Solar floatovoltaics lit review/Lake Mead Evaporation studies

Lake Mead Evaporation studies[edit | edit source]

Evaporation from Lake Mead, Nevada and Arizona, March 2010 through February 2012(2013)^[1][edit | edit source]

• Abstract

Evaporation from Lake Mead was measured using the eddy-covariance method for the 2-year period starting March 2010 and ending February 2012. When corrected for energy imbalances, annual eddy-covariance evaporation was 2,074 and 1,881 millimeters (81.65 and 74.07 inches), within the range of previous estimates. There was a 9-percent decrease in the evaporation rate and a 10-percent increase in the lake surface area during the second year of the study compared to the first. These offsetting factors resulted in a nearly identical 720 million cubic meters (584,000 acre feet) evaporation volume for both years. Monthly evaporation rates were best correlated with wind speed, vapor pressure difference, and atmospheric stability. Differences between individual monthly evaporation and mean monthly evaporation were as much as 20 percent. Net radiation provided most of the energy available for evaporative processes; however, advected heat from the Colorado River was an important energy source during the second year of the study. Peak evaporation lagged peak net radiation by 2 months because a larger proportion of the net radiation that reaches the lake goes to heating up the water column during the spring and summer months. As most of this stored energy is released, higher evaporation rates are sustained during fall months even though net radiation declines. The release of stored heat also fueled nighttime evaporation, which accounted for 37 percent of total evaporation. The annual energy-balance ratio was 0.90 on average and varied only 0.01 between the 2 years, thus implying that 90 percent of estimated available energy was accounted for by turbulent energy measured using the eddy-covariance method. More than 90 percent of the turbulent-flux source area represented the open-water surface, and 94 percent of 30-minute turbulent-flux measurements originated from wind directions where the fetch ranged from 2,000 to 16,000 meters. Evaporation uncertainties were estimated to be 5 to 7 percent.

A secondary evaporation method, the Bowen ratio energy budget method, also was employed to measure evaporation from Lake Mead primarily as a validation of eddy-covariance evaporation measurements at annual timescales. There was good agreement between annual corrected eddy-covariance and Bowen ratio energy budget evaporation estimates, providing strong validation of these two largely independent methods. Annual Bowen ratio energy budget evaporation was 6 and 8 percent greater than eddy-covariance evaporation for the 2 study years, and both methods indicated there was a similar decrease in evaporation from the first to the second year. Both methods produced negative sensible heat fluxes during the same months, and there was a strong correlation between monthly Bowen ratios (R2 = 0.94). The correlation between monthly evaporation (R2 = 0.65), however, was not as strong. Monthly differences in evaporation were attributed primarily to heat storage estimate uncertainty.

• Key Takeaways

Use of Eddy-Covariance and the method, and the Bowen ration energy budget method for evaporation of Lake Mead (2years time span)

Lake mead geographical and hydrology properties are described

Description of previous evaporation studies of the lake

Data from Las Vegas Airport could be used for evaporation calculation

Evaporation rate are given in the result section

EC is more accurate nut need more directed measured data

Evaporation data from Lake Mead and Lake Mohave, Nevada and Arizona, March 2010 through April 2015(2015)^[2][edit | edit source]

• Abstract

Evaporation rates were measured at Lake Mead from March 2010 through February 2012 for phase 1 of an evaporation study (Moreo, M.T., and Swancar, A., 2013, Evaporation from Lake Mead, Nevada and Arizona, March 2010 through February 2012: U.S. Geological Survey Scientific Investigations Report 2013–5229, 40 p., http://dx.doi.org/10.3133/sir20135229). Phase 2 of the study (March 2012 through September 2017) continues evaporation measurements at Lake Mead and begins evaporation measurements at another lower Colorado River Basin reservoir, Lake Mohave. Eddy covariance is the primary measurement method. Data currently (10/6/2015) are being collected for the phase 2 study. This USGS data release represents tabular data in support of the evaporation study. The data release was produced in compliance with the new 'open data' requirements as way to make the scientific products associated with USGS research efforts and publications available to the public. The data release consists of 2 separate items:

