Questions related to Semi-Arid Climate
I am doing LULC of the arid region, I have acquired landsate 8 image data from USGS website and I have done preprocess in qgis using semi-automatic classification plugin using the standard tutorial and I have converted by DN into reflections value for LULC. however, I facing difficulties in assigning classes for built-up area and bare soil as they have high overlap spectral values.
besides this, I have also used SAVI as well as Modified bare soil index though it's not helping in my problem.
Anyone can tell me what to do in that case.
Quantifying groundwater recharge in arid and semi-arid areas is a very challenging task because recharge amounts are small in comparison with the resolution of the investigation methods. Additionally, it depends on soil characteristics, geology, topography, land cover characteristics and land use, besides being affected by the temporal variability of precipitation and other hydrometeorological variables under arid and semi-arid climates. Several watershed models used to quantify recharge generally provide recharge estimates as a residual term in the water-budget. Which means that the estimation accuracy of recharge is controlled by the measurement accuracy of the various other parameters in the water budget. Moreover, according to the literature, daily time steps are desirable for estimation of recharge because recharge generally becomes a larger component of the water budget at smaller time scales.
How could we minimize the uncertainties accompanying the estimation of groundwater recharge under semi-arid conditions using SWAT model at small scale (around 350 km2 area)? Should the SWAT use be coupled with any other techniques or models (like Hydrus-1D) to get best results? Are you aware of any studies that have used SWAT to estimate groundwater recharge, or the impact of climate change and/or anthropogenic activities on groundwater recharge under arid or semi-arid conditions?
Who can enlighten me on the different trace fossil species in the attached file? The setting: Distal part of the Miocene Huesca fluvial fan (Ebro Basin, Spain). Semi-arid climate. Dominantly floodplain fines with thin-bedded terminal-lobe and crevasse-splay sandstone bodies. Traces are on the grey-colored (reduction) upper surface of the sandstone beds.
Help is appreciated. Thanks in advance,
i want to find a formula or a correlation between runoff coefficient using slope and land use (vegetation and type of soil)?
runoff coefficient and the slope and also land use
Hi!, hope you're having a great day, being safe at home.
I'm from La Paz, Baja California Sur, México, and I'm writting my proposal for my thesis project for my Bachelors Degree in Management and water sciences.
Currently I'm interested in researching the economic assesment methods for ecosystem services (ES), specifically those related to catchment and provision of water.
I should mention that the region where I'll be working is a property located in the upper zone of the watershed (, where the main population are smallholders whose actions have cased the deterioration of the soil due to livestock activities; coupled with the arid climate or the region where the average maximum temperature is 36°C and the mean annual precipitation corresponds to 180-200 mm.
I already understand these phases for making the assesment process:
1. Identify the purpose of the assessment.
2. Identify the geographic scope of the proposal.
3. Identify the ecosystem services located in the geographic scope of the program.
4. Identification and characterization of the economic agents that benefit from the ES.
5. Prioritization and characterization of ecosystem goods and services.
6. Identify the different types of value (use / non-use) that are of interest for their economic valuation.
7. Choice and application of the economic valuation method.
I know that these phases that I have identified may seem clear but, but I have not yet been able to determine the indicators with which I am going to study in the field, and how to apply them to the design of my assesment method.
Hope you can help me, and if you have anny recomendations, I'm open to read what you have to teach me.
Thank you so much!
I have known some physical-based models and emperical models, i.e., the original Stefan model (mainly used in permafrost regions) and its modified modes. However, I consider there would be some better methods to quantify the dynamics of frost depth in seasonal frozen soil region.
Due to the characteristics of two-way melting of the soil during the thawing period in seasonal frozen soil regions, the prediction of the frost depth during the thawing period becomes more complicated and difficult. Are there any good methods to quantify the dynamics of frost depth during thawing period?
Do you know the methods to estimate soil evaporation reliably in cold and arid region (especially with shallow groundwater level) other than in-situ experiments during freezing-thawing period? Some researchers used the Penman-Monteith equation to estimate the evapotranspiration during freezing-thawing period. Since there were not any crops in the freezing-thawing period in farmland, things were then concentrated on figuring out how much soil evaporation released. Things would be more complex if there were some land covers (straw, snow, or residues et al) on the farmland. I don't know whether the ET0 calculated by Penman-Monteith equation can represent the soil evaporation scientificly. If not, are there any other recommanded methods ?
Hi every one
I am studying the effect of the spread of the desert on the
occurrence of dust.
I first seek to change the vegetation of the studied area
My study area has a arid and semi arid climate. My question is about NDVI index classification. I want to know what is acceptable range for indigenous plants or desert shrubs?
