渭干河平原绿洲生态用水量初步估算

Primary estimation of ecological water use in Weiganhe river plain oasis

根据监测资料,采用蒸发系数法对渭干河平原绿洲各种土地类型的年耗水量进行了估算,并分析了其生态用水量。结果表明:(1)农林地的年耗水量为947～1026mm,草滩洼地的年耗水量为791～845mm,有稀疏植被荒地的年耗水量为308～415mm,未被利用土地、沙丘的年耗水量为137～172mm;(2)农林地的蒸发系数为0 83～0 86,草滩、洼地的蒸发系数为0 68～0 72,有稀疏植被荒地的蒸发系数为0 27～0 35;未被利用土地、沙丘的蒸发系数为0 12～0 15;(3)年生态用水量为11 18～13 47亿m3,占总收入水量(地下水入流、灌溉引水和降水量)的45%～49%。该结论可为西北地区平原绿洲水资源的合理配置提供科学依据。

Based on the measured data, annual water consumptions are estimated for different land-useing types by applying evaporation coefficient method, and the ecological water use is analyzed in Weiganhe river plain oasis. The results show that: (1) The water consumption for farm field and forest land, grassy marsh land and low-lying land, waste land with sparse vegetations, waste land without vegetations are 947-1?026?mm, 791-845?mm, 308-415?mm, 137-172?mm respectively; ((2) The) evaporation coefficient are 0.83-0.86, 0.68-0.72, 0.27-0.35, 0.12-0.15 respectively; And (3) the amount of ecological water use is 11.18 to 13.47×10~8m^3, which accounts for 45 to 49% of sum of irrigated water, groundwater recharge and precipitation. The results can provide the important scientific basis for rational water resources allocation in the plain oasis is northwestern China.