ArticlePDF Available

REVIEW ON WATER RESOURCES MANAGEMENT AND KEY THREATS IN RWANDA, EAST AFRICA

Authors:
  • Rwanda Space Agency (RSA)

Abstract and Figures

Water is important for human health, industry, agriculture and ensuring the integrity and sustainability of the ecosystem. The water resources are the top affected by climate variability and population growth. The current population of Rwanda is about 12 million heading to about 25 million in 2050 under the changing climate, where since 1970 temperature rose by 1.4°C and is predicted that in 2050 to be about 2.5°C with severe effects on water resources in Rwanda. Thereby, this study reviewed the status and causes of water quality problems and suggested appropriate options to undertake for sustainable water resources access, employ and management in Rwanda. It was noticed that among others, the key threats to water quality in Rwanda, include not limited to climate change causing rainfall patterns which generated flooding, landslides and periodic droughts, which loaded pollutants into water. In addition, water quality is jeopardized by the rapid population growth, agrochemicals, industrialization, urbanization, soil steepness and land mismanagement. Accordingly, the reviewed water quality indicate that the water quality pollution likelihood is increasing over time. These facts reveal that the water quality soon or late will be highly polluted and calls for further adaptation and management measures.
Content may be subject to copyright.
eISSN 2345-0363
Journal of Water Security, 2018, Vol. 4
Article Number: jws2018003
DOI: https://doi.org/10.15544/jws.2018.003
Copyright © 2018 The Authors. Published by Aleksandras Stulginskis University, Riga Technical University. This is an openaccess article
distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction
in any medium, provided the original author and source are credited. The material cannot be used for commercial purposes. 1
REVIEW ON WATER RESOURCES MANAGEMENT AND KEY THREATS IN
RWANDA, EAST AFRICA
Valentine Mukanyandwia, b, c, *, Lamek Nahayoa, b, c, Egide Hakorimanaa, b, c,
Aboubakar Gasiraboa, b, c, Shinebayar Otgona, b
a,* Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, 818 South Beijing Road, Urumqi
830011, Xinjiang, China. E-mail: valensmk@gmail.com
b University of Chinese Academy of Sciences, Beijing, China
c University of Lay Adventists of Kigali, Kigali, Rwanda.
Submitted 06 July 2018; accepted 17 November 2018
Abstract. Water is important for human health, industry, agriculture and ensuring the integrity and sustainability of the
ecosystem. The water resources are the top affected by climate variability and population growth. The current population
of Rwanda is about 12 million heading to about 25 million in 2050 under the changing climate, where since 1970
temperature rose by 1.4°C and is predicted that in 2050 to be about 2.5°C with severe effects on water resources in
Rwanda. Thereby, this study reviewed the status and causes of water quality problems and suggested appropriate options
to undertake for sustainable water resources access, employ and management in Rwanda. It was noticed that among
others, the key threats to water quality in Rwanda, include not limited to climate change causing rainfall patterns which
generated flooding, landslides and periodic droughts, which loaded pollutants into water. In addition, water quality is
jeopardized by the rapid population growth, agrochemicals, industrialization, urbanization, soil steepness and land
mismanagement. Accordingly, the reviewed water quality indicate that the water quality pollution likelihood is increasing
over time. These facts reveal that the water quality soon or late will be highly polluted and calls for further adaptation and
management measures.
Keywords: climate change, population growth, water resource, water quality, Rwanda.
Introduction
Water is the most important for human health,
agriculture, industry and in ensuring the integrity and
sustainability of the ecosystem. Most parts of the world,
particularly poor regions face water scarcity, pollution
and lack of mitigation and adaptation capabilities
(Muhirwa et al., 2010; Piao et al., 2010). The world
population considerably grew after the industrial
revolution, from 3.7 billion in 1970 to 6.08 billion in
2000, heading to about 9.7 and 11.2 billion by 2050 and
2100, respectively (Akresh et al., 2011). Therefore,
balancing the available water and its growing needs,
mainly driven by population growth and the changing
climate can be a good alternative for water resources
management (Kiptum, Sang, 2017).
In Rwanda, water resources are basic to many
sectors including power generation, agriculture and
fishery. Nevertheless, water resources are the top affected
by climate variability and population growth (Arsiso et
al., 2017; Vörösmarty et al., 2000; Piao et al., 2010).