Thanks for helping someone
My name is José Bandeira.
I am a doctoral student in agricultural engineering at the Federal University of Ceará.
I am currently working with loss by interception. I intend to investigate the characteristics of throughfall, for example: Distribution of droplet size and diameter reaching the soil and its importance in understanding the other hydrological processes.
This work is being carried out in a semi-arid climate region, with caatinga vegetation.
Faced with this situation, I found articles of his authorship and other collaborators. This article is very good and interesting.
I'd like to know a little about the development of your searches:
1 - What model of dysdrometer used in the project;
2 - I would like to know if there are other equipment equivalent to the dysdrometer, which has the same precision;
3 - With regard to price, I requested a budget here from Brazil and the price is in the range of R $ 52,000.00. What you are using in your searches is in this price range.
Follow my email, if you want to reply here: email@example.com
Grateful for the attention,
Yours sincerely, José.
Hello, I have checked some papers where it is mentioned that arid/ semi-arid climatic conditions is responsible for high fluoride concentration in groundwater. Can someone please explain me how it happens!
Is there a standard irrigation calendar to apply under saline conditions?
Some researchers apply just for one week, and others for 2 weeks. I want to try the effect of salinity for two weeks but I did not find a standard calendar to do this experience.
I studied two climatic condition i.e. arid and semi-arid. In each climatic condition I selected two statues: 1. Sites with conservation measures named mananged 2. Degraded sites.
These sites have similar conditions in terms of physiographic atributes.
I compared alph (within plots) and beta diversity (between plots) of all plant species.
Q1: in both arid and semi-arid regions alpha diversity was higher in mananged sites than unmananged . . Why?
Q2: above result also occured for beta diversity. But there was not significant different between unmananged sites in different climatic conditions. While in mananged sites beta diversity was significantly higher in semi-arid region than arid region. Simply unmanagement decline the postive effect of better climatic conditions on beta diversity.
I have some reasons for above results but I need more refrences and discussion.
I need data regarding average yearly topsoil loss in India and Pakistan for the period between 2000-2010. I also need data regarding the percentage soil organic matter (not just carbon content) for these two countries.
Deep soil drying due to artificial plantations is an important ecological issue in semiarid regions where ground water is generally unavailable. I have daily soil moisture data at deep layers (θd) in a semiarid plantation on the Loess Plateau. And I also have daily precipitation (P), daily transpiration (T) and daily shallow soil moisture (θs) as affecting factors. My purpose is to quantify the contribution of P, T and θs to the changes of θd, but I am not sure which method should be used. Thanks a lot for any help in advance.
Wheat respond to irrigation application even under shallow water table conditions but regular rains at reproductive stage had very little depletion in soil moisture content.
Dear all! The soil variability in Poland is very common. Thus, we can distinguish areas with optimum, insufficient and excessive humidity even on one field. For this reason I am looking for Visual Indices, which would be helpful to detect such areas. Till now, we were working mainly with NDVI and similar VIs. However, the NDVI is more related to biomass, and thus it is useful to distinguish high and low yield areas, but it does not provide information, if the low yields (biomass) result from the shortage, or excess of water? Any ideas? May be MSI (Moisture Stress Index) would be useful?
We are trying to depict the total inorganic N fraction NH4+ and NO3 - -N status in different growth stages of rice in 3 diff. cultivation techniques like direct seeding, SRI and conventional transplanting. We need similar type of earlier research with which we can compare our observations.
What are the success factors affecting the performance of rainwater managment, particularly spate irrigation, to minimize the risk of climate variability and recurrent drought in subsistance dryland production systems?
If the daily irrigation amount is determined beforehand and the crop fresh weight determined per pot !
Since urban cities house different species and can have different local temperature due to changing climate. I'm interested if it will be considered as a new Biome or just will it just be considered as a habitat?
Books and articles on increasing the watertable in urban and rural areas?
Calculation of moisture in the saturated and unsaturated soil and excavation and drilling associated with it?
I have past 30 years observed temperature and precipitation data available. How can the climate change impact be established using observed data ?
Dear researcher, professor, practician, Hydrologist
my name is Ali, I am a student of Gifu university. my research is comparison two small catchment with different vegetation types in central Japan. one part of my research is water quality.
I was measure water quality from broadleaf deciduous and evergreen coniferous forest. and one of my parameters in dissolved oxygen (DO).
based on my data, DO in coniferous evergreen is always lower than in broadleaf deciduous. who knows the reason?
I try to connect with baseflow data because baseflow in coniferous evergreen is lower than broadleaf deciduous. but some literature said groundwater have low DO.
based on my data, DO in coniferous evergreen is always lower than in broadleaf deciduous. who knows the reason?
