黑河流域中游灌区灌溉引水量与引水结构的变化分析

Variation of agricultural water supply amount and structure in the middle oases of Heihe River

基于1986-2009年张掖市灌溉引水统计资料,对黑河中游各灌区逐年灌溉引水总量和引水结构进行了系统分析。结果表明:1)在灌溉引水总量方面,黑河灌区有明显下降趋势,梨园河灌区呈现轻微上升趋势,而沿山灌区的引水总量与降水量的丰枯变化密切相关。2)黑河、梨园河与沿山灌区不同水平年的灌溉引水强度(m3/亩)在2000年后均有所下降,年均下降幅度分别为20.9%,32.6%,8.3%。3)就灌溉引水结构而言,黑河灌区受分水制度的影响最大,2000年后地下水年均引水比例上升了15%;梨园河灌区的地下水引水比例轻微上升;沿山灌区则基本无变化。

Based on statistical annual dataset of irrigation water supply in the oases of middle Heihe River during1986- 2009,the change of the quantity and structure of agricultural water supply and its possible driving factors in irrigated areas were analyzed. All irrigation areas were classified into three types： Heihe Irrigation Area（ HIA）,Liyuanhe Irrigation Area（ LYHIA）,and Piedmont Irrigation Area（ PIA）. The results showed that：（ 1） As for annual average irrigation water supply,there was a decreasing trend in both HIA and LYHIA,and in HIA it was little more than that in LYHIA. In PIR,the irrigation water was closely related to precipitation.（ 2）Total irrigation water supply per unit area in HIR,LYHIR and PIR were all decreased by 20. 9%,32. 6%,8.3%,respectively,after the policy of water reallocation was implemented from 2000.（ 3） The groundwater supply was increased by 15% in HIR after 2000. The groundwater supply had a slightly increasing trend in LYHIR,and little change was discovered in PIR.