塔里木盆地沙漠腹地潜水蒸发量的数值计算

摘要

Takilimakan desert which is in the central of Tarim Basin accounts for 32.48% of the area and the groundwa-ter in the alluvial-proluvial plain region finally discharges into the desert. Hydraulic gradient of groundwater in desert is small and the runoff is slow.Vertical exchange is the chief way of groundwater cycle,and phreatic water evaporation is the main discharge of shallow groundwater in the desert area.As one of the crucial factors of groundwater resource,it is significant to study the time and space distribution of evaporation intensity of phreatic water of evaporation intensity of phreatic water in order to evaluate the water resource of desert as well as groundwater resource protection.Based on the convert coefficient of desert natural water evaporativity and E601 water surface evaporation rate and the evaporation rate when the phreatic water depth is zero,the groundwater simulation method is utilized to improve the calculation accuracy. The calculation results show that the calculation results can be efficiently improved on the basis of comprehensive weath-er data and groundwater balance tests with the latest hydro-geological investigation achievements and topographic data. The research idea can be referred to for the groundwater evaporation capacity of desert area.%塔里木盆地中部塔克拉玛干沙漠占盆地面积的32.48%，沙漠外围冲洪积平原区地下水最终排入沙漠中。沙漠区地下水水力坡度小，径流滞缓，以垂向交换为主。潜水蒸发是沙漠区浅层地下水的主要排泄方式，是地下水资源均衡中的一个核心要素。研究沙漠区潜水面蒸发强度的时空分布，探讨沙漠区潜水蒸发量的计算方法及最新参数利用，对评价沙漠区水资源量、合理保护利用地下水资源具十分重要意义。利用沙漠区自然水体蒸发率与E601水面蒸发率的折算系数和潜水蒸发能力系数计算潜水埋深为零时的蒸发率，通过地下水数值模拟方法提高沙漠腹地潜水蒸发量的计算精度，提高地下水资源评价精度。结果表明，在充分利用沙漠腹地、沙漠边缘最新气象、地下水均衡试验、水文地质勘查最新研究成果基础上，采用数值模拟方法计算沙漠地下水蒸发量能最大限度利用地形数据，提高地下水蒸发量的计算精度。通过模拟过程展示，提出沙漠区利用数值模拟计算地下水蒸发量的一种新思路。