Urban Climatology - Science topic

Hi Manar, in this case I would go either for a manual sampling (based on visual interpretation and personal knowledge of the master plan) or a GIS-based approach. This will depend on how you intend to use the LCZ maps and for what reason. The GIS-based approach is generally preferred but it requires the availability of a digital topographic database, primarily including buildings and their heights (so that relevant indicators can be calculated, e.g. SVF and H/W ratios of representative street canyons) but also land use (to account for the different ground cover characteristics). For the GIS-based approaches, see, for example, the work of Lelovics et al. (https://doi.org/10.3354/cr01220) and the work of Geletič and Lehnert (https://doi.org/10.1515/mgr-2016-0012), where a full procedure for a applying a GIS mapping of LCZs is explained. Combined approaches, even if they are not directly applicable to your case, might be also a useful source of information for the GIS part. See, for example, the work of Gál et al. (shorturl.at/giDFS) or our recent work (http://dx.doi.org/10.5821/ctv.8663).

Lastly, have a look at these two recent publications, by Lehnert et al. (2021) and Jang et al. (2021) that comprehensively compare different mapping methods of LCZs and their application.

Best,

The research questions can read like this

Could there be a link between forest fires and climate change?

The automobile cut down the nature of travel and the meaning of distance between urban areas, while at the same time urban areas expanded. Automobiles created a greater sense of autonomy and thereby individuality, so had an enormous part in structuring western and global civilisation. At present, there seems nothing to take their place unless more efficient railway systems at created. Overpopulation demands highly efficient means of travel.

@Gerard Taulé Codinach

There are so many articles. You can take help from the attachment given below. Best wishes with regards.

Suraj

1. https://doi.org/10.1017/9781139016476.008

2. https://doi.org/10.1016/j.scs.2020.102471

Dear Muhammad Shafiq,

You can use CA-MARKOV Approach to predict the future urban sprawling surface. For that, you have to generate a future suitable probable surface based on current year using AHP (MCDM) techniques. Thus you can create a base map and a projected map of the same year. In this way you can predict upward trends of urban sprawling. Best wishes with regards.

For your better understanding, please follow the link given below.

Please go through this paper. I think it will help you. Best wishes with regards.

Ali Cheshmehzangi Thank you for sharing your latest research on this topic.

Dear Vignesh, depending on what you want to measure, but I think you should use as characteristic length the width of the building or its dimensions in the main direction of motion of the flow.

Let me add the following information FYI: the validity of wind tunnel results obtained in testing of scale models is based on the fluid mechanics Principle of Dynamic Similarity (White, F.M., Fluid Mechanics, 6 ed., Boston, USA: McGraw-Hill, 2003, p. 866) which states that: "If two physical phenomena can be described using the same formulation (same equations and same initial and boundary conditions), the solutions for one of the phenomena are valid for the other one." For the motion of air around and obstacle, this Principle guarantees that the non-dimensional results measured in a wind tunnel for a scale model (e.g., lift, drag, and pitching moment coefficients) will be the same as for the real, full-scale obstacle if the following conditions are fulfilled:

For CFD, this is not usually a problem, since you have much flexibility in defining the boundary conditions and other settings such that these 4 conditions are satisfied and, for example, Re and M match those of the real fluid problem.

Now the dilemma comes when trying to extrapolate wind tunnel results to the real fluid problem: If the fluid properties for both the tests and real case are the same (i.e., same speed of sound (T), ρ and μ), and the scale model is smaller or larger than the real obstacle, it is obvious that it is not possible to have simultaneously the same M and Re as in the real problem. If we cannot replicate simultaneously both parameters, it is then necessary to choose which one will be kept similar to the real case. Generally, we choose the parameter with a stronger influence on the flow. For instance, roughly speaking M is dominant for supersonic flows and Re for subsonic flows (your case). Thus, for example, in high-subsonic testing, we would strive to work with the same Re as in the real case, and would not pay so much attention to M. Effectively, this means that we are not complying fully with the requirements of the Principle of Dynamic Similarity, and thus the test results have some error respect to the behavior in the real case. Many researchers have characterized the Re and M scaling effects to be able to correct for this error when extrapolating the wind tunnel results to the real case, if the Re and/or M in the tunnel are different than those of the real case.

