scholarly journals Scenario Analysis of Water Supply and Demand using WEAP Model: A Case of Yala Catchment, Kenya

2017 ◽  
Author(s):  
Jared Ouma okungu

The counties traversed by Yala River Catchment in Kenya have been constrained by acute shortages of water resources because of the declining stream flows, which is occasioned by environmental changes, increasing population and changing land uses. This study applied Water Evaluation and Planning (WEAP) model to evaluate past trends and simulate current demand scenarios for the purposes of planning by authorities in regard to future use. The study used historical data (1970-2015) to assess water supply and demand in the catchment for the period 2016 to 2045 by simulation. Calibration and validation were each performed on 10-year streamflow datasets (1991-2000 and 2001-2010 respectively), drawn from 4 gauging stations. Simulations were then conducted for the scenarios namely: Reference (at 2.8% growth rate), High Growth (3.2%), High Growth (3.5%), and Moderated Growth (2.2%). The categories of water demand evaluated in WEAP included: Domestic-Institutional-Municipal, Agriculture, and Industry uses. In a 5-year time-step, WEAP demonstrated resultant increase in water demand for year 2020 by 7.46% from 2016 at Reference Scenario. WEAP further simulated a gradual increase in water demand during subsequent years. This trend would continue for the rest of the scenarios but with variations occasioned by adjustment of variables in WEAP such as population growth rates, monthly variations, annual activity levels, water use rates, water losses and reuse rates, industrial production units, agricultural acreages, and varied demand sites. In conclusion, there were demonstrated substantial increases in water demands within individual scenarios between 2016 to 2045, but these increases were significantly different scenario-by-scenario. The study recommends that supply and demand measures be employed with the aim of regulating activity levels, losses and consumptions so as to meet demands in case any of the studied scenarios would be applicable.

Author(s):  
Hang Li ◽  
Xiao-Ning Qu ◽  
Jie Tao ◽  
Chang-Hong Hu ◽  
Qi-Ting Zuo

Abstract China is actively exploring water resources management considering ecological priorities. The Shaying River Basin (Henan Section) serves as an important grain production base in China. However, conflicts for water between humans and the environment are becoming increasingly prominent. The present study analyzed the optimal allocation of water while considering ecological priorities in the Shaying River Basin (Henan Section). The ecological water demand was calculated by the Tennant and the representative station methods; then, based on the predicted water supply and demand in 2030, an optimal allocation model was established, giving priority to meeting ecological objectives while including social and comprehensive economic benefit objectives. After solving the model, the optimal results of three established schemes were obtained. This revealed that scheme 1 and scheme 2 failed to satisfy the water demand of the study area in 2030 by only the current conditions and strengthening water conservation, respectively. Scheme 3 was the best scheme, which could balance the water supply and demand by adding new water supply based on strengthening water conservation and maximizing the benefits. Therefore, the actual water allocation in 2030 is forecast to be 7.514 billion (7.514 × 109) m3. This study could help basin water management departments deal with water use and supply.


2016 ◽  
Vol 78 (5-5) ◽  
Author(s):  
Nurul Nadiah Mohd Firdaus Hum ◽  
Suhaimi Abdul Talib

Water in Selangor is getting scarce due to its rapid economic growth. A fast growing population and expanding urbanization in the state creates new demands for water availability. Thus, the present study analyses the effects of three different scenarios using Water Evaluation and Planning (WEAP) model to evaluate the plausible future water scenarios of water availability in Selangor. The first scenario is business as usual which is later referred to as reference in this study. Second, higher population growth and the third is the application of the demand side management onto the reference and higher population growth scenario. These scenarios were then used to calculate the impact on the supply – demand gap by the year 2050. Two catchments were used namely Selangor and Langat to illustrate the water supply and demand in the state of Selangor. The study then generates information for use in managing water allocations amongst economic sectors in Selangor as the explicit accounting in the description of the water supply and demand among the urban and industry water usage is advocated. Such detailed scenario simulation and the inclusion of previously unaccounted for factors like the higher population growth and water savings management can help to create awareness of potential future problems, inform water practices and suggest management alternatives. Results show that with proper water savings measures, water deficit within Selangor will be significantly reduced.  


