A kinematic conceptual model for kizinga basin for estimation of hydrological variables

Methods of separation of recession limbs of surface and base flows from total hydrographs resulting from successive storms on small watersheds are discussed, with special reference to Kizinga basin of the Coast Region. The average daily rainfall over the basin is derived using the Thiessen Polygon method, based on precipitation records from four stations. The effective rainfall is determined after successfully separating the base flow component from total runoff. Average distribution and one-day unit graphs are obtained based on data collected on fifteen most isolated storms on the catchment. Technique of estimation of the effective rainfall is also discussed. Attempts to correlate the flows preceding the storm hydrograph, base flows corresponding to flood peek and end of surface runoff resulted in a high degree of correlation among the three variables by hydrological standards Multiple regression analysis on the above variables yielded an equation which could be used to predict the base flow at the cessation of surface runoff for any storm pattern in any season. A method of estimating the suspended and bed components of the total load in the river in terms of characteristics of surface runoff hydrograph of the storm is also presented.