Observable and potential effects of climate change on
water resources in Rwanda include flooding, landslides,
change in the periodic droughts (Urama, Ozor, 2010;
Bizimana, Sönmez, 2015).
Hydrology of Rwanda
Description of the study area
Rwanda occupies a surface of 26,338 km2 on the eastern
shoulder of the Kivu-Tanganyika Rift in Africa. It lies
between 1°4' and 2°51' south latitude and 28°53' and
30°53' east longitude (Karamage et al., 2016). Rwanda
has two rainy seasons; the first begins from March to
May and the last begin from October to November with
an average rainfall of 110-200 mm per month. The first
and short dry season starts from December to the end of
February, while the longer one lasts from June to early
September. Rwanda’s average temperature ranges
between 19 to 27°C (Abimbola et al., 2017, Nahayo et
al., 2016, Ndayisaba et al., 2016).
Rwanda is made up of five administrative
subdivisions locally known as provinces (Northern,
Southern Eastern and Western Province and Kigali City,
the capital); each province is further subdivided into five
to eight districts (Fig. 1).
Rwanda is relatively rich in water resources; about
188,190 ha are occupied by lakes (Table 1 and figure 1);
approximately 7,260 ha are for rivers, while wetlands
seize an approximate area are 77,000 ha. The surface
water generally has a pH ranging between 6 and 8
(Nsengimana et al., 2012; Cavallo et al., 2013). This
expresses that Rwanda has many water resources being
lakes, rivers and marshlands.
However, rapid population growth, cropland
expansion and agrochemicals, inappropriate household
and industrial wastewater management and rainfall
harvest, insufficient water quality monitoring and few
researches along with soil topography (steep slope) that
facilitate the sediments and nutrients transport into
watershed are the major water pollutants in Rwanda
(Fidèle et al., 2015; Sekomo et al., 2011; Wronski et al.,
2015; Mupenzi et al., 2009).
Journal of Water Security, 2018, Vol. 4, jws2018003
2
Fig.1. Water resources network of Rwanda.
Table 1. Rwanda major lakes and their characteristics (International..., 2018)
Lakes
Surface area,
km2
Surface area in
Rwanda, km2
Mean elevation
above sea level, m
Maximum
depth, m
Mean
depth, m
Kivu
2700
1330
1460
480
220
Muhazi
34.6
34.6
1443
13.8
10.1
Burera and Ruhondo
28
28
1862
3.9
2.1
Cyohoha South
630
100
1553
11
5.2
Mugesera
40
40
1300
3.8
2.2
Rweru
100
20
1160
2.1
3.9
Ihema
90
90
1292
7.0
5.0
These phenomena have multiple repercussions on
the quantity and quality of water, like reducing the river
flows and lake levels, drying up of some water sources
and undermining water biodiversity. Therefore, this
expresses the problem of water quality in Rwanda despite
its abundance and calls for appropriate adaptation
measures.
Thereby, the objectives of this study review are to
indicate status and causes of water quality problems and
suggest appropriate options to undertake for sustainable
water quality access, use and management in Rwanda.
Trends in water quality in Rwanda
Climate change and population growth is the most
considerable factors that are affecting the ecosystems
consequently, the impact of climate change on water
quality is ascribed to changing hydrology and air
temperature (Hosseini et al., 2017; Liu, Chan, 2016). The
water quality in Rwanda is being exposed to several
degrading and polluting forces being natural and man-
made. Previous reports on the water physico-chemical
parameters and heavy metals (Nahayo et al., 2016;
Usanzineza et al., 2011; Mupenzi et al., 2009; Muhirwa
et al., 2010; Uwimpuhwe et al., 2014) estimated low pH
level 5.9 at the Nyabugogo River compared to the
standards of the World Health Organization and
European Union (pH 6.0-8.0). Moreover, the total
suspended solids of the Rweru-Mugesera wetland, Congo
and Nile basins (Rwandan side), 67.91, 920.90 and
162.86 mg/l, respectively, were above the standards (˂30
mg/l). Whilst, the estimated concentration of Iron,
Manganese and Lead were higher in the Lake Muhazi,
Cyohoha, Akagera Transboundary and Nyabugogo rivers
(Sekomo et al., 2011; Nshimiyimana et al., 2010). The
below table 2 represents the average of heavy metal
pollution of water sources analyzed by Water and
Sanitation Corporation Limited (WASAC Ltd) of
Rwanda.
