Land use optimization allocation based on improved NSGA-Ⅲ by GPU parallel computing

The contradiction between supply and demand of land resources has become increasingly prominent, as the rapid development of urbanization. This problem has hindered the improvement of urbanization and development quality. The optimization of land-use allocation can bean important approach to coordinate the limited land resources, and thereby to ensure the high-quality development of a city. This study aims to establish a spatial optimization model of land use via a multi-objective optimization model with NSGA-III. A multi-objective model consists of the main and the constraint objectives. The main objectives include the maximization of GDP value, the maximization of ESV, the minimization of changing cost from the status que, and the minimized incompatibility of land use types. Besides, the constraint objectives are comprised of 5 quantitative constraints and 4 spatial constraints dataset according to policy planning. The NSGA-III can be well used to solve the multi-objective space optimization of land use, due to its excellent ability of global optimization and spatial search. The recombination and mutation operator were improved, based specifically on the characteristics and developments of geographical units. The efficiency of modified model was improved remarkably via integrating the GPU parallel computing. The Dongxihu District of Wuhan, China, was taken as the study area to test the model. Two typical schemes, including ecological and economic priority, were analyzed to compare the time-consuming of model in the serial computing of CPU and parallel computing of GPU. Consequently, the results demonstrated that: 1) A better optimization efficiency of modified model can be obtained using the GPU parallel computing, where the computing time reduced from 158.08 hours to 1.68 hours. 2) The modified model can be used to coordinate multiple objectives, and thereby to reasonably optimizing land use in terms of quantity structure and spatial pattern, providing for the multiple selections indecision making. In the scheme of ecological priority, the ecological benefits of study area reduced by 6.16%, and the economic benefits increased by 13.64%. In the scheme of economic priority, the ecological benefits reduced by 6.19%, and the economic benefits increased by 15.86%.