Supply And Demand Balance Analysis And Water Supply Risk Of Jinghuiqu Irrigation District

Jinghuiqu Irrigation District has made a great contribution to the economic development of Shanxi, witch is a large irrigation district in Shaanxi Province. Understanding the current and future situation of supply and demand of water supply and demand and reducing the risk of water supply are essential works to achieve the sustainable use of water resources in irrigation districts.This paper takes Jinghuiqu Irrigation District as the study area and selects 2010 and 2020 as status and planning programming year respectively, then uses the quota method to predict its water demand of living, industrial and agricultural under two guarantee rates(50% and 75%) and conducts analysis of supply and demand level balance, and constructs the risk assessment index system of water supply in irrigation districts based on risk theory, next constructs comprehensive evaluation model of water supply risk by using analytic hierarchy process and entropy weight method, then Gets the agricultural water users’ planning programming year’s supply risk comprehensive evaluation value in different inflow frequency and then conducts analysis of water supply risk, also puts forward some countermeasures to reduce the risk of water supply. The main research contents and results are as follows:(1) Predicting irrigate area’s water demand and conducting analysis of water supply and demand balance: 2020 compared with 2010, irrigation water demand is decreasing, its number in total water demand is falling by about 7%, living and industrial water demand are both increasing, their number in total water demand are increasing about 1.6% and 5% respectively.Status and planning programming year of irrigation area are not water shortage under 50% guarantee rate. Water shortages and water shortage ratio are 7020.27 million m3、5800.97 million m3 and 11.08%、9.75% respectively under 75% guarantee rate.(2) Selecting reliability, coordination, recovery, vulnerability, daily maximum water shortage index constructs evaluation index system of water supply risk in irrigation districts according to the water supply risk index selection principle; Water supply risk assessment model witch bases on the combination of subjective and objective weights is constructed by using AHP and entropy weight method.(3) Water supply risk index’s calculation results in Jinghuiqu Irrigation District show that: Reliability index’s value is between 79.78%~97.54%, its mean value is 93.80%, which indicates that the reliability is high; Coordination index’s value is between 46.74%~84.89%, its mean value is 67.86%, which indicates that the coordination is relatively high; Recovery index’ value is between 4.05%~16.67%, its mean value is 9.05%, which indicates that the elasticity is low; Vulnerability index’s value is between 0.37%~0.83%, its mean value is 0.55%, which indicates that the vulnerability is low; Daily maximum water shortage rate’s value is between 28.30%~93.10%, its mean value is 65.61%, witch indicates that maximum water shortage rate is relatively high.(4) Analysis results of water supply risk in Jinghuiqu Irrigation District show that: water supply risk comprehensive evaluation values show an increasing trend with the overall frequency of runoff increase, their maximum value is 72.82%, witch is not acceptable risk, their minimum is 15.39%, witch is negligible risk, their extreme value ratio is 4.73,witch shows that their variation range is very large. Mean values of water supply risk in abundant water year, normal water years and dry years are 34.79% 、 42.06% 、 56.83% respectively. Abundant water years’ water supply risk is acceptable risk, witch is mainly influenced by the runoff distribution in the year; Normal water years’ and dry years’ water supply risk are both marginal risk, witch is mainly affected by the annual runoff and its distribution in the year; But special dry years’ water supply risk is very little affected by the distribution of runoff in the year.(5) Countermeasures on reducing Jinghuiqu Irrigation District water supply risk is put forward, witch are applying irrigation runoff production by constructing drainage and water storage facilities, carrying out water conservancy facilities construction supporting the transformation, building some new water source projects and expanding the reservoirs’ capacity that have been built, popularizing Water-Saving Irrigation and establishing a scientific and reasonable system of water price.