Rocky desertification occurs in many karst terrains of the world and poses major challenges for regional sustainable development. Remotely sensed data can provide important information on rocky ...desertification. In this study, three common open-access satellite image datasets (Sentinel-2B, Landsat-8, and Gaofen-6) were used for extracting information on rocky desertification in a typical karst region (Guangnan County, Yunnan) of southwest China, using three machine-learning algorithms implemented in the Python programming language: random forest (RF), bagged decision tree (BDT), and extremely randomized trees (ERT). Comparative analyses of the three data sources and three algorithms show that: (1) The Sentinel-2B image has the best capability for extracting rocky desertification information, with an overall accuracy (OA) of 85.21% using the ERT method. This can be attributed to the higher spatial resolution of the Sentinel-2B image than that of Landsat-8 and Gaofen-6 images and Gaofen-6’s lack of the shortwave infrared (SWIR) bands suitable for mapping carbonate rocks. (2) The ERT method has the best classification results of rocky desertification. Compared with the RF and BDT methods, the ERT method has stronger randomness in modeling and can effectively identify important feature factors for extracting information on rocky desertification. (3) The combination of the Sentinel-2B images and the ERT method provides an effective, efficient, and free approach to information extraction for mapping rocky desertification. The study can provide a useful reference for effective mapping of rocky desertification in similar karst environments of the world, in terms of both satellite image sources and classification algorithms. It also provides important information on the total area and spatial distribution of different levels of rocky desertification in the study area to support decision making by local governments for sustainable development.
•The RF–AFs model was constructed to precisely extract economic forests.•The SCs and VIs effectively improved the extraction accuracy of economic forests.•TEM, EL, PRE, PSRI, EVI, and TSAVI were key ...factors in extracting economic forests.•It provides factors selection and method reference for the extraction of forests.
Forests are generally extracted from remotely sensed images based on the spectral features, ignoring other important auxiliary information, and the techniques of precise extraction need to be further improved. By using the Sentinel–2 image and auxiliary factors (AFs) including site conditions (SCs) and vegetation indices (VIs), the random forest model with AFs (RF–AFs) was adopted for the extraction of the economic forests in Lancang County, which is a mountainous area with rich biodiversity and is witnessing rapid development of economic forests in Yunnan province of China. The results obtained using the RF–AFs model were compared with those obtained using the random forest model without AFs (RF). The results were as follows: (1) The kappa coefficient for extracting the first–level land use obtained using the RF model was 0.9531. Lancang County is dominated by forests, accounting for 73.76% of the total area. (2) After parameter optimization, the RF–AFs model yielded the highest accuracy in the extraction of the second–level forests, with a kappa coefficient value of 0.9493, which was 14.69% higher than that of the RF model. Thus, the RF–AFs model is more suitable for the precise extraction of economic forests. (3) The evaluation results of the factors’ importance of the RF–AFs model showed that the cumulative importance values of SCs such as temperature (TEM), elevation (EL), precipitation (PRE) and VIs such as plant senescence reflectance index (PSRI), enhanced vegetation index (EVI), transformed soil–adjusted vegetation index (TSAVI) was 76.09%, indicating that they were the main factors for the extraction of economic forests. (4) Economic forests are dominated by Simao pines in Lancang County, which are mainly distributed in the central, southwestern and northern regions, accounting for 31.37% of forests area. The proportion of tea plantations, eucalyptus, and rubber trees is 9.05%, 6.71%, and 3.05% of forests area, respectively. The RF–AFs model is conducive for precisely extracting the economic forests and is thus of great significance in studying the ecological and environmental effects of economic forests, performing forestry management, and maintaining regional ecological security.
Improving the supply-demand balance of ecosystem services (SDBES) from the perspective of land use is essential for managing regional ecosystem and realizing sustainable development. By combining ...land use with the supply and demand of ecosystem services (SDES), a technical framework for defining land use threshold and optimizing its structure to improve the SDBES state was constructed and applied to a practical case. The spatial pattern of supply and demand of each ES in Lancang county was distinctly heterogeneous, with significant differences in SDES across different land use types. Strong spatial heterogeneity existed in the ESDR of each ES at the grid scale, and the areas of deficit were ranked as carbon sequestration > water conservation > habitat quality > food production. The structure of dry land, paddy field, tea, evergreen broad-leaved forest, grassland, urban construction land, and industrial and mining construction land were the focus of land use optimization. Based on the land use area thresholds under the SDBES, the optimal land use structure for maximizing comprehensive benefits contributed to a balanced relationship between SDES and promoted sustainable regional development. The study provides a new perspective and method for improving the SDBES state, alleviating land conflicts, and managing ecological environment.
Rocky desertification in ecologically-fragile karst areas limit regional socio-economic development in the face of significant human–earth conflict. Coordination of ecological restoration and ...agricultural development is critical for sustainable development in karst areas. From the perspective of the human–earth areal system, the framework of sustainable agricultural development was proposed in typically karst areas. We integrated principles of ecological vulnerability, resource and environmental carrying capacity, agricultural foundation, suitability of agricultural land, and the farmers’ willingness. In this study, we found the ecological vulnerability of Guangnan County was slight, but the proportion of moderate and severe vulnerability areas was high, with significant differences between the two sides of the line “Zhe (Zhetu)-Lian (Liancheng)-Yang (Yang Liu-jing)-Ban (Banbang)”. Then, we divided Guangnan County into three ecologically vulnerable zones. Following that, we proposed sustainable agricultural models for various zones. In slightly to mildly vulnerable zones, we propose constructing economic–ecological agricultural models, including woody oil, plateau characteristic fruiting forest, ecological tea plantations, suburban agriculture, and cultural–ecological tourism. In moderately to severely vulnerable zones, we recommend developing a stereoscopic agriculture model that combines planting and breeding, vegetation restoration, and herbivorous animal husbandry. In extremely vulnerable zones, we suggest constructing an ecologically natural restoration model and an agricultural ecological–tourism model. Our research provides references for ecological restoration, agricultural development, poverty alleviation consolidation, and rural revitalization in ecologically vulnerable karst areas of southeast Yunnan and similar regions.
