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为了研究干旱区绿洲地下水位时空变化特征及其归因,以新疆开都河两岸绿洲为研究对象,利用实测地下水埋深数据和Landsat数据计算得到的改进型温度植被干旱指数(MTVDI)相结合,建立了地下水位监测关系模型(R2=0.82)。对研究区1999年到2016年地下水的时空分布进行了监测,利用2005年和2003年两年实测数据对模型进行了验证。结果表明:1)两年实测地下水位和监测水位相关系数(R2)分别为0.75和0.77,均方根误差(RMSE)分别为0.17和0.27,平均相对误差(RME)分别为11.4%和16.7%,研究结果符合研究区实际情况;利用MTVDI建立的地下水位监测模型对干旱区绿洲一定深度的地下水位监测是可行的;2)开都河两岸绿洲1999年到2016年地下水位年际变化逐渐降低,年内地下水位升降显著;3)地下水位年际降低的主要原因是耕地面积的增加和灌溉方式向高效节水方式转变,增加了地下水开采量和降低了补给量。在年内随着渠系灌溉水的作用,使地下水位在季节性里变化较大。
In order to study the spatio-temporal variations of groundwater level and its attribution in arid oasis, taking the oasis in the both sides of the Kaidu River in Xinjiang as the research object, by combining the measured groundwater depth data with Landsat data to calculate the improved temperature vegetation drought index (MTVDI) The establishment of the relationship between groundwater level monitoring model (R2 = 0.82). The spatial and temporal distribution of groundwater in the study area from 1999 to 2016 was monitored, and the model was verified with the measured data of 2005 and 2003. The results showed that: (1) The correlation coefficient (R2) of measured groundwater level and monitored water level was 0.75 and 0.77 respectively for two years, and the root mean square error (RMSE) was 0.17 and 0.27 respectively, and the average relative error was 11.4% and 16.7% , And the results are in line with the actual situation in the study area. The groundwater level monitoring model established by MTVDI is feasible for the monitoring of groundwater level in arid oasis at a certain depth. 2) The interannual variation of groundwater table in the oasis at both sides of the Kaidu River gradually decreases from 1999 to 2016 , And the groundwater level was significantly increased and decreased during the year; 3) The main reasons for the declining groundwater level were the increase of cultivated land area and the shift of irrigation method to high efficiency and water saving method, which increased groundwater extraction and reduced recharge. During the year, with the effect of canal irrigation water, the groundwater level changed greatly in the season.