Journal of Water Security, 2018, Vol. 4, jws2018003
3
Table 2. Averaged heavy metals in comparison with WHO
Standard (Nahayo et al., 2018).
Sampling
sites
Fe
Mn
Cu
Al
Zn
mg/l
Nyagatare
0.35
0.25
0.45
0.95
0.20
Kabarondo
0.13
0.26
0.49
0.10
0.31
Kibungo
0.18
0.19
0.59
0.10
0.80
WHO
Standards
0.30
0.10
1.0
0.20
3.0
According to the drinking water quality standards of
the World Health Organization, recent study on drinking
water quality (See Table 2) which analysed heavy metals
pollution in the Eastern province showed that drinking
water is mainly polluted during rainy season.
This exposes consumers to several risks as far as
some parameters like manganese and iron values are
higher than WHO suggested standards for drinking water
quality. Consequently, this may cause cancer, liver, heart
and pancreatic to consumers. This is congruent with the
report of Sekomo et al. (2011) which indicates that
drinking water sources are more polluted during rainy
season than dry season where sediments and other wastes
easily load into waters.
The assessment on microbiological water quality in
Kigali city, the capital of Rwanda (Table 3) revealed the
presence of Klebsiella, Enterobacter, Staphylococcus and
Escherichia coli in river water and ground water
(Uwimpuhwe et al., 2014; Rutanga, 2014; Nigatu et al.,
2015). Although the drinking water seems polluted, the
Government of Rwanda through her Ministry of health
recommends citizens to drink boiled water and use of
Sûr’Eau (water purification product, commonly used in
Rwanda) in order to minimize the pollution resulting
risks from the water being consumed. While bench
terraces are used on steep slope land to minimize the
runoff which transports pollutants into water sources.
Table 3. Microbiological analysis (Rutanga, 2014)
Type of Sample
P/A of
Klebsiella sps
P/A of
Enterobacter sps
P/A of
Staphylococcus aureus
P/A of
Escherichia coli
River water
+
+
+
+
Spring water
-
-
-
-
Tap water
-
-
-
-
(+) P presence; (-) A absence.
In addition, Kivu lake, the biggest lake of Rwanda
as previously reported (Mupenzi et al., 2017) gets it
source from 23 Rwandan rivers drain into the Lake Kivu.
These rivers are polluted at different scale, where those
rivers near by the forestland are less polluted than those
which move around farmland. In addition, the water
quality in Rwanda, as previously reported highlighted
(Habiyaremye et al., 2011; Bendito, Twomlow, 2015;
Karamage et al., 2017; Mupenzi et al., 2017) is
threatened by the rapid population growth,
agrochemicals, steepness of Rwandan soil and land
mismanagement, climate variability together with lack of
proper rainfall harvest which leads to sediments transport
and consequently pollute the water quality. This
expresses that the water quality soon or late will be
highly polluted and calls for further adaptation and
management measures.
Population growth in Rwanda
Population is the one of the fundamental elements of
sustainable development but also the vulnerability to
water resources. The reports of the United Nations
(Gerland et al., 2014) and National Institute of Statistics
of Rwanda (National…, 2014) indicate that both
Rwandan rural and urban population rapidly grew. The
current population is about 12,501,156 with population
density of 474.64 per kilometer square and it is projected
to be about 28 million in 2095 (Fig. 2).
Fig. 2. Rwandan population growth (from 1950 to 2095)
This rapid population growth is assigned to high
fertility, culture and illiteracy along with refugees who
came back from neighboring countries after the 1994
Genocide. Moreover, it is worthy noted that, population
growth is correspondingly associated with water demand
for daily uses such as bathing, cooking and other socio-
economic development activities requiring water such as
agriculture, industry, public utilities, etc. The following
table 4 illustrates how water demand in urban will be
increasing compared to rural settings.
Journal of Water Security, 2018, Vol. 4, jws2018003
4
Table 4. Water demand per settlements in Rwanda between
2012 and 2040 (l/home/day) (Consultancy…, 2014)
Types of
settlements
2012
2020
2030
2040
Rural
40
60
80
90
Urban
60
70
80
100
This, additionally can be associated to previous
reports (Majaliwa et al., 2012; Cavallo et al., 2013) on
water resources exploitation in Rwanda, indicating that
all available water resources (ground and surface water)
including rainfall are not fully exploited, meaning that the
higher rural to urban migration, the higher water demand,
and this implies more investments for maximum
available water use; otherwise, the available water
resources might be subject to overexploitation and
degradation due to increasing demand.
