Abstract: It is important to grasp the temporal change characteristics of water areas of main reservoirs in Gansu for the construction of comprehensive experimental zone of national ecological security barrier in Gansu Province. Based on the 8-day composited surface reflectance products of MODIS (MOD09) from 2000 to 2014, the water areas of Shuangta, Changma, Hongyashan and Liujiaxia reservoirs in Gansu were monitored by using water index of WI1, which was compared with the visual interpreted water areas of real-time satellite data from Lanzhou Regional Climate Center (LZRCC), and their relationship was established. And then the climatic change characteristics of water areas of the four reservoirs were analyzed. Results show that the water areas of the four reservoirs in Gansu retrieved by WI1 based on MOD09 data had better correlation with the real-time monitoring water areas from LZRCC, and their change trends were almost consistent, which indicated that MOD09 data were able to use the research on the climatic changes of reservoir water areas. The interannual change of water areas of the four reservoirs in Gansu was obvious, and the water areas were largest in spring or autumn, while it was smallest in summer. The annual change trends of water areas of the four reservoirs in different seasons were more complex over the last 10 years. Overall, the water areas of Changma and Shuangta reservoirs had no obvious change trend, while that of Hongyashan and Liujiaxia reservoirs in spring, summer and autumn increased volatility over the last 10 years, which was beneficial to agricultural irrigation in middle and western Gansu.

Key words: MODIS, reservoir, water areas, remote sensing monitoring, change characteristics

摘要： 掌握甘肃主要水库的水体面积变化规律，对“甘肃省国家生态安全屏障综合试验区”建设具有重要参考意义。基于2000—2014年MODIS的8 d合成地表反射率产品MOD09资料，利用WI1水体指数，对甘肃四大水库双塔、昌马、红崖山和刘家峡的水体面积进行监测，并与兰州区域气候中心实时接收的卫星资料目视解译结果进行对比、建立相关关系，进而对上述水库水体面积变化状况进行研究。结果表明：甘肃四大水库8 d合成产品MOD09反演的水体与卫星实时资料目视解译结果均具有很好的相关性，且变化趋势较一致，MOD09产品反演结果能够反映水体实时变化状况，可用于水库水体面积的变化特征研究。近10 a多，甘肃四大水库水体面积表现出春季或秋季较大、夏季最小的年内分布特征，各水库水体面积的年际变化趋势较复杂，疏勒河上的昌马和双塔水库春、夏、秋三季水体面积的年际变化趋势不明显，而红崖山和刘家峡水库水体面积均呈波动增加趋势，这对甘肃中西部农业灌溉极为有利。

关键词: MODIS, 水库, 水体面积, 遥感监测, 变化状况