Achieving the objective of ecological planning for arid inland river basin under uncertainty based on ecological risk assessment

Abstract

To study the impact of the uncertainties existed in nature and management on the ecological planning and the achievement of the planning objective under uncertainty, the General restoration planning of Shiyanghe river basin, which is for Shiyanghe river basin located in an arid inland area in China, is selected as the research object. The general thought of the essay is to get the probability of the objective achievement of ecological planning by analysing the floating region and possibility distribution of the uncertainties which is of the critical factors in achieving the planning objective. Firstly, the uncertainties of the critical factors are identified and analysed separately. Secondly, the two uncertainties are combined to study its impacts on the achievement of planning objective in each scenario. Lastly, the probability and the possible deviation of ecological objective achievement are analysed in each scenario. The methods used in the study include the scenario analysis, BPF based on BP neural network, PPCC analysis and interval analysis. The results show that the achievement of ecological objective is greatly influenced by the uncertainties, the objective achievement could be get only in the scenario of water resources utilization and management meet the planning requirement and high flow year in planning year, the results also show that the greater volume of local water resources and the higher level of local water resources utilization and management lead to the higher probability of achieving ecological objective and the lower possible deviation.