Urbanization and industrialization
The report of the United Nation (UN, 2014) indicates that
the world urban dwellers grew from 746 million in 1950
to 3.9 billion in 2014 and will surpass six billion in 2045.
Much of this planned urban expansion will take place in
developing areas, particularly Africa. However, these
urban dwellers’ water demand and the source of water
used are still unknown (McDonald et al., 2014, Barthel,
Banzhaf, 2016). Moreover, estimates show that 22% of
the world water is used by industries, while their
improper wastewater management is polluting water
quality (Chae et al., 2015; Ouyang et al., 2006; Maharjan
et al., 2016). This lack of proper determination of water
sources used and improper wastes management affects its
quantity and quality management.
The total population of Kigali, the capital city of
Rwanda, gradually grew from 357 in 1907 to 236,000
inhabitants in 1991 and reached 1,000,000 and 1.132
million in 2010 and 2012 respectively (National…,
2014). This however, affects the municipal wastes
management due to informal settlements, expansion of
the city and industrialization whose final results is water
quality degradation and pollution as well (Mohammed et
al., 2017; Uwimbabazi, Lawrence, 2011). Despite the
present Governmental initiative (which is not yet fully
completed) of re-allocating industries from or near
watersheds to appropriate and well equipped location
(Rwanda Special Economic Zone), their former location
led to immense wetland and biodiversity degradation
(Etale, Drake, 2013; Nhapi et al., 2011). In addition, the
report of the Kigali City Conceptual Master Plan
(Kigali…, 2007) indicates that the city will keep
expanding in size and its inhabitants will almost triple in
the next 25 years. For this fact, it is good to envisage
appropriate municipal wastewater treatment facilities and
adaptive measures for the water quality enhancement.
Food Demand
In Rwanda, agriculture employs about 80% of the total
population. This sector encountered a decline due to the
1994 Genocide, and this caused many socio-economic
failures (Lovell, Tumuri, 1999). However, as indicated by
the report of Organization & UNICEF in 2015 after the
1994 Genocide, high food demand-imposed cropland
expansion from 13,150 to 18,425 km2 in 1990 and 2013,
respectively, growing crops at appropriate and productive
area (Crop Intensification Program, CIP) with selected
seeds and fertilizers which increased from 6,537 tons in
2000 to 44,264 tons in 2012. However, despite this
agricultural progress, its practices are reported to pollute
the watersheds (Falkenmark, 2013; Sekomo et al., 2011).
Furthermore, Rwandan agriculture is subsistence,
and farmers own small plot land cultivated for household
consumption and mostly located near or in watersheds.
Additionally, a large cropland is on steep slope soils,
easily exposed to erosion, floods and landslides which are
major soil and water quality problems in Rwanda
(Bizoza, 2014; Nahayo et al., 2017; Rugigana et al.,
2013). Moreover, marshland over-exploitation, high
volumes of agrochemicals, and lack of approach to
farmers on appropriate and timely fertilizers’ application
are leading to watersheds degradation and pollution
(Bucagu et al., 2013; Fidèle et al., 2015). Therefore, as
water quality management is concerned under rising food
demand, agriculture-environmentally friendly practices
need to be envisaged for water quality management in
Rwanda. In addition, as illustrated in figure 3, the
periodical change on personal prediction land, it
predicted that in 2050 one person will use only 0.10 ha.
Fig.3. Change on individual land per decade in Rwanda (UN,
2014)
This expresses that the food demand will be rare
same as the water resources will be affected by
insufficient area to cultivate.
Climate change in Rwanda
The changing climate in Rwanda extant very serious
national challenges and risks transversely various sectors
such as agriculture and water resources.The report of the
Intergovernmental Panel on Climate Change (IPCC)
indicates that the climate is changing; the global average
temperature is rising with shifting rainfall patterns,
whereas the glaciers, arctic sea ice and Greenland ice
sheet are melting, primarily due to greenhouse gases
emitted in the atmosphere (Mahmood et al., 2016; Myhre
et al., 2013). It is predicted that warm sea temperature
and less precipitation may increase drought and
desertification in the subtropical and equatorial Eastern
Africa and consequently, these alterations will seriously
Journal of Water Security, 2018, Vol. 4, jws2018003
5
impact on the quantity and quality of water, economy,
food security and social welfare of poor countries mainly
the Sub-Saharan countries including Rwanda. The
following figures 4 and 5 details the projected changes in
temperature and rainfall in Rwanda.