1. Lake Mead evaporation data from March 2010 through April 2015 (Microsoft Excel workbook)

2. Lake Mohave evaporation data from May 2013 through April 2015 (Microsoft Excel workbook)

When will Lake Mead go dry?(2008)^[3][edit | edit source]

• Abstract

A water budget analysis shows that under current conditions there is a 10% chancethat live storage in Lakes Mead and Powell will be gone by about 2013 and a 50% chancethat it will be gone by 2021 if no changes in water allocation from the Colorado Riversystem are made. This startling result is driven by climate change associated withglobal warming, the effects of natural climate variability, and the current operating statusof the reservoir system. Minimum power pool levels in both Lake Mead and Lake Powellwill be reached under current conditions by 2017 with 50% probability. While these datesare subject to some uncertainty, they all point to a major and immediate water supplyproblem on the Colorado system. The solutions to this water shortage problem must betime-dependent to match the time-varying, human-induced decreases in future river flow.

• Key Takeaways

Importance of Colorado river for life and economy of the southwest of then U.S.

Method used

water balance model

Studied the impacts of different elements on the river flow

Global warming, evaporation, infiltration, runoff variability

Water level in Lake Colorado is declining

50% chance that the lake will go dry by 2021 in deterministic approach in nothing is done

Reduction in the lake level will damper the capacity of the hoover dam to produce electricity

Comment on "When will Lake Mead go dry?"(2009)^[4][edit | edit source]

• Abstract
• Key Takeaways

Criticize the finding of Barnett and Pierce

Still concludes that if lake might go dry if nothing is done

Found 50% chance of depleting storage occurs between 2035 and 2047

Agrees with Barnett and Pierce that mitigation action be taken

Water supply risk on the Colorado River: Can management mitigate?(2009)^[5][edit | edit source]

• Abstract

Population growth and a changing climate will tax the future reliability of the Colorado River water supply. Using a heuristic model, we assess the annual risk to the Colorado River water supply for 2008–2057. Projected demand growth superimposed upon historical climate variability results in only a small probability of annual reservoir depletion through2057. In contrast, a scenario of 20% reduction in the annual Colorado River flow due to climate change by 2057 results in a near tenfold increase in the probability of annual reservoir depletion by 2057. However, our analysis suggests that flexibility in current management practices could mitigate some of the increased risk due to climate change–induced reductions in flows.

• Key Takeaways

River supports population and economy growth in southwest

Argue that the relatively small risk of drying in the next 2 decades should not lull policy makers into inaction.

Policy action may be limited if climate change consequences in 2026 are confirmed

States there is still time to take action

THE EVAPORATION FROM PONDS IN THE FRENCH MIDWEST(2013)^[6][edit | edit source]

• Abstract

This research shows the results of a study about evaporation in five ponds in the Midwest of France. To realize this study we used climate data from the meteorological station of the Limoges-Bellegarde airport and the data of a weather station installed by us near one of the ponds. We used eight different methods to calculate the evaporation rate and we modified the Penman-Monteith method by replacing the air temperature by water temperature. To understand the role of ponds in water loss through evaporation, we proposed a hypothesis that says: if the pond did not exist, what results would we get? Based on this hypothesis we calculated the potential evapotranspiration rate taking into account the percentage of interception by vegetation. In conclusion, this study indicates that the ponds in the French Midwest present a gain of water.

• Key Takeaways

List of different water evaporation calculation methods

Use of water temperature in place of air temperature in Penmam-Monteith model

Estimation of open water evaporation: a review of methods(2005)^[7][edit | edit source]

• Abstract
• Key Takeaways

Description of several methods for calculating the evaporation of a lake

Use of water surface temperature instead of air temperature

Methods studied

Penman

Penman-Monteith

Equilibrium temperature

Penman empirical factor

FAO-56 empirical factors

Adjustment of method parameters with altitude

Researchers learning true scale of Lake Mead, Powell evaporation rates(2019)^[8][edit | edit source]

• Abstract

Precious water is vanishing into thin air at the Colorado River's two largest reservoirs, and scientists are only now learning the true scale of the problem.

• Key Takeaways

Evaporation in Colorado River might be worse than expected

Looking for new methods (Eddy current) to have a better evaluation

Estimates of lake evaporation in the recent years.

