Assessment of landuse/cover changes and their drivers in and around Nakivubo wetland.

Abstract

Wetlands such as Nakivubo provide a wide range of ecosystem services. Despite its well-known importance, Nakivubo wetland has been vulnerable to drivers of land use change which have affected its spatial coverage and functioning. This study’s specific objectives were to: determine the major land use/land cover types and their distribution within Nakivubo wetland; assess the trend of land use/land cover changes between 2000 and 2020 and assess and rank the drivers of land use/cover changes in Nakivubo wetland between 2000 and 2020. The start period (year 2000) was influenced by the study by Lucy Emerton about the economic benefit of Nakivubo Wetland which was published in 1999. My start year as 2000 was chosen to find out if the knowledge of the economic benefits of the wetland had contributed to its conservation or not.

Satellite images of 2000, 2015 and 2020 were classified to identify the land use land cover types of Nakivubo wetland, the maps were also used to calculate the trends of change of the land use types. Focus group discussions, key informant interviews, direct observations and a household survey were used to collect data on the activities carried out in the wetland and also to identify the drivers of changes in the wetland. The Drivers, Pressures, State, Impact, Responses (DPSIR) framework was used to explain the cause-and-effect relationship between the changes and their drivers. A total of 396 respondents living within 500metres from Nakivubo wetland were involved in a household survey. The main activities carried out in the wetland include establishment of infrastructure (residential and commercial), farming, fishing, and harvesting biomass. Other activities engaged in by residents include; welding, washing cars, and videography. From the households survey the major three drivers of land use/land cover change were ranked as poverty, high demand for wetland products and availability of cheap housing on reclaimed portions of the wetland (occasioned by lack of affordable housing elsewhere). The wetland has undergone extensive change in land cover over the last two (2) decades and the main causes of this decreased land cover being increase in built up areas and farmland. These changes are attributed to rapid urbanization and a high rate of population growth. From the results of this study, the major changes in land use have been the increase in built up areas and open water. The vegetation cover significantly decreased namely; swamp/papyrus by 42%, grassland/shrub by 33%. The built-up area has had the highest rate of growth among all the other land use types. The changes in the extent of the built-up area are attributed to rapid urbanization, a high rate of population growth and scarcity of affordable housing close to Kampala City. Wetland vegetation has greatly reduced and this has subsequently affected its ability to perform its functions. The five (5) land cover types in the wetland are: open water; developed/built; swamp/papyrus; grassland/shrub; and planted/cultivated.

The study recommends that the Wetlands Management Department puts in place effective monitoring protocols and enforcement mechanisms to ensure that the wetland boundary alongside other wetland attributes are respected. Kampala Capital City Authority (KCCA) should take into consideration sensitive ecosystems before building plans are approved and in instances where developers construct without permission, demolitions and penalties should be enforced so as to stop the degradation of wetlands such as Nakivubo which are important due to their varied functions.