Study On Optimization Model Of Ecological Water Replenishment Scheme In Nature Reserve For Improved Suitable Habitat For Rare And Endangered Water Birds

Momoge National Nature Reserve(MNNR)is an important inland wetland and a habitat for rare migratory water birds in China.Since the 1970 s,affected by natural factors such as climate change and the impact of human development and construction activities,the wetland ecological environment has been deteriorated and some lakes have dried up in MNNR.As a result,the wetland area and suitable habitat area for rare water birds in MNNR have been declined dramatically,along with the number of rare water birds such as Siberian crane,that come to rest in MNNR.The Jilin Western Water Supply Project implemented by Jilin province government can effectively restore the wetland ecological function in MNNR by suppling ecological water to MNNR through the “Yinnenrubai”project.However,the limited amount of water replenishment,the complex connection relationship between lakes in MNNR and many uncertainties in the process of water replenishment bring difficulties to the effective utilization of ecological water replenishment and the implementation of the water replenishment scheme recommended by project.In order to restore the wetland area and suitable habitat area for rare water birds in MNNR by using limited ecological water supplement scientifically and efficiently,this study,based on the design of “Yinnenrubai” project,fully considered the multiple uncertainties in the water resources management of MNNR,and used various uncertainty optimization methods to construct two optimization models for water resources allocation in MNNR.The optimization objective of the two models was to maximize the restored habitat area for rare water birds such as Siberian crane,while taking into account the ecological and environmental benefits.Based on the optimization models,the ecological water replenishment scheme of MNNR was optimized and adjusted under multiple scenarios.The results of this study can provide theoretical support for the optimization management of water resources system in nature reserve and the restoration and conservation of wetlands,rare water birds and their habitats.Firstly,considering the low,medium and high flood flow scenarios,the interval uncertainty of parameters such as ecological benefits per unit area and the random uncertainty of flood resources,and based on the relationship coefficient between the suitable habitat area for rare water birds such as Siberian crane and the water volume,an interval-parameter two-stage stochastic programming method was adopted to construct an interval-parameter two-stage optimization model for the optimization allocation of water resources in MNNR.The established model could make full and effective use of water resources under different flood flow scenarios,leading to that the suitable habitat area for rare water birds restored by the optimized ecological water replenishment scheme increased significantly,in comparison to the project recommendation scheme.In addition,the upper bound value of the restored habitat area was significantly higher than its lower bound value,so there was some room for adjustment,which can provide a feasible decision-making space for decision makers to optimize and adjust the optimization scheme according to the actual needs.Based on the interval-parameter two-stage stochastic programming model,the fuzzy uncertainty of the lake planning range in MNNR was fully considered,and the fuzzy mathematical programming method was incorporated to construct an intervalparameter fuzzy two-stage optimization model for the optimization allocation of water resources in MMNR.Compared to the interval-parameter two-stage optimization model,the overall decision-making range of the interval-parameter fuzzy two-stage optimization model was shortened by 18.28%,leading to the reduction of decisionmaking risk so as to facilitate the managers to make decisions.The constructed model also provided a membership interval reflecting the relationship between the target value,the possibility level and the risk level,which can provide decision support for decision makers to make the optimal management scheme of water resources with reasonable target value and risk level.In a word,this study firstly illustrated the necessity of optimizing the ecological water replenishment scheme of MNNR.And then,fully considering various uncertain factors such as flood resources,this study used various uncertain optimization methods to carry out the research on the optimization of the ecological water replenishing scheme of MNNR,which made an important exploration on the practice of restoring and protecting the wetland,rare water birds and their habitat through optimal utilization of the ecological water replenishment in nature reserve.