基于PLUS-InVEST模型的酒泉市生态系统碳储量时空演变与预测

Spatial-Temporal Evolution and Prediction of Carbon Storage in Jiuquan City Ecosystem Based on PLUS⁃InVEST Model

基于“双碳”战略背景探讨西北干旱区土地利用变化对碳储量的影响及碳储量空间分异驱动因素,对提高区域生态系统碳汇增量和促进区域碳收支平衡具有重要意义.中国西北干旱区为自然生态极端脆弱区,随着新型城镇化快速推进,土地利用变化速率明显加快并对生态系统碳储量及固持能力产生一定影响.运用PLUS-InVEST模型模拟了酒泉市2035年自然发展、集约发展、水资源约束和生态保护情景下碳储量的时空演变特征,并采用参数最优地理探测器模型分析了碳储量空间分异驱动力.结果表明:①1990~2020年酒泉市耕地、水域和建设用地面积呈显著增加趋势,其余土地利用类型面积呈减小趋势.②1990~2020年酒泉市碳储量从7722808.1 t增至7784371 t,草地转换成未利用地是造成区域碳储量损失的主要原因,占损失总量的85%.③2035年4种发展情景的碳储量均为增加趋势,其中生态保护情景增幅最为显著,增量为76989.29 t.④土地利用程度、人口密度、GDP密度和NDVI是酒泉市碳储量空间分异的主要驱动因子,其中土地利用程度解释力最强(q值为0.849),自然与人为因子的交互作用增强了各因子对碳储量空间分异的解释力.研究结果可为酒泉市生态系统综合管理及国土空间优化提供科学基础和决策依据.

Based on the background of carbon peaking and carbon neutrality goal strategies,it is important to explore the impact of land use change on carbon storage and the drivers of spatial variation in carbon storage in the Northwest Arid Zone,which is vital to improve the carbon sink increment of the regional ecosystem and promote the regional carbon breakeven.The arid region of northwest China is an extremely fragile natural ecology,and with the rapid advancement of new urbanization,the rate of land use change has accelerated significantly,which has a certain impact on the carbon storage and fixation capacity of ecosystems.The PLUS-InVEST model was used to simulate the spatial and temporal evolution characteristics of carbon storage under natural development,intensive development,water resource constraint,and ecological protection scenarios in Jiuquan City in 2035,and the parameter optimal geographic detector model was used to analyze the spatial divergence drivers of carbon storage.The results showed that:①the area of cultivated land,watershed,and construction land in Jiuquan City showed a significant increasing trend from 1990 to 2020,whereas the area of the remaining land use types showed a decreasing trend.②The carbon storage in Jiuquan City increased from 7722808.1 t to 7784371 t from 1990 to 2020,and the conversion of grassland into unused land was the main cause of the loss of regional carbon storage,accounting for 85% of the total loss.③All four development scenarios in 2035 showed an increasing trend of carbon storage,among which the ecological protection scenario had the most significant increase,with an increment of 76989.29 t.④The degree of land use,population density,GDP density,and NDVI were the main driving factors of the spatial variation in carbon storage in Jiuquan City,among which the degree of land use had the strongest explanatory power(q value of 0.849),and the interaction of natural and anthropogenic factors enhanced the explanatory power of each factor on the spatial variation in carbon storage.The results of the study can provide a scientific basis and decision basis for the integrated ecosystem management and territorial space optimization in Jiuquan City.