Southwest Guangxi Karst Beibu Gulf Region Spatial-temporal Change Of Land Use Carbon Storage And Its Simulation Prediction

Under the world situation of striving to reach the peak of carbon dioxide emissions by 2030 and achieve carbon neutrality by 2060,China will increase its independent contribution and adopt more powerful policies and measures.Achieving carbon peaking and carbon neutrality is an extensive and profound economic and social systematic change,as well as a major challenge for China’s economic and social development.Among them,optimizing the land use structure can guide the orderly and reasonable expansion of land,improve the efficiency of land use and reduce emissions reasonably while maintaining rapid economic development,achieving carbon peak and carbon neutrality on time and in quantity.Based on the land use data of 2000,2010 and 2020,combined with the data of elevation,traffic network,GDP distribution,population density distribution and other data,the land use dynamic degree and transfer matrix were used to analyze and study the spatial and temporal changes of land in the region in the past 20 years and build a PLUS model.Simulate and predict three different land use development scenarios in the research area in 2040.Then,in the In VEST model,the existing land use changes and the land use changes from the PLUS model under three future development scenarios are input into the carbon storage module,in order to obtain the quantity and distribution trend of carbon reserves in the study area under the three historical and future development scenarios.Based on the current development status and location conditions of the Karst Beibu Gulf region in southwestern Guangxi,optimize the regulation of land use in the research area,and delineate the growth boundary of land use types in the Karst Beibu Gulf region in southwestern Guangxi,providing reference for land planning and management work.The conclusion is as follows:(1)From 2000 to 2020,the cultivated land and grassland areas in the karst Beibu Gulf region of southwestern Guangxi showed a decreasing trend,while the water area showed a trend of first increasing and then decreasing;The forest land shows a trend of decreasing first and then increasing;The proportion of unused land is relatively small,showing a decrease followed by an increase.The conversion of farmland,grass,and forest land to construction land and water has become the main trend.(2)From 2000 to 2020,the carbon storage in the karst Beibu Gulf region of southwest Guangxi showed an increasing trend after decreasing.The main reason for the decline of carbon storage in the karst Beibu Gulf region of southwest Guangxi was the conversion of cultivated land and forest land to construction land.(3)In 2040,based on the natural growth scenario,the land use in the study area continued the trend from 2000 to 2020,with a decrease in arable land,grassland,and unused land,a continuous increase in construction land,forest land,and water areas,and no protection for arable land and ecological land.Restricting the conversion of research areas to construction land and increasing ecological land can achieve a certain degree of control over construction land under ecological protection scenarios;In the context of economic development,as the primary demand for urban development and the expansion of construction land,forest land has sharply decreased and construction land continues to expand.(4)In 2040,under three different development scenarios,carbon storage in the study area showed a significant downward trend except for ecological protection scenarios.Therefore,based on the reference of relevant materials such as the "Overall Land Use Plan(2006-2020)",combined with measures for farmland protection and ecological protection,and based on the concept of ecological civilization and low-carbon economic development,it is necessary to not only protect farmland but also increase efforts in ecological environment protection;We need to restrict the conversion of arable land and ecological land to construction land,effectively restrict the expansion of construction land,increase regional carbon reserves,and achieve low-carbon development goals.(5)The karst Beibu Gulf area in southwest Guangxi is a typical transitional space between mountains,rivers and seas.Its terrain decreases from northwest to southeast,and the new land use types also expand from northwest to southeast.The change of carbon storage also shows a trend of increasing from northwest to southeast.