After reading this article you will learn about the hydrologic cycle and its components. Runoff, a potential carrier of nutrients and sediment to streams and lakes is best described in the science of hydrology. Two basic physical principles governing the amount and distribution of water on the earth are those of mass conservation and energy conservation. These principles, along with [...]
Factors affecting runoff may be divided into those associated with the precipitation, and the watershed characteristics. Factor # 1. Precipitation: Since by far the largest portion of precipitation occurs as rain, and the rainfall directly affects soil erosion, the characteristics of rainstorm and intensity, duration and frequency of rainfall are of interest in describing the runoff. (a) Characteristics of Rainstorm: [...]
Several types of empirical expressions have been developed from time to time to predict peak rate of runoff from agricultural watersheds. Some of the most common expressions are described below: 1. Rational Method: The oldest and the most famous hydrological model of predicting peak rate of runoff is the rational formula, expressed as: q = CIA …(3.2) where, q = [...]