关键词: 中国北方, 新增耕地, 土地利用变化, 气候变化, 驱动因素

Abstract:

【Objective】 The spatial and temporal change pattern of newly cultivated land is affected by both climate change and human activities. It is important to clarify the spatial and temporal change pattern of newly cultivated land and its driving factors to ensure the sustainable development of cultivated land resources and agriculture. 【Method】 Based on the data of newly cultivated land in north China of 1980s-1990s, 1990s-2000s and 2000s-2010s, the spatial-temporal changes of newly cultivated land in north China were analyzed by using gravity model and regional statistics; Based on the climate data of the three times, we calculated the active accumulated temperature (≥10℃, AAT10) and the standardized precipitation evapotranspiration index (SPEI), and analyzed the driving effect of climatic factors on cultivated land reclamation; Based on the socio-economic statistics since the 1980s, the paper analyzed the promotion of human factors on cultivated land reclamation by combining spatial superposition model and regional statistical model; Based on the combination of climatic and human factors and the method of geographical subdivision, the new cultivated land in north China was subdivided. 【Result】 The center of gravity of new cultivated land in northern China has shifted from northeast to northwest; the most cultivated land reclamation existed in warm and dry climate, but the proportion of cultivated land reclamation occurring in warm and humid climate conditions was gradually increasing; the increase of agricultural population, the advancement of agricultural technology and the influence of national policies provided necessary foundation for the expansion of cultivated land resources in Northeast China and Xinjiang. Abundant cultivated land reserve resources and flat terrain conditions in the Xinjiang, Heilongjiang, Jilin and other regions provided a possibility for land reclamation; based on the climate and human activities factors, the northern China was divided into seven regions, which included the zone of grass to cropland due to climate in Northeast, the zone of forest and grass to cropland due to climate and human activities in north region of Northeast of China, the zone of paddy field to dry land due to climate and human activities in middle region of Northeast, the zone of forest and grass to cropland due to climate and human activities in the North, the zone of ecological restoration dues to human activities in the loess plateau, the zone of unused land to cropland due to human activities in the northwest region, and zone of the oasis agriculture due to human activities in Xinjiang. 【Conclusion】 Since the 1980s, the spatial and temporal patterns of the new cultivated land in northern China showed obvious differences. The warm and dry climate did not become the limiting factor of cultivated land reclamation, but the wetter climate promoted the cultivated land reclamation to some extent. The increase of agricultural population, the progress of agriculture and the influence of national policies played an important role in cultivated land reclamation.

Key words: Northern China, new cultivated land, land use change, climate change, driving factor