**6. Discussion**

Eastern Hindukush is mostly fed by glaciated water. When glaciers melt, it causes rapid erosion. This increased rate of erosion can affect the productivity of Dam which is located on Chitral River, leading to reduced power generation as well as loss of agriculture land. Initial output of the dam was about 250,00 kilowatts but with the passage of time, it reduced to 64,000–20,000 kilowatts.

RUSLE modeling approach comprises of following parameters; The Rainfall-Runoff Erosivity (R), Soil Erodibility (K), Slope Length and Slope Steepness (LS), Cover Management (C) and Support Practice (P) Factor. For the calculation of annual average soil erosion, the above five factors were estimated. Input layers of these factors were in ArcGIS individually. The high R factor values shows that the northern part of District Chitral receive more rainfall, as well as areas of Shoghar, Kalash and

**Figure 8.** *Cover management (C) of eastern Hindukush, Pakistan.*


#### **Table 1.**

*C-factor in the eastern Hindukush.*

the south eastern part of the study area as depicted by the results. The high elevation and topographical features of this region is the cause of excessive rain apart from other regions. The K factor of the study area ranges between 1 to 3.0. Soil erodibility map was generated using the ISRIC Soil Data of organic carbon, Clay, silt an = d sand content found in the region. Lower values of K factor show the soils having low

*Spatial Quantification of Soil Erosion Using Rusle Approach: A Study of Eastern Hindu… DOI: http://dx.doi.org/10.5772/intechopen.112346*

#### **Figure 9.**

*Erosion control practice management (P) of eastern Hindukush, Pakistan.*


#### **Table 2.**

*P factor values for slope as per agricultural practice.*

permeability and lower moisture content etc. The slope length and slope steepness (LS) factor has a range of 0 to 28,048. Flow accumulation and accelerated slope is represented by higher values of LS factor. Cover management, the C factor value falls in the range of 0 to 1.1 depicts the maximum land cover, whereas 0 represents the areas having minimum or very little land cover. The value of the support practice (P) factor is generated as 0.2 to 27.8. The region is mostly suffering from the ignorance of authorities on conservation, calculating this factor was a challenge because of the deficiency of data on conservation practices being carried out in the region. The annual average rate of soil loss of the study area is about 276 tons/ha/year, and the overall annual soil loss from this region is nearly 31 million tons/year. The results concluded by the severity classification of soil erosion estimated that % area of study

**Figure 10.** *Average annual soil loss rates (T/H/year) of the eastern Hindukush region, Pakistan.*

area falls in the very low zone, indicating soil erosion of <10 tons/ha/year, which is contradictory to the bearable limit of <2 tons/ha/year [24]. It clearly shows that this region needs to be addressed properly and timely in this regard. Moreover, almost 30% of the area falls in the low-erosion zone, 22% of the area in the region lies in the moderate zone, 16% lies in high-erosion zones, whereas 8% of the total study area lies under catastrophic erosion zone. The areas having minimum vegetation and steep slopes are more vulnerable to high soil erosion. Several land use activities, such as urbanization, overgrazing and deforestation, considerably increase erosion rates, and make it critical in areas having steep slopes and high elevation.

RUSLE has proved to be efficient and suitable tool for soil loss estimation and is globally acknowledged because of its accurate and reliable calculation of annual soil loss rates [20]. On the other hand, practical validation was not achieved because the resources were insufficient. The final outcome of this study is comparable to formerly conducted studies in the neighboring regions at watershed level. The result of a study proposed in the watershed of Fateh Jang showed that soil loss was 17–41 tons/ha/year for 1–10% slopes in uncultivated land, while the rate was relatively lower (9–26 tons' ha/year) for vegetative land [20]. Another proposed research for the soil loss appraisal in plain areas using RUSLE showed almost 8 tons/ha/year. Results of the study conducted above showed that the Eastern Hindukush is at more risk to soil erosion than the Potohar region, Pakistan.

This study shows that soil erosion is a severe hazard and is in dire need to be addressed. This study will help in identification and understanding risks associated with soil erosion. It does not only identify the risk but also listed the contributory factors

towards the erosion. The management and strategic planning to sustain natural resources and policymaking can analyze the findings of this study to minimizes oil loss.
