基于CLUE-S模型的不同情景下区域土地利用布局优化

Land use layout optimization under different scenarios by using the CLUE-S model

土地利用规划要求把土地资源最终配置在空间上,而现有文献更多是对土地利用结构的优化,很少对全局土地利用布局优化,鉴于此,为减轻土地利用规划的多目标冲突,同时为提高资源配置效率,释放空间效应,对不同情景下的土地利用布局优化进行研究。用非线性优化模型中的理想点法求取了不同情景下最优土地利用结构,用Logistic回归提取了不同用地的优化布局规则,以不同情景下的土地优化结构为数量约束,借助CLUE-S模型的全局配置能力对各情景下的用地布局作优化,并以扬州市为实例进行阐述。结果表明:(1)优先发展经济情景下,2025年扬州土地利用经济产值是10.4×10~7万元,优先保护生态情景下,目标年生态服务价值是9.7×10~5万元,保障公众福利情景下,公众福利大小是351271 hm^2;(2)经济增长目标对土地利用结构的情景变化最为敏感,而公众福利目标的敏感性最小;(3)与基期年比,发展经济与保育生态情景下的土地优化布局变化最大,前者主要是市区城镇工矿用地向东部及西北扩张,后者则是在西南丘陵及南部长江岸边配置了大量园地、林地。提出的不同情景下土地利用布局的优化方法可为土地利用规划及生态规划提供有力技术支持。

Land use planning involves categorizing spatial units on the basis of land use type to yield optimum productivity. While the planning is known to have two approaches-land use proportion optimization and land use layout optimization,-studies have mostly focused on the former quantitative approach, rarely attending to the latter. The existing literature applies some time-consuming heuristic methods to optimize land use layout, and therefore, this study attempts to solve this using the CLUE-S model with a reference point approach. While this model has been widely used to simulate future land use layout, there exist great differences between optimization and simulation, as optimization aims to achieve better benefits from land use layout, while simulation is used to deduce a layout with rules involving historical changes. In order to realize the multiple objectives of land use and to optimize land use layout for spatial welfare, thus increasing land resource allocation efficiency, this study focuses on the regional land use layout optimization under different scenarios. First, a reference point programming approach is formulated to optimize land use structures in the different scenarios. Then, optimal distribution rules for different land use types are extracted from current land use map through logistic regression. Finally, using optimal land use structure as the quantity constraint, the CLUE-S model embedded with optimized layout rules is applied to optimize overall land use layout in the different scenarios. The results of this study show the following：the economic value of land use is 1040 billion RMB under the economic priority scenario, the ecological value is 9.7 billion RMB under the ecology priority scenario, and the area of land that represents human well-being is 351271 hectares under the scenario of public well-being priority. The goal of economic growth is the most sensitive to scenario variation of land use structure, while the public well-being goal is the most insensitive to scenario variation. Compared with the existing layout, there are drastic differences in the land use optimal layout under the economic priority scenario, where urban land expands towards east and northwest as well as in the ecology priority scenario, where the amount of garden and forest land was allocated to the hilly area in the southwest and the Yangtze River side in the south of downtown of Yangzhou city. The method of optimizing land use layout under different scenarios as proposed in this study could supply effective technical assistance for land use plan and ecological plan.