农村宅基地整治潜力的空间显式测算与模拟

三峡工程的建设对库区生态环境的影响极大，为了深入分析三峡工程建设前、后土地利用活动的生态环境效应，该研究基于三峡库区土地利用变化和精细化生态系统服务价值（ecosystem services value，ESV）评估结果，细致地测度ESV时空演变及其对土地利用变化地敏感性。结果表明：1）三峡工程建设前，库区土地利用变化最主要的特征是耕地转为建设用地，而建设后则表现为林地、草地和耕地三者间的相互转换以及建设用地扩张。2）1980-2018年，三峡库区整体生态系统功能改善，ESV净增加18.49亿元，这主要由于三峡工程建设后大量耕地转为林地。但重庆主城区及其周边地区ESV持续减损。3）三峡工程建设前、后库区生态系统服务价值敏感性指数分别为0.73和1.46，敏感性增加。在空间分布上，库区东部夷陵、秭归，中部石柱、丰都以及重庆主城区生态系统服务和9种子服务功能的敏感性较高。总体来看，三峡工程的实施对库区生态系统服务功能的影响利大于弊。研究结果有助于加深对大型水利工程生态环境效应的认识，且为库区生态环境建设和保护提供指导。

Spatially explicit calculation and simulation of estimating housing land consolidation potential in rural areas

Abstract: Land use/land cover change(LUCC) is one of the important driving forces of ecosystem services change. Because ecosystem services depend on different ecological and geographical on different spatial and temporal scales, it is of great significance to study ecosystem services based on LUCC. As the world''s largest and most influential water conservancy project, the Three Gorges Project has the largest number of immigrants and submerged land in the world. Since the implementation of the Three Gorges Project, the ecological environment of the reservoir area has undergone tremendous changes. Different scholars also hold different views on the advantages and disadvantages of the Three Gorges Project on the ecological environment. Therefore, we divided the study period into the pre-construction period (1980-2000) and post-construction period (2000-2018) of the Three Gorges Project, and analyzed the pros and cons of the Three Gorges Project from the perspective of ecosystem service value(ESV). Here, we first explored LUCC in the Three Gorges Reservoir area for two time periods. Then, applying a value transfer method with an equivalent value factor spatialized using the normalized difference vegetation index(NDVI), we estimated the changes of ESV in response to LUCC in a spatially explicit way. Finally, we constructed the gains and losses model of ESV and ecosystem services sensitivity model of nine kinds of secondary ecosystem services to deeply analyze the interference degree of land use activities to ESV. Major findings:(1) The LUCC during 2000-2018 was much more dramatic than 1980-2000. Before dam construction, the conversion of cultivated land to construction land was the main feature of land use change. After dam construction, it was manifested in the mutual conversion of forest land, grassland, cultivated land and the expansion of construction land. And the construction land in the main urban area of Chongqing continued to expand in 1980-2018. (2)ESV decreased first and then increased in the Three Gorges Reservoir area with a net increase of 1.849 billion yuan, and the ecosystem service function improved as a whole. The main reason for the improvement of regional ecosystem functions before and after dam construction was the conversion of cultivated land to forest land. Due to the continuous expansion of construction land, ESV in the main urban area of Chongqing continued to decrease. (3) The sensitivity indexes of ESV to land use change before and after dam construction were 0.73 and 1.46, respectively. The sensitivities of food production, hydrological regulation, waste treatment, soil conservation, and provision of aesthetic landscapes were increased. In spatial distribution, the nine kinds of sensitivities were all highly in the east of the reservoir area, Shizhu and Fengdu in the middle and the main urban areas of Chongqing, which indicated that ecosystem functions in these areas were easily affected by land use activities.The Three Gorges Project has greatly avoided the drought and flood disasters in the middle and lower reaches of the Yangtze River, and has also played an important role in protecting the ecosystem along the river. Therefore,. from the perspective of ESV, the advantages of The Three Gorges Project outweigh the disadvantages.