The Plant Height of Rice in Delta

The rice plants in the deltaic area of the Chao Phraya are classified into eight types, from I to VIII, based on the plant height.Type I occursin a geological depression in the middle of the delta, cal]ed Trough, and is distinc- tively characterized by an extreme]y wide height range, varying from 150 c:m to 400 cm {Figs, 2& 3), Type II covers the Old Delta and has a reasenably widc height range and a rapid lateral change ef plant height (Figs. 2 & 4).Type III grows all along the marginal zenes of the deltaic area, and has a pattern of plant height distribution simi]ar to Type II, though the uverage height is slightly shorter than Type II.Type IV to VIII sre found in thc Yeung Delta and are charaeterized by a narrow range and a smooth lateral change ef p]ant height distribution .The subdivisien of the Young Delta divided according to Types IV to VIII demonstrates that the further inland one goes the taller the plants arc (Fig. 2), This phenomenon is explained by the help of a simpl{fied delta mode] in which a searp, characteristic of all deltas, separates the Old and Young Peltas..During a !arge and prelonged flood, the water inundates the deltaic area, with the flood depth increasing a$ one goes inland (Fig. 7).The greatest depth occurs at the foot of the scarp.The existing distribution of the plant height in the Young Delta seems to be a reflection of the tepo-hydrographic conditions mentioned above

Delta · Delta wing · Flood myth · Hydrology (agriculture · Intensity (physics · Range (aeronautics · River delta · Genetic Mapping and Diversity in Plants and Animals · Plant responses to water stress · Rice Cultivation and Yield Improvement