未来气候变化下中国西南地区节水抗旱稻适生区变化特征研究

Suitability Area of Water-saving and Drought-resistant Rice Cultivation in Southwest China under Future Climate Scenarios

摘要:

节水抗旱稻对实现农业可持续发展和保障粮食安全具有重要作用，西南地区是节水抗旱稻的主要推广地区之一，气候变化会显著改变节水抗旱稻种植的水资源和热量资源，从而对适生区产生影响。本文通过构建地理信息系统(GIS)和多准则决策(MCDM)模型(BCM-GIS)，考虑气候、地形和土壤因子对节水抗旱稻种植分布的影响，综合分析了当前（2000—2019年）和未来（2020—2099年）不同气候变化情景下（RCP4.5和RCP8.5）中国西南地区节水抗旱稻适生区变化特征。研究结果表明，BCM-GIS模型预测精度较高，AUC(Area under curve)值为0.884，表明其适用于节水抗旱稻适生区分析。年降雨量、生育期内大于等于10℃积温、坡度和土壤质地对节水抗旱稻的适宜种植分布有显著影响。当前节水抗旱稻高适生区主要分布在云南德宏、临沧、普洱、西双版纳、文山、曲靖，贵州黔西、安顺、黔南、铜仁、黔东南，四川成都、内江、自贡、达州、广安和重庆中西部等地区，占西南地区耕地面积的20.82%，约3.279×104km2。中适生区和低适生区面积分别占西南地区耕地面积的43.83%和35.24%，约为6.903×104km2和5.551×104km2。在未来RCP4.5和RCP8.5气候情景下，2020—2099年节水抗旱稻的高适生区面积显著增加，并呈向北移动趋势，中适生区和低适生区面积则出现一定幅度下降。研究结果可为节水抗旱稻种植和推广提供重要科学依据，并减少气候变化对农业生产的影响。

Abstract:

Climate change will significantly alter the water and heat resources necessary for cultivating water-saving and drought-resistant rice, thereby affecting the suitable areas for such cultivation. A geographic information system (GIS) and a multi-criteria decision-making (MCDM) model (BCM-GIS) were established. The impacts of climate, topography, and soil were comprehensively considered to evaluate the suitability area for drought-resistant and water-saving rice in the Southwest China under both currents (2000—2019) and future climate change scenarios (RCP4.5 and RCP8.5). The results indicated that the BCM-GIS model had a high prediction accuracy with an area under curve (AUC) value of 0.884, confirming its applicability for suitability analysis of water-saving and drought-resistant rice cultivation areas. Annual rainfall, equal to or greater than 10℃ cumulative temperature during the reproductive period, slope, and soil texture had significant effects on the distribution of suitable cultivation of water-saving and drought-resistant rice. The current highly suitable zones for water-saving and drought-resistant rice were primarily located in Dehong, Lincang, Pu’er, Xishuangbanna, Wenshan, and Qujing in Yunnan Province;Qianxi, Anshun, Qiannan, Tongren, and Qiandongnan in Guizhou Province;Chengdu, Neijiang, Zigong, Dazhou, and Guang’an in Sichuan Province;and the central-western regions of Chongqing City. These areas accounted for 20.82% of the total cultivated land in Southwest China, approximately 3.279×104km2. The medium-suitability and low-suitability zones accounted for 43.83% and 35.25% of the total cultivated land in Southwest China, respectively, amounting to approximately 6.902×104km2 and 5.552×104km2. Under the future RCP4.5 and RCP8.5 climate scenarios, the areas of water-saving and drought-resistant rice in the highly suitable zone were increased significantly during 2020—2099 and showed a northward trend, while the areas of the medium suitable zone and the low suitable zone decreased to some extent. The latest multi-criteria decision-making methods were used and the response of suitable areas for water-saving and drought-resistant rice were analyzed.