Research On Spatio-Temporal Discretization Methods Of Land Use Sequence Data Under The Integrated Assessment Framework Of GCAM

The Intergovernmental Panel on Climate Change(IPCC)report describes the possibility that global warming is attributable to human activity increased from "more than 66%" in 2001 to "more than 95%" in 2013.Therefore,it is important to study the interaction between human activities and global climate change.The Global Change Assessment Model(GCAM)is a dynamic regression model based on global scale local equilibrium,which reflects the global impact of human activities by simulating greenhouse gas changes,energy emissions,and land use change.Land use change data is an important input condition for global climate model simulation,but GCAM output value is based on global administrative divisions and agro-ecological zoning land use change statistics,in time and space is difficult to use directly.In this paper,we focus on the spatial and temporal discretization of land use sequence data under the framework of global comprehensive assessment.The main research contents include the following aspects:1.Introduction to GCAM models and data type consolidation.This paper introduces the basic principles and the basic data sources of GCAM and GLM.Based on the similarity between GCAM and GLM,the merge method of GCAM landforms based on GLM model are designed,the GCAM terrain type was combined.2.GCAM data time discretization experiment and analysis.The characteristics of stationary,regularity and periodic time series interpolation are analyzed.Combined with the characteristics of GCAM data,the nearest distance interpolation method in the stationary time series interpolation method and the linear interpolation,cube interpolation and Spline interpolation is selected,the GCAM data discretization process is designed to carry out the annual output of GCAM statistical data,and the results of several interpolation methods are evaluated with accuracy,and the minimum value is chosen as the optimal output.3.GCAM data space discretization experiment and analysis.According to the partition data of 32 Political Economy and 18 agricultural ecological zoning provided by GCAM team,the spatial mapping relationship of grid size of 0.5°×0.5° was established with 32×18 partition.At the same time,based on GLM grid ratio and GCAM model global grid area data at the scale of 0.5 °×0.5°,to achieve the sum of GLM area in the global AEZ.At the same time,the GCAM population,GCAM area and the area of the cell grid as a constraint,to Adjust the grid area and through iterative methods.So the GCAM statistical data in the space of the discretization,and finally the accuracy of spatial discretization is evaluated.The experimental results show that the proposed method can be used to discretize the temporal and spatial discretization of GCAM statistics at global scales and obtain discretization of land use change grid data.The results of this paper can provide a reference for the data of land use grid data input in global climate model simulation,and provide basic data for global land use change deduction.