基于InVEST和CA-Markov模型的黄河流域碳储量时空变化研究

Spatio-temporal evolution of carbon stocks in the Yellow River Basin based on InVEST and CA-Markov models

  • 摘要: 区域土地利用/覆被变化是导致生态系统碳储量变化的主要原因,预测未来土地利用/覆盖变化及其对碳储量的影响对区域陆地生态系统的认识具有重要意义。本研究基于黄河流域2005—2018年土地利用/覆被变化规律,运用CA-Markov模型分别预测了生态保护情景(EVC)和自然变化情景(NVC)下的土地利用/覆被空间格局,采用修正后的碳密度,运用InVEST模型评估黄河流域2005—2030年6期碳储量。结果表明:2005—2018年黄河流域林地、水域和建设用地面积持续增加,耕地、草地和未利用土地面积减少,13 a间全流域碳储量减少28.734×106t。与自然变化情景相比,在生态保护情景下2030年草地和耕地相比2018年减少幅度较小,建设用地规模扩大得到了限制,产生了生态效应。2030年,自然变化情景和生态保护情景下的碳储量较2018年分别减少258.863×106t和30.813×106t,生态保护情景下土地利用覆被格局固碳能力高于自然变化情景,该研究可为黄河流域土地利用结构调整和土地利用管理决策提供科学依据。

     

    Abstract: The Yellow River Basin is an important carbon sink and carbon stock area of terrestrial ecosystems in China, and land use/cover change is the primary reason for variation in the carbon stocks. Therefore, accurately predicting future land use/cover changes and their impacts on regional carbon stocks is important for a better understanding of regional terrestrial ecosystems. This study aimed to explore the law of spatio-temporal changes in land use in the Yellow River Basin from 2005 to 2018 and to predict the characteristics of carbon stock changes under two scenarios of ecological protection and natural change in 2030. The CA-Markov model was used to predict the land use/cover spatial pattern in two scenarios:the ecological conservation scenario and the natural change scenario, based on its law in the Yellow River Basin from 2005 to 2018. The InVEST model was used to estimate the carbon stock in six phases of the Yellow River Basin from 2005 to 2030 based on the revised carbon density. The results highlighted land use change and transition among land use types. From 2005 to 2018, the areas of forest, water, and built-up land in the Yellow River Basin continued to increase, but the areas of cropland, grassland, and unused land decreased. The main transfer characteristics of land use types were from cropland to built-up land and grassland, and from cropland and grassland to forest. During the 13 years, the carbon stock of the whole basin decreased by 28.734×106t. The simulation results of land use changes under two scenarios with the CA-Markov model showed that compared with the natural change scenario, the ecological protection scenario led to reductions in grassland and cropland in 2030, which was less than that in 2018. The expansion of built-up land was restricted under the ecological scenario, and the scale of expansion was substantially reduced, both of which facilitated the generation of ecological effects in the Yellow River Basin. Furthermore, in 2030, the carbon stocks under the natural change scenario and the ecological protection scenario were reduced by 258.863×106t and 30.813×106t, respectively, compared with 2018. This study provides a scientific basis for adjusting the land use structure and land use management decision-making, improving the regional carbon stock capacity, and promoting ecological civilization construction in the Yellow River Basin.

     

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