Study On AHP-Grey Relation Analysis Evaluation Model In River Health Assessment Based On GIS

With the rapid economic development and increasingly intensive human activities, the interior configuration, functional organization and ecosystem health of the rivers, an important part of the ecosystem, are suffering extent influences. More attention has been paid to river restoration and sustainable river management, accordingly, as a new tool to assist management of rivers, the river health assessment have become the major focuses in the field of ecology and environmental science. Study on river health assessment is of great theoretical and practical significance.Basing on the studies on rivers ecosystem health status home and abroad, in accordance with the study area from Lingxia to Boluo reaches in the downstream of Dongjiang River, an indicator system for river health assessment which provides scores for 5 factors and 20 indicators is established. By collecting historical literature and field monitoring and using the method of analytic hierarchy process to confirm indicator weight, a model of analytic hierarchy process and grey relation analysis evaluation model was designed to carry out the assessment.The paper taking the area at Lingxia to Boluo reaches in the downstream of Dongjiang River as a case, based on the model before and GIS technique, the situation of river health of the studied area was evaluated, it make the theory and method gain practical test. The assessment results showed that the situation of river health in the studied area was "sub-healthy". Therefore, it was necessary to adjust and control the situation of river health, and the appropriate measures and suggestion were recommended. The paper also makes a comparison between grey relation analysis evaluation model and fuzzy comprehensive evaluation model. Finally, the conclusion and the orientation of research for future are discussed.The research was the basic work to provide decision-making base for rivers protection, maintenance and restoration, and it will provide reference to the evaluation work of the health of the Pearl River Basin and to the water resources management, rational development and utilization, the effective and scientific protection in the future. The evaluation index system has been studied in this thesis to pave the path for the further improvement of the system. The research results were of great theoretical and practical significance and it will help to harmony the development of the environment, society and economics.