以提高生态系统服务为导向的土地利用优化研究——以兰州市为例

分析从1997年到2009年兰州市土地利用类型变化,对其生态系统服务价值进行核算,结果表明,兰州市生态系统服务功能主要表现为土壤形成与保护、维持生物多样性,气候调节等,但土壤形成与保护功能和水文调节功能从1997年开始一直呈下降趋势,由于盲目扩展建设用地而占用生态用地的现象使兰州市生态用地面积不断减少,从而造成生态恶化。以生态系统服务价值作为适应度函数,利用改进的混合蛙跳算法建立土地优化模型,得到生态型、发展型、综合效益型三种优化方案,优化后兰州市生态系统服务价值可达到58.89亿元。优化方案为提高兰州市生态系统服务价值提出以下建议:(1)保证退耕还林、还草的力度,加强南北两山绿化改造。(2)保证耕地、牧草地、园地面积,尽量控制建设用地的扩张。(3)建设用地所占用耕地面积,必须进行补偿,其中开发宜耕未利用地、挖掘土地利用潜力为较好的解决办法。

Land use optimization in order to improve ecosystem service: a case of Lanzhou City

Change of land use type in Lanzhou City from 1997 to 2009 is analyzed, and the ecosystem service value is counted in this paper. The results show that ecosystem service of Lanzhou is mainly for soil formation and protection, maintaining biodiversity, climate regulation. But the function of soil formation and protection, and the function of hydrological adjustment, has been declining since 1997, and because of blind expansion of built land and occupation of ecological land, the area of ecological land is reducing gradually in Lanzhou, which cause the ecological deterioration. The improved shuffled frog leaping algorithm is used to establish land optimization model, and the value of ecosystem services is chosen as its fitness function. Three kinds of optimization schemes, which are ecological, development and comprehensive benefit, are produced by this model. The optimized ecological system service value of Lanzhou City can reach 58.89×10⁸ yuan. In order to improve the value of ecological system service of Lanzhou City, the following suggestions is proposed: (1)The farmland should be transformed to forest and grassland reasonably, and the north south mountain''s green transformation should be strengthened. (2) The farm land, grassland, garden land should be protected, and the expansion of the built land should be under control. (3)The farm land occupied by building should be compensated, and the better solution should be development of unused land which is available and exploring the potential of land use.