Study On Evaluation Of Regional Water Ecological Carrying Capacity Based On Complex Ecosystem Theory

The Sanjiang Plain is located in the eastern part of Heilongjiang Province and has excellent natural conditions which are suitable for agricultural development.It is the largest agricultural land area in China and is also an important commodity grain producti on base in China.However,in recent years,under the disturbance of human social activities,the phenomena of over-exploitation of groundwater,the decline of regional groundwater level,the continuous expansion of local falling funnels,the accumulation of salinity in well-irrigated rice fields,the lack of seasonal ecological water demand,and the serious environmental pollution of irrigation waters have broken the ecological balance that broke the ecological balance has appeared in the Sanjiang Plain,which has a major impact on the regional ecological stability and social and economic development.Based on the analysis of the characteristics of the complex ecosystem,a comprehensive evaluation index system for regional water ecological carrying capacity based on the composite ecosystem theory was built in this study,and a particle swarm optimization projection pursuit evaluation model with less adjustable parameters and high computational efficiency was used.The classification criteria of water ecologi cal carrying capacity with regional characteristics were defined,and the level of water ecological carrying capacity in the Sanjiang Plain area was comprehensively evaluated.The main research contents and results are as follows:(1)Establishment of an indicator system for water ecological carrying capacity.According to the characteristics of the region,based on the theory of complex ecosystems,a comprehensive evaluation index system for regional water ecological carrying capacity in the Sanjiang Plain was constructed.(2)Classification of regional water ecological carrying capacity evaluation.According to the dynamic and complexity characteristics of water ecological carrying capacity evaluation,the comprehensive evaluation model of regional water ecological carrying capacity based on particle swarm optimization projection pursuit was used to solve the problem of artificially determining the random interference of weights,which has a significant effect on analyzing high-dimensional data involving multiple objectives and factors.(3)Evaluation and analysis of regional water ecological carrying capacity in the Sanjiang Plain.According to the classification criteria proposed in this paper,the regional water ecological carrying capacity of the 5 cities in the Sanjiang Plain,including itself,and the whole area of Heilongjiang Province were analyzed and evaluated,and the results of 7 evaluation samples were obtained: the level of the regional water ecological carrying capacity of Jiamusi City and Sanjiang Plain was at Grade IV,and the carrying capacity level is overloaded,which is manifested by the inconsistency between regional ecological environmental protection and social economic development.The water ecological carrying capacity of the remain ing 4 cities(Qitaihe City,Jixi City,Shuangyashan City and Hegang City)and Heilongjiang Province were all at Grade III,and the carrying level was weak.According to the evaluation results,the eco-environmental protection and protection plan adapted to the characteristics of regional evaluation and the suggestions for sustainable and stable development of social economy were formulated,and the supporting role of water resources and ecological environment to regional socio-economic development was fully exerted to achieve sustainable green development in the Sanjiang Plain.