Rainfall erosivity in the Republic of Korea

Excerpt

Rainfall erosivity (the R-factor) is an important factor used in calculation of soil erosion by the Universal Soil Loss Equation (USLE) (Wischmeier and Smith 1978) and the Revised USLE, or RUSLE (Renard 1997). Wischmeier et al. (1958) showed that the R-factor explains about 80% of the variation in soil loss. Its annual and monthly values serve as a main guide for designing soil conservation practices in many countries (Renard et al. 1997; Babu et al. 1978; Bollinne et al. 1980; Mikhailova et al. 1997). In this paper, we describe the rainfall erosivity in South Korea.

South Korea has an area of 98,480 km² mostly in mountainous terrain. About 20% of the land is suitable for agriculture. Rice (Oryza sativa) is the major crop, and is planted on about 90% of the cultivated land annually. The remaining agricultural land is in upland fields and used for production of corn (Zea mays L), soybean (Glycine max), and major vegetables (Figure 1). Cultivation of these upland fields has been intense and is driven by a very high demand for vegetables. The cultivation has caused excessive erosion and ruined productive soils. Erosion from upland areas also damages valley fields …