Impacts of Urbanization on Kicukiro Water Supply Network: Spatio-Temporal Investigation Using Geospatial Models and Watergems
No Thumbnail Available
Date
2020-11-03
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
In Kigali, the capital city of Rwanda, the population is growing faster than the provision of services
with a strong population growth of average annual growth rate of 4.0 percent. The high population
growth has led to expansion of Kigali city. Nevertheless, the expansion of the city does not have
in parallel a clear viability plan of water supply, and also due to rapid urbanization, the burden on
the existing Kigali water distribution network is increasing along with widening gap between
supply and consumer water demand. The aim of this study was to investigate the spatio-temporal
impacts of urbanization on Kicukiro water supply network and water availability in order to
propose the sustainable adaptation strategies. Landsat imagery were used to examine spatiotemporal
changes in urbanization. The result of accuracy showed that overall accuracy of land
use/land cover (LULC) is 89.030 %, 93.715 %, 94.359 % and Kappa (K) is 85.40 %, 91.50 %,
89.80 % for 1999, 2013, 2019 respectively. The outputs showed that the total built-up land has
grown by 31.52 km2 from 1999 to 2019. Therefore, it was crucial to recognize that Kicukiro has
clearly experienced significant and rapid expansion. It was observed that the existing water supply
system of Kicukiro does not have a wider coverage of water distribution to some parts of the area.
This will lead to persistence water shortage, water scarcity and lack of accessibility to the basic
need of water for residential utility. The results indicate that the population of Kicukiro district
will increase from 419,209 inhabitants in 2019 up 918,538 inhabitants in 2039. The results also
showed that the current daily water demand (2019) is 76,854.98 m3 and 183,707.60 m3 for 2039.
It was observed that there is a large gap between demand and supply of water and there is no sign
of instant relief in the near future. At the end, WaterGEMS was used to analyze the existing water
supply system of Kicukiro district and it was found that the resulting pressures at all the junctions
and the flows with their velocities at all pipes are not enough to provide water to the study area.
The outcome of this study will be an efficient tool for water management as well as to support
planning processes and formulate policies to guide or redirect spatial growth in Kicukiro district;
it will also provide a foundation for a long-term plan to maintain, repair, augment, or replace a
water system when necessary in parallel with the urbanization. Furthermore, the result of this
research will serve as baseline for future scientific researches by applying the remote sensing and
GIS techniques in investigating impacts of urbanization on water supply system and water security.
Description
Keywords
Urbanization, Water Supply System, LULC Mapping, ENVI, Watergems