生态安全格局背景下干旱内陆河流域土地资源优化配置研究—以石羊河流域为例

In order to solve the increasing ecological problem and land resource shortage during the development of economy and urbanization in recently, the reasonable determination of the land use structure and allocation under ecological security pattern (ESP) are very important for arid inland region. In our study, the GIS technologies of spatial analysis and the MCR (Minimum cumulative resistance) model as well as CLUE-S (conversion of land use and its effects at small regional extent) model were applied to optimize the land use structure and the allocation of Shiyang river basin. First, 18 driving factors of land use change were selected to make prediction map through logistic regression and analyze the land use change process. Second, the ESP was defined through MCR model, which including ecological source and resistance surface. The ESP level partition was the fundamental reference of the optimization, which was divided into six types according to the MCR value. Third, we set the corresponding land use change and spatial optimizing allocation of the basin in 2030 under three scenarios integrated MCR and CLUE-S model based on the land use map in 1986, 1995, 2000, 2005, 2010 and 2015.Three optimization scenarios of land use allocation under ecological security scenario (ESS), farmland protection scenario (FPS), and social-economic development scenario (SEDS) were calculated. And then the spatial optimized results in 2020,2025 and 2030 were obtained through calculating the MCR value of land use resources. Three scenarios of land use structure and layout of Shiyang River Basin were optimized and configurated by means of land use data in six periods of 1986, 1995, 2000, 2005, 2010 and 2015. Further, the optimization configuration results were compared and analyzed through comparing the different ecological partitions. The selected woodland and water body as ecological sources to determine the ecological process of land use changes and calculate the resistance values and classifications through the MCR model. We improve the characterization and presentation of the land use allocation by combining CLUE-S model with MCR model, which give a new insight into better understanding of the possible configuration of land use based on coordination of environment and economy development. We also provide scientific support for land use planning and managements under the ecological security patterns.

为解决干旱地区的水土资源短缺问题，促进内陆河流域用地结构逐步走向节约和集约，项目以干旱内陆地区石羊河流域为例，将GIS技术、MCR和CLUE-S模型应用到该流域土地利用优化配置研究中，提出了一种基于生态安全格局的土地资源优化配置方法。主要研究任务是：（1）预测土地资源变化的控制因子，确定引起土地资源变化的驱动因子并构建Logistic 回归模型参数，在此基础上计算模拟生态安全情景、耕地保护情景和社会经济快速发展3种情景下的土地资源优化配置结果；（2）以1986-2015年现状土地利用为基础，计算石羊河流域土地资源最小累积阻力，并在此基础上构建基于生态安全格局的2020、2025和2030年土地资源优化配置结果，绘制优化配置分区空间分布图；（3）对3种不同情景下的优化配置分区进行对比分析并进行实践应用，提出符合石羊河流域可持续发展的土地资源优化方案和目标措施。

石羊河流域作为河西走廊三大内陆河之一，且作为祁连山国家级自然保护区的核心区块，对我国西北乃至全国的生态屏障建设具有十分重要的战略意义。因此对其土地利用结构进行调整优化，不仅对提高土地资源利用效率具有十分重要的意义，而且对集约节约用地、充分开发利用土地后备资源也具有现实意义。. 基于此，项目采用CLUE-S模型，结合多目标动态规划模型（MODP）和土地利用变化驱动因子Binary Logistic回归方法，预测和模拟了2020、2025和2030年三个时期生态安全情景、耕地保护情景和社会经济快速发展情景下的土地利用空间布局和优化配置结果；并将最小累积阻力模型（MCR）引入到土地利用空间优化配置中，与CLUE-S模型模拟的生态安全情景相结合，最终生成了基于生态安全格局的石羊河流域土地利用优化配置结果。结果表明，在生态安全情景下耕地有所减少，林地、草地和水域有较明显增加；耕地保护情景以土地开发和整治及宅基地还耕为主要目标，科学有效控制了建设用地规模，大力开发未利用地潜力；社会经济快速发展情景综合考虑了政府宏观政策指导情况下土地利用各类型的数量及空间结构基本情况。根据土地利用优化配置分区结果，禁止开发区主要分布在上游祁连山地区和高海拔地区，是生态保护的核心区；限制开发区主要分布在天祝县北部、凉州区南部和中部、古浪县北部、金川区北部及民勤绿洲盆地，是绿洲和水源涵养林的生态过渡区；重点开发区主要分布在中游凉州区城镇中心及周边区域、金川区大部分地区及永昌县北部地区、民勤县城及周边地区，是今后作为城乡建设用地重点开发建设的区域；优化开发区主要分布在各县城、凉州区以及金川区的周边，是今后进行土地整治、土地开发的重点区域；生态治理区主要分布在古浪县北部、凉州区东北部及民勤北部广大沙漠地带，是未来进行生态恢复、生态产业发展的重点地区。该方法与结果可为石羊河流域未来土地利用规划、土地资源科学高效利用提供参考依据。