribution.
4) w(i)=sqrt(-2*log(p(i)) (valid for p(i) lower than 0.5)
5) By applying the formula suggested by Vicente-Serrano (SPEI web page) you will have a good estimation of the SPEI. 
I hope these suggestions are useful for your study. If you have any question, please do not hesitate to contact me.
Also, I suggest you to read the attached work for the calculation of the 3-month SPEI for large regions. Some outputs could also be useful for you. Finally, in two weeks aprox. we will have an accepted paper related to this topic, and we will be happy to share it. 
Regards, Alvaro Sordo-Ward
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I would like to calculate SPEI using the R package developed by the authors. There seems to me to be two major reasons why I can't use the R package (I'm currently trying to figure out SPEI in Matlab). I'm computing SPEI for a city over 17 years at 30-meter resolution. Currently, I have all of my precipitation, potential evapotranspiration, and water balance data for the time series. Since I want the 3-month SPEI I also summed the water balances in three month chunks (April+May+June, May+June+July, etc.)
First, my data has a lot of NaNs, and the R package doesn't accept any NaNs. I can't delete my NaNs because the location of each data point in the matrix represents its location in space (lat/long). Is there any way around this? I need to know specifically which lat/long pixel an SPEI value corresponds to.
Second, my data is relatively high resolution. I have lots of pixels for each month in my 17-year study, however, it looks to me like the R package only accepts one data point per month, since each new row represents the following month. I was thinking of putting all my data points for each month into a vector along each row, particularly since the R package computes SPEI for each column individually, and I would like SPEI on a pixel-per-pixel basis. However, each row would be over 3 million points long, and I think I read somewhere that this is far beyond what the R package is able to handle.
Is there any way around these two issues so that I can use the R package? I'm having a lot of difficulty figuring out how to calculate SPEI in Matlab (trying to figure out probability-weighted moments). Thanks for any feedback.
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You might be able to impute missing values, for example using the mice package.
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I need information on how I can estimate  water use efficiency and water productivity (methodology). What equipment could be suitable for this kind of work. If possible suggest any articles on the same. Many thanks
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Irrigation Modeling in Forage Sorghum and Silage Corn Hybrids Production in Florida and Jordan - Experimental Findings (Part 2)
This research done in Florida in a simple scientific way.
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what is the best GIS and remote sensing method of estimating water balance model for a basin?
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Dear Olutoyin A Fashae,
You can take help of my recently published article in Environmental Earth Sciences on water balance study using SWAT model. If u need any further help, u r most welcome.
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I am trying to model velocity through a wetland and have flow, water level, depth, etc. (enough for a water balance) but would like to model velocity or residence times. Is there a difference between residence and detention times? Both have the same units (time).
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Dear professor Al-Khashman, it is encouraging learning of your views, thanks for the comment, do get from Mexico saludos,jjoel carrillor
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I want to model the downstream sub cachment of a large river basin, I wonder if there is a way to input the upstream discharge in the model while I am only dealing with  the downstream basin ( I have to assess the water balance at the outlet). I will be using SWAT for my work.
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Adding the upstream hydrograph ordinates to the output flow (simulated from downstream watershed) would be a suggestion!
You can calculate the flow Travel Time through main channel (considering the delay) and get the results by summing up the delayed upstream flow data and simulated downstream ordinates.
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I am interested in the model like GISAREG application. GISAREG is not available since the language used to develop it (ArcView 3.2) is out of date and does not work in the current versions of windows.
So, can anybody suggest open source and freeware GIS application wich can take irrigation data (net irrigation requirements for different fields and crops, irrigation scheduling scenarios) from irrigation program such as: CROPWAT, AquaCrop or WINISAREG and turn them to spatial data and maps. 
Thank you.
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There is no "best"!
Gisareg is discontinued because ArcView was discontinued
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Hi All,
Does anyone can share paper/knowledge about the methodology for analysis of water balance in tropical peat area?
Thank you
Gigit
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You can use the water balance equation to assess this. Try to list and quantify all the inputs into the systems. Similarly, list and quantify all outflows in the systems. This should equal to change in storage within the area. Each of the flows and stock could be assessed either through experiments or from past statistics. You need to define the time you are interested in. For annual budget, use accumulated values for the year. An example, rainfall, surface flow into the area, groundwater inflows, water added (irrigation) are some inflows. Outflows are evapotranspiration, discharge out of the area, groundwater outflow, withdrawal of water from the area. Storage could be surface storage, subsurface and groundwater storages.  
