Integrated assessment of soil erosian processes and policy in Oguta Lake watershed IMO state South East Nigeria

Abstract

Soil erosion is one of the most severe environmental problems in Nigeria, especially in the south east region of the country. Oguta Lake watershed is one of the affected watersheds in the region because of various human activities in the area. This thesis presents a thorough assessment of soil erosion processes and policy analysis which simultaneously integrates the physical condition, socio-economic context, institutions, and policy reforms in which stakeholders are embedded. Remote Sensing (RS), reconnaissance survey, two modelling assessment techniques (RUSLE and MPSIAC models) were applied to produce land use/land cover dynamics maps and spatial map of soil erosion, and key factors responsible for soil erosion in the location. Review of environmental regulations, semi-structured interview and focus group discussion were applied and analysed using Institutional Analysis and Development (IAD) framework. Land use and land cover changes were significant during the period 1990 – 2014 as 17% of the watershed was shifted to unstable zones and, thus, contributed to soil erosion by water in the watershed. Human activities like sand mining, deforestation, overgrazing and poor crop farming practice contributed significantly to land use/cover dynamics. Consequently, 14% of the forest and pastureland cover was lost due to human activities in the watershed. The spatial soil erosion map showed that severe soil erosion class was 25-36 tonnes/h/year and covered about 18% of the watershed. On the other hand, two (2) focus group discussions and forty-four (44) semi-structured interviews were conducted with the relevant stakeholders. It was observed that poverty and unemployment were the key drivers of land misuses and environmental degradation in the watershed. Based on the Institutional Analysis and Development (IAD) result. For the land ownership and allocation, this study proposes that the powers and influence of the traditional leaders and local government staff in land allocation and ownership in the watershed should be recognised by the government to increase land use compliance as stipulated in the Land Use Act 1978. For the sand mining, this study proposes an alternative arrangement that empowers the state government to have a shared management responsibility of managing sand mining activity in the watershed. For agricultural practice, this study proposes that operational level organisations should be domiciled in the local community where soil erosion is dominant. Women should be empowered with land and have an improved official representation in agricultural management. This would eliminate the barrier of poor communication channel and promote on the ground monitoring of farming activities and compliance among farmers.