Appraisal of Aquatic Environment in Mining Subsidence Based on Multiple Biological Indexes

A fuzzy composite appraisal of multiple biologica indexes was proposed in order to monitor the aquatic environment in mining subsidence. This method can overcome the shortcoming of the un-precision of traditional biological evaluation. Through the fuzzy mathematics principle, the functions of membership were constructed by using middle value of boundary line of water quality grade appraisal results based on traditional biological indexes as datum point. Four representational mining subsidence ponds in Huainan mine area were surveyed. Based on the physical-chemical properties and distribution of aquatic vascular plant and phytoplankton community, the BIP index, Diatom index, Shannon-Wiener diversity index and Chlorophyll-a content were calculated. The four indexes above mentioned were applied to carry out fuzzy composite appraisal water environment. The results show that all sampling subsidence water have been polluted in different eutrophication extent.