**Table 2.**

*m-value.*

**Figure 5.** *Crop management factor.*

#### *2.3.4 Crop management factor (C)*

The crop management factor which represents the ratio of soil loss under a given crop to that of the base soil [30] is perhaps the most important USLE factor because it represents conditions that could be managed most easily to reduce erosion [10]. The land use map was developed and used for analysing the c-value. The coverage was changed to grid where a corresponding c-value was assigned to each land cover class using reclass method in ArcGIS 10.3 and results presented as shown in **Figure 6**.

#### *2.3.5 Erosion management practice factor (P-value)*

The support practice factor, P, is a soil loss ratio for a specific support practice to the corresponding soil loss with up-and-down slope tillage [10]. The P-value ranges from 0 to 1 depending on the soil management activities applied in the specific plot of *Spatial Soil Loss Assessment Using USLE in Lake Ol Bolossat Catchment DOI: http://dx.doi.org/10.5772/intechopen.112129*

#### **Figure 6.** *Erosion management factor.*


#### **Table 3.** *P-value.*

land. These management activities highly depend on the slope of the area [30]. Wischmeier and Smith [23] calculated the P-value by delineating the land into two major land uses, agricultural land and other land. The agricultural land sub-divided into six classes based on the slope percent to assign different P-value as shown in **Table 3**. The study applied this same technique to assign the P-value of the catchment. The results were computed and presented in raster format as shown in **Figure 7**.
