摘要：Abstract
Background
This study was aimed at examining land use/cover changes over 48 years and its causative factors in the Gumara watershed of Lake Tana basin, Northwestern Ethiopia. Two sets of aerial photograph (1957 and 1985) and a multispectral Spot5 image (2005) were used as inputs to produce three GIS-based land cover maps of the study area. Socio-economic surveys, focus group discussion and field observation were also used to determine the cause and effects of these land use/cover
dynamics.
Results
The results showed that cultivated and settlement land expanded by 21.99 %, whereas forest land, shrub land, grass land and wetland declined by 85.30, 91.39, 76.15 and 72.54 % over the analysis period respectively. Population pressure, demand for fuel wood and construction material, agricultural expansion and policy and tenure insecurity were the major driving forces behind the land use/cover change. Environmental and local livelihoods implications such as lake water and its aquatic resources and soil degradation, biodiversity loss and forest cover decline are resulted from the changes.
Conclusion
The cumulative effect of these implications caused poverty and environmental degradation. Hence, there should be strategies of managing open access resources through participation of local people in the management. There should also be appropriate land use planning by identifying the proper land for specific purpose so that the marginal lands will not be put into agricultural use.
