Using MODIS EVI to detect vegetation damage caused by the 2008 ice and snow storms in south China

Abstract

This study develops a new method for detecting areas with severe vegetation damage caused by a serious ice and snow storm event that occurred in southern China over the period of 10 January to 2 February 2008. The new method adopts one of the Moderate Resolution Imaging Spectroradiometer (MODIS) MOD13A1 products, the enhanced vegetation index (EVI). Using a series of 16 day EVI maps at the 500 m spatial resolution in the 2008 growing season, the vegetation damage due to the event could be observed at a great number of patches, most of which are located outside of the regions with a flat topography. From a comparison of the MODIS Leaf Area Index (LAI), the Land Surface Temperature (LST) products, and the Landsat images obtained before and after the event, the severe vegetation damage is substantiated by a decreasing LAI, an increasing LST, and the "browning" of green vegetation in these patches. The analysis of topographic features discloses that the locations with the severe vegetation damage are mainly on slopes with easterly, southerly, and southeasterly aspects and in the moderate elevation region of between 500 and 700 m. During the event period, most of the patches that exhibited vegetation damage had a minimum temperature slightly above 0°C, experienced a minimum relative humidity of more than 75%, and accumulated a precipitation depth of more than 130 mm. Copyright 2010 by the American Geophysical Union.