广西喀斯特干旱农业区干旱遥感监测模型研究

Research on remote sensing drought monitoring model for Guangxi karst arid agricultural area

广西中部喀斯特平原区是广西重要的粮食生产基地,但旱灾已成为该地区经济发展的障碍。利用EOS/MOD IS数据,采用植被状态指数(IVC)和温度条件指数(ITC),构建了干旱指数ID的遥感监测模型,统计分析了ID与农业受旱率的相关系数,从而确定了模型中各参数的权重系数。将该模型应用于2005年秋旱监测,经与旱情实况及前人研究成果进行对比分析,验证了干旱指数ID的有效性。通过对ID随ITC和IVC变化的敏感性评价,结果表明,ITC和IVC都能反映旱情变化,但ITC反映旱情的敏感性高于IVC,以ITC和IVC为因子构建的干旱遥感监测模型适用于广西中部喀斯特干旱农业区的旱情遥感监测。

The karst plain area in middle Guangxi is an important grain production base ,but drought has become serious impediment to regional development＇ Land surface temperature dataset and NDVI dataset derived from EOS/ MODIS were used to calculate vegetation condition index and temperature condition index, and a dryness index ID was constructed. The weight of each parameter was determined by analyzing the correlative coefficients between dryness index ID and agriculture drought percentage, Using the ID, the spatiotemporal distribution of autumn drought in middle Guangxi karst plain area in 2005 was studied, spatiotemporal pattern of ID was compared with the real drought condition data from the observatories around Guangxi. Then, the sensitivity of ID to temperature condition index and vegetation condition index was evaluated. The results show that the change of dryness are more sensitive to temperature condition index than to vegetation condition index , and dryness indexes ID based on temperature condition index and vegetation condition index are reasonable for the middle Gugnxi karst plain area.