The process of eliminating absolute poverty is inevitable for China’s social and economic transformation. However, there are currently few studies on the relationship between land use transformation ...(LUT) and rural income under different stages of poverty governance. This study, therefore, uses spatial autocorrelation analysis and a multiscale geographic weighted regression (MGWR) model to explore the mechanisms of LUT on rural income and its spatiotemporal heterogeneity in Yunnan Province during the comprehensive poverty alleviation (CPA) period and the targeted poverty alleviation (TPA) period at the county scale. The results demonstrate that: (1) the numbers of both low-income and high-income counties continued to decrease, while the number of middle-high-income counties increased, and rural income demonstrated a positive spatial correlation. (2) Most of the variables in the dominant recessive increased in the CPA and decreased in the TPA period. As for recessive morphology, the ecological function variables decreased first and then increased. (3) The driving force of dominant morphology is strong and sustained, and the driving force of recessive morphology is gradually enhanced. The results are vital for consolidating the results of poverty eradication and bridging rural revitalization. They may also provide useful references for sustainable land use and effective poverty alleviation in other developing countries.
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•Propose optimization method for territorial spatial functional areas under double evaluations.•Construct sustainable development patterns of territorial space in karst areas to ...improve ecological quality.•Analyze different functions of territorial spatial functional areas for environmental governance.•Discuss control approaches for territorial space in karst areas.
Optimizing and controlling territorial space have become national strategic issues for China. However, urban-agricultural-ecological functions have serious conflicts in karst areas, causing differences in regional development and leading to severe problems related to the ecological environment and poverty. In this study, based on evaluations of urban-agricultural-ecological suitability and resource and environment carrying capacity, we explored an optimization method for territorial spatial functional areas and amendment rules for unsuitable areas in karst areas, identified different territorial spatial function areas, and proposed territorial spatial control approaches taking the functional area control and rock desertification space control as cores. On the one hand, the results showed that the optimization of the territorial space was divided into three single functional areas (i.e., urban space, agricultural space, and ecological space) and four multifunctional areas (i.e., urban-agricultural space, urban-ecological space, agricultural-ecological space, and urban-agricultural-ecological space). Among those different functional areas, the largest was ecological space, which was primarily distributed in the northwest, southwest, and northeast with good ecological environments and the south and southeast with severe rocky desertification. The second was agricultural-ecological space, which was primarily distributed in the north with better ecology and the south and southeast with severe rocky desertification. This region was the most important multifunctional area of the karst areas. The smallest type was urban-ecological space, which was primarily distributed in the central and northeastern regions with higher ecological and residential values. On the other hand, in terms of territorial spatial control, the region formed control patterns of functional areas of the “trinity”, which centered on classified protection, comprehensive improvement, and cluster development. Additionally, from the three aspects of control of deteriorating rocky desertification area, control of severe rocky desertification area, and control of corresponding policies, we explored new approaches and methods for the development and protection of rocky desertification space. The results of this research provide references for territorial spatial planning and management in karst areas.
Land degradation, water shortages, and low utilization of water and land resources (WLR) in the karst mountainous region of Southwest China have become key factors restricting socioeconomic ...development. Therefore, it is necessary for rural revitalization to study the zoning regulation and development model of WLR in the karst mountainous region from the perspective of WLR coupling coordination and resource and environmental carrying capacity (RECC). The coupling coordination degree model and the fuzzy comprehensive evaluation model were used to evaluate the coupling coordination degree of WLR and the RECC, respectively. The framework for WLR coupling and regulation was proposed, and the corresponding zoning and development model for WLR was proposed based on the different spatial combinations of coupling coordination degree and RECC level. The overall level of WLR coupling and coordination was good, with high coordination as the main area, medium coordination as the second area, and low coordination as the smallest area. The coupling coordination degree of WLR was consistent with the spatial distribution of rocky land desertification. The higher the degree of rocky desertification is, the lower the degree of coupling coordination, indicating that land degradation has a significant impact on the coupling coordination level of WLR. The RECC was mainly a medium carrying capacity, followed by a high carrying capacity, and the low-carrying capacity area was the smallest. High carrying capacities were mainly distributed in areas with developed socioeconomics, good environments and rich resources; medium carrying capacities were widely distributed in areas with common resources, environments and socioeconomic conditions; and low carrying capacities were mainly distributed in areas with poverty, obvious rocky desertification and fragile ecological environments in the northwest and northeast. Six WLR regulation zones were designated, and corresponding development models were proposed from the perspectives of industrial development, improvement of WLR utilization efficiency, and protection of the ecological environment. The research results have important reference value for the formulation of rural revitalization strategies and socioeconomic development in karst mountainous region, especially for research on the methods and approaches of WLR regulation and rural revitalization in China and even in global karst poverty-stricken mountainous region.
•A framework for the coupling and regulation of WLR was proposed.•Zoning regulation and development model for WLR was proposed to promote rural revitalization in karst mountainous region.•The evaluation index and classification systems of WLR coupling were established in karst mountainous region.•The evaluation index and classification systems of the RECC were established in karst mountainous region.•All evaluation and analysis results are based on spatial grid scale.
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