Agricultural Droughts in Southern China from 1961 to 2010

Southern China is a major agricultural region with frequent droughts. The major crop in this region is paddy rice which includes early rice, middle rice and late rice.  Drought indices based on soil moisture are inappropriate to assess agricultural droughts for this region. In this study, an agricultural drought intensity index (ADI) which is suitable for rice planting area was proposed based on the difference between crop water requirements (evapotranspiration) and precipitation. The whole study area was divided into three region based on the distributions of climate and agriculture.  Agricultural droughts in each region were analyzed for the period from 1961 to 2010 based on ADI.    ADI and agricultural drought years in each region were verified by the actual drought area and crop yield in drought years during the period from 1978 to 2010.  The results show that the agricultural drought intensity index had significant correlation with the ratio of the actual drought area over the total planting area and the meteorological yield in three regions. These results suggest that ADI could be used in agricultural drought studies.