Construction of Watershed Ecological Network Based on Spatial Syntax

Abstract

[Objective] The Dianchi Lake ecological corridor, the ecological nodes and obstacles were identified, and then the ecological network of the watershed was optimized in order to provide a reference for the maintenance and improvement of the ecological function of the ecological migration corridor in the Dianchi Lake basin. [Methods] The study was conducted for the Dianchi Lake basin. Morphological spatial pattern analysis was combined with circuit theory to identify the ecological sources, pinch points, and obstacle areas in the study area, and to construct an ecological network. At the same time, spatial syntax was introduced to quantify the road network in order to optimize the electrical resistance surface. The back resistance surface and the ecological network were compared to determine the impact of the road network on the ecological network. [Results] ① The overall ecological source area accounted for a relatively high proportion of the total study area. The 17 extracted ecological source areas had an area of 101 248 hm2 and accounted for 34.7% of the total area of the study area, mainly located in the northern mountainous area and the central area around Dianchi Lake; ② The optimized high resistance area of the resistive force surface was transferred from the surrounding area to the main urban area, and the number of corridors increased from 35 to 41. The total length increased from 185.9 km to 216.2 km. The degree of network closure, connection degree, and connection rate were increased by 0.20, 0.35, and 0.13, respectively; ③ The corridor width was determined to be 600 m through the threshold analysis of corridor width. 15 116 hm2 of ecological pinch points and 71 875 hm2 of ecological barrier areas were extracted form the Dianchi Lake Basin ecological safety network. [Conclusion] The fragmentation of ecological patches in the Dianchi Lake basin was obvious, and their distribution showed the characteristics of dense ecological foci in the north and sparse ecological foci in the south. The cutting effect of high-grade and high-traffic roads on the ecological network was very prominent, and these kinds of pinch points and obstacle areas should be given greater attention in the construction and restoration of ecological networks.

Keywords

• ecological network
• circuit theory
• spatial syntax
• mspa (morphological spatial pattern analysis)
• dianchi lake basin