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Hi everyone,
For all the SWAT user, could you help me with the SWAT water balance equation for soil storage and shallow aquifer storage? I have checked my SWAT model output at the HRU level (output.hru), but it always out of balance. It seems there is a 'mysterious' storage in between soil storage and shallow aquifer storage that also stores water. Any help will be appreciated.
Kind regards,
Hero
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Hi Cva,
Fully understand that the balance in the storage is calculated based on the storage before, inflows and outflows. What I want to know is what variable consider as inflows and outflows in the Output.hru in SWAT. There are three variables that make me confused about water balance calculation in SWAT i.e. percolation out of soil storage, ground water recharge and revaporation. In my SWAT Output.hru, percolation is not equal to ground water recharge so that seems water is abandoned in the 'mysterious' vadose zone below the soil storage.
To make it clear and straightforward, do I have a correct SWAT WB equation?:
(1) Change in soil storage = (Precipitation + Revaporation) - Percolation - ET - Surface runoff - Lateral Flow
(2) Change in shallow aquifer = (Ground water recharge, not the Percolation) - Base flow - Revaporation - Recharge to deep aquifer
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In my case, I have a very shallow salty groundwater table (less than 2 m), a sandy gypsyferous soil, rather monthly irrigation events, a perennial crop with deep root system. Can you please recommand some properly documentations and/or tools for my study case. Thanks in advance
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Imed, Pl have a look at thie paper, esp. the section on ''Estimation of evapotranspiration from groundwater' based on White (1932). Best,
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Since decades we are working on this aspect with plethora of models, modelers and projects at global scale. Still unit hydrograph, SCS CN and other synthetic means are appearing good enough or atleast base tools/methods. Reason is lack of real field data & commitment at micro scale. Every researcher prefer to work on a table placed in AC room and conducting experimental or other efforts in numerical form with end target of a publication in high impact journal. This weakness of micro level real data and real exposures to ground conditions, and a fear of loosing time & diluted research publication , keep away most researcher away from this challenging difficult task. This is the probable reason in my way of thinking , why even the best rainfall-runoff  models are giving equally bad answers/simulations what we get from simpler model, but here it is at higher costs. Researchers are shifting their attention towards high tech water balance water budgeting kind of phenomenon  excluding runoff overland component and getting more concentrated on remotely estimated other hydro logical constituents   like transpiration evapotranspiration moisture that too via setelite remote or sensors. Some time calling rainfall runoff modeling as ' gone era of hydrological research'  I personally feel disappointed with such kind of views. As on day, I am confident enough that even we are not in a position    to accurately define or parametrise the loss function in a rainfall runoff modeling and choose its value in very arbitrary manner, what to say about runoff prediction capabilities. Jumping towards a comfort zone just to be concentrated on publication and leaving aside understanding real ground schenerios is what I consider very much worrying situation what I guess/realize.
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Dr. Gaur, Unfortunately, you may be hitting the nail on the head, but as semi-retired, I may not be absolutely up to date.  Many researchgate questions seem to be about models to get them to function, rather than if they are applicable.  Modeling was a step in research after you developed a research plan, collected data, and tried to come up with relationships and understand watershed/stream functions.  The models of yesterday need a full review and update, perhaps rewrite or total revision.  As more and more hydrological data is collected and available, why are we not moving forward?  The problem may be as you say, many use what is available, crunch numbers in an office and do not conduct an appropriate degree of field review and data collection.  Today, we can get so much information from just GIS, and  research and stream gauging in general is perhaps getting underfunded.  Perhaps to some, hydrology is running models, maybe that is being taught too much.  And true, hydrology is not the easiest field to master, and the definition of a professional hydrologist may be blurred by the variability in expertise, as well as the complexity of water related subjects.  
Yes, hydrologists should be conducting field surveys, data collection, utilizing new technology especially LiDAR and high resolution aerial photos, testing and revising old models and developing new and improved ones.  There is nothing inherently wrong with high tech, but it should not replace attention to field data and developing that experience in being able to read the ground and stream conditions. Hydrology training should include some combination in existing models, data collection, analysis techniques and stream/watershed experience and field validation.  Hydrology studies are not necessarily quick, requiring long term funding and researcher committments.  Maybe there is a migration away, but many water issues affect life on this planet, so maybe the pendulum will swing back to better funding, long term committment, increased attention.
