Assessment On Ecosystem Health Of AoJiang Basin

Ecosystem health is a hot research topic at home and abroad in recent years, getting more and more attention. Taking AoJiang river basin as the study area, By setting water quality monitoring section of river type and reservoir type, samples section of benthic animals and fish, Monitoring the water quality situation and sampling,combing with2009’s dynamic update data and remote sensing data in2010, understands the structure of the terrestrial pollutant sources andanalysises the main source of pollutants and finds out the terrestrial ecosystem health pressure source. Based on the monitoring data such as water or fish or benthic animals,analysises the water quality of river basin and current situation of water ecosystem. Choosing Three categories and eight indicators of waters ecosystem health assessment of habitat structure and aquatic organism and ecological stress, three kinds seven indicators of terrestrial ecosystem health assessment of ecological landscape and ecological function and ecological pressure,Using the methods of index system evaluation, isto evaluate watershed and land and comprehensive ecosystem health of AoJiang. The results prove that:(1) From the analysis of terrestrial ecosystem health stress, COD emissions of AoJiang mainly come from livestock and poultry breeding. Ammonia nitrogen emissions mainly come from urban life. Total nitrogen emissions mainly come from urban life and agricultural non-point source. Total phosphorus emissions mainly come from urban life and livestock farming. Therefore, urban life is the main source of all kinds of pollutants.Various types of ecosystem area ratio of AoJiang basin is more evenly. The grassland area is the largest, and artificial surface areais the second and Shrubs area is the third.The artificial surface mainly concentrated in the downstream of AoJiang and tributary NiuXi basin.(2) With the analysis of water ecosystem health pressure, overall water quality of AoJiang watershed is good. But the total nitrogen and total phosphorus of shanzai reservoir exceeds bid for a long time. The ecological environment problems of eutrophication and algae outbreaks exist in water.According to the benthic animal species survey, species of aquatic insects> oligonucleotides hair type> crustacean> snails> leeches> gill class.The speciesspatial distribution law present that tributaries is greater than the main, and river is greater than reservoir. Benthic animal diversity and richness are highly correlated with the high quality habitat provided. Fish species of AoJiang valley appears as:fish species present no significant difference in the form upstream to downstream. Fish fauna characteristics has obvious tropical and subtropical floristic characteristics.(3)Upstream unit water ecological health of AoJiang basin is good.The fish and large benthic animal diversity is the limiting factors.Ecological health of middle unit water is good.Water quality index and diversity index of large benthic animals are the limiting factors.This ismainly concerned with excess of TN and TP of and eutrophication.Water ecosystem health of downstream unit in general.This is mainly because that aquatic habitat disturbance index and large benthic animal diversity index are poor.Upstream unit land ecological health AoJiang basin is good.The evaluation results of landscape fragmentation andforest coverage rate and proportion of construction land emissions pollution load indexare excellent but without reserve. Midstream unit land ecological health of AoJiang basin is good.Percentage of construction and land landscape fragmentation Soil conservation function evaluation are best, but the ratio of reserve is medium. The downstream unit land ecological health is poor. This is mainly becausethat landscape fragmentation and forest coverage rate and proportion of construction land evaluation are poor.Vegetation is destroyed and soil and water loss extsts in downstream unit. Water conservation function is general, and the reserve is small in downstream unit. Integrated ecological health of upstream and middle unit of AoJiang basin is good.(4) According to the results of basin ecosystem health evaluation, In view of the main problems and risk of river basin ecological health protection, Put forward that it should key control man-made pollution of watershed and improveprotection of drinking watersource.It should strengthen ecological preservation and restoration of stone processing zone.And it should enhance the treatment level of urban life pollution and carry out pollution treatment measures of the small watershed, etc.The the focal point and main object of priority protection and key control in land and water are Clear.