Evaporation from a small water reservoir: Direct measurements and estimates(2008)^[9][edit | edit source]

• Abstract

Knowing the rate of evaporation from surface water resources such as channels and reservoirs is essential for precise management of the water balance. However, evaporation is difficult to measure experimentally over water surfaces and several techniques and models have been suggested and used in the past for its determination. In this research, evaporation from a small water reservoir in northern Israel was measured and estimated using several experimental techniques and models during the rainless summer. Evaporation was measured with an eddy covariance (EC) system consisting of a three-dimensional sonic anemometer and a Krypton hygrometer. Measurements of net radiation, air temperature and humidity, and water temperature enabled estimation of other energy balance components. Several models and energy balance closure were evaluated. In addition, evaporation from a class-A pan was measured at the site. EC evaporation measurements for 21 days averaged 5.48 mm day−1. Best model predictions were obtained with two combined flux-gradient and energy balance models (Penman–Monteith–Unsworth and Penman–Brutsaert), which with the water heat flux term, gave similar daily average evaporation rates, that were up to 3% smaller than the corresponding EC values. The ratio between daily pan and EC evaporation varied from 0.96 to 1.94. The bulk mass transfer coefficient was estimated using a model based on measurements of water surface temperature, evaporation rate and absolute humidity at 0.9 and 2.9 m above the water surface, and using two theoretical approaches. The bulk transfer coefficient was found to be strongly dependent on wind speed. For wind speeds below 5 m s−1 the estimated coefficient for unstable conditions was much larger than the one predicted for neutral conditions.

• Key Takeaways

Description of the Penman-Monteith-Unsworth (PMU) model

Difficulties in using Eddy Covariance method

Penman-Monteith Estimates of Reservoir Evaporation(2005)^[10][edit | edit source]

• Abstract

Weather and Lake Berryessa(LB) temperature profile data were collected from May 2003 through September 2004 to enable estimating lake evaporation using the Penman-Monteith equation. Current evaporation estimates from LB by the U.S. Bureau of Reclamation (USBR) are based on Class A pan evaporation and the original pan coefficients developed in the 1960s. Since then, the location of the pan has been moved several times and measured pan evaporation measured at the current or old site is much lower than that measured at a new site that is fully exposed to solar radiation. USBR calculated inflow to LB is based on measured lake elevation, estimated evaporation, and measured releases from the reservoir. The estimated lake evaporation based on the pan data and original pan coefficients are too low. Because of the method of calculating lake inflow, calculated daily negative lake inflows commonly occur from mid-July until fall-winter rains begin. Estimates of evaporation from the lake were made using the Penman-Monteith (P-M) equation, estimates of daily change in heat in the water, and advection of heat energy into or out of the lake. Estimates of P-M evaporation were reduced by a factor of 0.95 because a small part of the lake surface area is shaded part of the day, and weather data were measured at a location near the lake instead of over the lake. The P-M evaporation estimates and estimates using pan evaporation at the new site with Lake Elsinore monthly pan coefficients indicated that USBR evaporation estimates are about 20% too low mainly because of pan site conditions. A computer model was developed to process, store, and calculate estimated daily or monthly evaporation from the lake.

• Key Takeaways

Details on Penman-Monteith equation

Use of water surface temperature

Walke Lake Conservation Effort[edit | edit source]

WALKER RV NR MOUTH AT WALKER LAKE, NV (USGS-10302025) site data in the Water Quality Portal(2021)^[11][edit | edit source]

• Abstract
• Key Takeaways
  • Data Source for Walker Lake

History of Walker Lake(2020)^[12][edit | edit source]

• Abstract
• Key Takeaways
  • Agriculture diversion of water and dams leads to lake level drops
  • Increased dissolved solid => marine life in danger
  • water acquire from sellers to maintain lake
  • Funds created to sustain lake conservation

USGS Current Conditions for USGS 10302025 WALKER RV NR MOUTH AT WALKER LAKE, NV(2021)^[13][edit | edit source]

• Abstract
• Key Takeaways
  • Temperature data source for Walker Lake

Disappearing Walker Lake(2018)^[14][edit | edit source]

• Abstract

Like this lake in northwestern Nevada, many of the world's prominent salt lakes are drying up.

