|Paige, G. - UNIV. OF ARIZONA|
|Shillito, R. - UNIV. OF ARIZONA|
Submitted to: ARS Workshop on Real World Infiltration
Publication Type: Proceedings
Publication Acceptance Date: July 22, 1996
Publication Date: N/A
Interpretive Summary: The amount of water running off from rainfall determines the extend of flooding for large storms. In addition, runoff water can be stored in ponds or dammed areas for irrigation, animal use or power generation. The amount of runoff cannot be accurately determined unless a good estimate is made of the amount of rainfall that goes into the ground (infiltration). Infiltration is a difficult quantity to measure over large areas. But it was found that a simple estimate of infiltration over a small area compared well with a large area estimate. This may enable infiltration to be estimated in a more economical way. However, it was also found that the rainfall must also be measured accurately to obtain good runoff estimates.
Technical Abstract: It is crucial to understand infiltration phenomena over range of spatial scales to fully assess its impacts on both soil-plant-water interactions at the small scale and runoff and erosion at large scales. In particular, the field and small watershed scale is important as this is a typical area subject to management as well as the scale at which observed hydrographs and associated runoff water quality samples are available. These measurements are often our only realistic means to evaluate the impacts of management decisions on hydrologic response, and therefore indirectly, on infiltration behavior. Therefore a coupled understanding of runoff and infiltration processes is required. Two primary issues in obtaining accurate estimates of infiltration and runoff over a range of scales are discussed. The first involves a preliminary assessment of the comparability of infiltration estimates obtained from different techniques applied over a wide range of spatial scales. The second discusses the necessity of accurate temporal and spatial estimates of rainfall to obtain infiltration estimates at both small and large scales.