Regards, Bill
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The FAO Irrigation and Drainage Paper No.54 gives the Dual Crop Coefficient equation. This method requires a lot of climatic parameters to be input for each day of the study period. It is a very extensive process and some parameters may have to be interpolated.  I am curious of other ways to estimate actual Et.  The ultimate goal is to plug Et into a mass water balance to get drainage data, paired with tension-lysimeter nutrient concentration data to measure nutrient loads leaching past the root zone. 
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 you can estimate potential evapotranspiration (ET) from meteorological data (e.g., only air temperature with Thorntwaite or Blaney-Criddle eqs) and then SMAP soil moisture (SM) data for obtaining actual ET:
actual ET ~ potential ET * SM/porosity
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I want to calculate soil water balance of a bare soil. How can I determine the depth of the soil which effectively contributes to bare soil evaporation? This depth is required to determine the water-holding capacity of the soil.
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Dear Dr Joodavi, Apologies for this late comment. I know it might be complicated for you to send all related hydrogeological details of your project..  In many a case the problem of recharge determination is the major concern as you must try to find: i) how much water is going down, then ii) how long is it going to take to reach the water.table, iii) which is the path (on x,y,z) the water is to follow. and iv) which was the actual amount from rainfall that really reached your area of interest  Experience points that  a better definition of above is to "ask" the water those points (i, to iv) once the water has reached the area of interest....  we should aim to use the capability of water to keep this information, but the water will know that only after it has passed through (i to iv) not before. I know this not the "standard" procedure... do get  from Mexico saludos,jjoel carrillor  
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Dear SWAT Users,
I am supposed to carry out water balance study using a different LU cover scenarios in ArcSWAT.
I have a well calibrated and validated model,
I have the following percentages of LU cover in the watershed.
FRST 30%
FRSE 15%
RNGB 40%
AGRL 10%
RNGE 2%
URML 3%
Future land use projections show the following LU change percentages
FRST -20%
FRSE -10%
RNGB +2%
AGRL +37%
RNGE -20%
URML +10%
SWAT manual shows that we can use "SWAT’s land use update routines (lup.dat)" to update the land uses. It seems that in this update routine we edit only one LU at a moment.  Anyone who can show me how i can update all land uses based on the projected land use change?
May be a video or a detailed manual will be appreciated. Thanks
Canute
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Dear Canute,
Here is an example lup.dat file, for two land-use changes, one taking place on 1 1 1990 and the other on 1 1 2000 (i.e., 1 January). See the manual for the format of the data files themselves (what I've named Lup1990s,dat and Lup2000s.dat below). I included every hru in the data file, whether its hru_fr value changed or not:
1 1 1 1990 Lup1990s.dat
1 1 1 2000 Lup2000s.dat
For this to work, your model simulation must begin on or before 1 1 1990 -- otherwise it will ignore any land use change.
And -- note that for some reason, the second line also needed to start with a "1". I thought it should be a "2", but when I put that in, I got a floating point error. It took me several hours of trial and error to get these things figured out.
That's the limit of my experience -- things worked for me at this point. Hopefully one of these minor formatting issues is the source of your problem.
(answer by Jim Almendinger)
I hope this may help you.
All the best !
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Hi 
can I apply WFA method to city level WF assessment, when I am assessing WF of all sectors not only agriculture. If not, Why?
please give me your suggestions & references
 Thanks
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Definitely, you can apply WFA for a city. recently we have concluded the WFA study fro Delhi-NCR at NIH including all three major sectors (i.e. Agri. Domestic and Industrial) for Blue, green and grey component. We have also considered the floating population as well as virtual water import and exports in form of commodities. 
Rgds
Nema
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I am planning use water balance approach for which I need to calculate soil water storage.
