<Notes> Rice Cropping Patterns in Southern Asian Delta

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。This paper aims at finding a set of correlations possibly existing between rice cropping patterns and land forms of deltaic regions in Southern Asia where rice is planted. The Ganges-Brahmaputra, Chao Phraya, Mekong and Songkoi deltas are studied. Land forms are schematically categorized into six types, viz., Flood Releasing Area, Old Delta, Floodplain, Young Delta, Coastal Zone and Local Swale (Fig. 15). Five rice cropping patterns are distinguished, viz., Transplanted monsoon rice single cropping, Broadcast monsoon rice single cropping, Post-monsoon rice single cropping, Pre-monsoon rice single cropping and Double rice cropping (Fig. 14). The following correlations are obtained : 1) Transplanted monsoon rice single cropping is practiced in such well drained area as Flood Releasing Area, Coastal Zone and the higher level of Old Delta; 2) Broadcast monsoon rice single cropping is adopted in such poorly drained area as Floodplain, the lower level of Old Delta and the most part of Young Delta; 3) Post-monsoon rice single cropping is found in such flood accumulating area as Local Swale; 4) Pre-monsoon rice single cropping occurs forming patches in those plots where either irrigation facilities or natural moisture is available during the early monsoon period; 5) Double rice cropping is practiced on areas where water control is possible with irrigation and/or drainage installations, regardless the physiographic units