<Notes>Physiography of Rice Land in Peninsular Thailand

Abstract

Rice land in Peninsular Thailand is categorized into three groups with respect to physiographic environment during the wet season and patterns of cultivation. The areas under consideration are the lands on the coast, in the young fan region, and in the old fan-terrace region. On the coast region rice is grown in silted lagoons and in swales between beach ridges. These low-lying areas are moderately inundated for a considerable part of the year and therefore, are good for rain-fed rice growing. However, there still remain seizable amounts of potential rice land unreclaimed. In most cases, they are too remotely located for easy commuting from existing dwellings. Rice lands in the young fan region are found on gently sloping fan surfaces which are well watered by numerous bifurcated streams. Due to this ideal physiographic condition for both rice growing and human habitaiton, the region is highly developed as wet season rice land with simple water control devices. At present it is on the way to acquiring a more sophisticated irrigation system with the aid of the schemes of the Royal Irrigation Department. The old fan-terrace region, comprised of undulating and rolling ground surface, is primarily a terrain for tree crops rather than rice. But rain-fed rice fields were introduced to the region and have been expanding for a dozen years or so despite the danger of drought.