Modelling and Estimation of Average Annual Soil Loss in Ika South Local Government Area of Delta State, Nigeria

Abstract

Soil-related phenomenon and the Sustainable Development Goals (SDGs) particularly SDG-15 are strictly tied. A healthy soil ecosystem encourages the existence of life on Earth and for agricultural purposes. One of the key factors that is contributing to unhealthy soil ecosystems is soil erosion. The research involves the assessment and modelling of soil erosion using the Revised Universal Soil Loss Equation (RUSLE II) with the sole aim of ascertaining the annual Soil loss within the study area, this will be a veritable tool in estimating soil loss in farming systems and in supporting the achievement of the SDGs. It provides a concrete estimation of the distribution of soil erosion at Ika South LGA, through the combination of the influencing factors such as rainfall aggressivity, soil erodibility, topography, vegetation cover, and soil conservation practices. The soil loss estimated at Ika South ranges from 0 to 49119.93 t/ha/year. Results have shown that 5% of the surface area displays a high rate of soil loss, and it represents zones with moderate to severe soil erosion. These areas are mainly situated in moderate to very high slope where the runoff is high. This loss is favoured by the other factors of erosion, which are also combined to accelerate erosion losses significantly (58% of the total area has a very high rainfall erosivity), moderately erodible soils (49% of the soils show a K factor between 0.128 and 0.27t ha H/ha MJ mm), 78% of the soil have nearly level to gently undulating plains, and 14% of the areas representing steep slopes. The results revealed that, there is a probability that the rate of erosion will increase in the future in this area which pose a great threat to the achievement of the SDG-15. Therefore, proper land-use planning should be adopted such as cropping pattern for agricultural land in local area. Accurate planning should be done as a means for restoring degraded vegetation.