On-Site Cost of Gully Erosion and Benefit-Cost of Rehabilitation vs. Establishment of Conservation Measures in the Kilimanjaro Region, Tanzania

Abstract

This study provides empirical justification for prevention of on-site costs of gully erosion so as to raise political and public awareness of the impacts of land degradation and significance of sustainable land management from an economic perspective in the Kilimanjaro Region. In the context of this paper, the on-site cost of gully erosion is about TZS 82.61 million ha-1 and TZS 82.22 million ha-1 respectively assuming maize, a staple in the Kilimanjaro Region and sunflower, a commercial crop is grown. From an economic perspective, it is more viable to establish soil-erosion control structures than gully rehabilitation. The average benefit-cost ratios for the latter are almost three times as much as for the former if maize is grown, but two times more in the case of sunflower. These results support the old adage that says “prevention is better than cure”. This information is of particular significance because some decision-makers and land-users have inadequate knowledge of the need for preventing soil loss from an economic viewpoint. They contend that the durability of rehabilitation interventions outweighs the short-term gains of investing in soil-erosion control structures. Considering that land in the region is being degraded by soil erosion, while the rest is vulnerable because of physical factors and anthropogenic activities, it would be prudent of decision-makers especially to support sustainable land management initiatives that aim at controlling soil loss instead of rehabilitation after vast amounts of land are rendered unproductive due to soil loss.