基于PLUS与InVEST模型的内蒙古自治区土地利用变化及碳储量评估

Assessment of Land Use Change and Carbon Storage in Inner Mongolia Autonomous Region Based on PLUS and InVEST Models

为实现内蒙古自治区的“双碳”目标。根据内蒙古自治区2000年、2010年和2020年土地利用数据(LULC),按照内蒙古自治区“十四五”政策规划,建立自然发展、耕地保护与生态保护3种情景,利用PLUS模型对内蒙古自治区2030年土地利用空间分布进行预测分析,并用InVEST模型对内蒙古自治区不同开发情景下碳储量的变化进行分析。结果表明:(1)2000—2020年间内蒙古地区林地与建设用地面积均有增加,耕地、水域、草地与未利用地面积均呈减少态势,且转移方向上主要表现为耕地转为建设用地。(2)自然发展状态下,草地、耕地、水域及未利用地呈下降趋势,林地及建设用地呈上升趋势;在生态保护状态下,林地、草地和水域面积均比自然开发情景有所增加;耕地保护情景下,耕地面积相较于自然发展情景呈扩张趋势,扩张面积达4.69×10~4 hm^(2)。(3)2000年、2010年、2020年内蒙古地区碳储量分别达到1.371 7×10^(10),1.370 9×10^(10),1.370 6×10^(10) t,呈逐年减少趋势。2030年自然发展、耕地保护、生态保护3种情景下总碳储量分别为1.370 1×10^(10),1.370 6×10^(10),1.371 9×10^(10) t,耕地保护和生态保护相比较自然发展情景下碳储量更多,表明保护措施的实施,可有效地控制碳储量下降。实施耕地保护和生态保护政策以控制耕地扩展为建设用地和未利用地,改善土地利用结构有助于延缓区域碳储量流失。

In order to achieve the"Dual carbon"target of the Inner Mongolia Autonomous Region,based on the land use data(LULC)in 2000,2010 and 2020 and followed the 14th Five-Year Plan of Inner Mongolia Autonomous Region,three scenarios of natural development,cultivated land protection and ecological protection were established.The PLUS model was used to forecast and analyze the spatial distribution of land use in 2030 of Inner Mongolia Autonomous Region.The changes of carbon storage under different development scenarios in the Region were analyzed with the InVEST Model.The research results showed that:(1)The area of forest land and construction land in Inner Mongolia increased from 2000 to 2020,while the area of cultivated land,water area,grassland and unused land showed a downward trend,and the main transfer direction was from cultivated land to construction land.(2)Under the state of natural development,the area of cultivated land,grassland,water area,and unused land decreased,while the area of forest land and construction land showed an upward trend;under the state of ecological protection,the area of forest land,grassland,and water area increased compared with the natural development scenario;under the cultivated land protection scenario,the cultivated land area showed an expansion trend compared with the natural development scenario,and the expanded area reached 4.69×104 hm^(2).(3)In 2000,2010,and 2020,the carbon storage in Inner Mongolia reached 1.3717×10^(10),1.3709×10^(10) and 1.3706×10^(10) t,respectively,showing a decreasing trend year by year.In 2030,the total carbon storage under the three scenarios of natural development,cultivated land protection and ecological protection was 1.3701×10^(10),1.3706×10^(10) and 1.3719×10^(10) t,respectively.Compared with the natural development scenario,the carbon storage of cultivated land protection and ecological protection was larger,indicating that the implementation of protection measures could effectively control the decline of carbon storage.Therefore,the implementation of cultivated land protection and ecological protection policies could control the expansion of cultivated land into construction land and unused land,and improve the land use structure,and help to delay the loss of regional carbon storage.