• Key Takeaways
  • Example of shrinking lakes in the world
  • Lake is used for irrigation
  • 90% water lost a century ago
  • Decreased water inflow => increased dissolved solid => lake half as salty as seawater (17g/l) => impact on marine and wild life (83% loss of fish species)
  • increase of inflow by 24% would decrease salinity level
  • map showing lake decrease b/w 1988 - 2017
  • Possible causes:
    • Climate change (warmer temperatures, increased evaporation, and altered precipitation)
    • Water development (agriculture, mining, and cities)

Ripple effect: Walker Lake evaporation leaves cultural strains - Las Vegas Sun Newspaper(2003)^[15][edit | edit source]

• Abstract

HAWTHORNE -- Controversy is a constant at Walker Lake.

• Key Takeaways
  • 140 ft drop in 120 years
  • Cause: ongoing drought + irrigation
  • Increase saltiness, struggling fish + migratory birds, Endangered tourism => economic impact
  • Conflict b/w preserving the lake level and irrigation (water from the irrigation contributes 1/5 agricultural yield of state)
  • tourism provide 40% of mineral county economy
  • Lake has historical value to indigenous pop.
  • Walker Lake Working Group looking for solutions to save lake
  • Evaporation rate: 4ft/year
  • evaporates leaves dissolved solids => increase in saltiness
  • saltiness rises naturally but is increased by evaporation.
  • 224 ft in 1882 to 90 ft in 2003

Walker Lake Recreation Area(2021)^[16][edit | edit source]

• Abstract
• Key Takeaways
  • Increase salinity of the lake => less fish (Lahontan Cutthroat disappeared)

Water Budgets of the Walker River Basin and Walker Lake, California and Nevada(2009)^[17][edit | edit source]

• Abstract

The Walker River is the main source of inflow to Walker Lake, a closed-basin lake in west-central Nevada. The only outflow from Walker Lake is evaporation from the lake surface. Between 1882 and 2008, upstream agricultural diversions resulted in a lake-level decline of more than 150 feet and storage loss of 7,400,000 acre-feet. Evaporative concentration increased dissolved solids from 2,500 to 17,000 milligrams per liter. The increase in salinity threatens the survival of the Lahontan cutthroat trout, a native species listed as threatened under the Endangered Species Act. This report describes streamflow in the Walker River basin and an updated water budget of Walker Lake with emphasis on the lower Walker River basin downstream from Wabuska, Nevada. Water budgets are based on average annual flows for a 30-year period (1971-2000). Total surface-water inflow to the upper Walker River basin upstream from Wabuska was estimated to be 387,000 acre-feet per year (acre-ft/yr). About 223,000 acre-ft/yr (58 percent) is from the West Fork of the Walker River; 145,000 acre-ft/yr (37 percent) is from the East Fork of the Walker River; 17,000 acre-ft/yr (4 percent) is from the Sweetwater Range; and 2,000 acre-ft/yr (less than 1 percent) is from the Bodie Mountains, Pine Grove Hills, and western Wassuk Range. Outflow from the upper Walker River basin is 138,000 acre-ft/yr at Wabuska. About 249,000 acre-ft/yr (64 percent) of inflow is diverted for irrigation, transpired by riparian vegetation, evaporates from lakes and reservoirs, and recharges alluvial aquifers. Stream losses in Antelope, Smith, and Bridgeport Valleys are due to evaporation from reservoirs and agricultural diversions with negligible stream infiltration or riparian evapotranspiration. Diversion rates in Antelope and Smith Valleys were estimated to be 3.0 feet per year (ft/yr) in each valley. Irrigated fields receive an additional 0.8 ft of precipitation, groundwater pumpage, or both for a total applied-water rate of 3.8 ft/yr. The average corrected total evapotranspiration rate for alfalfa is 3.2 ft/yr so about 0.6 ft/yr (15 percent) flushes salts from the soil. The diversion rate in Bridgeport Valley was estimated to be 1.1 ft/yr and precipitation is 1.3 ft/yr. The total applied-water rate of 2.4 ft/yr is used to irrigate pasture grass. The total applied water rate in the East Fork of the Walker River and Mason Valley was estimated to be 4.8 ft/yr in each valley. The higher rate likely is due to appreciable infiltration, riparian evapotranspiration, or both. Assuming a diversion rate of 3.0 ft/yr, stream loss due to infiltration and riparian evapotranspiration is about 3,000 acre-ft/yr along the East Fork of the Walker River and 14,000 acre-ft/yr in Mason Valley. In the lower Walker River basin, overall and groundwater budgets were calculated for Wabuska to Schurz, Nev., and Schurz to Walker Lake. An overall water budget was calculated for the combined reaches. Imbalances in the water budgets range from 1 to 7 percent, which are insignificant statistically, so the water budgets balance. Total inflow to the Wabuska-Walker Lake reach from the river and others sources is 140,000 acre-ft/yr. Stream and subsurface discharge into the northern end of Walker Lake totals 110,000 acre-ft/yr. About 30,000 acre-ft/yr is lost on the Walker River Indian Reservation from agricultural evapotranspiration, evapotranspiration by native and invasive vegetation, domestic pumpage, and subsurface outflow from the basin through Double Spring and the Wabuska lineament. Alfalfa fields in the upper Walker River basin are lush and have an average corrected total evapotranspiration rate of 3.2 ft/yr. Alfalfa fields on the Walker River Indian Reservation are not as lush and have a total corrected evapotranspiration rate of 1.6-2.1 ft/yr, which partly could be due to alkaline soils that were submerged by Pleistocene Lake Lahontan. The total applied-water rate is 7.0 ft/yr, almost twice the

