基于TM影像的钱塘江入海口水体透明度的时空变化分析

Analysis of Temporal and Spatial Changes of Water Clarity Based on TM Image in the Estuary of Qiantang River

研究了水体透明度的遥感监测方法,并在钱塘江入海口水体的时空变化监测中应用.利用EXP(TM1/TM3)模型来提取水体透明度(SDD)信息.通过6个感兴趣区域的SDD均值对比分析发现,在1984—1997—2000年间,该水域的水体透明度都呈下降趋势.用对2000年SDD图像划剖面的方法,来研究水体的空间变化特点,结果表明,从西到东,水体透明度大体上呈下降趋势.基于TM影像,尝试着从土地利用和围垦的角度来探讨水体透明度这种时空变化的原因,从而为钱塘江的河口治理提供决策支持.

The monitoring method of remote sensing on water clarity is studied in this chapter, which is used in the Estuary of Qiantang River. Model of EXP(TM1/TM3) is applied to extract SDD information from TM image. It is found that the water clarity in this area was declining during the past about 20 years on comparison of SDD value of 6 AOIs from three images. A section plane is made on the SDD image of the year 2000 to study the spatial changes of water clarity along Qiantang River. The results show that the water clarity declined from west to east. Also based on TM image, two reasons resulting in the spatial and temporal changes of water clarity are discussed: land use and kinning, which is useful to the governance of Qiantang River estuary.