Research On Optimized Allocation Of Slope Green Infrastructure In Huangshui River Basin

As a systematic strategy to solve water problems,Neacow fully integrates the concept of"mountains,rivers,forests,farmlands,lakes," as a community of life,improves the watershed's ability to regulate multiple processes of the water cycle,and systematically manages and slows down the extremum.Slope Green infrastructure is an important part of new water control model of Neacow,research shows that it has good regulation performance for the water cycle.Therefore,based on Neacow construction objectives,quantitatively identify the effectiveness situation of current Green Infrastructure construction,and then follow the law of nature,reasonable optimization of the allocation of Slope Green Infrastructure,which can give full play to the natural attributes of the watershed and provide the foundation for the comprehensive management of the basin and the solution of complex water problems.Taking Huangshui River above the center of Minhe county as the research area,the thesis first analyzed the concept of watershed-scale Slope Green Infrastructure,Based on the three maj or functional requirements of natural enriched,functional types and attributes coordinated,an evaluation index system and Slope Green Infrastructure evaluation are constructed.combined with the distributed hydrological model WEP,quantitatively evaluate the construction effect of different periods Slope Green Infrastructure.Comprehensively consider the distribution of natural forests,plantations,and residential sites,improve the traditional land suitability evaluation method,determine the allocation principles and goals based on the land suitability evaluation results,and construct the optimal allocation of Slope Green Infrastructure.Combined with the evaluation index system and the analysis of the mitigation effect of the Slope Green Infrastructure on climate change,the adjustment capacity of different allocation schemes on the ecological and hydrological functions was compared,and the most optimal allocation scheme was obtained.The main conclusions are as follows:(1)Extract the scale of Slope Green Infrastructure in different periods,and construct the evaluation index system.Based on the concept of Slope Green Infrastructure,the construction scales of Slope Green Infrastructure in different periods was identified:overall,the scales of Slope Green Infrastructure was significant,and the time scale change was mainly after 2000 and the area is 3736km2,and the change in spatial scale was generally concentrated in the downstream of the river and along the banks of the river.Further,from the perspective of nature enriched(green infrastructure scale,composition and quality),function types(hydrological regulation function and ecological support function),and attributes coordinated,selected 10 secondary indicators that can represent this function Build a new evaluation index system for Slope Green Infrastructure,and use the index system to evaluate Slope Green Infrastructure at different construction periods.The results show that as the slope green infrastructure is deepened,the comprehensive functions have improved significantly.However,the fluctuation of individual functions tends to decrease.For example,the quality of Slope Green Infrastructure is declining.The hydrological adjustment functions in the function types have some spatial heterogeneity.The attributes coordinated is still on the verge of imbalance and needs to be improved.This is also the current problem of Slope Green Infrastructure,which needs to be further improved to ensure the coordinated development of various functions(2)Improve the land suitability evaluation method and construct the optimal allocation scheme of Slope Green Infrastructure.Respect the nature and urbanization process,revise the evaluation criteria and classification of various factors,and improve the land suitability evaluation method.In general,the land use pattern to forest land showed the highest degree of suitability,followed by residential areas and grasslands,for cultivated land,the proportion of highly suitable areas was very small.Further,according to the results of the land suitability evaluation,by the principles of "livability,field protection,forest protection,grass adjustment",and the goal of disappearing unsuitable plots and minimizing the area of critically suitable plots,Transforming the residential construction sites and cultivated land into critical suitability or general suitability.Meanwhile,according to suitable grades,transforming the suitable forest and grass parts into all grass,half grass&half forest and all forest.Therefore,general suitable,medium suitable and highly suitable allocation schemes were optimized.(3)Combining the evaluation index system and the analysis of the mitigation effect of Slope Green Infrastructure on climate change,the adjustment ability of different allocation schemes on the ecological and hydrological functions was compared and selected to obtain the most optimal allocation scheme.From the perspective of single functional requirements,the three optimization allocation schemes have improved the corresponding functions of various indicators to a certain extent,but they are inconsistent in different indicators.In terms of natural enriched and attributes coordinated,the highly suitable scheme performs best,especially in terms of attributes coordinated,the coupling coordination index increases to 0.59,close to the primary coordination state.Further,combined with future climate scenarios,compared with the current Slope Green Infrastructure,the optimized allocation schemes will play the role of "eliminating peak and replenishing dry ",which significantly reduced the variability of runoff processes across the river basin and various sections to a certain extent.Mitigated the effects of climate change.Finally,the comprehensive evaluation index is calculated to obtain the highest suitable program with the highest score of 0.71,indicating that under the highly suitable scheme conditions,that is,when the residential construction sites and cultivated land are generally suitable grades,and the suitable forest and grass parts are all forest land,it has more advantages whether it is to deal with the functions of the current climate conditions or to mitigate the extreme value of the future climate change,and has a better effect in optimizing the allocation.