干旱灌区规模扩张下的地下水位演化特征

Evolution Characteristics of Groundwater Level under Scale Expansion of Arid Irrigated Areas

灌区面积的变化会对生态环境与社会经济产生相应的影响,通过探求沙湾县土地扩张模式下灌区的地下水位动态特征,以达到土地资源与地下水资源的协调发展。本文通过收集沙湾县2002-2017年的土地利用类型面积变化及近10年(2008-2018)的地下水位资料,结合数理统计法,研究土地面积变化与地下水位间的响应机制。结果表明:2002-2017年,耕地面积发生较大的变化,2017年耕地面积较2002年增加8.14×10~4 hm^2;林地、果园地、牧草地面积略有波动,但变化幅度不大。2008-2018年,沙湾县地下水位总体呈下降趋势,其中老沙湾镇小东渠村、柳毛湾镇等监测井下降速率较大,达2.35 m/a、2.52 m/a,水位下降较严重。耕地面积的快速增加导致地下水开采量的增加,是地下水水位下降的主要原因。

Changes of irrigation area will have a corresponding impact on eco-environment and social economy. Through exploring the dynamic characteristics of groundwater level in irrigation areas under land expansion mode of Shawan County, the coordinated development of land resources and groundwater resources can be achieved. This paper, by collecting the data of land use type area change from 2002 to 2017 and groundwater level in recent 10 years (2008-2018) in Shawan County, studies the response mechanism between area change of land and groundwater level on the basis of mathematical statistics. The results indicate that, from 2002 to 2017, the cultivated land area changed greatly, and the cultivated land area in 2017 increased by 8.14×10^4 hm 2 hectares compared with that in 2002;the area of forest land, orchard land and grassland fluctuated slightly. From 2008 to 2018, the groundwater level in Shawan County generally showed a downward trend. Among them, the monitoring wells in Xiaodongqu Village in Laoshawan Town and Liumaowan Town showed a large decline rate up to 2.35 m/a and 2.52 m/a. The increase of groundwater exploitation caused by the rapid increase of cultivated land area is the main reason for the decline of groundwater level.