Thank you very much for your help
What are the pedological benefits of improving cereal crop yields in semi-aride areas?
Are these exotics are one of the reasons for the depletion of ground water table in nilgiris
I have calculated the crop water requirement of all the crops grown in the micro watershed of the area 2 Hec. The area is situated in rural part of the semi-arid mountainous region.
Can anyone suggest me the way to calculate the water productivity and water use efficiency? What is the significance for calculating these two common terms commonly used?
How can the efficiency be improved in other ways?
Agricultural saline land is big problem in irrigated tract of western Maharashtra. i just want to know existing status and practices to overcome the same problem.
I am working on soil fertility evaluation and classification for upland crops using differences systems, which FCC system from Sanchez was used as a based system. Since I need some experiences and applications from other regions or countries which are to apply for the Mekong Delta, Vetnam
I have self made equipment for measuring infiltration rat of the land/ soil. But it has some limitations, in case, at the time of over-flooding. In addition, it is difficult to use it when the surface of the land is light-to-hard one.
I am interested in wetlands and non-tidal ones and how they keep their animal and plant populations, especially those in dry and semiarid regions and also those placed in high elevations. I would like to know about your experience on this subject and have you approached it, if it is possible.
How does the availability of micronutrient is affected by changing climate scenario and what are the possible management practice specially under extreme erratic events of weather.
I am working on determining water loss due to open canals used by irrigation districts in agricultural regions of the western United States. Taking flow measurements throughout the canal system to measure water loss has proven difficult as there are many uncontrollable variables. Instead I was thinking it would be possible to model irrigation losses from an open canal based on a collection of quantifiable variables related to soil type, canal size/wetted perimeter, and canal riparian zone classification. For example: you have 10 miles of canal, 3 miles are on a clay base and 7 are on silty loam. 2 miles of silty loam canal is has a riparian zone classified as "overgrown", 4 miles are "moderate" and 1 mile is "bare". All 3 miles of clay canal are "bare." Estimated water efficiency values for each section are A, B, C, and D. Variables could be added for temperature, humidity, canal size, etc to determine water loss in that section. Does something like this exist as I think it would be an extremely valuable tool. If not, could someone direct me to other literature related to this subject. Thank you.
I am interested in the prime influencers of electrical conductivity in soil; so far groundwater salinity, temperature, and moisture content seem to be the key influencing factors. Does anybody have any suggests as to what else may effect electrical conductivity in soil, other than these three?
Sub-soil sodicity, salinity and calcariousness are going to be the biggest threats in semi arid tropics with irrigated agriculture like subsoil acidity and aluminium saturation in hot humid tropics
Euphorbia taifensis is a new species of Euphorbia discovered in Saudi Arabia in 2007, its fruits are eaten by Hamadryas baboon "Papio hamadryas" in case of severe hunger, it seems very unusual that the fruits are eaten by animals because the genus Euphorbia contains very irritant diterpenens.
Is there in literature some similar cases?
In desert areas drought often coincides with elevated temperatures. I have worked on cuticular transpiration of desert plants and most of the plant species possess stomata on both adaxial and abaxial surfaces.
It seems to be contradictory when these plants should reduce the water loss and increasing the stomata density implies in enhancing the probability to lose water to the dry atmosphere. However, it may be a good solution for cooling down the leaf temperature by stomatal transpiration under high temperatures.
Hence, to better understand the ecology of desert plants, I would like to know whether any morpho-ecophysiological trait has been pointed out as efficient to deal with both stressors at the same time.
Thank you in advance!
I'm very interested in understanding the sate of the art on hydrogeological modelling with special concern to semi-arid environments in order to implement a system within FEFLOW software.
I am working with a doctoral student and we need to calculate water loss from lichens on trees in arid and semi-arid regions in Australia. We have theorised that lichens will act like a water reservoir (and therefore be somewhat equivalent to topsoil), they will recharge by stem flow during rainfall events and loose water when the air is dry. Can we ignore ET and just assume Eo? We have sample all over South Australia, but for most locations only basic temp and rainfall data. So we would need a simple equation to calculate either Eo or ET. Any ideas?
What is the well field tested relationship between catchment vs pond area for semi arid region of India with flat topography?
parameters that has role impact on efficiency of WSP system in arid and semi arid regions
I measured total Iron and Aluminum in water extracts of soil samples (1:10) by an IPC-OES. For our soil quality analysis/index method we like to use, these elements turn out to be incorporated for distinguishing differences between land uses.
The soils have a pH of 7-8, a CaCO3 content of ~30-50% and are located in a semi-arid climate, so I wouldn't expect to find any toxic or harmful concentrations.
