北疆水库富营养化污染遥感快速监测方法研究

水库受富营养化污染后,水生植物群落结构变的简单,主要以藻类为主。北疆污染水库冬季冰封加排污,使水体含氧量急剧降低,导致绿色光合植物大量死亡或以孢子形式越冬。春季冰雪融化后水体表现为无明显的绿色植物光合色素吸收峰和反射峰,利用二阶衰减指数函数对污染水库水体光谱曲线进行拟合,其拟合优度(R~2)值高。正常水库水生植物群落结构完整,冬季水体含氧量高,植物不会因缺氧死亡,在春季冰雪融化后水体表现为有明显植物光合色素吸收峰和反射峰,利用二阶衰减指数函数对正常水库光谱曲线进行拟合,其R~2值低。本文利用冬季到春季不同水库光谱曲线的二阶衰减指数函数R~2值斜率的变化,衡量了水库富营养化污染状况,即污染程度重,该段R~2的斜率值高,反之该段R~2的斜率值低,污染程度轻。研究结果经水质抽样分析验证,监测结果正确。该研究方法为今后北疆水库水质快速监测提供了新的思路。

The study on rapid remote sensing monitoring method of reservoir eutrophication pollution in North Xinjiang

After the eutrophication pollution of the reservoir, the structure of aquatic plant community becomes simple, mainly dominated by algae. The reservoirs that were frozen and polluted in North Xinjiang in Winter, it sharply reduced the oxygen content of water and caused many green photosynthetic plants to die or live through the winter in the form of spores. The water body shows no obvious absorption and reflection peaks of photosynthetic pigments of green plants after the ice melts in the Spring. The research used ExpDec2 to fit the spectral curve of polluted reservoir water body, and its goodness of fit (R2) value is high. The aquatic plant community structure of normal reservoir is intact, the water body has high oxygen content in winter, and the plants will not die from hypoxia. After the ice melts in the Spring, the water body has obvious photosynthetic pigment absorption peak and reflection peak. The research used ExpDec2 to fit the spectral curve of normal reservoir, and its R2 value is low. The research used the slope change of R2 value from Winter to Spring for spectral curves of different reservoirs to measure the eutrophication pollution of reservoirs. That is, the more serious pollution degree of reservoir is, the higher the slope value of R2 in this section is; otherwise, the slope value of R2 in this section is low, pollution level is also low. The results of the study were verified by sampling analysis of water quality, to show that the monitoring results are correct. The research method provides a new idea for the rapid monitoring of reservoir water quality in North Xinjiang.