If the fluid properties for both your tests and real case are the same, you should try to work with a model as similar as possible in dimensions the real obstacle, bearing in mind also these recommendations (Barlow, J.B., Rae, W.H., Pope, A., Low-speed Wind Tunnel Testing, 3 ed., NY, USA: Wiley & Sons, 1999, p. 713):

If you manage to have same Re and M, then the lift and drag coefficients (cL = Lift/(0.5*rho*V^2*S) and cD = Drag/(0.5*rho*V^2*S)) that you obtain from the tunnel can be extrapolated to the real vehicle. If you manage to have only the same Re, the lift and drag coefficients that you obtain should be corrected, but this error should not be very large and maybe the values from the tunnel are still valid to you. If you don't manage to have the same Re, then you could correct the cL and cD following the procedure described in the attached image from White's book Fluid Mechanics, for which you need to have values of cL or cD at several flow velocities (i.e., at several Reynolds numbers).

Thank you so much sir@Ingo Riess

RayMan

Great question!

So, do you mean like effectively all cities? Then maybe, but I think almost no.

I don't like rating systems in general. They will produce infrastructure that is far better than the status quo, but not likely good enough. The assumption is that in the setting they were developed in, over the time period being considered, this is the best balance of cost and performance (broadly speaking) that the designers of the system could come up with. But costs change and not all settings are created equal. I would consider the highest standard of any rating system as a reasonably good place to start, but not where to finish.

Look up GATE - global association of transition engineers - and think about what transitions are coming. We know about peak fossil carbon, peak conventional agriculture, peak ecological footprint; all of these are predictable. We know the future we're going to be seeing in 40 years will be not very much like the future we were expecting 40 years ago.

If we're building infrastructure that will have an expected lifespan of 100 years, and will be receiving it's first maintenance in 25 years, we shouldn't just be thinking about what that maintenance cycle will entail, but rather what the whole lifecycle maintenance is going to be. Most of the design life of that infrastructure will be existing in a low energy intensity environment where the amount of available labour will be significantly reduced (certainly on a per capita basis, but I think also on an absolute basis). Will concrete wall panels and high-tech heating and cooling be serviceable at 50 years? Likely not.

I think individual sustainability is an oxymoron. Individual resilience makes sense to me. Be a net energy producer, manage more land than your ecological footprint, be able to grow your own food, make good solid community connections - all of these things will add to individual resilience.

It could be possible to design buildings with the same principles. How do you make sure the changes in energy availability in the future will not make your building a pile of junk?

In Canada, for residential applications, I would use STES to hold the heat required to get through winter, and to store winter for AC and refrigeration through the year. I would be off-grid, so that my operating costs will not change with energy costs. That means a HUGE thermal mass, and good insulation, and lots of south facing glazing. I would use solar thermal hot water, and store heat in the phase change of paraffin, so I could have instant solar hot water. I would use just enough solar electric to drive the ventilation system (on batteries) and manage my water system (direct solar pumps, cisterns, no well). Cost is similar to conventional, but uses more land than typical urban designs.

In your setting, you'd have to work out what you get for free, and what services you must have. Keep the energy as close to the original form as possible when it is stored, so you have the least losses. Interest rates are likely to stay low, and almost the entire cause of inflation will be from energy costs - if you can effectively eliminate your energy demand, your property value will increase faster than inflation. Figure out how you're going to service the infrastructure when the cost of energy is high and low, and when the cost of labour is high and low. All 4 cases will exist in the foreseeable future, regardless of setting.

Good luck.

Both US EPA and the US Army (Dugway Proving Ground in Utah) have conducted extensive urban dispersion modelling studies with both real and modelled buildings. 

C3 and C4 plants is physiological item founded every where not only in Egypt. C4 crops like sorghum and corn. However, C3 plant like wheat and barley. 

Try to get any reference book in physiology, you will find what are you looking for !! Good luck 

Dear Francis,

We have not yet considered the influence of atmospheric pollutants that cause acification on the paintings we study. One set of paintings is in an hermetically enclosed environment and we have the impression that that causes problems. Do not why yet. They are in Norway so we expect a clean atmosphere. 

ENVImet takes into account, climaticwise speaking, the water bodies but not the water flow. 

