Regression analysis was used to establish the relationship between urbanisation in Harare and
river yield of Manyame River at gauging station C21. To detect the effects of urbanisation,
Landsat images were downloaded from USGS website (http://landsatlook.usgs.gov/viewer)
and they were processed in Quantum GIS and System for Automated Geoscientific Analysis.
Image classification was carried out in SAGA were the images were classified into five main
classes which were Forest, Scrub, Ground, Water and Built up. Change detection was then
carried out in SAGA and also the changes that occurred were calculated as a percentage in
SAGA. The results showed that in Upper Manyame, forests were totally deforested by 18.04
percent. The area that was covered by scrub was reduced by 10.2 percent. Built up area
increased sharply by 11.2 percent and the area that was covered by bare ground drastically
expanded by 17.8 percent. The average NDVI for C21which showed the reduction in
vegetation was calculated in Arc GIS. The median NDVI values were then calculated in
Excel and it showed that there was a general decrease in the NDVI values in C21 catchment
with the highest 0.47 in 1998 showing a healthier forest and lowest was 0.36 in 2011 showing
a degraded forest. The river yield for Manyame river at gauging station C21 was calculated in
excel and showed that there was a general increase in the river yield as a percentage from 104
percent to 129 percentage although there was a sharp decrease in 2008 to 109 percent where
there was a draught in Zimbabwe. Linear least square regression analysis was run to establish
the relationship between river yield and NDVI and the relationship was statistically
significant with p<0.05 tested by Gen stat 2014 edition . The NDVI and river yield had a
strong inverse relationship of -0.72. The r2 value for NDVI and river yield was 0.5199.
SSA, R (2021). Effects of urbanisation in Upper Manyame on the flow of Manyame River at Gauging Station C21. Afribary.com: Retrieved May 08, 2021, from https://afribary.com/works/effects-of-urbanisation-in-upper-manyame-on-the-flow-of-manyame-river-at-gauging-station-c21
Research, SSA. "Effects of urbanisation in Upper Manyame on the flow of Manyame River at Gauging Station C21" Afribary.com. Afribary.com, 03 May. 2021, https://afribary.com/works/effects-of-urbanisation-in-upper-manyame-on-the-flow-of-manyame-river-at-gauging-station-c21 . Accessed 08 May. 2021.
Research, SSA. "Effects of urbanisation in Upper Manyame on the flow of Manyame River at Gauging Station C21". Afribary.com, Afribary.com, 03 May. 2021. Web. 08 May. 2021. < https://afribary.com/works/effects-of-urbanisation-in-upper-manyame-on-the-flow-of-manyame-river-at-gauging-station-c21 >.
Research, SSA. "Effects of urbanisation in Upper Manyame on the flow of Manyame River at Gauging Station C21" Afribary.com (2021). Accessed May 08, 2021. https://afribary.com/works/effects-of-urbanisation-in-upper-manyame-on-the-flow-of-manyame-river-at-gauging-station-c21