生长季流动沙地水量平衡研究

利用水分分配箱对流动沙地土面蒸发量和入渗补给量的月动态特征及其水量平衡作了定量研究。结果表明:①生长季流动沙地土面蒸发量从４月开始逐渐增大,至８月达到蒸发的最高点,９月蒸发量开始回落;5月、6月受气温的影响蒸发量相对较小,只占到同期降水量的30%~40％,有利于土壤储存更多的水分;生长季总蒸发量为167.42 mm,占同期降水量的76.07％,远小于固定沙地小叶锦鸡儿灌丛蒸散量占同期降水量的135.83％的比值。②补给量从4月开始逐渐增大,8月达到最大值16.79 mm,进入9月,随着降水量的减少以及8月较大的蒸发消耗,补给量迅速减少。补给系数从5月至8月逐渐增大,最大值可达到26.73％,平均值为15.09％。

Water Balance of Mobile Sandy Land during the Growing Season

Based on application of the theory of water balance, quantitative research on the water balance and the dynamical characteristics of monthly evaporation and replenishment of mobile sandy land in the growing season is conducted. The results show that evaporation quantity in mobile sandy land increases gradually from April to August, and the evaporation reaches the largest in August and then tends to decrease in September; evaporation quantity in May and June is less than that in the other months, and it is only 30% to 40% of the corresponding period precipitation. This evaporation pattern is useful for accumulating more water in soil. Total evaporation in the growing season is 167.42 mm, which is less than evapotranspiration of Caragana microphylla shrubs, and the former only reaches 76.07% of the corresponding period precipitation, but the latter reaches 135.83% of the corresponding period precipitation. The quantity of replenishment increases gradually from April to August, and reaches the largest (16.79 mm) in August, then deceases rapidly in September due to the higher evaporation in August and less precipitation in September. The coefficient of replenishment increases gradually from May to August, the maximum reaches 26.73%, and the average value is 15.09%.