基于遥感影像的丹江口水库水域面积动态变化与原因研究

丹江口水库是南水北调中线工程的水源地,水库水域面积的动态变化研究,对保障调水有重要意义。针对丹江口水库水域面积变化较快、短期波动明显,对南水北调中线工程稳定调水有较大影响的问题,采用2000年3月~2015年10月逐月遥感影像,基于归一化差异水体指数(NDWI)提取水体,研究了丹江口水库水域面积的动态变化。结果表明:丹江口水库近16 a来月际平均水域面积均超过400 km2,2~7月份为枯水期,8月份~翌年1月份为丰水期。按季节来看,夏季至秋季水库水域面积呈增大趋势,冬季至次年春季水库水域面积呈减小趋势,同时水库水域在秋季波动最为剧烈,冬季较为平缓。自2014年12月~2015年10月,受大坝加高蓄水影响,水库水域面积均维持在550 km2以上。水库的水位涨落形成的消落区主要集中在丹江水库北部、东部和汉江水库的西部。

DYNAMIC CHANGE AND CASUE OF WATER AREA IN DANJIANGKOU RESERVOIR BASED ON REMOTE SENSING IMAGE

Danjiangkou reservoir is the water source area of Middle Route of South-to-North Water Transfer Project. Studying the dynamic change of reservoir water area, it has important significance to safeguard the diversion. In view of the Danjiangkou reservoir characteristic of water area change significantly faster and short-term fluctuations obviously, using month by month remote sensing image from March 2000 to October 2015, basing on normalized difference water index (NDWI) to extract water body, Danjiangkou reservoir water area dynamic change has been resrech. Results show that the monthly average water area in recent 16 years of Danjiangkou reservoir is more than 400 km², from February to July are drought period, and from August to the following year in January are wet period. According to the season, reservoir water area showed a trend of increase from summer to autumn, reservoir water area showed a trend of decrease from winter to spring, reservoir water fluctuation the most intense is in the autumn, and winter is more gently. Down area mainly concentrated in northern and eastern of Danjiangkou reservoir, and the west of the Han River reservoir.