呼图壁县地下水位动态对土地利用变化响应

研究干旱缺水地区地下水位(埋深)时空动态特征及对土地利用变化的响应,对于加强农业地区土地利用和地下水资源管理具有重要意义。以呼图壁县平原灌区为研究区,基于地统计学和GIS结合技术,应用普通克里金插值拟合研究区2000年、2010年及2018年地下水埋深时空分布,并且利用同期遥感数据解译生成了土地利用类型图,叠加分析不同时期地下水埋深变化与对应时期的土地利用类型转移之间的响应关系。结果表明:呼图壁县地下水埋深的空间变化主要是由地形地貌、气候等结构性自然因素引起的,空间相关性逐年增强,空间异质性逐渐减弱;地下水埋深在空间上主要表现为从南向北逐渐变浅,时间动态上为2000—2010年地下水埋深值10 m的面积减小比例高达86.61%,2010年后控制耕地面积的大幅扩张,但由于耕地本身基数较大,地下水开采量在2014年达到最大值后开始减少,局部地区地下水位开始恢复;研究区主要土地利用类型为耕地,地下水中农业用水占比高达84.68%,地下水埋深动态变化与耕地面积变化高度相关。

Response of Groundwater Level Dynamics to Land Use Change in Hutubi County

It is of great significance to study the temporal and spatial dynamic characteristics of groundwater level depth and its response to land use change in arid and water-scarce areas for strengthening land use and groundwater resource management in agricultural areas. Taking the plain irrigation area of Hutubi County as the research area, based on geostatistics and GIS, the spatial and temporal distribution of groundwater depth was fitted by ordinary Kriging interpolation in 2000, 2010 and 2018. Moreover, the land use type map was generated by interpreting remote sensing data during the corresponding period. Superposition analysis was conducted on the response relationship between the change of groundwater depth in different periods and the transfer of land use types in the corresponding periods. The results showed that space variation of groundwater depth in Hutubi County was mainly due to structural natural factors such as topography and climate. The spatial correlation of groundwater depth increased year by year, while the spatial heterogeneity weakened gradually. Spatially, the groundwater depth was gradually shallow from south to north, and from 2000 to 2010, the area with the groundwater depth less than 10 m decreased by 86.61%. The substantial increase of arable land was controlled after 2010. However, due to the large base of cultivated land, the amount of extracted groundwater began to decline from the maximum value in 2014, and the groundwater began to recover in some areas. The cultivated land was the main land use type in the study area, and the proportion of agricultural water in groundwater was as high as 84.68%. Therefore, the dynamic change of groundwater depth was highly correlated with the change of cultivated land area.