The implications of geography and climate on drought trend

Abstract

The implications of geographical factors (i.e. elevation, freshwater area, urbanization, and proximity to coast) and climatic factors (i.e. air temperature, wind speed, relative humidity, and solar radiation) with regard to drought trend were investigated by analyzing the monthly averaged daily climate data (i.e. precipitation, temperature, wind speed, relative humidity, and solar radiation) recorded from 1973 to 2006 at 53 climatological stations in South Korea. In addition, geographical characteristics were identified by GIS analysis and land cover data were analyzed for these 53 stations. Further, multivariate regression analyses were performed by setting the Standardized Precipitation Index (SPI) trend as the dependent variable and the geographical and climatic factors as the independent variables. The results indicated that, overall, the droughts in South Korea are becoming more severe in spring for the short- and seasonal term; however, the droughts in all seasons are becoming less severe for the long term. The effects of geographical and climatic factors on drought trends are also closely related to seasonality and drought duration for short-, seasonal-, and medium-term droughts, but not for long-term droughts. Therefore, for efficient water resources management for drought preparedness, drought duration and seasonality should also be considered along with geographical and climatic characteristics of a region.