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[学术文献 ] Monitoring periodically national land use changes and analyzing their spatiotemporal patterns in China during 2015–2020 进入全文
Journal of Geographical Sciences
High-resolution mapping and monitoring of national land use/cover changes contribute significantly to the knowledge of the interaction between human activities and environmental changes. China’s Land Use/cover Dataset (CLUD) for 2020 and its dynamic changes in 2015–2020 were developed to extend the CLUD to over 30 years (i.e., the 1980s to 2020 at 5-year intervals) by integrating remote sensing big data and knowledge-based human-computer interaction interpretation methods. This integrating method for CLUD 2020 improved the efficiency of national land use/cover mapping and the accuracy of land use pattern change detection compared to earlier CLUD products, with an overall accuracy of 95%. The intensity of land use change decreased across China in 2015–2020 compared to 2010–2015, although both characteristics of its spatial changes were similar. The cropland area continued to shrink at national scale in 2015–2020, with two regional hotspots including the widespread conversions from dry land into paddy land in Northeast China and the coexistence of widespread land cultivation and cropland abandonment in Xinjiang of Northwest China. Built-up land area continued to expand in China, showing consistency between 2015–2020 and 2010–2015, in which hotspots transited from the surroundings of coastal megacities to the city surroundings of the central and western zones. For natural land, although the woodland and grassland decreased in 2015–2020, its magnitude expanded compared to 2010–2015. In comparison, the water body area in Qinghai-Tibet Plateau increased significantly under the continuous impact of climate change. These characteristics of land use change were closely related to the development strategy of the top-level design of the 13th Five-Year Plan (2016–2020) (e.g., ecological civilization construction and high-quality development).
[学术文献 ] Spatiotemporal variation of forest land and its driving factors in the agropastoral ecotone of northern China 进入全文
Journal of Arid Land
As an important natural resource, forest land plays a key role in the maintenance of ecological security. However, variations of forest land in the agropastoral ecotone of northern China (AENC) have attracted little attention. Taking the AENC as an example and based on remote-sensing images from 2000, 2010 to 2020, we explored the spatiotemporal variation of forest land and its driving factors using the land-use transfer matrix, spatial autocorrelation analysis and spatial error model. The results showed that from 2000 to 2020, the total area of forest land in the AENC increased from 75,547.52 to 77,359.96 km2 and the changes were dominated by the transformations among forest land, grassland and cropland, which occurred mainly in areas with the elevation of 500–2000 m and slope of 15°–25°. There was obvious spatial agglomeration of forest land in the AENC from 2000 to 2020, with hot spots of forest land gathered in the southern marginal areas of the Yanshan Mountains and the low mountainous and hilly areas of the Loess Plateau. The sub-hot spots around hot spots moved southward, the sub-cold spots spread to the surrounding areas and the cold spots disappeared. The spatiotemporal variation of forest land resulted from the interactions of natural environment, socioeconomic and policy factors from 2000 to 2020. The variables of average annual precipitation, slope, terrain relief, ecological conversion program and afforestation policy for barren mountains affected the spatial pattern of forest land positively, while those of annual average temperature, slope and road network density influenced it negatively.
[学术文献 ] Research on the evolution and the driving forces of land use classification for production, living, and ecological space in China’s Qilian Mountains Nature Reserve from 2000 to 2020 进入全文
Environmental Science and Pollution Research
With the rapid development of the economy, problems such as resource depletion, environmental degradation, and increasingly strained human-land relations have become increasingly prominent. The rational layout of the production, living, and ecological spaces is the basis for solving the contradiction between economic development and environmental protection. This paper analyzed the spatial distribution pattern and evolution characteristics of the Qilian Mountains Nature Reserve based on the theory of production, living, and ecological space. The results show that the production and living function indexes are rising. The most advantaged areas are in the northern part of the research area, where the terrain is flat and transportation is convenient. The ecological function index rises, falls, then rises again. The high-value area is located in the south of the study area, and its ecological function is intact. The study area is dominated by ecological space. During the study period, the area of production space increased by 858.5 km2 and the living space area increased by 341.12 km2. The intensification of human activities has separated the continuity of ecological space. The area of ecological space has decreased by 233.68 km2. Among geographical factors, altitude has a significant impact on the evolution of living space. Population density is the main socioeconomic factor in changing the areas of production space and ecological space. This study is expected to provide a reference basis for land use planning and sustainable development of resources and environment in nature reserves.
[科技报告 ] Advancing NASA’s Climate Strategy 进入全文
NASA
NASA uses the vantage point of space and its expertise in aeronautics to innovate, inform, and inspire for the benefit of all. NASA is a leader and trusted partner in providing climate and Earth system observations, modeling, research, applications, technology, and actionable information to scientists, decisionmakers, and the public. NASA’s free and open data powers research across the federal government, academia, and the private sector. The agency also works alongside international, federal, state, and local partners to advance understanding of and response to our changing planet. NASA’s climate portfolio is varied, extensive, and covers multiple missions and focus areas. To help assess and advance NASA’s climate strategy, a Climate Strategy Working Group (CSWG) was created and now falls under the guidance of the Office of the Chief Scientist. The CSWG found: • With more than two dozen satellites and instruments observing key climate indicators, NASA, in coordination with its domestic and international partners, remains the world’s leading agency for observing and understanding changes to the Earth system; • NASA has decades of experience developing technologies that contribute to reducing emissions and enhancing sustainability; and • NASA delivers climate-related information and resources to a wide range of government and university partners as well as the public.
[前沿资讯 ] Flooded Rice Fields in Louisiana 进入全文
NASA
As the Mississippi River meandered through several southern states over tens of thousands of years, it left a valuable layer of fertile soil in its wake. This low-lying floodplain and the flat coastal prairies of Louisiana and Texas are now home to most of the rice farms in the United States. Louisiana is the nation’s third-largest producer of the crop, after Arkansas and California. The state’s warm climate, abundant water, and water-retaining clay soils are well-suited for growing rice. Jefferson Davis and Acadia parishes in southwest Louisiana produce the most rice in the state, according to United States Department of Agriculture (USDA).
[学术文献 ] Land Degradation Neutrality for Achieving Climate Resilience in Agriculture 进入全文
Towards Sustainable Use of Rangelands in North-West China
Land degradation is predicted to damage more than a quarter of the world’s land surface, resulting in decreased or lost soil performance owing to physical and chemical degradation, as well as falling biological and economic productivity. Land loss and climate variation are two interrelated routes with biophysical and man-made drivers, consequences, and remedies. Land restoration has an influence on agro-ecological systems’ socioeconomic constancy. Changes in the quantity and quality of ecosystem services as a result of climate resilience will have an impact on livelihoods in a variety of businesses. Agriculture adaptation planning should emphasize continuous land restoration, as well as the possibilities that come with restoring degraded land. While some national agricultural adaptation plans recognize the need of soil protection, many still fail to include land restoration as a component of such strategy. Management choices such as changing crop types and animal breeds, as well as adjusting the timing and location of management actions, have been a major emphasis for crop and livestock production systems. In order to achieve land degradation neutrality (LDN), efforts must be made to minimize additional net losses of land-based natural capital as compared to a reference condition, or baseline. Within individual land types, where land type is determined by land potential, planning for neutrality entails counterbalancing predicted losses with steps to obtain corresponding benefits. LDN adoption contributes to SDG 15 and other associated targets, providing possibilities for achieving these objectives in a cost-effective and environmentally sound manner at the same time.
