Journal de télédétection et SIG

Abstrait

Analyzing the Rate of Land Use and Land Cover Change and Determining the Causes of Forest Cover Change in Gog District, Gambella Regional State, Ethiopia

Obang Owar Othow*, Sintayehu Legesse Gebre and Dessalegn Obsi Gemeda

This research study examines the causes of forest cover change, the rate of land use land cover change in Gog district, Gambella regional state between the years 1990-2017 using Geospatial techniques. Land sat TM image of 1990, ETM+ of 2002 and OLI-TIRS of 2017 were used to generate land cover map. Field observation, FGDs, KIs and remotely sensed data were used to analyze the causes and rate of land use land cover change. Six land cover classes including bare land, farmland, water, bush land, forest cover and grass land were used for classifications.

An explanatory sequential approach of mixed research design were used in this study where maximum likelihood technique of the supervised classification was used to classify land cover categories using ERDAS Imagine 2014 software. Out of the six classes, the results show a dramatic increase of farm land from (4%) in 2002 to (23%) in 2017 with annual expansion rate (24.86%) per annum, where forest cover declined from (23%) in 2002 to (18.11%) in 2017 with annual decreasing rate (-1.41%) per annum. The accuracy assessment report for 2017 map shows that an overall accuracy (83%) and Cohen kappa coefficient (82%) for the classifications. This massive declined in forest cover change of the study area was resulted due to commercial farm land expansion, forest fire, population growth, illegal logging, charcoal extraction, fuel wood collection and poor management of the natural resource. Out of all, expansions of large scale commercial agriculture become the leading cause for forest cover change in the study area. This dramatic change in forest cover change has further resulted in soil erosion, loss of soil fertility, migration of animals towards neighborhood countries. This has leaded to low agricultural productivity per plot of land, which contributes to low livelihood status of the rural community in Gog district.