Case Studies Of Ecological Integrity Assessment In Ecological Impact Assessment

The mainly perspective of the research is landscape ecology and from two aspects,restore stability and impedance stability,we select eight ecological indexes to construct the ecological system integrity evaluation model.Eight indexes include average vegetation productivity,existing biomass,vegetation coverage,landscape patch dominance,ecological resilience,species diversity,landscape diversity and evenness.Research takes the Luo Ning pumped storage power station as an example.The data is obtained by means of GIS remote sensing tools.The ecological system integrity evaluation in the project area is selected as the target layer,and the stability and impedance stability are restored as the sub-target layer,and eight ecological indicators are used as the index layer to construct the evaluation system.In order to solve the problem that each indicator unit does not unified,we consult relevant references,and then grade and evaluate the indexes,and the index weight is obtained by expert scoring and analytic hierarchy process.Comprehensive index of ecosystem in evaluation area is obtained by weighting sum of each index.The qualitative problem of evaluation is quantified to provide reference for ecological impact assessment of engineering projects.The result of research shows that:Vegetation productivity,biomass,vegetation coverage,landscape patch dominance,landscape diversity index and evenness index are all reduced after the project completed.On the contrary,species diversity index and ecological resilience index are increased,which related to the introduction of new species and the increase of anthropogenic disturbance in engineering construction.From the spatial pattern of the landscape,it can be seen that maximum advantage value is forest grassland type,whose dominance value is 85.74% before construction and 79.91% after construction.The forest grassland area before andafter construction accounts for more than 70% of the evaluation area.The advantage value of cultivated land types was 11.97% before construction and 11.20% after construction,and the overall decline was small.The dominance of water areas,construction land and other land after construction increased by a large margin compared with before construction.The water area increased by 3 times,the construction land and other land increased by nearly 2 times,but the two types accounted for less than 15% of the entire evaluation area.Consequently,the project construction has little influence on the spatial pattern of the ecological system in the evaluation area.After the construction of the project,the stability index of ecosystem restoration has declined,but the decline is not significant,and the stability of the impedance remains unchanged.The ecological system integrity index was 6.20 before construction and 6.04 after construction,which value declined obviously.The change of ecosystem integrity is related to the area of landscape type.Finally,the research proposes relevant prospects based on the application of concrete examples of the system model and the existing phenomena in the current ecological evaluation.Specifically,the ecosystem is a macroscopic entity.When evaluating the integrity of ecosystems,the division of evaluation scope can be considered from the aspects of the structure and function of the ecosystem.The ecological system of the region is different,which can further improve the evaluation standard for some typical regions.The study on the dynamic change of ecosystem integrity in the evaluation area will be the direction of future research.