Research On Urban Expansion Prediction And Pattern Optimization Of Yinchuan Plain

Urbanization process has become a global concern and been seen to be responsible for the ecological degradation. Urban spatial expansion has been seem as the representation of urbanization process. Using remote sensing technique, geographic information system, SLEUTH model and mathematical statistical analysis, we simulated and predicted urban spatial expansion and land use change, and developed an interdisciplinary modeling framework to evaluate the effectiveness of integrated urban expansion management or its shortcoming. Our study demonstrated a joint application of landscape pattern analysis, ecosystem service value evaluation and multi-scenario comparison into urban growth planning and urbanization qualifying through mathematical statistical analysis and SLEUTH-3r model. We established an interdisciplinary modeling framework and applied it in Yinchuan Plain which is located in the northwest are of China and has specific natural geography characteristics due to the Yellow River through it.The research approach was consisted of three steps. Firstly, based on SLEUTH model, we simulated and reconstructed urban expansion and land use dynamic process in 1989-2014. The change of landscape pattern and ecosystem service values under urbanization was evaluated and the relationship between landscape pattern and ecosystem services value was explored using mathematical statistics. Secondly, we chose an agent-based model SLEUTH to compare the influence of different urban expansion policies on regional landscape pattern and ecosystem service value through multi-scenario prediction. Finally, design and validation an optimization scenario that integrating both historical analysis result and future multi-comparison result. Integrating of landscape pattern, ecosystem service values, urban expansion modelling and scenario prediction at the regional scale has been demanding for mitigating urbanization-related impacts on terrestrial ecosystems.The main conclusions of this paper are as follows: 1) As urbanization intensified, the whole landscape became more irregular and fragmented, and with agricultural land increased in 1989-2006 and decreased in 2006-2014, the entire level of isolation and diversity first decreased then increased. Diversity, composition and configuration in landscape patterns could further significantly affect the provisions of ecosystem services. The ecosystem service values are more correlated with the landscape pattern of grass land and water. As to built-ups, its fragmentation and shape indexes are negatively correlated to the ecosystem service values. 2) The results of multi-scenario comparison suggest that integrating policy plan would be better than single policy, compact urban growth and medium environment protection policy are both benefit for ecosystem services maintain and suitable for local environment. 3) Optimized scenario was thus designed which could impair the impact of urbanization, largely protect the ecosystem services and give consider to urban expansion demand by economic development and environment protection. In the future 20 years, there would be more 304.8 km2 for urban area, meanwhile ecosystem service value would increase by approximately 54.05 million yuan, expressing the feasibility of both economic development and environmental protection.