| Abstract | A number of deltaic plains, built out by sediments transported to
the coast by rivers, has been studied. Special consideration has been given to their distinct patterns and the causative independent variables, namely: river, ocean, and climatic forces. The river variables include mean annual discharge, sediment yield and river slope on plain to the
sea. While ocean variables consist of continental shelf characteristics, i.e., width, depth of edge, bed slope, sea and swell waves duration, swell direction, and salinity. Climatic elements are represented by temperature and rainfall. Regression analysis was used in obtaining predictive equations for discharge and sediment yield as a function of catchment characteristics. From the chosen variables, the following showed best correlation: mean annual rainfall and area for the discharge; and percentage of mountainous area, relief, area, and perimeter for the sediment yield. These equations were used to provide data for discharge and sediment
yield of other rivers where the information was not otherwise available. A similar regression analysis was applied to determine the relative influence of delta producing variables. Among the selected delta
features, the following gave good correlations with the independent variables: apex-to-sea length, area, maximum width, maximum width to
number of mouth ratio, ratio of maximum width to total number of distributaries, topography and side topography. The significant independent variables acted on each of these, either individually or in combination. |
