Impact Of Land Use Change On Carbon Effect In Damming River Basin Of Karst Plateau

As technology continues to improve and urbanisation continues,mankind’s demand for fossil fuels has risen,leading to the emission of large amounts of greenhouse gases into the atmosphere,causing a series of ecological problems such as climate warming and rising sea levels.At the75th General Debate of the United Nations General Assembly,China proposed for the first time the goal of achieving carbon peaking by 2030and carbon neutrality by 2060.Land use/cover type change is second only to fossil energy combustion in terms of carbon emissions,and it is important to understand the effect of land use/cover type change on carbon emissions in order to achieve peak carbon and carbon neutrality.This paper takes the Pingzhai reservoir watershed as the study area,and uses a supervised classification method to interpret ALOS satellite images,GF-1and GF-2 satellite images for 2010,2015 and 2020,obtain land use/cover data for 2010-2020 for the Pingzhai reservoir watershed,combine the carbon emission factors and energy consumption data for each land use/cover type The net carbon emissions of the Pingzhai reservoir watershed from 2010 to 2020 were calculated.Finally,the main factors affecting carbon emissions in the Pingzhai reservoir basin are analyzed using geographic detectors,and corresponding countermeasures to reduce carbon emissions are proposed,with a view to providing reference for decision-making and theoretical support for achieving low-carbon and high-quality development in the Pingzhai reservoir basin.The main conclusions are as follows:(1)During the study period,land use/cover changes in the Pingzhai reservoir Watershed are characterized by four increases and two decreases,with a large decrease in arable land,with a 6093.4 hm~2 decrease in 2020compared to 2010,a continuous decrease in unused area,a relatively stable but generally increasing trend in forest land,and a steady increase in built-up land area.The area of construction land has been increasing,with the area of construction land increasing by nearly 1.67 times in ten years,the area of grassland experiencing changes of first increasing and then decreasing,but with an overall increasing trend,and the area of water area experiencing changes of first being more stable and then rapidly increasing,with the area of water increasing by 5.88 times compared to 2010.(2)With the continuous urbanisation and industrialisation,the net carbon emissions of the Pingzhai Reservoir Watershed have increased very significantly,from 121558.95 tonnes in 2010 to 2004077.90 tonnes in 2020,an increase of nearly 1.65 times.between 2010 and 2015,the Pingzhai Reservoir Watershed was in a phase of rapid development,with net carbon emissions increasing by 45917.12 tonnes with an average annual increase of 9183.42 tonnes;from 2015 to 2020 net carbon emissions increased by32971.83 tonnes,with an average annual increase of 6,597.37 tonnes of net carbon emissions,a decrease compared to 2010-2015.(3)There are large differences in carbon emissions from various types of land use/cover in the Pingzhai Reservoir watershed.Cultivated land and construction land are the two major sources of carbon in the Pingzhai Reservoir watershed,with carbon emissions from construction land accounting for more than 87%of the total carbon emissions,with carbon emissions increasing from 121,558.95 tonnes in 2010 to2004,077.90 tonnes in 2020,and the trend of carbon emissions from construction land is basically consistent with the change in net carbon emissions,indicating that carbon emissions from construction land have a crucial influence on the total carbon emissions in the Pingzhai Reservoir watershed.emissions in the Pingzhai Reservoir watershed.Although carbon sequestration from woodlands,grasslands and watersheds is generally on the increase,the carbon sink effect is not obvious compared to carbon emissions from cultivated land and construction land;carbon sequestration from unused land is small and on a decreasing trend.(4)Land use structure,industrial structure and energy structure are the main influencing factors of carbon emissions in Pingzhai reservoir basin,with risk factor detection q-values of 0.549,0.583 and 0.461,respectively.