Quantitative Simulation of Dynamic Changes in Cultivated Land in Areas of Reclamation and Returning Cultivated Land to Forest or Pastures under RCPs Climate Scenarios

气候情景下典型开垦与退耕区耕地动态变化的定量模拟（英文）

Northeast China as one of important agricultural production bases is an area under reclamation and returning cultivated land to forests or pastures. Therefore, it is of great practical significance in guaranteeing the sustainable development and national food security to study the spatial and temporal variation of cultivated land in Northeast China under future climate scenarios. In this study, based on data of land use, natural environment and social-economy, dynamics of land system（DLS） model was used to to simulate the spatial distribution and changing trends of cultivated land in the typical areas of reclamation and returning cultivated land to forest or pastures in Northeast China during 2010-2030 under land use planning scenario and representative concentration pathways（RCPs） scenarios quantitatively.The results showed that the area of cultivated land had an overall decreasing trend under the land use planning scenario, but the area of upland field increased slightly from 2000 to 2010 and then declined greatly, while the area of paddy field continuously declined from 2000 to 2030. Under the Asia-Pacific Integrated model（AIM）scenario, the total area of cultivated land had a tendency to increase considerably,with the upland field expanding more obviously and the paddy field declining slightly.In addition, the cultivated land showed a greater decreasing trend under the model for energy supply strategy alternatives and their general environmental impact（MESSAGE） scenario compared to the land use planning scenario. Moreover, analysis on the conversion between different land use types indicated that the reclamation and returning cultivated land to forests or pastures was likely to continue under future scenarios, but the frequency of occurrence could decrease as the time goes by. The conclusions can provide significant decision-making information for the rational agricultural planning and cultivated land protection in Northeast China to adapt to the climate change.

全球气候变化是当前关注的热点问题,研究气候情景下中国典型开垦与退耕区耕地动态变化对保障中国粮食安全具有重要意义。该研究以东北地区作为典型区,基于设计的土地利用规划情景和RCPs（representative concentration pathways）气候情景,采用土地利用变化动态（DLS,dynamics of land system）模型模拟了在规划情景和RCPs气候情景下开垦与退耕区2010~2030年耕地的空间分布格局,分析不同耕地类型未来的变化趋势。研究结果表明：规划情景下水田呈持续减少的态势,而旱田在2000~2010年有小幅增长的态势,而后出现大面积减少;AIM（Asia-Pacific integrated model）气候模式情景下旱田增长趋势也较明显,水田则保持小幅减少的态势;MESSAGE（Model for energy supply strategy alternatives and their general environmental impact）气候模式情景下,耕地面积呈减少的态势。从不同用地类型之间的转移分析得出,该区域开垦与退耕相逆的现象在未来情景下仍会延续,但是发生的频率却随时间的推移逐渐降低。该研究为开垦与退耕区应对气候变化,合理进行农业规划和耕地保护提供参考。