2000-2020年昌吉州东部平原区地下水位埋深对土地利用及干旱时空演变的动态响应

联合土地利用与覆被变化及气象干旱综合分析区域地下水位埋深变化及其动态响应关系,明晰地下水位埋深变化的阶段性主导因素,对地下水超采地区综合治理和地下水资源有效管控具有现实意义。选取昌吉州东部平原区2000-2020年78眼地下水监测井月尺度地下水位埋深数据资料及5期遥感影像数据并结合同期多尺度标准化降水蒸散发指数SPEI,分析不同时空尺度地下水位埋深对土地利用/覆被变化及SPEI的动态响应规律,探讨研究区土地利用变化与干旱变化趋势对地下水埋深变化的综合影响。结果表明:研究区21年间地下水位埋深表现出不显著变化(2000-2005年)-显著增大(2005-2014年)-变缓(2014-2017年)-持续增大(2017-2020年)的变化特征,整体呈持续增大动态趋势,空间分布呈北向南逐渐增大特征;同期土地利用类型面积发生了显著变化,耕地为其主要的土地利用类型,面积呈持续增加趋势,分形维数呈现出先降低(2000-2005年)后升高(2005-2010年)再降低(2010-2020年)的变化特征;SPEI年际动态变化呈显著干旱趋势变化特征,年尺度序列在2012年、2017年发生突变,2016年开始气象干旱发生频次增加;2000-2015年研究区地下水位埋深动态变化对土地利用变化尤其是耕地变化响应显著,2016-2020年地下水位埋深动态变化是对土地利用变化与气候干旱因素的联合响应。

Dynamic Response of Groundwater Depth to Land Use and Temporal-Spatial Evolution of Drought in the Eastern Plains of Changji Prefecture from 2000 to 2020

Based on Land Use and Cover Change (LUCC) and meteorological drought, comprehensively analysis of regional Groundwater Depth (GWD) change and its dynamic response, and clarifying the periodic leading factors of GWD change has practical significance for comprehensive management and effective control of groundwater resources in groundwater overexploitation area. Collecting the monthly-scale GWD data of 78 groundwater monitoring wells in the eastern plain area of Changji Prefecture from 2000 to 2020 and five phases of remote sensing image data, and combing with the multi-scale Standardized Precipitation Evapotranspiration Index (SPEI) during the contract period, the dynamic response of GWD at different spatial and temporal scales to LUCC and SPEI were analyzed, and the comprehensive influence of land use change and drought change trend on the change of GWD in the study area was discussed. The results showed that during the 21 years from 2000 to 2020, the GWD in the study area showed the change characteristics of no significant indigenous change (2000-2005)-significant indigenous increasing (2005-2014)-slowing down (2014-2017)-continuous increasing (2017-2020). The overall trend was increasing continuously, the spatial distribution gradually increased from north to south. During the same period, the area of land use types changed significantly. Cropland was the main land use type, and its area increased continuously. The fractal dimension showed the change characteristics of first decreasing (2000-2005) then increasing (2005-2010), and then decreasing (2010-2020). The interannual dynamic change of SPEI showed a significant trend of indigenous drought. The annual-scale sequence mutated in 2012 and 2017, and the frequency of meteorological drought increased since 2016. From 2000 to 2015, the dynamic change of GWD in the study area responded significantly to land use change, especially cultivated land change. From 2016 to 2020, the dynamic change of GWD was a joint response to land use change and meteorological drought factors.