水污染遥感监测

不同水质的水体在遥感影像上有较明显的反映。通过分析TM影像上不同水质水体的视反射率特征,发现1-4波段的视反射率(R1、R2、R3和R4)对不同的水质比较敏感。利用R2/R1>1可以区分出较高悬浮泥沙区域,R4/R3可以作为水体有机污染的指标。以黄河三角洲地区的小清河口为例,利用不同时相的TM影像,对水污染的遥感提取进行了尝试,得到了小清河口的水污染分布。

Water Pollution Monitoring Using Remote Sensing

It seems much difference on remote sensing images with different quality water. After analyzing
the relative spectral reflectance of different quality water on TM images, we found that the relative spec-
tral reflectance of band 1 to band 4 (R1, R2, R3 and R4) were sensitive to the different quality water. R2
will be greater than R1 (R2/R1>1) for high suspended sediment regions, in which, if the suspended sedi-
ment concentration is very high, R3 is greater than R2 (R3>R2), otherwise R3 water, the more serious the polluted water is, the higher value R4/R3 is. According to the water monitor-
ing data from Environment Protect Bureau of Dongying City, the main pollutants of drainage system in
Yellow River Delta are organic substances. So R4/R3 may be used as an important index of water organic
pollution in the area. After numerous tries and comparisons, we found the average and standard deviation
of R4/R3 may be used as a semi-quality index for water pollution classification. The mouth of Xiao-qing
River was taken as an example to test the above rules and its water pollution distributions were got from
TM images in different years. The regions with high suspended sediment and serious polluted water can be
extracted from TM images using the method introduced above. And the method has some references for
water monitoring with large area.