基于CA-Markov的土壤有机碳储量空间格局重建研究——以泛长三角地区为例

Spatial Pattern Reconstruction of Soil Organic Carbon Storage Based on CA-Markov——A Case Study in Pan-Yangtze River Delta

选取了泛长三角地区的高程、坡度、坡向、GDP、人口、温度、降雨量、河流距离、城市距离和海岸线距离10个驱动因子作为土地利用变化驱动力,基于这些驱动力因子,利用Logistic分析制作土地适宜性图集;运用CA-Markov模型模拟得到2000年、1995年、1990年、1985年、1980年、1975年6期的土地利用格局;采用全数检测的方法对模拟结果进行精度检验;在此基础上,得到了泛长三角地区土壤有机碳储量,进而重建历史土壤有机碳储量空间格局。研究结果表明:(1)模型模拟精度为88.73%,说明CA-Markov模型对历史土地利用模拟具有一定可行性;(2)泛长三角地区历史土壤有机碳储量从今往前逐期递增,且明显高于2010年土壤有机碳储量水平,1995、1990、1985、1980、1975年土壤有机碳储量分别为3.235 1、3.241 9、3.247 6、3.251 8、3.255 3;(3)各时期泛长三角地区土壤有机碳储量空间格局呈现出南高北低的趋势,土地利用类型与土壤有机碳储量密切相关,城市建成区有机碳储量低于其他区域,土壤有机碳储量增加区域主要出现在其高值区周边;(4)耕地与林地面积的增加,建设用地面积减少,导致了1995~1975年间有机碳储量的增加。基于CA-Markov模型可以有效重建历史土壤有机碳储量的空间格局。

According to the national and international theories and the actual situation of Pan-Yangtze River Delta,the authors select ten driving factors as the leading forces of land use change,such as elevation,slope aspect,slope grade,GDP,population,temperature,rainfall,river distance,urban distance and coastline distance. Firstly,the study accomplish the maps of land suitability by Logistic analysis based on above factors.With the application of CA-Markov model,the land use pattern of six periods in 2000,1995,1990,1985,1980 and 1975 is simulated. Secondly,the paper uses the method of full number detection to test the accuracy test for simulation results. Lastly,the paper calculate the soil organic carbon storage in Pan-Yangtze River Delta.On the basis,we reconstruct the historical spatial pattern of soil organic carbon storage in research area. There are several important findings：（1）CA-Markov model is feasible for historical land use simulation owing to the model simulation accuracy is 88. 73%.（2）The history of soil organic carbon storage in the Pan-Yangtze River Delta was significantly higher than 2010,and it was increasing progressively from now to historical periods; soil organic carbon reserves were as 3. 2351 Pg,3. 2419. Pg,3. 2476 Pg,3. 2518 Pg and 3. 2553 Pg in 1995,1990,1985,1980 and 1975,respectively.（3）The spatial pattern of soil organic carbon storage in the Yangtze River Delta was high in the north,low in the south,the land use types were closely related to the soil organic carbon reserves,and the organic carbon reserves in urban built-up areas were lower than those in other areas,the increase of soil organic carbon storage mainly appeared in its high value area,land use types were closely related to the soil organic carbon reserves,and the organic carbon reserves in urban built-up areas were lower than those in other areas,the increase of soil organic carbon storage mainly appeared in its high value area.（4） The increase of cultivated land and forestland area and the decrease of construction land area led to the increase of organic carbon storage from 1995 to 1975. The spatial pattern of soil organic carbon storage in historical period can be effectively reconstructed based on the CA-Markov model.