It is not much practical to control atmospheric conditions such as temperature, humidity, wind speed, radiation etc. to reduce evaporation. Instead you may try to increase infiltration by changing land cover, vegetation and ground practices (contouring, terracing, digging cavities etc.). Further it is possible to reduce surface area, if open water bodies are available. Deep lakes do better than shallow ones in preserving water against evaporation.

Anyway, this is a very good question for opening up a discussion since water scarcity is a common problem all over the world.

Dear Haile Arefaine

Quickly, among suggestions i would recommend intermediate tree cover, see for example the paper :

Ilstedt, U., Tobella, A.B., Bazié, H.R., Bayala, J., Verbeeten, E., Nyberg, G., 2016. Intermediate tree cover can maximize groundwater recharge in the seasonally dry tropics. Nat. Publ. Gr. 1–12. https://doi.org/10.1038/srep21930

and land managment based on rotational mixed land uses see another paper :

Ribolzi, O., Lacombe, G., Pierret, A., Robain, H., Sounyafong, P., de Rouw, A., Soulileuth, B., Mouche, E., Huon, S., Silvera, N., Latxachak, K.O., Sengtaheuanghoung, O., Valentin, C., 2018. Interacting land use and soil surface dynamics control groundwater outflow in a montane catchment of the lower Mekong basin. Agric. Ecosyst. Environ. https://doi.org/10.1016/j.agee.2018.09.005

Hoping this rapid suggestions will help.

Best regards

Olivier

In another comment, I mentioned a presentation given by Moshe Cohen about 25 years ago. The area historically was cedars, but land use conversions resulted in arid, desert-like, with no permanent streams. Due to dry climate, just planting trees was unlikely to work. So the approach was to make scalp depressions into landscape, one depression pit per tree, to capture rainfall and condensate and funnel to each tree (cedar I think). Pick a native tree, and avoid pine as they typically use alot of water. Avoil non-native invasive trees and plants. Recovery of forest reduced runoff and sediment, but resulted in permanent baseflow, an indicator of a rising water table. Consult a botanist or forester on which native species are likely to use less water, help build soils to absorb water and limit storm runoff and erosion. If the landscape is gullied, these channels help to dewater, increase stormflow and reduce water table. Regular checkdams in channel or gully plugs can help detain, retain and force runoff back into groundwater. Agricultural terraces or contourtrenches can help retain rainfall so it can be absorbed, but as with most mitigations, they must be designed and maintained. I generally recommend agricultural terraces to be about a meter deep, and a gradient of 1.5-2%. Too flat, they may aggrade and fill, too steep they erode and degrade. Terraces require maintenance, especially until full ground cover and limited runoff is achieved. Agricultural Terraces that fail on sloping terrain, may result in gully erosion.

When you plant trees, you may need to water them during dry periods until they establish, so monitoring their condition and access with ATV or wheel tractor or other suitable vehicle with water tank may be needed.

In addition, native grasses can also provide good watershed cover, and grasses tend to use less water than trees. Establishing native grasses can be a challenge, and some species are difficult to establish. I forgot to mention soils, have them analyzed for nutrients, organics, structure, etc. Some trees and grass covers require more water and nutrients than others.

Vetiver grass is a good choice, with:

- better surface cover compared with other grasses, hence reduce evaporation more

- tolerant to water stress conditions, hence, suitable to semi/arid

- good root webs and thus, increase soil infiltration

better surface cover compared with other grasses, hence reduce evaporation more

- tolerant to water stress conditions, hence, suitable to semi/arid

may be it can help you

https://ascelibrary.org/doi/abs/10.1061/(ASCE)0733-9437(2008)134:6(745)

Thank you all,

I think, something has be done to fill such a gap by the way. A kind of review that answers such questions is needed. I can see that most of the required information is available here and there. But, compiling these into one as a solid review should be something that we should plan for. Thanks once again.

Good question I will follow answer

Hi,

Maybe these could help;

https://www.amnh.org/learn-teach/curriculum-collections/young-naturalist-awards/winning-essays2/2014-winning-essays/a-method-to-reduce-water-evaporation-from-soil-using-the-absorbent-properties-of-organic-wheat-straw

https://www.researchgate.net/post/How_can_I_reduce_the_soil_water_evaporation_rate_Will_canopy_or_mulching_help_and_how_can_we_reduce_the_drain_water_in_a_field

Good question I will follow answer

In one of the counties in New Mexico, USA which is an arid region, they have been successful in reducing evaporation losses by providing a roof over the water storage tanks as well as coming up with a dome-shaped plastic canopy; the condensed water from the canopy falls back into the water tank thus minimizing losses.

