Towards Modernization of Water Management System in Upper East Bank of Chao Phraya Delta -Follow-up Activities of the Modernization of the Water Management System Project in Thailand-

摘要

Agriculture in the Kingdom of Thailand (Thailand) relies heavily upon the water resources in the Chao Phraya River basin (Fig. 1). The basin has an area of 162,000 km~2 and occupies about one-third of the entire area of Thailand. The lower basin is called the Chao Phraya Delta (CPD), which is one of the greatest rice granaries in the Asian monsoon area, The CPD has an area of 13,400 km~2, of which 10,800 km~2 (80.6%) is irrigable. The land elevation of the irrigable area ranges from 0 to 19 m above mean sea level. The annual rainfall in the area fluctuates from 1,000 mm to 1,600 mm. A year is divided into the dry season and the rainy season; the rainy season begins in mid-April and ends in late October. In general, at the beginning of the rainy season, it rains locally and within a short period. Rain is extremely rare in the dry season, and days with no rains occasionally continue for a significantly long period even in the rainy season (Yuyama et al., 2004).