• Key Takeaways
  • at least 863 milions of m3 to maintain solid concentration at 12g/l
  • Only outflow at the lake is evaporation
  • Lake diverted for irrigation => lake decline, increase salinity, endangerment of species
  • $200 million provided in 2002 by secretary of interior to rehabilitate lakes like Pyramid, Summit and Walker Lake in Nevada
  • 4.3 ft/year.

Water Budget and Salinity of Walker Lake, western Nevada(1995)^[18][edit | edit source]

• Abstract

Walker Lake is one of the rare perennial, terminal lakes in the Great Basin of the western United States. The lake is the terminus for all surface- water and ground-water flow in the Walker River Basin Hydrographic Region that is not consumed by evaporation, sublimation, or transpiration. The concentration of dissolved solids (salts) in the lake-surface altitude depend primarily on the amounts of water entering and evaporation from the lake. Because Walker Lake is a terminal sink--it has no documented surface- or ground-water outflow--dissolved solids that enter it accumulate as the lake water evaporates. Declining lake levels, owing to natural and anthropogenic processes, have resulted in most Great Basin terminal lakes being too saline to support fish. In Nevada, the only terminal lakes that contain fish are Pyramid Lake, Ruby Lake, and Walker Lake. Dissolved-solids concentration in Walker Lake increased from about 2,500 milligrams per liter in 1882 to 13,300 milli- grams per liter in July 1994 (U.S. Geological Survey analysis), as the lake-surface altitude declined from about 4,080 to 3,944 feet above sea level. This dramatic increase in dissolved-solids concentration threatens the Walker Lake ecosystem and the fish that depend on this ecosystem.

• Key Takeaways
  • 4.1 ft/year

Decline of the world's saline lakes(2017)^[19][edit | edit source]

• Abstract

Many of the world's saline lakes have been shrinking due to consumptive water use. The Great Salt Lake, USA, provides an example for how the health of and ecosystem services provided by saline lakes can be sustained.

• Key Takeaways
  • World's saline lakes are shrinking at alarming rates => reduced waterbird habitat, reduced economic benefit, threat to human health
  • Saline Lakes => 44% of all lakes volume
  • Cause: increased water use by humans
  • example of other shrinking lakes
  • Economic, social and ecological benefit of saline lakes not easily monetized
  • Dessicated saline lakes dust harms human health and agriculture => increase respiratory disease => increase in money spent for mitigation
  • Increase temperature will increase evaporation in lakes

Global lake evaporation accelerated by changes in surface energy allocation in a warmer climate(2018)^[20][edit | edit source]

