Hydrological Conditions Of The Xiangjiang River Valley River Health Assessment

With the development of socio-economic and the increasing of the population, hydrological conditions have seriously affected. The river hasn't been utilized properly and the ecosystem has lost its balance of efficiency of water usage. A main problem concerning the river system is the degradation of the service function, therefore, river systems restoration and sustainable development is a major issue in the research field of natural science. Recently, the new concept of river health has been prompted in river systems research, and it's a new tool of river management and assessment.This article will apply the concept of a healthy river to the hydrological conditions of the Xiangjiang River Assessment. In the previous study of river health, the combined domestic and international river health assessment methods and principles of indicators established a hierarchy of a hydrological evaluation system (Target layer, Criteria layers and Index layer) of river health. The target layer is the hydrological conditions of the Xiangjiang River health evaluation; Criteria layer, including the five Xiangjiang River hydrology:river supplies, water level, river flow change, sediment delivery, and water chemistry; The Index layer is formed by a number of indicators, divided into qualitative and quantitative. The River health levels are divided into five:very healthy, health, sub-health, disease, serious illness. This paper used the information theory, the "entropy method", the indicators of weight distribution, gray relational method combined with factors associated with the evaluation.Take the Xiangjiang River Xiangtan station as an example, the results showed that in the index layer, precipitation recharge, navigable depth guarantee rate, pH value and other indicators of the evaluation rating was "very healthy". Groundwater recharge, sediment transport rate and other indicators of the evaluation grades for the "health", lakes and swamps of water supply, the absolute rate, dry Evaluation of water levels and other indicators of "sub-health", rule evaluation results show that most of the grade level of "health", combined with the weight coefficients, the final score of the Xiangjiang River Xiangtan station values for 0.674 (the overall level of assessment for the "health"). Following this method to evaluate the Xiangjiang River and other tributaries of the site showed the following:station Xiangtan, Hengyang and Baisha etc. for the "health"; Jianghua station for "very healthy". Generally speaking, the Xiangjiang hydrological conditions are in good health. Jiang Hua in the river upstream stations as part of the superior natural conditions, human impact is small, the evaluation showed a higher level.This paper assessed the hydrological situation of Xiangjiang River on the typical stations. It is for the river management assessment to make case studies and practical examination, for the assessment of river health is a research support, for the river management and development, to provide a reference.