Assessment Of Water Ecological Carrying Capacity Of Upper Fenhe River In Shanxi Province

Water ecological carrying capacity is developed from the concept of water environmental carrying capacity and water resources carrying capacity.At present,there are few studies on water ecological carrying capacity.As the birthplace of Fenhe River and the pilot area of ecological protection and restoration project on mountain,water,forest,field,lake and grass in the upper and middle reaches of Fenhe River in Shanxi Province,the condition of water ecosystem in Ningwu County not only affects the ecological environment and economic development of the county,but also affects the safety of drinking water in the downstream areas.In view of this,this paper takes Ningwu County as the research object,systematically analyses the factors that disturb the aquatic ecosystem,constructs the index evaluation system of aquatic ecological carrying capacity,uses particle swarm gravity search algorithm based on projection pursuit model,and applies MATLAB R2017 b,GIS and other software to quantitatively evaluate the aquatic ecological carrying capacity.The main contents of the study include:(1)Based on the analysis of the concept,connotation and related theories of water ecological carrying capacity,the main influencing factors of water ecological carrying capacity are analyzed,and the evaluation index system of water ecological capacity in Ningwu County is established according to the design principles of the index system;(2)the open and complex nature of water ecological system and the abnormal information of the system itself are discussed.Based on the projection pursuit model and particle swarm gravity search algorithm,the evaluation model of water ecological carrying capacity of towns in Ningwu County was established.According to the evaluation results of the model,the water ecological carrying capacity of towns in Ningwu County was evaluated.Finally,according to the evaluation results,the scheme of water ecological restoration in Ningwu County is put forward.The main results are as follows:(1)PSOGSA-PP calculation results are consistent with the actual situation of Ningwu County,indicating that PSOGSA-PP is suitable for the evaluation of water ecological carrying capacity at the township level;(2)the overall situation of water ecological carrying capacity of Ningwu County in 2017 is better.The water ecological carrying capacity of Ningwu County can be divided into four levels,i.e.Grade I(ideal)(Junshan Township,Xuejiawa Township),Grade II(good)(Dongmafang Township,Dongzhai Township,Xinbao Township,Shijiazhuang Township,Geliao Township,Dietaisi Township),Grade III(critical)(Huaidao Township,Huabeitun Township,Yuzhuang Township,Ximafang Township,Fenghuang Township),Grade IV(overload)(Yangfangkou Town).(3)According to the projection eigenvalue formula of PSOGSA-PP model,we can extract the "advantage index" and "disadvantage index" which have great influence on the towns.Through the analysis of the advantage and disadvantage index and the key index,we put forward protection and repair measures for the water ecological protection area(grade I and II towns)and the water ecological restoration area(grade III and IV towns)in Ningwu County.