Spatial Analysis of Gully Erosion Control Measures in Gombe Town, Gombe State Nigeria

Abstract

The performance of gully erosion control measures in Gombe metropolis is presented. This paper aimed at assesses the spatial distribution of gully erosion control measures in Gombe town since 2004 to 2015. The objectives of the research are to identify the spatial distribution of gullies in Gombe town and to analyze the length of gullies so far checked or controlled. High resolution images of the study area (Quick bird 2004 and 2015) were acquired for GIS analysis and ground truth measurement. Information gathered from field and image digitization was used Error! Hyperlink reference not valid. to determine increase in the size and length of gully erosion from 2004 to 2015. In order to identify recently developed gullies, ArcGIS software was used to perform spatial analysis. Result of the study revealed that most of the previous uncontrolled or partially checked gullies have increased in length to 131.02 km as against the 121.50 km in 2003. This represents an increase of 9.72 km (7.42 %) over the 13 years period or about 75 metres annual increase in gully length. The analysis further revealed that there were 615 first order gullies representing 62% second order has 173 gullies or 18%, third order gullies has 89 in number and represent 12%, the fourth order has a total of 51gullies in number representing 5%, the fifth order consist of 30 gullies or 2% and the sixth order number which is the main gully has 11 in number representing 1.0% respectively. Out of the 131.02 km length of gully erosion inventory in Gombe town in 2015 only 41.32 km length has been controlled and 35.92 km under engineering method representing 87%; 5.1 km (12.3%) length of vegetation and only 0.3km under stone wall control measures out of the total 41.32 km length of the three methods of control measures under study. It is therefore suggested that apart from government efforts other stakeholders should be encourage and participate in gully erosion control especially adoption of vegetation method which is affordable, accessible and acceptable.