The Implication of Landslide Characteristics on Land use patterns in Upper Manafwa watershed of Eastern Uganda.
MetadataShow full item record
The Elgon region of Eastern Uganda is continuously becoming vulnerable to landslides which have destroyed crops, property, socio-economic infrastructures and led to loss of lives. There is however, paucity of data on the influence of these landslides on land use patterns and effective restoration and re-utilisation of landslide landscapes in the region. A study to analyse the implication of landslides on land use and utilization of landslide landscapes within the upper Manafwa watershed was undertaken. The study aimed at establishing and evaluating landslide characteristics for effective utilization of landslide landscapes in the watershed. Field investigations were undertaken to map and measure geometric and spatial distribution of landslides in the watershed. Satellite imagery data (Land sat7 ETM+ and Land sat8 OLIS) was acquired from USGS to analyse the spatial-temporal land use patterns spanning 2000 to 2020. Household and key informant interviews as well as FGDs were administered to establish landslide impacts, land use types and local interventions in landslide scars. Likert scale method was employed to assess people’s perceptions on level of effectiveness of local interventions. SPSS software was used to generate significances of the different local interventions against key factors and also to compute Chi-square tests. From the landslide scar geometric characteristics analysed, over 28.3% of the landslides were shallow and were dominant in the Eastern parts of the watershed. Study findings also show that 71.7% of the landslide scars were large and deep seated and were mainly dominant in the Southern and Northern parts of the watershed. The study established that 20% of the large and deep-seated landslide scars were rotational in nature. The geometric characteristics of landslide scars provided a basis for understanding the damages that may result from landslides on the land use. Landslide scars and coverage in the study area are unevenly distributed. The spatial-temporal distribution of landslides in the watershed has increased over the last 20 years. This implies that the disaster risk and vulnerability of communities to landslide disasters is increasing. Analysis of the spatial-temporal distribution of land uses indicates that settlements, cultivated land, pasture land, natural forests and woodlots as the major land use types in the watershed. The land use pattern have been changing due to landslide occurrences in the watershed as some of the former land use types have been replaced by others. Positive and negative linear relationships were achieved among key adoption factors with local interventions. Significant relationships (P≤0.05) were, observed for education levels with grass stripping and application of artificial fertilizers. Significant relationships were also observed for the income levels with application of artificial fertilizers. There were also significant relationship for the number of household members with afforestation and digging of run off channels. In conclusion, the most affected land use by landslides in the watershed was cultivated land followed by settlements and have led to destruction of farmlands as well as land abandonment. Local communities have adopted various interventions to rehabilitate the landslide scars. Although afforestation and agroforestry are the most dominant, they are the least effective local intervention measures in the restoration of landslide landscapes. Whereas grass striping, digging of run off channels, mixed farming, application of organic manure are considered as the most effective they are the least adopted interventions in the restoration and rehabilitation of the landslide landscapes. The study recommends that local communities should not only focus on short term recovery strategies but consider long term sustainable landslide scar rehabilitation measures. The study further recommends that application of grass stripping especially Napier grass, use of organic manures, digging of run off channels and mixed farming be emphasised in the region. Although afforestation and agroforestry are not considered by communities as being effective measures in restoring the landslides, the study recommends that these should however be encouraged especially for areas experiencing shallow landslides. This is due to the fact that such measures have been found to be effective elsewhere landslides are common.