Trend Analysis of Desert Area Change in East Asia Using NDVI
Abstract
Desert region in East Asia is spreading by global warming and reckless human activity. The source of yellow dust, which affects Korea, is changing as the desert spreads. Various studies have been conducted on changing the origin, but there is a lack of research on recent trends. Therefore, in this study, we are interested in studying recent trends in eastern Asian desert area changes, using Normalized Difference Index (NDVI), which is widely used in land cover studies. We acquired S10 NDVI data, which were made by using the NDVI maximum values from 2001 to 2013 using SPOT satellite's Vegetation sensor. Although NDVI is decreased by clouds, solar angle atmospheric conditions and various factors, the only factor increasing to the NDVI is the vitality of the vegetation. To compensate for this, the S10 NDVI data is provided using MVC techniques. However, even though this preprocessing process has been performed, a low peak with a low value occurred. Therefore, this study used a calibrated NDVI which removes low peaks using multiple regression equation. After eliminating noise values contained in the data, unsupervised classifications were performed using the ISODATA method. The analysis of unsupervised clusters of East Asia desert shows that increasing and decreasing are repeated. However, they saw an increase in desert area over a whole period and, in particular, a tendency for deserts to expand eastward.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMEP53E1955H
- Keywords:
-
- 1813 Eco-hydrology;
- HYDROLOGYDE: 1824 Geomorphology: general;
- HYDROLOGYDE: 1825 Geomorphology: fluvial;
- HYDROLOGYDE: 1826 Geomorphology: hillslope;
- HYDROLOGY