The document discusses river drainage basins and flooding. It defines key terms related to the water cycle within a drainage basin such as precipitation, infiltration, interception, surface runoff, throughflow, evaporation, evapotranspiration, percolation, and the water table. It also explains the components of a flood hydrograph including the rising limb, falling limb, peak discharge, peak rainfall, storm flow, and normal base flow. Factors that influence the shape of a hydrograph are described such as land use, geology, soil, vegetation, and topography.