| dc.description.abstract | While many wetlands in the central region are being degraded due to encroachment, Lwera
wetland system is facing degradation from over harvesting of natural resources, sand in particular.
The main objective of this study was to generate the total wetland change from the year 2010 to
2019. The study utilized three sets of Landsat TM/ETM+/MSS temporal images (30 m) of 2010,
2013 and 2019. The classification procedures were carried out using an arc GIS software version
10.3. The classified images were validated in a ground-truthing exercise using high resolution
imagery to improve the classification accuracy. Household interviews in Lukaya and Bukulula sub
counties were conducted to generate information on the factors that influence people into sand
mining and the observed impacts of sand mining activities on the wetland. The major factors
included poverty, high demand for sand, high value of sand, land tenure system, availability of
sand deposits and poor law enforcement. Majority (93.3%) of the local people perceived wetlands
in the area to have undergone high degradation within the last 19 years, and to have declined in
quantity and quality of vegetation, soil fertility and water quality. In the period of 2010 to 2019,
the area experienced a decline in the wetland coverage changed by 44.2%, from 102.67 to
58.45km2 and grassland by 14.78%. This was in contrast by an increase in coverage ofsand mining
sites by 53.1%, from 1.67km2 to 2.078km2; built-up with 77%, while bushland, mined area, open
water and bare ground, by 30%, 0.5%, 2.6% and 43.35% respectively. Fragstats, a spatial analysis
tool was used to assess the impact of sand mining on the diversity of the wetland vegetation. The
number of patches (np) for sand mines increased from 6, 23 and 104 in 2010, 2013 and 2019
respectively due to increase in sand mining areas. The np for wetlands increased from 860 to 1743
then decreased to 713 for the years 2010, 2013 and 2019 respectively and its, pd increased from
2.8 in 2010 to 5.6 in 2013 and then decreased to 2.3 in 2019. Pland of the wetland also continuously
reduced from 33.8 to 32,6 and 18.9 for the years as a result of increasing sand mining. Np for
grasslands increased from 1053 to 2122 in 2013 and later decreased to 1453 in 2019. The pd
increased for 3.4 in 2010 to 6.9 in 2013 and reduced to 4.3 in 2019. The pland also reduced from
23.5to 19.8 in 2013 and the slightly increased to 20.2 in 2019. The mps reduced from 6.9 in 2010
to 2.9 in 2013 and then increased to 4.3 in 2019. The landscape in 2013 was most fragmented and
had the most isolated patches. However, there was a slight regeneration in 2019. The lpi however,
continued to reduce from 18.7 to 17.69 and 10.7 in 2010, 2013 and 2019 respectively, implying
that the landscapes became more heterogeneous with time. | en_US |
