The assessment of the ecosystem health of urban rivers and lakes is the scientific basis for their management and ecological restoration.This study developed a three-level indicator system for its assessment.The resul...The assessment of the ecosystem health of urban rivers and lakes is the scientific basis for their management and ecological restoration.This study developed a three-level indicator system for its assessment.The results indicated that:Zhonghai and Nanhai are in the state of transition from unhealthy to critical state and all the other lakes are in unhealthy states.Water environmental quality,structure and function of the aquatic ecosystem,and the structure of waterfront areas were the constraints.Nanhai was ranked as poor and the others were all ranked as very poor.However,the ecological environment of Zhonghai and Nanhai were better than the others,the sums of the degree of membership to the healthy state and critical state were all close to 0.6.and the restorations of these lakes were moderate.The sums of the degree of membership to the healthy state and critical state of the other lakes were under 0.3,as it was difficult to restore these lakes.Some suggestions on scientific management and ecological restoration of the six lakes were proposed:①To control non-point pollution and to improve the water quality of six lakes and the water entering into these lakes;②To improve the hydrological conditions of six lakes;③To rehabilitate the aquatic ecosystem and waterfront areas.展开更多
Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,mak...Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,making it difficult to evaluate them using traditional assessment methods of linear and explicit functions.We introduce a back-propagation neural network model optimized by a genetic algorithm to evaluate ecosystem health in 16 districts in Yunnan Province.Result:(1)The model required fewer inputs to evaluate complex and nonlinear systems,avoided the need for subjective weights,and performed well in this practical application to regional ecosystem health assessment.(2)The ecosystem health in Yunnan Province was increasing,and there was a significant positive spatial autocorrelation during 2000-2020,showing that districts with high Ecosystem Health cluster together and the ecological protection policy of the region has produced a diffusion effect,leading to continuous improvement of the ecological health of the surrounding areas.High-low outlier areas of ecosystem health should be paid more attention,because of the increasing instability of local health levels.Conclusion:This study provides a methodological exploration for assessing spatial mosaics of different ecosystems at a regional scale.展开更多
基金This study was supported by the National Basic Research Program of China(Grant No.2006CB403403)Key Program of the National Natural Science Foundation of China(Grant No.50238020)。
文摘The assessment of the ecosystem health of urban rivers and lakes is the scientific basis for their management and ecological restoration.This study developed a three-level indicator system for its assessment.The results indicated that:Zhonghai and Nanhai are in the state of transition from unhealthy to critical state and all the other lakes are in unhealthy states.Water environmental quality,structure and function of the aquatic ecosystem,and the structure of waterfront areas were the constraints.Nanhai was ranked as poor and the others were all ranked as very poor.However,the ecological environment of Zhonghai and Nanhai were better than the others,the sums of the degree of membership to the healthy state and critical state were all close to 0.6.and the restorations of these lakes were moderate.The sums of the degree of membership to the healthy state and critical state of the other lakes were under 0.3,as it was difficult to restore these lakes.Some suggestions on scientific management and ecological restoration of the six lakes were proposed:①To control non-point pollution and to improve the water quality of six lakes and the water entering into these lakes;②To improve the hydrological conditions of six lakes;③To rehabilitate the aquatic ecosystem and waterfront areas.
基金This work was supported by the National Natural Science Foundation of China[52078160]。
文摘Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,making it difficult to evaluate them using traditional assessment methods of linear and explicit functions.We introduce a back-propagation neural network model optimized by a genetic algorithm to evaluate ecosystem health in 16 districts in Yunnan Province.Result:(1)The model required fewer inputs to evaluate complex and nonlinear systems,avoided the need for subjective weights,and performed well in this practical application to regional ecosystem health assessment.(2)The ecosystem health in Yunnan Province was increasing,and there was a significant positive spatial autocorrelation during 2000-2020,showing that districts with high Ecosystem Health cluster together and the ecological protection policy of the region has produced a diffusion effect,leading to continuous improvement of the ecological health of the surrounding areas.High-low outlier areas of ecosystem health should be paid more attention,because of the increasing instability of local health levels.Conclusion:This study provides a methodological exploration for assessing spatial mosaics of different ecosystems at a regional scale.
