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  • ThesisItemOpen Access
    Quantitative analysis of runoff parameters in selected river basins of Kerala
    (Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1990) JJayasree, S; KAU; John Thomas, K
    The evolution of a drainage basin is the result of the flow of mass and energy and the resistance of topographical surface. Precipitation is the major source of matter and solar radiation, the source of energy. The stream flow is a function of geomorphological and hydrological factors of the river basin. The objectives of this study were to make a quantitative analysis of the effects of geomorphological and climatic factors on the stream flow and to study the inter – relationships between these factors. The selected river basins were Chaliyar and Kabbani. The specific objective was to express stream flow in terms of morphological factors and rainfall. The river basin was divided in to sub basin, each of which contains a rivergauge station. Morphological factors were measured from the map. Monthly rainfall from all the raingauge stations were collected and the arithmetical average for each sub-basin was computed. The monthly stream flow was also collected. It was found that the morphological factors were interrelated. The number of stream segments of successive order form a decreasing geometric progression whereas the length of stream segments of successive orders form an increasing geometric progression. Confluence ratio is inversely related to stream flow. Elongation and drainage area are highly correlated. A larger value for the confluence ratio indicates a more elongated basin and a lower flood peak. The sub - basins are similar to the form of a rectangle. Area and elongation are the morphological parameters strongly influencing the stream flow. Drainage density and stream frequency are highly correlated. Drainage density gets altered by the land use, vegetal cover, deforestation and urbanization. Drainage density also affect stream flow. Finally, the expressions for drainage area in terms of the main stream length, drainage density in terms of stream frequency and average monthly stream flow contributed by unit area in terms of the average monthly rainfall were obtained. The data used for the final equation was inadequate. The equation may be improved, by increasing the number of rivergauge stations and providing more representative raingauge stations.
  • ThesisItemOpen Access
    Development of rational formulae to predict the advance and recession flow in border irrigation method
    (Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1992) Mary Regina, F; KAU; Ramadevi, A N
    An investigation was undertaken to develop the predictive relationship for water advance and recession in field borders with cow pea as the test crop. The experiment was conducted at the KCAET, Tavanur during February-April 1992. Border strips of 2 m width and 40m length were used for the study. The strips were laid out on three different slopes, 0.4 %, 0.3%, and 0.2%. Stream sizes of 4 Ips, 3 Ips, and 2 Ips per meter widths were used to irrigate the strips. There was nine treatments each replicated twice. Advance and recession times were noted at every 5 m distance from the upstream end of border. Advance and recession curves were plotted to draw conclusions on the effect of the three parameters viz stream size, slop and distance on advance and recession times. Uniformity of irrigation was also analysed for the different treatments and the treatment with 0.2% slope and 4 Ips/m width stream size showed the best uniformity. Multiple linear regression was done considering stream size, slope and distance from upstream end as independent variables. Advance and recession times were taken as dependent variables. Rational formulae to predict the advance and recession times were developed from the results of the multiple regression analysis.