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For satellite soil moisture products, here is a list (with sensor, frequency, spatial sampling, temporal resolution, and data period) of products freely available (microwave band, coarse resolution):
ESA-CCI, C-X-band, ~25 km, 1-day, 1979-2013
TMI, C-band, ~25 km, 1-day, 1998-now
AMSR-E, C-band, ~25 km, 1-day, 2002-2011
ASCAT, C-band, ~12 km, 1-day, 2007-now
SMOS, L-band, ~50 km, 3-day, 2010-now
AMSR2, C-band, ~25 km, 1-day, 2012-now
SMAP, L-band, ~36 km, 2-day, 2014-now
No high resolution (e.g., 100 m-1 km) product is available so far, in the near future a soil moisture product from Sentinel-1 will be available. Moreover, a 1 km downscaled soil moisture product integrating SMOS and MODIS data should be available soon.
For soil water balance modelling, you can use our soil water balance model (see attached link). It was applied successfully in many places worldwide.
Good luck, L
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I am trying to use vegetation index (NDVI and SDVI) to predict evaporation and transpiration and co-relate it with recharge and water table in a medium watershed?
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develop your own mass balance system using object oriented approach.  STELLA software is excellent tool for such system analysis.  Building a model for your area will assist you in estimating and evaluating your system
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Asides Stream flow, river guage data and climatic data
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Hello! It is necessary to attempt to quantify components of the hydrological cycle. I believe the following links may be useful:
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what is the best method to compute the water balance model of drainage basin using remote sensing and GIS method?
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Interesting is the use of the WASIM-ETH model for that purpose as this is a well-proofed model and it is freeware.
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Salt Concentration 
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Dear Prathap!
If I understand the question, it is a method to reduce the salt content in well water before water is taken for use. There is a method patented by me in 2015 in Ukraine.  Basically it is to change the filtration properties of the soil in the area of the well supply. As a result, atmospheric power ultrafresh waters increases and decreases the total salt content. It also reduces the nitrate content - the main problem of manhole water. In concrete terms, there are specific quantitative parameters of soil reclamation.
All the best,
Valery Yakovlev
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Many regions in developing countries have few rainfall/river discharge measurements. In addition, water table level measurements and meteorological data (for evapotranspiration) is often lacking. Yet, many water management authorities do collect some basic rainfall and river level data. Are there any simple tools to compute a basic water balance for such regions? GIS/hydrological modeling software can do this, but can be expensive, require trained personnel, and be overkill as the underlying data would be spatially patchy.
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Hello,
I think the good method for your needs is Thornthwaite & Mather (1955) monthly water balance method. Simple method, based only on mean monthly temperature, monthly precipitation, geographical location of the study area and the available soil water content (AWC). For calculation you require mean temperature and precipitation, other parameters can be estimated indirectly. Also, in the original method temperature and geographical location is used to estimate Potential Evapotrasnpiration (PET), but in the water budget you can use any other (more precise) ET equation such as FAO 56 Penman-Montheith (calculating ETo for standard grass vegetation, ET limited or ETc for specific vegetation). One of the results of the water balance method is water surplus/runoff.
Thornthwaite & Mather (1955) monthly water balance method:
Software to calculate Reference evapotranspiration (ETo) according to FAO Penman-Monteith equation:
Explanation of water balance method:
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Hi all, I am writing a water balance equation for a basin for year 1995 and 2010. The balance equation is simple (P-E=Δs) and soil moisture storage is a part of Δs . I first try to use GLDAS root zone soil moisture product to determine monthly soil moisture storage but among the monthly values were big numbers that were more than field capacity, that can't be correct.
I also try to use satellite soil moisture data like SMOS, AMSR-E or ASCAT for year 2010 but it seems that there aren’t any root zone product for these satellite at least for the years 1995 and 2010.
Is there any satellite product for the root zone soil moisture (before 2010)?
extra information: the basin is located in Iran and there is lake inside the basin, the basin area is almost 52000 km2
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The real missing variable of the water cycle obtained from remote sensing is the root zone soil moisture. We have surface soil moisture from microwave sensors (e.g. ASCAT, AMSR, SMOS, SMAP), total water storage from gravity (e.g., GRACE), but we have no measurements for root-zone soil moisture.
An indirect estimate of root-zone soil moisture from remote sensing needs some modelling: 1) simplified, e.g. the exponential filter (https://www.researchgate.net/publication/233946180_A_physically_based_approach_for_the_estimation_of_root-zone_soil_moisture_from_surface_measurements?ev=prf_pub), 2) land surface modelling, e.g. the SMAP root-zone product (L4_SM, http://smap.jpl.nasa.gov/data/)