An Overview on the Causes and Spatial Pattern of Erosion in Katsina State, Nigeria

Abstract: This paper presents an overview of the major causes of erosion and the spatial pattern of erosion in the Katsina region. The factors that cause erosion are mostly climatic, environmental and anthropogenic. The factors operate together depending on the environmental circumstances and time. Climate, geology, soil character and vegetation or land cover characteristics are the important influences on erosion. The climatic factors that influence runoff and erosion in the Katsina region are precipitation, temperature and wind. Precipitation is obviously, by far, the most important. The entire Katsina region has generally very ‘hard’ rainfall associated with tropical thunderstorms but differences do exist between the northern and southern parts of the region. In the southern part, around Funtua, Temperature and Rainfall average 24.8 °C and 1024 mm respectively, while in the northern part around Daura, the Temperature and Rainfall average 28.8 °C and 578 mm per annum respectively. Vegetation cover also decreases from north (Sudan Savannah) to south (Guinea Savannah). These might have affected the soil characteristics and land-use to some extent as the situation has facilitated erosivity of the regional soils. Slope length and steepness also play some role in erosion event in the region. In terms of soil erodibility, the southern parts of the Katsina region stand an advantage due to the better conditions of soil. The study reveals that all the types of erosion identified in the region could be found in all locations regardless of the little differences in climatic and environmental conditions. The extent of erosion facilitated by high rainfall duration and slope angle in the southern parts of the region, around Dandume and Sabuwa, is equitable by the bare surfaces and loose soil conditions in the northern parts of the region. In spite of the fact that erosion is widespread in the region, there are areas identified as prominently more devastated by erosion menace, particularly gulley erosion. These erosion sites are found along major roads, in farmlands and even in settled areas as either extension of burrow pits or river expansion. Rills and gullies that flourish along the channels are largely responsible for the expansion of some depressions and elongation of stream channel networks.

Keywords: Erosion, Overview, Katsina State, Spatial pattern