2019 ◽  
Vol 11 (21) ◽  
pp. 5893 ◽  
Author(s):  
Li ◽  
Ma ◽  
Wei ◽  
Zhang

In order to meet the needs of water-saving society development, the system dynamics method and the Cobb–Douglas (C–D) production function were combined to build a supply and demand model for urban industrial water use. In this model, the industrial water demand function is expressed as the sum of the general industrial water demand and the power industry water demand, the urban water supply function is expressed as the Cobb–Douglas production function, investment and labor input are used as the control variables, and the difference between supply and demand in various situations is simulated by adjusting their values. In addition, the system simulation is conducted for Suzhou City, Jiangsu Province, China, with 16 sets of different, carefully designed investment and labor input combinations for exploring a most suitable combination of industrial water supply and demand in Suzhou. We divide the results of prediction into four categories: supply less than demand, supply equals demand, supply exceeds demand, and supply much larger than demand. The balance between supply and demand is a most suitable setting for Suzhou City to develop, and the next is the type in which the supply exceeds demand. The other two types cannot meet the development requirements. We concluded that it is easier to adjust the investment than to adjust the labor input when adjusting the control variables to change the industrial water supply. While drawing the ideal combination of investment and labor input, a reasonable range of investment and labor input is also provided: the scope of investment adjustment is , and the adjustment range of labor input is .


2012 ◽  
Vol 58 (4) ◽  
pp. 41-48
Author(s):  
Jan Thomas ◽  
Miroslav Kyncl ◽  
Silvie Langarová

Abstract Periods of drought represent a serious problem in the management of water resources. Currently used climatic models assume the onset of major climatic changes and periods of drought. Irrespective of whether the forecasts will be fulfilled or not, it is essential to prepare measures to ensure the supply of drinking water in dry periods. This paper deals with the preparation of water balances for the areas of the Odra and Morava River basins and the prediction of relationships between water supply and water demand in the given area.


Author(s):  
Zheng Wang ◽  
Yue Huang ◽  
Tie Liu ◽  
Chanjuan Zan ◽  
Yunan Ling ◽  
...  

Lower reaches of the Amu Darya River Basin (LADB) is one of the typical regions which is facing the problem of water shortage in Central Asia. During the past decades, water resources demand far exceeds that supplied by the mainstream of the Amu Darya River, and has resulted in a continuous decrease in the amount of water flowing into the Aral Sea. Clarifying the dynamic relationship between the water supply and demand is important for the optimal allocation and sustainable management of regional water resources. In this study, the relationship and its variations between the water supply and demand in the LADB from the 1970s to 2010s were analyzed by detailed calculation of multi-users water demand and multi-sources water supply, and the water scarcity indices were used for evaluating the status of water resources utilization. The results indicated that (1) during the past 50 years, the average total water supply (TWS) was 271.88 × 108 m3/y, and the average total water demand (TWD) was 467.85 × 108 m3/y; both the volume of water supply and demand was decreased in the LADB, with rates of −1.87 × 108 m3/y and −15.59 × 108 m3/y. (2) percentages of the rainfall in TWS were increased due to the decrease of inflow from the Amu Darya River; percentage of agriculture water demand was increased obviously, from 11.04% in the 1970s to 44.34% in 2010s, and the water demand from ecological sector reduced because of the Aral Sea shrinking. (3) the supply and demand of water resources of the LADB were generally in an unbalanced state, and water demand exceeded water supply except in the 2010s; the water scarcity index decreased from 2.69 to 0.94, indicating the status changed from awful to serious water scarcity. A vulnerable balanced state has been reached in the region, and that water shortages remain serious in the future, which requires special attention to the decision-makers of the authority.


2013 ◽  
Vol 448-453 ◽  
pp. 995-1001
Author(s):  
Ning Na Wang ◽  
Qin Lin Zhou

An effective management of water supply is critically significant to a countrys water utilities, and accurate prediction of water supply and demand is of key importance for water supply management. The objectives of this paper are to use Grey System Model (GSM) and Linear Regression Model to forecast the water demand and water supply respectively in China 2025, and then propose a new Optimal Allocation Model (OAM) to generate solution so that analysts and decision makers can gain insight and understanding. The two predictive models take into account four major factors including domestic development, agriculture, industries and eco-environment, calculating a deficit between water demand and water supply in China 2025. Then the OAM, which considers desalinization, irrigation saving and urban recycling, provides a feasible solution to fill the gap and an effectual management of water supply.


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