Research Of Diagnosis Of The Degree Of Degradation And Correspondence Relation On River Ecosystem Of Huaihe River Basin (Henan Section)

As an important part of natural ecosystems, river ecosystem is an importantchannel for material circulation and energy flow. River ecosystem itself has a certainof self-recovery capability, but with the addition of human disturbance, the capabilityis limited. As an important foundation and prerequisite, the degradation extent isimportant and become a top priority to be accurately diagnosed. In this paper, asstudy area, the Huaihe River Basin (Henan Section) is upstream region of the HuaiheRiver. The degree of its degradation is directly related to the midstream anddownstream regions and it has practical significance.Firstly, Research progress of related concepts on degradation and responserelationship are elaborated. Secondly, river ecosystem in the Huaihe River Basin(Henan Section) as study area, the physical geography, socio-economic andecological characteristics of the study area are described. Then, following certainprinciples, using the frequency of analysis, the index system of degradation degreediagnosis is built, which contains a target layer, four criteria layers, and17indexlayers. Meanwhile, referring to foreign ISC and domestic authoritative studies, therating scales are determined, which include five scales of “no degradation, slightdegradation, moderate degradation, severe degradation and extreme degradation” andthey are given appropriate score “3-4、2-3、1-2、0-1、0” respectively. Based on this,getting datas from survey and collection, adopting AHP to get weights, thendiagnosing degradation degree based on the “the individual is not up to the grade, theoverall drop” and comprehensive index. The results show that the degradation degreehave four kinds, which are slight degradation, moderate degradation, severedegradation and extreme degradation. They are respectively accounting for1.92%、40.38%、53.85%、3.85%. Its main influencing factors and causes are analyzed, whichshow that sinuosity, water pollution index, sediment pollution index, flow rate,diversity of aquatic plants, water resources development and utilization are maininfluencing factors. Causes are mainly reflected in①activities of artificial sandmining②artificial modification of river③industrial wastewater, sewage, agricultural and livestock-point source pollution④p oor technologyof pollution control.Stepwise regression analysis is used to analyse quantitative relationship betweendegradation composite index and indicators, and best regression equations is obtained;Correlation analysis is used to analyse the relationship of indicators and therelationship between degradation composite index and indicators; The relationshipbetween aquatic organisms and their environment are studied, too.