基于MODIS数据的百色水利枢纽水库水域提取研究

Extraction of Water Area of Baise Multi-purpose Dam Reservoir Based on MODIS Data

利用2006年11月4日的美国EOS-MODIS/TERRA卫星的MODIS遥感数据,采用图像差值运算和阈值法提取百色水利枢纽水库蓄水后的水域范围,统计像元数计算水域面积。结果表明,在差值图像上,水域具有较高的灰度值,表现为灰白色或白色,而陆地具有较低的灰度值,表现为灰黑色到黑色的过渡变化,水陆边界较为清晰,可以用于水域的目视判别和阈值的选定;提取出的百色水利枢纽库区水域呈树枝状分布,蓄水后形成一个大型人造湖泊,湖泊内形成多个岛屿,提取出的水域面积为167.875km2;受MODIS空间分辨率的限制,对于实际较细小的线状水域,提取出来的结果出现不连续现象。

Based on the remote sensing data of MODIS which received from the satellite of EOS- MODIS/TERRA of USA in November 4th, 2006, the water area of Baise Multi-purpose Dam Reservoir was extracted. The methods of image differential algorithm and threshold were used. The area was computed by counting pixels. The result demonstrates that on the difference image, the gray intensity of water area are higher than the gray intensity of land ,and the water area display as gray-white or white, while the land display as transition color from gray-black to black. The boundary of water and land is clear, it is possible to distinguish water area and select the threshold value. The shape of water area of Baise Multi-purpose Dam Reservoir is like dendritic,it is a big lake after impoundment, and there are several islands inside. The result of extraction of water area is 167. 875km2. Because of the restriction of resolution of MODIS,for the narrow and small water area,the result of extraction is not in a row.