Study On Landscape Optimization Of Dujiangyan Canal Corridor Based On Multi-Scale Green Space Ecological Network Analysis

The huge artesian irrigation canal system of Dujiangyan for more than 2,000 years is an important part of Chengdu’s landscape pattern.However,due to modern urban and rural construction,a large number of historical canal systems have been buried,the vegetation buffer zone has been occupied,and artificial channels have become water pipelines.Ecological problems have seriously affected Dujiangyan.Dujiangyan channels is the good ecological corridor spaces,are an important part of the green space ecological network.Based on the construction of a multi-scale green space ecological network,from the perspective of regional ecological security,this paper identifies the key areas for the optimization of the canal system landscape.Under the skeleton,the "point"-shaped channel optimization measures can maximize the "plane"-shaped regional ecological effect,and realize the systematic optimization of the function-process-structure at different levels of the canal system.Based on the process-pattern coupling analysis,this study carried out a multi-scale nested study of irrigation canal system corridors.First of all,from the organizational dimension,the ecological process of three organizational levels of landscape,canal corridor and channel of the river canal system is studied and analyzed.Secondly,from the spatial dimension,a key area identification model of canal corridors based on the spatial nesting analysis of multi-scale green space ecological network is proposed.The model consists of two parts.Including ecological source and corridor identification,multi-scale green space ecological network construction and spatial nesting analysis;the second is the identification of key sections of canal corridors based on the spatial analysis of green space ecological network,including trunk,branch,bucket-level canal systems and multi-level canals.Scale green space ecological network overlay analysis.The identified key areas of canal system landscape optimization are divided into three categories: source,corridor and composite,and the general structural characteristics of various canal corridors are summarized.The study takes the canal system of Dujiangyan Essence Irrigation District as an example for practical application.The research results identified a total of 159 key areas of canal corridors in Dujiangyan Jingshen Irrigation District.The length of canal corridors is about 130.21 km.The number of key sections of corridors is the largest and the length is the longest.58 km,the number of composite key sections is the least.Based on the identification results of key areas,this study summarizes the ecological significance of various key areas of the Dujiangyan canal system,and then proposes the evaluation principles for landscape optimization of various types of canal corridors,assigns scores to the identification results,and divides the five-level priorities for canal section optimization.According to the landscape optimization level of the key sections of the canal system,the priority strategies for the protection and optimization of various canal sections at each level are sorted out.Finally,taking Dujiangyan Essence Irrigation District as the planning and design scope,integrating the above research results and methods,select representative river and channel corridors such as Puyang River Corridor,Lingshouyan Corridor,and Mapoyan Corridor to complete the planning and design of the landscape optimization scheme.