Water Quality And Ecology Assessment Of Heihe River Basin

Heihe River Basin is the second largest inland river in the Northwest China, which is an important water source of the Hexi Corridor. The author did analysis and evaluation of the Heihe River Basin water quality and aquatic ecological environment.The results showed that:We could conclude from arcmap interpolated surface data that, salinity, total hardness and suspended solids concentration appeared to increase,a spatial variation characteristics,from upstream to downstream, but TN, TP, ammonia nitrogen and permanganate index in space had, higher concentration of the middle reaches and lower concentration of the remaining area, which was related to midstream areas of Zhangye more frequent human activities and other factors.TP and TN are the main factors affecting the Heihe River Basin water pollution. Heihe basin overall water quality are most class Ⅱ water and most of water Ⅰ-Ⅲ.The Yingluoxia section meets the water quality of water planning category. Water qualities of Gaoya hydrological stations section, Liaoquan bridge section were in line with the requirements of environmental functions. The Shandan bridge section does not meet the requirements of the environmental functions. Heihe River Basin upstream were meagrely-populated and underdevelopment,less of man-made pollution, water quality was excellent. Water quality of the middle reaches changes a lot, water pollution was much serious; water pollutants from midstream were accepted by the downstream, mild concentration.River basin habitat, biodiversity and water ecological security evaluation Sort (Ⅰ-1Qilian mountain cold desert of solid water to maintain aquatic ecosystem function area, Ⅰ-2the Qilian Zhongshan needle grass water to maintain water ecological functions District Ⅱ-1the Longshoushan Heli Mountain alluvial plains shrub desert aquatic ecosystem function district, II-2of the Heihe slow tilt plains oasis agricultural water ecological functions, II-3Beidahe gently inclined plains oasis ecological functions of agricultural water District, District of II-4corridor northwest desert aquatic ecosystem function, Ⅲ-1Ejina Juyan Delta water ecological function zones, Ⅲ-2Alashan plateau Gobi desert aquatic ecosystem function area.):(1) habitat for safety:Ⅰ-2>Ⅱ-2>Ⅲ-1> Ⅰ-1>Ⅱ-3>Ⅲ-2>Ⅱ-1=Ⅱ-4.(2) biodiversity conservation importance:Ⅱ-2>Ⅰ-2>Ⅲ-1>II-3> Ⅰ-1>Ⅲ-2>Ⅱ-1=Ⅱ-4.(3) Water ecological security:Ⅰ-2>Ⅱ-2>Ⅲ-1>Ⅰ-1>Ⅲ-2>Ⅱ-3>Ⅱ-4>Ⅱ-1.