Study On Optimizing Land Use Structure In The High-efficiency Ecological And Economic Zone Of The Yellow River Delta Under The "Dual Carbon" Goals

In September 2020,China set the ambitious goal of"achieving a carbon peak by2030 and carbon neutrality by 2060"demonstrating the nation’s determination as a responsible global power to proactively combat climate change.The Yellow River Delta,currently the most ecologically preserved delta in China,has established a high-efficiency eco-economic zone that departs from the traditional high-energy-consumption development model,paving the way for a new"eco-efficient"development approach.The burning of fossil fuels is the primary driver of global climate change,while changes in land use patterns also play a significant role in carbon emissions.The interplay between carbon sources and sinks due to land use changes within the study area holds substantial importance for the"low-carbon"development of the high-efficiency eco-economic zone in the Yellow River Delta,ultimately contributing to the achievement of the"dual-carbon"objectives.This study employs visual interpretation of salt fields and aquaculture ponds within the Landsat TM/OLI remote sensing images for the high-efficiency eco-economic zone in the Yellow River Delta.The interpreted land use data is integrated into the Chinese Academy of Sciences’30m land use remote sensing monitoring dataset from 1990 to 2020 using the update function in ArcGIS 10.6,resulting in a new remote sensing land use database tailored for this research area.The study investigates the land use change rate and land use transfer patterns in the research area by employing land use dynamics and land use transfer matrices,respectively.It also calculates the carbon fluxes associated with both retained and transferred land use within the region.Building on the analysis of historical land use changes,the Logistic-CA-Markov model is utilized to forecast land use scenarios and estimate carbon emissions under natural conditions for the"dual-carbon"target years of 2030 and 2060.Moreover,the GeoSOS-FLUS model is applied to optimize land use change simulations and carbon emission estimations in the eco-economic zone.The research findings are as follows:(1)From 1990 to 2020,the overall land use types in the Yellow River Delta high-efficiency eco-economic zone exhibited a"three increases and four decreases"trend.The area of cultivated land,construction land,salt fields,and aquaculture ponds expanded,with construction land and salt fields as well as aquaculture ponds experiencing the most rapid growth.Over a 30-year period,these areas expanded by53.13%and 169.02%,respectively.Conversely,the area of forestland,grassland,water bodies,and unused land contracted,with grassland and unused land witnessing the most significant reductions.By 2020,their areas had shrunk to only 18.78%and16.44%of their respective 1990 levels.(2)The primary direction of land use conversion involves the transformation of cultivated land into construction land,and the transition of other land use types in coastal areas towards salt fields and aquaculture ponds.From 1990 to 2000,the most prominent change was the conversion of unused land into salt fields and aquaculture ponds.Between 2000 and 2010,the transitions among various land use types became more evident,with construction land experiencing the most significant expansion,primarily at the expense of cultivated land.The growth of salt fields and aquaculture ponds was second only to construction land,while grassland and unused land areas saw substantial reductions during this period.From 2010 to 2020,the rate of conversion among different land use types noticeably decelerated,resulting in continuous decreases in cultivated land,forestland,water bodies,and unused land areas,while forestland,construction land,salt fields,and aquaculture ponds experienced increases.(3)During the carbon transfer process,the transformation of various land use types into construction land emerges as the most significant carbon source,followed by conversions towards unused land.The shift of different land use types towards forestland,salt fields,and aquaculture ponds functions as carbon sinks.Given that the expansion rate of salt fields and aquaculture ponds is considerably higher than that of forestland,the carbon sequestration effect resulting from the conversion towards salt fields and aquaculture ponds proves to be the most prominent.(4)The Logistic-CA-Markov land use prediction results indicate that by 2030,compared to 2020,the areas of cultivated land,grassland,water bodies,and unused land will decrease,while forestland,construction land,and salt fields and aquaculture ponds will experience growth.The primary contributor to construction land expansion continues to be cultivated land,while the expansion of salt fields and aquaculture ponds mainly stems from water bodies and construction land.During this stage,carbon emissions from the conversion of cultivated land will decline,and the carbon sequestration capacity of preserved land use types will increase.Between 2030 and2060,the areas of forestland,construction land,and salt fields and aquaculture ponds will expand,while other land use types will diminish.In this phase,the carbon sequestration capacity of preserved land use types will see a significant increase,and carbon emissions from land use conversions will noticeably decrease.(5)Utilizing the GeoSOS-FLUS model for land use structure optimization,compared to the Logistic-CA-Markov model,the simulated cultivated land and forestland in 2030 from the GeoSOS-FLUS model are greater by 40.2 and 1.4 km~2,respectively,while the construction land area is reduced by 41.44 km~2,and the areas of other land use types display no significant differences.By 2060,the GeoSOS-FLUS model simulation results reveal that the areas of cultivated land,water bodies,and unused land are larger by 94.84,2.32 and 14.6km~2,respectively,while the simulated construction land area is smaller by 94.84 km~2.In terms of land use carbon emission estimations,compared to the Logistic-CA-Markov model,the GeoSOS-FLUS model results in lower carbon emissions,with a decrease of 303.3748×10~3t C in 2030 and580.0575×10~3t C in 2060.The land use structure simulated by the GeoSOS-FLUS model surpasses that of the natural development scenario and supports the earlier achievement of the"dual carbon"goals.