河套灌区地下水埋深空间异质性分析

综合灌区井灌面积、引黄水量、土地利用类型等影响因素,通过地统计分析,研究河套灌区2000—2013年地下水埋深的空间异质性特征。研究表明:灌区地下水埋深的年内变化曲线呈驼峰型,最高最低值分别出现在秋灌期9月和秋浇期11月;相反,人口集中的城镇地区水埋深年内恒定不变;总体而言,由于井灌面积增大、引黄水量逐年减少等原因使得地下水埋深逐年增高。分析可知,研究区域地下水埋深的空间相关性适中且逐渐增长,空间分布各向异性增大,且因为城镇地区水埋深逐年增大,从而影响了整个灌区的地下水空间结构。克里金插值结果显示,地下水埋深由灌区中部地区至灌区边界总体呈上升趋势。地下水埋深最小值所处区域多为农田,极少部分为裸地,主要集中在解放闸灌域西部边缘地区、义长灌域东南部地区,最大埋深主要集中在巴彦淖尔市。

Spatial variability of groundwater depth in Hetao irrigation area

Based on the statistical analysis of the well irrigation area, water diversion capacity, land use type and the spatial heterogeneity of groundwater depth in Hetao Irrigation District from 2000 to 2013 was studied. The research shows that the annual variation curve of groundwater depth in irrigation area is hump-type, and the highest and lowest values appear in the autumn irrigation period in September and the autumn pouring period in November. On the contrary, the urban areas with concentrated population are constant in the deep years; In other words, due to the increase in the area of well irrigation and the decrease in the amount of water diverted from yellow to water, the groundwater depth has increased year by year.The analysis shows that the spatial correlation of groundwater depth in the study area is moderate and gradually increasing, the spatial distribution anisotropy is increased, and the water depth in urban areas is increasing year by year, which affects the groundwater spatial structure of the entire irrigation area. The Kriging interpolation results show that the groundwater depth is generally increasing from the central part of the irrigation area to the boundary of the irrigation area. The minimum area of groundwater burial depth is mostly farmland, and very few are bare land, mainly concentrated in the western marginal area of the liberation gate irrigation area and the southeastern part of the Yichang irrigation area; the largest burial depth is mainly concentrated in Bayannur City.