Construction and Optimization of Urban and Rural Ecological Security Patterns Based on Ecological Service Importance in a Semi-Arid Region: A Case Study of Lanzhou City

Abstract

The construction of ecological security patterns has become a crucial approach to assessing ecosystem health and integrity and is essential for achieving sustainable and high-quality development in both urban and rural areas. Using Lanzhou City as an example, our study employed the InVEST model, ecological service importance evaluation, and hotspot analysis to classify ecological sources. Additionally, ecological corridors were identified and optimized using the least resistance model and circuit theory. The identified corridor pattern was further analyzed using space syntax and neural networks to determine the influences of various factors. This framework can be applied to the circular construction of corridors. Our findings revealed a three-stage differentiation trend in the importance of ecosystem services. Ecological source areas and corridors were densely distributed in the northwest of Lanzhou. The optimized ecological source area increased from 2914.1 km2 to 4542.5 km2, raising its proportion in the study area from 22.2% to 34.7%. The total number of corridors after optimization was 217, spanning a 2657.3 km length. The Gaolan Mountain area had the highest current density, whereas the ecological barrier area was mainly distributed in the northwest of Yongdeng County and the north of Yuzhong County. The spatial syntax index indicated significant potential reachability between the Honggu area and the northwest area. Finally, using neural network perceptrons to simulate ecosystem service functions, our findings revealed that habitat quality showed the best fit under single-dependent-variable prediction, followed by water yield, with soil conservation showing a poor fit. Under three-dependent-variable prediction conditions, population factors had the greatest impact on ecosystem services, while slope had the least impact. Therefore, it is important to promote the construction of green infrastructure in the northwest and southeast, improve the connectivity of ecological corridors in Honggu District, and adopt corresponding spatial corridor optimization strategies according to different ecological needs. Collectively, our findings provide a theoretical and practical basis for the construction and optimization of urban and rural ecological security patterns in the semi-arid region of Lanzhou.