The answer to your question is not straightforward. Firstly the suitability of the software depends on you goals and abilities. RayMan is an accurate, user friendly, quick and well documented software. You can estimate lot of biometeorological parameters with RayMan such as PET, PMV, Tmrt etc. The calculations refers to a point.

Another reasonable choice is  ENVImet. Using ENVImet you can calculate the spatial distribution of several parameters such as PMN, Ta, RH% etc. ENVImet requires high computer power and physical memory (RAM). The learning curve of this model is steep and the crash of the model is an everyday situation. But I think worth a chance.

SOLWEIG is a model based on MATLAB. It is steady and user friendly. It is accurate on radiation calculations. 

To cut a long story short, my first choice is RayMan, after that is ENVImet and after that is SOLWEIG.

Best Regards

Dear Dr. Markus Neteler, Thank you very much for this wonderful and useful research,

That's really what i want.

Thanks again

Hossam

Mainly they have to get used to sustainable lifestyles then it covers the ethical considerations!

If the UHI stands for Urban Heat Island, here are some useful articles:

Dear  Fuzail Jawaid ,

I would like to recommend you my conference paper entitled Various Aspects of Ecotourism Concept and Their Impact on Shape of The World Ecotourist Actions .

I hope it would be useful.

Kind regards

Barbara

^{* Regulators of pH (acidity and alkalinity), including buffers, respiration, and kidney function}.

Hi Sai Krishna

I think it is better that, at first, Simulate the whole urban area by a Macro-scale (or Meso-scale) model, Then, put the results of every part of the urban as input in a Micro-scale model. In other words, boundary conditions of the Micro-scale model  could be determined by using the outputs of Macro-scale (Meso-scale) model. This process, known as "Down-Scaling" is.

Regards

Alipour

Cities in South Asia should consider catchment and drainage in such a way that the necessary conditions of operational reliability and resilience to shock are met, while ensuring that the sustainability of the system allows for future growth and expansion. The following paper sets forth criteria for the design of water resilient cities through a joint consideration of a set of index on reliability, resilience and sustainability. The conclusion of the paper on a hybrid between centralization and decentralization seems to be relevant to the largely centralized effort that we see in South Asia. In general, decentralilzation working along more deregulated and market-driven approaches would benefit South Asian cities.

Yes, sir i am working on influence of wind also

Contact -National climate data center,IMD,Shivajinagar,Pune 411005

Dear colleagues, let me humbly suggest that this is not the site to keep this kind of discussion. Please, post only answers to Andrea's question.

(On the other side, I do not see any denialist tendency in http://climatesight.org/tag/urban-heat-island-effect/ ...)

I need information on small scale research funding in the area of climate change and urban adaptation. I am doing the study in Africa and the focus is also African cities.

Urban climatology has got renewed interest for two main reasons. First, to analyse impacts of urbanisation on the global climate change as centres of industrial production and therefore atmospheric pollution at local, regional and global scale. Secondly, in view of perceived climate change to find out adaptation and mitigation measures in urban areas. The latter concern is expressed in a voluminous and growing literature on urban heat island (UHI), thermal comfort as well as environmental ergonomics and architectural design in built environment.

After, first work on urban climatology Luke Howard, The Climate of London, which contained continuous daily observations from 1801 to 1841, recently a number of books are published on the topic and the number is growing. An International Association for Urban Climate is also founded lately:

A few of titlels on the topic are listed below:

The Urban Climate by Helmut E. Landsberg

Energy and Climate in the Urban Built Environment (BEST (Buildings Energy and Solar Technology)) by M. Santamouris (Editor)

Constructed Climates: A Primer on Urban Environments by Will Wilson, Sr., William G Wilson

Urban Climate Change Crossroads by Richard Plunz

Urban Aerodynamics: Wind Engineering for Urban Planners and Designers by American Society of Civil Engineers

Cooling Our Communities: A Guidebook on Tree Planting and Light-Colored Surfacing by Hashem Akbari

Energy and Climate in the Urban Built Environ… (Kindle Edition)

by M. Santamouris

The Urban Atmosphere by Terry A Ferrar

The Urban Costs of Climate Modification by Bruce Wilson Atkinson

Urbanization and the atmospheric environment in the low tropics : experiences from the Kelang Valley Region, Malaysia by Sham Sani