Now we measured 0.2-1.2 mg/kg (or 10-140 ug/L) of both elements, but it's hard to find any references on what are "good" or "minimum" values as most research focuses on toxicity (so more acidic soils) or on the solid soil solution.
Can anyone comment on these values or recommend literature on this which can help me establish good/bad/minimum boundary values?
I like to grown some jujube seedlings in my private garden ,so i wish any one to assist me in choosing the suitable rootstock for budding cultivars on.
The policy planners are emphasizing to increase the water use efficiency. However, I understand a minimum leaching fraction is essential even for canal water irrigation under arid climates. Arid regions are already facing shortage of good quality water, to meet this shortage poor quality irrigation waters are in use everywhere. I fear, unless magnitude of LR is not considered and met, there must be problems of soil salinity followed by sodicity that is even more difficult to reclaim and manage for crop production for food security.
In tropical soils especially in semiarid region continuous cropping without manure or Fertilizer depleted soil organic carbon by 30-60%.Long-term experiments showed that Fertilizer and manure under Irrigated conditions increased the organic carbon content in soil.Soils have capacity to sequester carbon upto certain level of saturation.Adopting good agricultural practices ,can the soil organic carbon status be raised to saturation level in tropical areas especially in semiarid regions?
Dozens of papers and reports state that planting pits increase infiltration but none of them state by exactly how much or provide and figures whatsoever. Does anyone have any data in this regard?
Karakum is a desert in Central Asia. It occupies about 70 percent, or 350,000 km², of the area of Turkmenistan. Khorasan Razavi is located in northeastern Iran and south of Karakum. I`m going to know it`s effect on dusty days in Iran. Last year, Mashhad city was dusty in some days and months. Is it made by Karakum desert ?
Can someone kindly provide suggestions or resources that will help me to derive soil salinity from Landsat images in a semi-arid environment. Thank you in advance
Due to the high consumption of water in the potato, ways to increase the water productivity in order to maximize water use efficiency and increased production in arid and semi-arid regions is?
We are writing up our work on semi-arid rangeland rehabilitation in South Africa where our core argument is about the contribution that rangeland rehab can make towards climate change adaptation by increasing the availability of natural forage for livestock. But, climate impacts look likely to increase aridity and therefore water stress and to round the argument out, we would like to be able to say something about revegetation contributing to groundwater recharge in the arid zone if possible (groundwater is the main source of freshwater in our region). All we can find so far is literature on increased soil moisture under shrubs in the arid zone (relative to interpatch) and literature indicating that vegetation actually reduces groundwater recharge through evapotranspiration etc. Any ideas?
I want to estimate subsurface inflow (qbf) from the eastern hardrock aquifer into the downstream part of my study area (attached figure). The area has an arid to semi-arid climate. Long-term average annual rainfall ranges from 14 to 178 mm, with an average of 63 mm. The considered water balance equation is as follow:
where P is rainfall, qrunoff is surface runoff, qdischarge is discharge by springs and qanats, E is evaporation from rainfall and ΔV is the change in groundwater storage. P, qrunoff and qdischarge are known and ΔV is assumed to be negligible. I have no idea about how I can estimate evaporation from rainfall in this condition. Any helps/insights would be really appreciated.
Thank you in advance.
Regarding adaptions of prehistoric hominins to drinking water resources, what is the maxima in brackish waters modern humans from native and indigene groups living in such environments can deal with? References regarding this question would be appreciated, thank you in advance!
Does any one have publication and idea on windbreaks in arid and semiarid area please? the factors that effect windbreak? the design of windbreak? any thing on windbreaks? thank you.
Due to maximum use of spring rainfall in arid and semi-arid and increase water productivity, can spring potatoes in cold areas, we planted in the fall?
In the literature there are conflicting results. I am looking for hard evidence based on data collection and not just empirical data
Due to low rainfall, people in central Iran have some amazing ways.
These methods have been developed over several thousand years and may have a higher accuracy than the current academic methods.
For example, in some days of September and October, they put cotton on their roofs in order to check weight change due to wetting. They use this method to determine whether the current year is going to be dry or wet.
I want to have information about the of species, plantation area, plantation age as well as hydrological effects of these species in the semiarid and area climate zones.
Arid land including mountains and Piedmont. Thus, we couldn't recognize a unique topographic map. Because topography changes especially in Piedmont area. Stream flow pathway change in ever precipitation event.
In aprticular I am interested in allotmetric equations using vegetation cover, precipitation, etc.
It is known that woody encroachment is occurring in grassland worldwide. I want to know which factors will affect this process, please give me some relating references.