What is a river regime and what factors influence the character of a river regime?

A river regime is the annual variation in the discharge of a river, the amount of water that travels through a river and how this changes throughout the year. When we consider what factors affect how much water is flowing through a river, the obvious thing to consider would be precipitation. The amount, pattern and intensity of precipitation impacts when and how much water enters the river system. I.e. During the wet season in monsoon countries, rivers will have a significantly higher discharge than during the dry season.However, much of the water flowing through a river is not from immediate precipitation or run-off, but from sources such as ground water (this is called base flow). Therefore we must consider what factors impact water getting into the rivers (how these factors increase the response time of rivers to periods of precipitation), and therefore the discharge. Temperatures experienced. The Yukon river, in Alaska, experiences low discharge from december to may due to frozen conditions. From may to june, there is a dramatic increase in discharge due to melting snow and ice. The temperature will also impact rates of evaporation, which influences how much water makes it to the river. Geology and overly soils. This impacts whether water infiltrates and perculates into rocks, being stored as groundwater and increasing the time it takes for water to reach the river. For example, British rivers flowing over chalk (such as the River Kennet) maintain their flow even in very dry conditions, due to the baseflow being supplied by significant chalk aquifers. Amount and type of vegatation cover. Impacts the amount of water intercepted and the amount of evapotranspiration. For example, wetlands hold and release water very slowly into the river system.Human activities. Infrastructure influences the time it takes water to enter the river system, with man made materials such as tarmac decreasing rates of infiltration into soil and artificial conduits such as drains moving water into rivers quickly. On the other side of the spectrum, dams slow and regulate the flow of rivers, often with very little variability. The size of the river. Large rivers many cross several catchments and therefore have a combination of these factors influencing the discharge of the river