Land and Water Conservation Center Project in the East of Thailand

摘要

Thailand has been expanding the amount of its farmland area in order to increase agricultural production, destroying a huge area of forest in a short time. This has caused serious soil erosion damage and drought in Thailand. The total area of Thailandis 513,000 km~2. Of this total, farmland accounted for 211,300 km~2 (41.2%) in 1992. On the other hand, forests covered 149,000 km~2 (29%) in 1985 but since then have been reduced to 24% by 1995. Since 1980, the Department of Land Development (DLD) in the Ministry of Agriculture and Cooperatives (MOAC) in Thailand has been conducting a preliminary investigation into actual soil erosion. The results made clear that the most serious soil erosion occurs in the East of Thailand. Encroached forest is the main reason for soil erosion in the East, where forest encroachment has accelerated very rapidly, reducing the forest area from 58% in 1961 to less than 20% in 1995. This means that 1% of the eastern forest has been destroyed every year. The predicted soilloss in the East is estimated at more than 30 million tons/year in total. The monetary value of such soil loss is estimated to be equivalent to US$ 200 million/year. Consequently, the soil has become poor and crop yields are decreasing year by year. Inthe case of cassava (the main upland crop in the East), yield has decreased from 29 tons/ha in 1981 to less than 10 tons/ha in 1995 in some areas.