Accurate computation of runoff amount from a watershed is difficult, as it depends on several factors concerned with the atmosphere and watershed characteristics, to evaluate which effect on runoff is not so easy. On the basis of field experiences and observations, the following methods are frequently used in the field of soil and water conservation for estimating the maximum or [...]
The raindrop size, shape, mass, velocity, size distribution and its direction of fall are the main characteristics of raindrop regarding soil erosion. These characteristics are described as below: Characteristic # 1. Rain Drop Size: The rain drop size has been evaluated by Lowe (1967), who caught several raindrops on a flat sheet of slate which was ruled into squares so [...]
For any time duration, the average depth of rainfall falling over a catchment can be found by the following three methods: 1. The Arithmetic Mean Method 2. The Thiessen Polygon Method 3. The Isohyetal Method. 1. The Arithmetic Mean Method: The simplest of all is the Arithmetic Mean Method, which taken an average of all the rainfall depths as shown [...]