It is not much practical to control atmospheric conditions such as temperature, humidity, wind speed, radiation etc. to reduce evaporation. Instead you may try to increase infiltration by changing land cover, vegetation and ground practices (contouring, terracing, digging cavities etc.). Further it is possible to reduce surface area, if open water bodies are available. Deep lakes do better than shallow ones in preserving water against evaporation.

Anyway, this is a very good question for opening up a discussion since water scarcity is a common problem all over the world.

I totally agree with Prof. Prema Hettiarachchi to the points mentioned in her comment on the good question by @Haile Arefayne and the difficulties of water atmospheric demand reduction. In this case, you may control the ET and reduce the amount of number steps as follow:

1) Change the the land use of the area either changing the crop type (less ETc), irrigation method or using greenhouses for agricultural purposes. In this case, you control the ET and reduce the amount of water supply for agricultural areas for example.

2) Water harvesting could be one of best solution for groundwater recharge. Further details on the water harvesting in arid regions could be obtained from: Article Water Harvesting and Flashflood Mitigation-Wadi Watier Case ...

I agree with Prof. Prema Hettiarachchi to the points mentioned in her comment

Dear Hailush, which evapo-transpiration is concerned with? I think it is a potential evapo-transpiration which bases on the driving force regardless of the supply moisture. So, you better express the potential evapo-transpiration on a defined time basis, either daily or monthly. Furthermore, determine in which range of months or month of a year will the potential evapo-transpiration get maximum which may give you a clue to the size and type of structures needed. From this on, you may think structures which reduce leisure time of the surface run-off of your target study area. Parallel to this, take the land use/cover of your area in to your consideration, because this affects your actual evapo-transpiration, if not you may be miss-leaded.

Good Luck!!

Mulching with biomass or plastic.

I think the optimal management may reduse the evapotranspiration....selecting the crops that may consuming afewer water requriments with good revneu and leaving fallow area lead to more balance in water management. I think you have multiple objectives in your question that should be considered.

Interesting.....

An interesting question.

I would recommend a paper at: https://www.researchgate.net/publication/259565226_Environmental_change_in_the_last_150_years_in_Bakeyao_Southeastern_Horqin_Sandland_Northeast_China

In the above paper, we collected and analyzed two sediment cores in Bakeyao Lake, southeastern Horqin Sandland, central Northeast China. We focused on the analysis of pollen and algae spore from one of the cores. The result is very interesting.

We showed that there was a simultaneous and opposite change of arboreal pollen and Pediastrum spores during the past 150 years, indicating that the de-vegetation and active dunes (re-vegetation and stable dunes) were accompanied with the rising (falling) lake level. It is thus clear that, when the sand dunes were activated, probabaly by human activities, the evapotranspiration loss was reduced, and the lake level rose; and vice versa. The reason for this association between the surface characteristics and evapotranspiration is easily understandable, because the transpiration from vegetation was significantly reduced in case of sand dunes activation , and also the evaporation from the soil was largely cut down due to the cover of sands at surface which led to a lack of capillary effect.

Therefore, it would be good to clean vegetation and at the same time spread the sands over the surface of the dry land to reduce evapotranspiration.

An interesting question.

As Srini Vasan points out, you can provide extra shade over certain places (particularly ones which are not too extensive). In addition, you can build wind-breaks to shield the water surface from excessive wind.

I also agree with the researchers in reducing the evapotranspiration and in particular with Dr.Islam Sabry Al Zayed by conducting some of the following field practices:

1 - using the agriculture covered system, whether covered with a plant residual (straw) or industrial coverings.

2. Field crop cultivation among drought-tolerant crops and high canopy cover trees for soil water sustainability.

3 - The final solution, which is somewhat expensive is to follow the technique of water harvesting.

Mulching with biomass or plastic

cover crops

Follow

You could implement a shelterbelt, or row of trees, which has been found to impact surface winds and evaporation.

Nice discussion.

If your area is gullied, from severe erosion, gullies are efficient at delivering water and lowering adjacent water table. Gullies are entrenched, so no access to floodplain where water can be delayed or stored long enough to augment some recharge. Frequent low rise check dams added to channel can help slow runoff. The filter fabric fences we used to capture sediment in one of our researchgate papers would be inexpensive and help capture sediment and detain flow for headwater catchments.

Arid areas may lack soil conditions so water from intense can be absorbed efficiently. Over 20 years ago, Moshe Cohen presented results of reestablishing cedars to eroded, arid lands lacking perennial flow. The land was scalped for each seeding to capture rain and deliver to tree. Eventual recovery led to recovered perennial streams and reduction of erosion and sedimentation. Not all trees and vegetation are efficient with transpiration, and can handle periods of arid conditions. Native species to the area are often best. Many studies identify pine trees as using excessive water, as their stomates remain open or do not close as some other plants. Some plants have waxy leaves to help retain water.