Implications of Geographical Factors and Trends of Climatic Factors on Aridity/Humidity Trends

Abstract

The study aimed to find the implications of geographical factors and trends of climatic factors (precipitation, temperature, relative humidity, wind speed and solar radiation) on aridity index trends at 56 sites in South Korea. Monthly, seasonal, and annual normal aridity index values for the 56 study stations in South Korea were estimated for a 30-year period (1974-2003). The aridity index was estimated as the ratio of precipitation (P) to potential evapotranspiration (PET) (P/PET). Detailed geographical information and multiple linear regression (MLR) analyses were used to assess the implications. The trends of climatic factors had more close implications on aridity index trends than geographical factors. The aridity index changes were driven mainly by changes in precipitation; and the changes in other climatic factors (wind speed, relative humidity, and solar radiation) also showed significant correlations with the aridity index trend. When considering the relative importance of geographical factors (elevation, freshwater area, urbanization, and proximity to the coast) on aridity/humidity trends, the elevation were found to be the most important factor. The changes in precipitation as climatic factor and elevation as geographical factor are turned out to be the most important factors affecting on regional aridity/humidity trends in South Korea.