Hi. May i know how to get the password? I have already subscribe to the newsletter but there is no password sent to me or something so i cant run the setup

Here http://www.cnrm-game.fr/spip.php?rubrique134&lang=fr there's the link to download the TEB code

You can download V4 Preview directly from here:

The following information may be useful for your research

Abstract. A method to estimate the zero plane displacement is presented that is based on in situturbulence measurements. As it does not depend on flux-gradient relations, it can be applied overnon-homogeneous surfaces if they are dynamically but not thermally distorted. The zero plane displacementat an urban site is found to vary considerably with wind direction. The results compare well withestimates from conventional methods using the heights and distribution of the upwind roughness

elements.  

Ref: 1)DETERMINATION OF THE ZERO PLANE DISPLACEMENT

IN AN URBAN ENVIRONMENT

M. W. ROTACH

Boundary-Layer Meteorology 67: 187-193, 1994.

www.researchgate.net/...zero_plane_displacement...urban.../00463518bf..

2) AERODYNAMIC ROUGHNESS OF URBANAREAS DERIVED FROM WIND OBSERVATIONS

by C.S.B. Grimmond et al,.

oundary-Layer Meteorology 89: 1-24; , 1998.

The Green CTTC (green - cluster thermal time constant ) Method is the thermal model that includes  vegetation - mainly trees - influence (including Heat Transfer, Solar Radiation, Humidity, Wind, Evapo-transpiration ) on the thermal conditions. Main co-authors Limor Shashua-Bar, and Milo E. Hoffman (Faculty of Architecture and Town Planning, IsraelInstitute of Technology)and others Main publication:"The Green CTTC Model for predicting air temperature  in small urban wooded sites" Building and Environment 37 (2002),1279 -1288.

In any case, I propose to you and others to consider in the warm stations that people will feel the closer as possible  to comfortable, when seating in the shade: Lowest Metabolic Rate, or at least walking in the shade. Where, in the cold stations,pedestrians will  prefer wind defended sunny places. For thermal comfort evaluation, consider the above, and use the simplest methods for evaluation in the shade, but at least with 1 m/sec for wind speed near pedestrians wearing 0.5-0.7 clo, Where in the cold station, consider 1.2- 1.5 clo or more. in the sunny places with Fanger's Model CONSIDERING ALL THE RELATION,WITH SOLAR RADIATION.

All the best,

Milo E. Hoffman

Climate change is not dependent on urban ponds, they only mitigate the urban heat island. Also the size of the blue pools is more important than the total number, as green areas

There have been few ENVI-met studies with spatial distribution of PET across the study area. Most of the studies put certain number of receptors in the site and get PET values by using Ray-man, though these values are confined to few points. There have been several studies in Germany particularly, with spatial distribution of PET. I guess CalcPET is not available for public. It would be good to know how to get it. Anyway, many thanks for your contribution ;)

THanks....

Juan

I hope this could be helpful:

Saaroni H., Ziv B., 2003, The impact of a small lake on heat stress in a Mediterranean urban park: the case of Tel Aviv, Israel, Int J Biometeorol 47, 156-165.

Best regards

Kate

It is maybe, I could use models seperately from macro to regional and micro scale models. The synoptic weather charts will be used for analysis and find weather patterns affecting intensifying on urban air pollution. Then, we should be introduce a mechanism for predicting occurrence of air pollution events in future using synoptic weather charts.

In the model, should be entrance air quality stations data and urban elements affecting to resonance air pollution. In this point, GIS has good ability for special and temporal modelling and analysis. In addition, after that, I think it should be used the empirical models; such as the method of calculating pollution from passing traffic on street.

Ahmed,

You are right, but urban settlements themselves change their climate in terms of evaporation rate due to consumption of water, creating barriers for on wind side and giving corridors etc. However, typically urban centres as centres of consumption have depleted surrounding of vegetation cover altering temperature intensity and local water cycle, are heavy burden on waterways further deteriorating downstream ecosystems affecting their temperature moderating role and water cycle. Construction activities can also add to aerosols, all these conditions are related to intensify climate change in the region of a big urban centre.

well, if you want to discuss the issue, not problem. I have also calculated the built-up index and the NDVI, in case. Let me know!

Thank you for your responses