基于热红外遥感的广西平果县石漠化初步研究

中国西南喀斯特地区石漠化问题十分严重。为更好地利用卫星遥感监测和评价石漠化现状,提出了一种基于卫星热红外遥感的石漠化等级划分的新方法。以广西平果县为研究区,利用2014年Landsat 8热红外遥感影像分别提取夏季和冬季的亮温值并计算亮温差,经过高分影像建立典型样本区并分析亮温差,确定不同石漠化等级的亮温差阈值,最后对全县石漠化进行等级划分。结果显示,平果县2014年重度石漠化面积占喀斯特区域面积的比例为3.87%,中度石漠化占9.19%,轻度石漠化占22.26%,潜在石漠化占57.46%,非石漠化占7.22%。研究表明,通过确定适当的夏冬季亮温差阈值可以有效地对石漠化程度进行分级划分,该新方法与已有方法相比,具有物理意义明确、方法简单有效、结果客观等优点,具有推广应用价值。

EVALUATION OF KARST ROCKY DESERTIFICATION BASED ON THERMAL INFRARED REMOTE SENSING IN PINGGUO COUNTRY,GUANGXI

Karst rocky desertification is a serious problem in Southwest China. For better monitoring and evaluation of rocky desertification present situation by remote sensing, a new method for classification of rocky desertification based on thermal infrared remote sensing has developed. Taken Pingguo County in Guangxi province as the study area, Landsat 8 thermal infrared images in 2014 was acquired in summer and winter, brightness temperature was extracted and the difference of brightness temperature was calculated. After analyzing the different levels of brightness temperature rocky desertification threshold, rocky desertification was conducted to grading in Pingguo country. The results of the proportion of the total karst area of Pingguo County in 2014 were as follows. Severe rocky desertification was 3.87%; moderate rocky desertification accounted for 9.19%; mild rocky desertification accounted for 22.26%; potential rocky desertification accounted for 57.46%; non-rocky desertification accounted for 7.22%. By determining the appropriate threshold of temperature difference between summer and winter, it could divide effectively the rocky desertification degree grade. Compared with other methods, the new method has the characteristics with clear physical meaning, simple and effective, objective results etc.