基于地下水均衡的灌区合理渠井用水比例

基于地下水均衡模型,分析了陕西泾惠渠灌区不同频率典型年的地下水均衡状况,结果表明降水入渗补给、渠系渗漏及田间灌溉入渗补给、井灌回归补给是灌区地下水的主要补给源,占总补给量的85.99%~82.89%;而人工开采是灌区地下水的主要排泄途径,农灌地下水开采量、人畜和工业用水开采量占总排泄量的69.7%~72.86%.以2010年为现状基准年,2020年为规划水平年,结合灌区发展规划,设置了4种不同的灌区发展情景模式,运用所建立的地下水均衡模型计算了不同情景模式下的地下水位埋深,其变化范围为0~0.07 m;以地下水位变幅最小为准则,得出了不同频率典型年合理的渠井用水比例范围为1.49~1.53,从而为灌区地下水资源的高效持续利用提供了依据.

Reasonable canal-to-well irrigation water quantity ratio in irrigation district based on groundwater balance

Based on a groundwater balance model, the groundwater balance in different frequency typical years is analyzed in Jinghui Canal Irrigation District in Shaanxi Province. The results show that the precipitation recharge, canal seepage and the field irrigation infiltration and well irrigation regression recharge are the major recharge sources of groundwater in the irrigation district, accounting for 85.99%-82.89% of the total recharge. However, the artificial exploitation is the main discharge way of groundwater, and the exploitation quantity of water accounts for 69.7%-72.86% of the total exploitation for the use of agricultural irrigation, human and animals and the industrial water supply. Regarding 2010 as the reference year and 2020 as the planning year, four different development scenarios are established by considering the irrigation district development plan, then the groundwater depths in those scenarios are calculated by using the groundwater balance model, which is ranged from 0 to 0.07 m. By minimizing the change in groundwater level, the reasonable canal-to-well irrigation water quantity ratio is determined to be in a range of 1.49-1.53 in different frequency typical years acquired. This study provides a basis for groundwater to be utilized in a more sustainable and efficient manner in the irrigation district.