The natural factors that influence infiltration rate include soil characteristics, plant and animals, and topography. Man can modify these features to highly influence runoff. For instance, areas with grass/vegetation will reduce runoff by reducing speed of water on surface hence increasing percolation chances. On the other hand, bare lands will offer less resistance to water hence faster runoffs. In the event that rainfall produces much water to the land surface than it can be absorbed by the soil, the excess water will be left on the surface to flow down slopes as runoff. Wet areas with higher vegetation covers can have higher water tables that lead to faster saturations hence runoff. On soil characteristics, finer soils will reduce infiltration and increase runoff and vice versa. Still, the size of rain drops can help compact soil reducing runoff. Concerning plant cover, they increase infiltration rates in that they slow the pace of water falling to surface and reduce chances of faster runoff. Areas that lack vegetation are subject to flash floods whenever high precipitation takes place. In an incidence when there is a steep slop at headwaters, then more runoff is apparent. All this water will eventually reach the...

If the runoff is much, it means much water will reach the streams hence higher chances of flooding, if runoff is less, less water reaches streams hence less potential for floods. Remember the rate of runoff is a factor of topography where steep slopes have faster flows compared to gradual slopes.
In conclusion, land activities and vegetation cover affects the speed and duration surface water from rainfall/storms takes before reaching streams significantly affecting stream flow hence flooding potential. Natural factors like soil characteristics, plant and animals, and topography can be modified by human activities to greatly influence runoff which dictates the amounts of water running over land and streams hence the potential of floods. Increasing vegetation cover will increase percolation, reducing run off hence less chances for flooding.

Works cited

Rodriguez, Daniel Andres, Javier Tomasella, and Claudia Linhares. Is the forest conversion to pasture affecting the hydrological response of Amazon catchments? Signals in the Ji-

Parana basin. 26 March 2010. Web. 25 April 2010. Article available from http://www3.interscience.wiley.com/cgi-bin/fulltext/123261361/PDFSTART