基于高分辨率遥感影像的石漠化演变趋势分析--以蒙自东山生态治理区为例

Evolution trend of KRD based on high-resolution remote sensing images: An example of the east mountain, Mengzi ecological management region

为了快速准确获取小区域高精度、大比例尺岩溶石漠化的演变趋势,为小区域岩溶石漠化的定量评价和精准治理提供科学依据和基础数据,本文选择岩溶石漠化典型地区——蒙自东山生态治理研究区为例,基于2006年11月SPOT5和2015年1月Pleiades两期高分辨率遥感影像,通过研究区归一化植被指数(NDVI)与植被覆盖度(FVC)进行岩溶石漠化遥感信息提取,得到生态治理区2006年与2015年岩溶石漠化空间分布特征,并对两期FVC数据进行叠加,分析生态治理区石漠化的演变趋势。遥感调查表明,研究区内石漠化十分严重,重度石漠化面积占比73.55%,中度石漠化5.36%,轻度石漠化0.53%,无石漠化14.86%,阴影及水域面积5.71%。不同等级石漠化面积的变化情况显示,2006-2015年,重度石漠化和无石漠化面积比例增加,重度石漠化由72.37%增加到73.55%,无石漠化从6.06%增加到14.86%,而中度、轻度石漠化面积比例减少,中度石漠化面积从11.58%减小到5.36%,轻度石漠化面积从4.35%减小到0.53%。轻度、中度和无石漠化区变幅明显。研究区石漠化发生率从88.27%降低到79.43%,总体呈降低趋势。

The purpose of this work is attempt to quickly and accurately determine the karst rock desertification(KRD)evolution trend with high-precision in small areas and provide scientific evidence and basic data for quantitative evaluation and precise treatment of KRD.We select the typical area of KRD-ecology management area in the east mountain of Mengzi as the study area.Based on SPOT5 data acquired in November 2006 and Pleiades data in January 2015,we use a method combining NDVI and FVC of the ecological management region to collect KRD information form remote sensing data.Statistical analysis on the data of 2006 to 2015 shows that the KRD were very serious,high KRD accounting 73.55%,moderate KRD 5.36%,and slight KRD 0.53%,respectively,while none-KRD only 14.86,with the shadow and water area accounting for 5.71%of the total.From the year 2006 to 2015,the area of high KRD increased slightly,from 72.37%to 73.55%,and the area of moderate KRD reduced from 11.58%to 5.36%.Although the area of mild KRD was small,it represented the significant reduction,from 4.35%to 0.53%,nearly disappeared.The area of non-KRD increased substantially,from 6.06%to 14.86%,so on the whole the occurrence of KRD tended to decline.