• Abstract

Lake evaporation is a sensitive indicator of the hydrological response to climate change. Variability in annual lake evaporation has been assumed to be controlled primarily by the incoming surface solar radiation. Here we report simulations with a numerical model of lake surface fluxes, with input data based on a high-emissions climate change scenario (Representative Concentration Pathway 8.5). In our simulations, the global annual lake evaporation increases by 16% by the end of the century, despite little change in incoming solar radiation at the surface. We attribute about half of this projected increase to two effects: periods of ice cover are shorter in a warmer climate and the ratio of sensible to latent heat flux decreases, thus channelling more energy into evaporation. At low latitudes, annual lake evaporation is further enhanced because the lake surface warms more slowly than the air, leading to more long-wave radiation energy available for evaporation. We suggest that an analogous change in the ratio of sensible to latent heat fluxes in the open ocean can help to explain some of the spread among climate models in terms of their sensitivity of precipitation to warming. We conclude that an accurate prediction of the energy balance at the Earth's surface is crucial for evaluating the hydrological response to climate change.

• Key Takeaways
  • Lake evaporation is linked to climate change => current level will increase by 16% by the end of century

Climate change will affect global water availability through compounding changes in seasonal precipitation and evaporation(2020)^[21][edit | edit source]

• Abstract

Both seasonal and annual mean precipitation and evaporation influence patterns of water availability impacting society and ecosystems. Existing global climate studies rarely consider such patterns from non-parametric statistical standpoint. Here, we employ a non-parametric analysis framework to analyze seasonal hydroclimatic regimes by classifying global land regions into nine regimes using late 20th century precipitation means and seasonality. These regimes are used to assess implications for water availability due to concomitant changes in mean and seasonal precipitation and evaporation changes using CMIP5 model future climate projections. Out of 9 regimes, 4 show increased precipitation variation, while 5 show decreased evaporation variation coupled with increasing mean precipitation and evaporation. Increases in projected seasonal precipitation variation in already highly variable precipitation regimes gives rise to a pattern of "seasonally variable regimes becoming more variable". Regimes with low seasonality in precipitation, instead, experience increased wet season precipitation.

• Key Takeaways

Defining salinity limits on the survival and growth of benthic insects for the conservation management of saline Walker Lake, Nevada, USA(2013)^[22][edit | edit source]

• Abstract

Walker Lake, Nevada, a saline desert lake, has been undergoing loss of stream inflows, lowering of lake level, and concentration of dissolved salts for over a century due to agricultural diversions of water. This lake is or has been inhabited by native fish and visited by many species of waterbirds that depend on productive invertebrate life for food resources. The extent to which salinity limits the present and future viability of resident invertebrate fauna was evaluated using salt-tolerance bioassays and studies of salinity effects on growth and behavior in larval stages of the midges Cricotopus ornatus and Tanypus grodhausi, and nymphs of the damselfly Enallagmaclausum. We found that salinities into and above a range of 20–25 g/L present either lethal limits or sublethal inhibitions to survival and growth that will eliminate or substantially reduce the current community of common benthic invertebrates. All species survived best at salinities below the current ambient level, suggesting these populations are already under stress. The 72-h LC-50 for Cricotopus was 25 g/L, and while mature damselfly nymphs were somewhat more tolerant, early instars survived for only short times in increased salinity. Damselflies also grew more slowly and fed less when salinity increased from 20 to 30 g/L. A conservation level for the lake that incorporates survival of native fish and recovers diversity and viability of invertebrate life should be within the range of 10–15 g/L salinity of Walker Lake water.

• Key Takeaways
  • Main reason for lake decline = agricultural diversion of water
  • Lethal salinity levels: 20-25g/l
  • Species already under stress
  • Viability salinity of the lake = 10-15g/l
  • maintenance of saline important on ecosystems maintenance
  • Characteristics of the lake in 2012

Walker Lake - Terminal Lake at the Brink(2014)^[23][edit | edit source]

• Abstract
• Key Takeaways
  • Presents conservation solutions for the lake

The world's vanishing lakes(2017)^[24][edit | edit source]

• Abstract

Some of the world's largest lakes have shrunk dramatically in the last few decades, while many more face serious pollution problems. A new global database of lakes may help to protect the water bodies that offer irreplaceable wildlife habitats and valuable ecosystem services. Michael Gross reports.

