基于PLUS-InVEST模型的渭河流域生态系统碳储量评估及多情景预测

Ecosystem carbon storage assessment and multi-scenario prediction in the Weihe River Basin based on PLUS-InVEST model

土地利用变化是导致碳储量变化的主要原因,对未来土地利用变化进行多情景预测并探究其对碳储量的影响,对于维持区域碳平衡具有重要意义。近年来,在自然和人为政策的共同作用下,渭河流域土地利用变化显著,碳储量也相应发生变化。本研究基于PLUS-InVEST模型,评估并预测了渭河流域生态系统碳储量时空变化,探究土地利用变化对碳储量的影响。结果表明:2000-2020年,渭河流域土地利用分布格局变化不大,土地利用变化呈现“耕地面积减少而其余土地利用类型面积增加”的特点,耕地向建设用地转换以及耕地、林地、草地的相互转换是渭河流域土地利用类型转换的主要方式。渭河流域碳储量呈上升趋势,共增加15.31×10^(6)t,碳储量高值区分布呈“东北片状-西部散点状-中南部带状”,低值区分布在下游关中平原城市群。2030年4种情景下渭河流域碳储量较2020年均有所增加,经济发展情景增加最少,生态保护情景增加最多,不同情景的碳储量空间差异主要体现在上游耕地、林地和草地的分布交错地带。研究结果可为渭河流域土地利用管理决策以及碳储量的提升提供数据支撑。

Land use changes are the main cause for the changes of carbon storage, which is of great importance for maintaining regional carbon balance to make multi-scenario projections of future land use change and explore its impacts on carbon storage. In recent years, under the combination of natural factors and policies, with the land use changing significantly, carbon storage of the Weihe River Basin has also changed. Based on the PLUS-InVEST model, we assessed and predicted the spatial and temporal variations of ecosystem carbon storage in the Weihe River Basin and explored the impacts of land-use change. The results showed that land use distribution pattern of the Weihe River Basin did not change much from 2000 to 2020, which was characterized by the decreases of cropland area and the increases of the area of the remaining land use types. The main ways of land use type conversion were cropland to built-up land and inter-conversion of cropland, forest, grassland. Carbon storage in the Weihe River Basin showed an upward trend from 2000 to 2020, with a total increment of 15.31×10^(6) t. The areas with high carbon storage presented the characteristics of “northeast patch-western scatter-central and southern belt”, while low carbon storage distributed in the Guanzhong Plain urban agglomeration located in the lower basin. Compared to 2020, carbon storage in the Weihe River Basin in 2030 would increase under the four scenarios. Carbon storage would increase the least under the economic development scenario, and the most under the ecological protection scenario. The variation of carbon storage in spatial distribution would be embodied in the staggered zone of cropland, forest, and grassland in the upper basin. The results could provide data support for land use management decisions and carbon storage enhancement in the Weihe River Basin.