新疆迪那河流域轮台人工绿洲耕地时空变化特征分析

Characteristics Analysis on Spatial-temporal Changes of Farmland in Luntai Artificial Oasis in Dina River Watershed of Xinjiang

摘要:

对新疆迪那河流域轮台人工绿洲耕地进行动态监测，量化和描述26年来绿洲耕地的时空变化规律。在RS与GIS支持下，通过解译1992年8月、1998年8月、2007年9月和2018年8月4期卫星遥感影像和野外调查获取的无人机影像数据，提取迪那河流域轮台人工绿洲耕地信息，采用数理统计、动态度、转移矩阵和重心模型分析绿洲耕地26年内时空变化特征。结果表明：26年来，迪那河流域轮台人工绿洲耕地面积从1992年的8 381hm2增长到2018年的46 284hm2，耕地面积在人工绿洲总面积中所占的比例从1992年的40.18%增长到2018年的71.28%，耕地面积在迪那河流域总面积中所占比例从1992年的1.61%增长到2018年的8.91%。迪那河流域轮台人工绿洲耕地面积呈现“缓慢增加—急剧增加—缓慢增加”的变化过程。1992—1998年，绿洲耕地增加主要由政府推动的开垦政策驱动，耕地面积年均增长速率2.28%；1998—2007年，绿洲耕地增加受开垦政策和棉花产业发展状况两种因素共同影响，耕地面积急剧增加，年均增长速度达16.85%；2007—2018年，绿洲耕地增加主要受棉花产业发展状况影响，耕地面积年均增长速率为8.46%。迪那河流域轮台人工绿洲耕地动态变化主要表现在：耕地开垦扩张面积（41545hm2）远大于耕地转出面积（3441hm2），绿洲外围土地的开发是轮台人工绿洲耕地扩张的最主要途径，耕地转为果园是轮台人工绿洲耕地减少的最主要途径。迪那河流域轮台人工绿洲耕地呈现向沙漠区扩张明显、向戈壁区扩张较弱的趋势。

Abstract:

The main purpose was to explore the spatialtemporal changes of farmland in Luntai Artificial Oasis in Dina River Watershed, aiming to provide basic data and theoretical basis for the spatial planning and management of artificial oasis in small watershed. The land use information of farmland was extracted from the remote sensing images（obtained in August 1992, August 1998, September 2007 and August 2018）and unmanned aerial vehicle data（obtained in July and August 2018 in the field survey）by means of visual interpretation supported by RS and GIS, and analyzed via mathematical statistic, dynamic degree, transfer matrix and gravity center model. Results showed that the area of farmland in Luntai Artificial Oasis was increased from 8381hm2 in 1992 to 46284hm2 in 2018. In 1992, totally 40.18% of artificial oasis was occupied by farmland, which was decreased to 37.04% in 1998, and then followed by a long time increase to 71.28% in 2018. In 1992, totally 1.61% of watershed area was occupied by farmland, which was increased to 8.91% in 2018. The area of farmland in Luntai Artificial Oasis was developed rapidly and experienced three stages: the stage of moderate increase（1992—1998）which was driven by reclamation policy launched by local government with annual average growth rate of 2.28%; the stage of rapid increase （1998—2007）which was influenced by both the cotton industry and reclamation policy with annual average growth rate of 16.85%; and the stage of moderate increase（2007—2018）which was only influenced by cotton industry with annual average growth rate of 846%. In the past 26 years, the land that was transferred into farmland（41545hm2）was far more than the land that was transferred out（3441hm2）. The land outside artificial oasis（35179hm2）was the main source supporting the extension of farmland. The land that transferred out of farmland was mainly into the forestry and fruit industry（2671hm2）. The gravity centers of farmland was gradually moved in the direction of sandy desert because the exploration and maintenance cost of sandy desert was lower than that of Gobi desert, and the cotton which was the most popular crop in Luntai Artificial Oasis had adapted to the atmosphere of the oasissandy desert transition zone in Dina River Watershed.