Explain how a physical factor can change the shape of flood hydrographs

Physical factors have a huge effect upon the shape of flood hydrographs. The main factor would be the climate of the area that the river flows in, which dictates the volume of precipitation; usually ordained by the season. For example, the river Rhone has a peak of river discharge during the month of May through to June; during France's early summer, when the glacier at the Rhone's source is melting, increasing discharge. Meanwhile in Guadiana, the river discharge is at it's lowest during the months of June through to September. This is the height of summer in Portugal, when precipitation is at it's annual lowest. This causes the hydrograph to drop when the hydrograph of the Rhone increases. However, despite the differences in hydrograph, the precipitation between these two countries may not be that different.