| The spatial planning of land use is the process of allocating different uses or activities to specific areas in a region and is the core content of land use planning systems. Land use planning is increasingly becoming complex because of the multifaceted problems it faces, such as guaranteeing economic growth, maintaining social equity, and preserving the environment. These objectives present conflicting demands from various land use groups and interest groups. The increased inclusion of objectives leads to different demands on the expected results. Moreover, the increased complexity of land use planning problems is influenced by the involvement and definition of multiple objectives. These objectives may be unstructured, nonlinear, and difficult to handle. Within this context, computer-based techniques have been developed to assist planners in decision making. Among all of the techniques, multi-objective optimization (MOO) approaches are the most well-known techniques in addressing multi-objective problems in land use planning. MOO approaches have successfully accomplished significant achievements. However, literature shows that some spatially-related environmental objectives, such as carbon emission, non-point source pollution, and soil erosion, are missing because of the difficulty in evaluating, analyzing, and measuring such complex land use objectives.;The land use planning process in China is divided into a series of land use plans at different levels. Among these plans, the municipal overall land use plan and the urban master plan are involved in managing the land use resources in a city. The municipal overall land use plan administers the urban and non-urban areas in an administrative scope, whereas the urban master plan focuses only on the development of urban areas. These two types of land use plans are conducted by two different government departments. These plans are usually inconsistent, particularly in terms of space.;Considering the spatial inconsistency between the municipal overall land use plan and urban master plan in China, a MOO-based two-level spatial planning of land use is conducted. The spatial planning aims at managing and coordinating the land use at different geographic extents and involves spatial layouts and structures of land use at different levels. In spatial planning, the geographic information system (GIS) and remote sensing (RS) are used to evaluate, analyze, and measure environmental, economic, and social issues with regard to the spatial land use change. The quantitative relationships between these objectives and spatial land use allocation are then used as rules in the MOO process to simulate environmental conditions under different spatial land use allocation scenarios.;Shenzhen, a rapidly developing city in China, is selected as the case study area to validate the proposed approach. The objectives and constraints in the spatial planning of land use are defined at two different levels based on the land use principles, local and national policies in China, and characteristics of Shenzhen. At the first level, nine objectives are proposed, namely, maximizing economic benefit, maximizing ecosystem services value, minimizing soil erosion, minimizing non-point source pollution, minimizing carbon emission, maximizing compatibility, minimizing change cost, maximizing accessibility, and minimizing landslide susceptibility. The objectives of spatial planning of land use at the urban level are subsequently proposed, as follows: maximizing housing capacity, maximizing employment capacity, minimizing changing cost, minimizing pollution from industrial lands, maximizing mixed land uses, maximizing green space, maximizing accessibility, maximizing compatibility, and maximizing spatial equity. The proposed spatial-related objectives are quantified by GIS.;Results indicated that the MOO-based two-level spatial planning can create trade-offs among the conflicting objectives, and a set of Pareto solutions is provided as options for decision makers or planners. Moreover, the MOO-based two-level spatial planning can generate a consistent land use planning system for Shenzhen. |
