Simulation And Analysis Of 1km Land Use And Land Cover Change In China Under Full SSP-RCP Scenarios Based On GCAM-FLUS Models

Land use and land cover change(LUCC)plays an important role in the interaction between human and earth systems.In the past few decades,China has experienced great changes in land use and land cover.It is of great significance to simulate the future LUCC distribution in China with high spatial resolution,which can contribute to analyzing the local spatial details of LUCC and to further understanding the local interaction between human activities and ecological processes in the future.In addition,comprehensively evaluating LUCC under all the possible combinations of the Shared Socio-economic Paths(SSP)and Representative Concentration Pathways(RCP)with high spatial resolution can help to analyze the future LUCC spatial distribution in China under different socio-economic assumptions and radiation forcing targets.This can further provide support for the research on the impact of future climate change on a finer spatial scale,and also provide reference and basis to formulate mitigation and adaptation policies in China.However,the existing researches on LUCC in China often ignore some important RCP scenarios,and there is a lack of complete analysis and research on the SSP baseline scenarios and full SSP-RCP combinations.These RCP scenarios such as RCP1.9,RCP3.4 and RCP6.0,which are often ignored in the existing research,are also of great significance.For example,studying RCP1.9 is very important for achieving the goal of keeping the increase of global mean temperature below 1.5°C.In order to better understand the potential impacts of different emission and socioeconomic conditions on the environment,it is necessary to simulate and analyze the high spatial resolution LUCC in China under the complete SSP-RCP scenarios.To addressed the issues of the lack of high-resolution LUCC data in China under full SSP-RCP scenarios,we first generated 1 km LUCC demands using the GCAM model,under 24 different SSP-RCP scenarios including 5 baseline scenarios which do not include climate mitigation policy,and 19 combined scenarios which integrate with mitigation goals in a 10-year interval.The demands of LUCC in a watershed scale under the full scenarios provide a foundation for high spatial resolution LUCC simulations,and it is also of great significance for comprehensive understanding and analyzing the LUCC uncertainty under different climate change and socio-economic conditions.Further,after modifying the demand of urban land,the future land use simulation model(FLUS)was used to generate the high spatial resolution(1km)LUCC data in China with a 10-year interval.The evaluation based on satellite remote sensing data(CCI-LC)demonstrates that the produced 1 km LUCC data is of high quality.The high spatial resolution LUCC data could provide support for the understanding of the future LUCC spatial details in China,and lay a foundation for the research on ecosystem service and flood risk on a fine spatial scale.Finally,further analysis on the spatial and temporal change patterns of LUCC in China under different SSP-RCP scenarios in 2010-2100 shows that there will be a large LUCC change in China.Compared to the SSP baseline scenarios,cultivated land and forest will increase in a larger area,while shrub and grassland will show substantial reduction,under the SSP scenarios in combination with RCP.Under the same RCP3.4scenario,there will be more increase of cultivated land in southeast China under SSP3 scenario,while there will be more increase of forest in eastern China under SSP1 scenario and more grassland decrease from southwest to northeast China.Under the same SSP5 scenario,there will be more increase of forest in southeast China under RCP6.0 scenario and less cultivated land in southeast China under RCP3.4 scenario.In addition,the generated 1 km LUCC data were compared with the widely-used LUH2 data.The results show that the simulation data of LUCC with high spatial resolution are consistent with LUH2.These provide important basis for formulating policies and regulations in China to deal with the issues of future climate and environmental change.