Hiryong Byun Sukyoung Hong And Vijendra K Boken

South Korea (hereinafter referred to as Korea) lies in the middle latitudes of the Northern Hemisphere. Until the 1960s, Korea was a typical agrarian country, with agriculture generating roughly half of its gross national product (GNP) and employing more than half of the labor force. Agriculture still plays an important role in the Korean national economy, but it accounts for a relatively much lower share of the GNP (5.3% in 1997) and engages much less of the population (11.0%). The agricultural share of the national economy is declining continuously. Farms in Korea, as in many other Asian countries, have traditionally been small. Average farm size has been growing slowly from 0.86 ha in 1960 to 1.39 ha in 2001, despite a significant reduction in the average number of persons per household engaged in farming—from 6.20 persons to 2.91 persons. As a result, agriculture has become more intensive.

The country has four distinct seasons: summer, fall, winter, and spring. Summer and winter have a longer duration than spring or fall. The summer rainy season (Changma) in the Korean Peninsula includes the period from late June to late July. About three quarters of the annual precipitation falls during the summer season. The average annual precipitation in Korea is 1,274 mm, which is about 1.3 times the world average (973 mm). The variation in annual precipitation is larger, with an annual minimum of 784 mm and an annual maximum of 2675 mm in Seoul. Heavy rains fall during the Changma season, which is influenced by monsoons.

The National Institute of Agricultural Science and Technology (NIAST) classified Korea (except Jeju Island) into 19 climate zones (figure 30.1) to efficiently use agricultural resources for wetland rice production. Among the 19 zones, zone 14, which is the Southern Charyeong Plain, yields the best harvest and the most stable rice production. Zones 11 (Yeongnam Basin), 17 (the northeastern coast), and 18 (the mid-eastern coast) are

Figure 30.1 Nineteen climate zones of South Korea and seven climate zones of North Korea (Choi and Yun, 1989).

categorized as drought-risk areas at transplanting stage based on the ratio of evaporation to precipitation (Choi and Yun, 1989).

About 157,000 ha (8% of Korea's arable land) is damaged by climate disasters every year, costing about half a billion dollars for mitigation. Table 30.1 shows areas affected by severe droughts during the 1960s. The most severe drought occurred in 1968. Drought also occurred in 2001. In spring, even a small rain deficit can cause agricultural damage due to the high demand for water for rice transplanting. Every spring, there is at least some level of water shortage. However, the most severe drought generally occurs during summer.

0 0

Post a comment