Modeling Evaporation-Seepage Losses for Reservoir Water Balance in Semi-arid Regions

A new design and experiments on a parasol-type float for retardation of excessive evaporation in open water bodies are described. Laboratory-scale experiments with the water surface open and partially covered by the device showed halving of the level drop in the latter case. The experimental data were compared with theoretical calculations which yield a lower absolute level drop compared with the experiment; by contrast, there was agreement, on the average, when relative values were used. The design provides also a sufficient buoyancy reserve and is durable in long-term exploitation.

Section: Discussionsupporting

confidence: 61%

Retardation of Water Evaporation by a Protective Float

Segal

Burstein

2009

“…The authors questioned the practice of adding an arbitrary allowance to the storage capacity to consider evaporation losses. Modeling evaporation and spills for the management of reservoirs has been the object of recent research (Celeste and Bilib 2009;Sivapragasam et al 2009). Opricovic (2009) proposed a compromise solution in water resource planning in a decision problem for reservoir system design of surface flows of the Mlava River and its tributaries.…”

Section: Review Of Reservoir Capacity-yield Proceduresmentioning

confidence: 99%

Modeling the Yield–Evaporation–Spill in the Reservoir Storage Process: The Regulation Triangle Diagram

Campos

2010

From the dimensionless reservoir water budget equation, a graphical method to model the yield-spill-evaporation loss trade-off in the reservoir storage process was built. The reservoir inflows were transformed into three parts that sum to the total mean inflow for long-term operation: evaporation, spill and yield. A regulation triangle diagram (RTD) has been proposed to provide a better understanding of the reservoir storage process as a function of reservoir capacity, hydrological river regime, evaporation and reservoir morphology. The inflows were assumed to be serially uncorrelated and to originate from a Gamma probability distribution function. The diagrams were developed using the Monte Carlo method, while the graphics were developed for intermittent rivers with a coefficient of variation of annual inflows that ranges from 0.6 to 1.6. In the model, the reservoir is a single over-year system, and the values are referenced to the steady state conditions.

“…Evaporation ratio from water surfaces of fountains was estimated from May to September, inclusive, the hottest months in the study area. Many methods have been reported for the estimation of evaporation losses from free water surfaces (Sivapragasam et al 2009). We estimated water evaporation over 1 year using the relationship established by Kazim (2003) between air temperature and humidity and the rate of water evaporation, which gave a figure of 5.5% evaporation of the water inflow in Montjuïc Park (Fig.…”

Section: Water Flow Accountingmentioning

confidence: 99%

Water Management in Integrated Service Systems: Accounting for Water Flows in Urban Areas

Núñez

Oliver-Solà

Rieradevall

et al. 2009

This article focuses on studying the natural and artificial water flows of the service sector from an industrial ecology perspective. The purpose is to determine, in the area under study, the water consumption of the service sector and the most water demanding services in global and relative terms, total water consumption per year and liters per user per year (Lpu) respectively, as well as the existing and potential water flow interrelations among service facilities to reduce their water consumption. Finally we propose measures for water consumption minimization, recycling and reusability based on the results of the diagnosis. The analyzed system is Montjuïc Urban Park (Barcelona, Spain), where the economic activity is based on the service sector (about 200 service facilities and no industrial activities). In the individual study of services we found an average consumption of 75 Lpu, with a large range in the water consumption by service types (between 17 and 156 Lpu), and between facilities of the same service type (51 and 155 Lpu). These results indicate a high level and low regulation of water consumption among the service facilities. In the study of the All amounts of water are expressed in round figures in the text, tables and figures for the sake of simplicity. Núñez et al. interrelations between the services we found that a high potential for hydrological saving exists in the system (equivalent to 50% of the potable water inflow from the supply network). The results indicate a lack of ecosystemic and synergic vision in the service sector. Interrelations among water flows have to be established, by means of rainwater collection and the reuse of water flows from swimming pools and ornamental fountains. The article proposes the application of industrial ecology methods to improve water management inside Montjuïc Urban Park and, in general, within any system where the service sector is the main economic activity.