• Key Takeaways
  • Description of vanishing lakes worldwide
  • lake disappearance effect on fish, birds, and people, and economy
  • Another cause => building dam for hydroelectricity

Impacts of climate change on the evaporation and availability of water in small reservoirs in the Brazilian savannah(2020)^[25][edit | edit source]

• Abstract

The Cerrado (Brazilian savannah) is one of the few places in the world that has the potential to increase crop production to meet the projected food demand for 2050. However, for agriculture to be sustainable in this region, irrigation must be efficient. This depends on the water stored in small reservoirs, which play an important role in supporting the local economy. The increase in temperature and net radiation predicted by global climate models may increase the evaporation and reduce the availability of water in these small reservoirs. This work assesses the projected impact of climate change on small reservoir evaporation and water availability in the Brazilian savannah using data from the Eta-HadGEM2-ES and Eta-MIROC5 regional climate models under representative concentration pathways (RCP) 4.5 and 8.5. Evaporation increases of 7.3% (1.09 mm/year−1) and 18.4% (2.74 mm/year−1) are projected in RCP 4.5 and RCP 8.5, respectively, by the year 2100. The water stored in reservoirs is projected to decrease in the future, resulting in higher risks of failure in water supply, especially from the smaller reservoirs. Overall, evaporation increases are expected to reduce the availability of water in small reservoirs during the dry season by 5.5% in RCP 4.5 and 10.4% in RCP 8.5.

• Key Takeaways
  • Highlights the impact climate change on evaporation in small reservoirs.
  • Small lake feel climate change effects more intensely than larger, deeper, and freezable lakes
  • need to understand climate change importance in water conservation strategies

Lake Management Perspectives in Arid, Semi-Arid, Sub-Tropical and Tropical Dry climate(2007)^[26][edit | edit source]

• Abstract

Water scarcity is natural- typical feature of arid and semi-arid regions.. In arid zones precipitation is <250 mm/y, whilst in semi-arid areas 250-500 mm/y. Due to atmospheric circulation (convection cells) arid and semi-arid zones are common within 23.50 north and south latitudes, ("Horse": CapricornCancer), where, warm and dry conditions are dominant. Total area of arid and semi-arid deserts >0.05x106 km2 (38) is 19.5x106 km2 : in Africa- 3, Asia-6, Australia-9, Europe-5, Middle East-6, North America and Mexico-4 and 5 in South America. Eco-hydrological changes in arid and semi arid aquatic ecosystems are due to climate fluctuations and human intervention. Sufficient water availability (quantitative and qualitative) in arid and semi arid zones is the key factor for economical and cultural prosperities and might be a reason for geo-political conflicts. Water demands per capita is depends upon resource availability, and cultural and political heritage. Lakes in arid zones are mostly shallow and fed by underground sources and seasonal floods whilst those in semi-arid and sub-tropical regions are mostly fed by continuous surface flows, direct rain and sub-lacustrine influxes. Due to the high evaporation, salinity in desert lakes is high, sometime suitable for fish production and frequently-not. Fish production in semiarid and subtropical lakes, water supply and recreational tourism are common usage. Climatological changes (global warming) and ecological sensitivity of these ecosystems, deserve utilization precautious. Several lakes were partly (or higher) destructed, some became very polluted and some are well protected by thorough study and consequent implementation. Four case studies of arid, semi arid and subtropical lakes are presented: Lake Chad in the Sahara desert, two Egyptian lakes in the Sahara desert, Wadi El-Rayan and lake Quarun, Lake Kinneret in Israel and Lake Tai-Hu in China. Some of them represent deterioration of water quality and perturbation of further utilization, limnological changes, pollution and an urgent need of protection policy.

• Key Takeaways
  • Fina status of a lake is the combination of all parameters: climate + human activity

[URL Title](Year)^[27][edit | edit source]

• Abstract
• Key Takeaways

Contributors[edit | edit source]

• ---Arpit, Pravin, Sreenija, Surya, Tanmoy, Pierce, Koami
• ---

References[edit | edit source]