Author(s): Jun Niu; Ji Chen; Liqun Sun
Linked Author(s): Ji Chen, Jun Niu
Keywords: Drought; VIC model; Soil moisture; EVI; Spatial distribution; Pearl River
Abstract: This study investigates the features of the major drought events through using simulated soil moisture series and the Enhanced Vegetation Index (EVI) over the West River basin in South China for the period of 2002–2010. The macro-scale hydrological model, Variable Infiltration Capacity (VIC), is applied to simulate terrestrial hydrological processes over the basin. The major drought events are identified in terms of the temporal magnitude of top 1-m soil moisture over the whole region by using a threshold approach. The detected dry events exhibit long-term persistence of lower soil moisture, especially in the west part of the river basin. The results show that the spatial evolutions of the drought area are partly associated with the topographic and river network features. In addition, the EVI data derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data are used to inspect the effects of spatial distribution of droughts. We examine the correlations between seasonal variation in EVI and the severity of droughts. The different time lags between them are detected for four severe drought sites. The study results will be helpful for basin-scale water resources management, especially for monitoring and mitigating the drought events.