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In order to optimize the spatial pattern of land use and promote the sustainable development of the land, taking the Jiangchuan District of Yuxi City, Yunnan Province as the research area, in this paper, we adopted the CLUE-S (The Conversion of Land Use and its effects at Small Region Extent) and ecological sensitivity analysis methods that were applied to the optimal allocation of land use spatial pattern in Jiangchuan District. We took the highly sensitive region as the regional constraint document in the CLUE-S model to highlight the key areas of ecological protection in the studied area. Based on the comprehensive ecological sensitivity zoning as the driving force factor affecting the land use change in the study area, a land use scenario simulation method was proposed in which the ecological sensitivity was integrated into the land use spatial pattern optimization configuration process and results. With the use of land use data in 2006 and 2016, the land use spatial pattern of 2025 in the two modes of natural development scenarios and land ecological optimization scenarios in Jiangchuan District would be optimized. The simulation results of optimized configuration were analyzed and validated based on ecological sensitivity partition. The results showed that by selecting five secondary indicators of soil erosion intensity, land use type, vegetation coverage, distance from water source and disaster susceptibility, we constructed a watershed ecological sensitivity evaluation index system. Jiangchuan District's ecological sensitivity was mainly moderate or above sensitivity, and the area was 57 111.37 hm², accounting for 70.91% of the total area of Jiangchuan District. According to the results of ecological sensitivity assessment, Jiangchuan District was divided into highly sensitive, moderately sensitive, mildly sensitive and non-sensitive, and it was divided into ecological protection core area, control development area and suitable development area. In addition, based on the 2006 land use data, and use of the CLUE-S model, the spatial pattern of land use in Jiangchuan District in 2016 was simulated. Compared with the land use data in 2016, the correct raster number of the simulation results accounted for 81.59% of the total number of grids. The Kappa coefficient was 0.779 1, and the CLUE-S model can be used to simulate the spatial pattern of land use in Jiangchuan District in 2025. Moreover, in the two scenarios, the land use pattern of Jiangchuan District in 2025 had both common features and differences. In the two scenarios, the original forest land, farmland, unused land and urban and residential land pattern were effectively protected, but the spatial distribution patterns of newly added forest land and grassland were different. The results of the optimal allocation of land use spatial pattern in Jiangchuan District in 2025 were verified. According to the distribution of major land use types in different sensitive areas in 2025 and the land use status in 2016, the spatial pattern of land use in Scenario 2 was better than natural development scenarios and the status of land use in 2016. The research results showed that the land ecological optimization scenario was more reasonable, which not only could reduce the area of cultivated land, but also consider the needs of ecological protection and urban development. [ABSTRACT FROM AUTHOR]

Slope farmland is an important part of cultivated land resources in hilly areas of China. Identifying the spatio-temporal distribution and evolution characteristics of slope farmland resources is of great significance for rational planning and utilization of slope farmland resources and water and soil ecological environment construction. In this paper, using the land use data for 7 time points from 1980 to 2015, based on GIS spatial analysis technology, dynamic degree model, kemel density estimation and landscape pattern index model, the spatio-temporal distribution pattern and evolution law of slope farmland in Yunnan for nearly 35 years were quantitatively analyzed. The results showed that: 1) the area of slope farmland in Yunnan was 472.55×104 hm², accounting for 69.79% of the cultivated land area, and the average slope was 15.62°. The relationship between the area ratio of slope farmland in different agricultural divisions was: Southwestern Yunnan>Northeastern Yunnan>Northwestern Yunnan>Southern fringe>Western Yunnan> Southeastern Yunnan>Central Yunnan, and the average slope size relationship was: Northwestern Yunnan>Southwestern Yunnan>Northeastern Yunnan>Western Yunnan> Southern fringe >Southeastern Yunnan > Central Yunnan. 2) In the past 35 years, significant dynamic transfers had occurred in slope farmland, forest land, grassland and paddy fields, but the process of transfer in and out was generally balanced, and the area of slope farmland has a slight increase trend during the process of land use transfer. 