Aquatic Ecosystem Health Assessment Of Liao River Basin

Human civilization originated in the river, river nourishing and nurturing the vast people on the earth from generation to generation, provides invaluable resources and services. However, in our exploration, sacrifice the environment for economic development had devastating repercussions on watershed. Such as, river aquatic ecosystem were repeatedly disrupted,river functional declined, ecological health problems have rised to the surface. With the enhancement of people’s environmental consciousness, aquatic ccosystem health assessment of river basin has become an important reference of capability of whole basin in the process of river restoration. Explore the ways which are suitable in domestic, strengthen the recovering work,not only provide data support for river situation judgment, but also offer scientific basis for river management policy, moreover, contribute to sustainable development and ecological construction.This study is based on 65 monitoring sections of Liao river basin in Liaoning province. Gathered water and biological samples from each section in June,2014. Established a comprehensive index system include 15 indexs under four categories: Water Quality, Nutrients, Algae and Invertebrate. Then collected index data from sample analysis. Assessment consisted of two part:basic evaluation and aquatic ecosystem health assessment. The latter used multimetric method to do the score calculation. The results was composed of present color polygon and Ecological health report card, shows the comprehensive health status of sections and whole basin.Basic evaluation from Water Quality and Nutrients shows that 2 sections achieve level Ⅰ, level Ⅱ and Ⅲ both include 6 sections,31 to level Ⅳ,7 to level Ⅴ and 10 are worse than Ⅴ, the average achieve level Ⅳ. Then from part of Invertebrate diversity evaluation, a majority sections are in the condition of "Worse" to "Normal". And from Algae diversity evaluation, most are in "Normal" to "Good". Aquatic ecosystem health assessment revealed that 19 sections are "Good",32 are "Normal", 12 are "Worse" and 1 is "Worst". The Water Quality score is 0.741, Nutrients score is 0.401, Invertebrate is 0.307 and Algae is 0.631. The average of whole basin include all index is 0.522, on "Normal" status.