3) The slope of most slope farmland was more than 8°, and the proportion of slope farmland with slope >15° was 78.54%. The area of slope farmland with different slopes in the past 35 years had a dynamic process. It showed an increasing trend for the slope farmland area with slope <15°, while decreasing trend for the slope farmland area with slope >15°. The area of slope farmland with different slopes has the dynamic process of “decreased→increased→decreased” or “decreased→increased→ decreased→increased”, and the fluctuation degree of >25° slope farmland was the largest. 4) With the evolution of spatio-temporal distribution of slope farmland in the past 35 years, the distribution characteristics of kemel density value in slope farmland have changed, but the change range was small. The distribution of slope farmland in most areas was in low-density value, and the area of high-density value was the smallest. Slope farmland distribution clusters were represented by four significant distribution zones: the Lincang distribution zone, the Lincang-Xishuangbanna distribution zone, the Pu’er distribution zone and the Zhaotong distribution zone. 5) Among the eight types of land use, the landscape dominance of slope farmland was in the middle position, and the fragmentation characteristics of slope farmland were the most significant among all land use types. In the past 35 years, the degree of fragmentation of slope farmland landscape has decreased, and the degree of contiguous use of slope farmland has been strengthened. The research results can provide theoretical support for the rational planning and utilization of sloping farmland and soil and water ecological environment protection in Yunnan. [ABSTRACT FROM AUTHOR]

Slope farmland is an important part of cultivated land resources in hilly areas of China. Identifying the spatio-temporal distribution and evolution characteristics of slope farmland resources is of great significance for rational planning and utilization of slope farmland resources and water and soil ecological environment construction. In this paper, using the land use data for 7 time points from 1980 to 2015, based on GIS spatial analysis technology, dynamic degree model, kemel density estimation and landscape pattern index model, the spatio-temporal distribution pattern and evolution law of slope farmland in Yunnan for nearly 35 years were quantitatively analyzed. The results showed that: 1) the area of slope farmland in Yunnan was 472.55×104 hm2, accounting for 69.79% of the cultivated land area, and the average slope was 15.62°. The relationship between the area ratio of slope farmland in different agricultural divisions was: Southwestern Yunnan>Northeastern Yunnan>Northwestern Yunnan>Southern fringe>Western Yunnan> Southeastern Yunnan>Central Yunnan, and the average slope size relationship was: Northwestern Yunnan>Southwestern Yunnan>Northeastern Yunnan>Western Yunnan> Southern fringe >Southeastern Yunnan > Central Yunnan. 2) In the past 35 years, significant dynamic transfers had occurred in slope farmland, forest land, grassland and paddy fields, but the process of transfer in and out was generally balanced, and the area of slope farmland has a slight increase trend during the process of land use transfer. 3) The slope of most slope farmland was more than 8°, and the proportion of slope farmland with slope >15° was 78.54%. The area of slope farmland with different slopes in the past 35 years had a dynamic process. It showed an increasing trend for the slope farmland area with slope <15°, while decreasing trend for the slope farmland area with slope >15°. The area of slope farmland with different slopes has the dynamic process of “decreased→increased→decreased” or “decreased→increased→ decreased→increased”, and the fluctuation degree of >25° slope farmland was the largest. 4) With the evolution of spatio-temporal distribution of slope farmland in the past 35 years, the distribution characteristics of kemel density value in slope farmland have changed, but the change range was small. The distribution of slope farmland in most areas was in low-density value, and the area of high-density value was the smallest. Slope farmland distribution clusters were represented by four significant distribution zones: the Lincang distribution zone, the Lincang-Xishuangbanna distribution zone, the Pu’er distribution zone and the Zhaotong distribution zone. 5) Among the eight types of land use, the landscape dominance of slope farmland was in the middle position, and the fragmentation characteristics of slope farmland were the most significant among all land use types. In the past 35 years, the degree of fragmentation of slope farmland landscape has decreased, and the degree of contiguous use of slope farmland has been strengthened. The research results can provide theoretical support for the rational planning and utilization of sloping farmland and soil and water ecological environment protection in Yunnan. [ABSTRACT FROM AUTHOR]