Fig. 4. Projected temperature patterns and rainfall in Rwanda
adopted from (Isidoro, Grattan, 2011).
As shown in figure 4, in Rwanda, as evidenced by
the Kamembe, Gisenyi, Kigali and Ruhengeri weather
stations, there is a mixture of both low and high
temperature records in the future. These numbers in
figure 4 are congruent with the reports of (Houghton et
al., 2001) and (Uzamukunda, 2015) that highlight that
Rwanda recorded a 1.4°C rise in temperature since 1970,
which is predicted to be about 2.5°C in 2050, and this
will lead to change in intensity and frequency of rainfall
causing either drought or flood, which in turn alter the
water quality.
Fig. 5. Precipitation prediction at different sites in Rwanda from
2010 to 2099 (Haggag et al., 2016).
As indicated in figure 5, a precipitation trend is
obvious from almost 1 to 1.29% of increase within the
years of 2010 and 2099. This as a result, is being
experienced in Rwanda, where some regions are under
water shortage causing its quality depletion and socio-
economic failure, while others register high precipitation
which generates flooding and transport of sediments into
water with pollution and eutrophication likelihood. As far
as climate change is impacting on water resources and
other associated socio-economic impact (Veraart et al.,
2017) there is great call in developing appropriate
mechanisms including mitigation and adaptation policies,
awareness and skilled human resources able to combat
and deal with the impact of climate change on water
quality.
Conclusion and Recommendations
Water quality and scarcity are widespread problems and
its sustainable management is becoming a quite
challenge. Even though a range of resolving suggestions
have been provided such as provision of investment in
water infrastructure maintenance, water reuse, recycle,
flotation, chemical precipitation, ion exchange and
membrane filtration and coagulation-flocculation, the
rapid human population growth, increase on point and
non-point water pollution sources are threats to water
quality.
The government of Rwanda has launched the
Integrated Water Resources Management, an approach of
developing, monitoring and managing water resources.
Nonetheless, for the policy to be fruitful and sustainable
there is a great need of managing the wastewater, the
rapid expanding urbanization and informal settlements,
industrial and mining activities. Therefore, the followings
are suggested for the water quality management in
Rwanda under the above-mentioned threats:
1. Rapid population growth is increasingly leading to
natural resources degradation; it is advised to set a
fixed number of children per family with penalties or
tax incentives to those disregarding the policy.
2. Since Rwanda is rich in precipitation throughout the
year, it is good to consider maximum rain harvest;
this will increase the underground storage and
enables local communities to supply water to their
infrastructure and reduces sediments carried into
watershed.
3. Population growth requires sufficient food, to do so,
irrigation is proposed to boost the agricultural
production, however, it is good to first check on
environmental pros and cons of every irrigation
technique (sprinkler and flood irrigation, drip
irrigation) before use.
4. Rwanda as a developing country with high water
demand, water re-use and desalination would help
much, where industrial, saline water and household
wastewater can be turned into usable water for other
uses such as garden watering, carwash, toilet uses.
This will be a good option and reduce the wastewater
associated consequences.
5. It is suggested to promote environmental research
and education from basic schools; hydrological data
sharing and free access for water quality
management enhancement.
6. Although the government prioritized Crop
Intensification Program (CIP), with one crop at
appropriate location, it would be good to initiate and
promote break crop system, different crops at once,
Journal of Water Security, 2018, Vol. 4, jws2018003
6
this will enhance soil fertility and maintain soil at a
level of not demanding high chemical fertilizers, and
reduces water pollution.
7. Even though, environmental management is a cross
cutting issue at every decision-making level,
monitoring and evaluation of its execution and
success basing on community’s reality and national
development plans is highly suggested
References
Abimbola, O.; Wenninger, J.; Venneker, R.; Mittelstet, A. R.
2017. The assessment of water resources in ungauged
catchments in Rwanda. Journal of Hydrology: Regional
Studies, 13, 274-289.
https://doi.org/10.1016/j.ejrh.2017.09.001
Akresh, R.; Verwimp, P.; Bundervoet, T. 2011. Civil war, crop
failure, and child stunting in Rwanda. Economic
Development and Cultural Change, 59, 777-810.
https://doi.org/10.1086/660003
Arsiso, B. K.; Tsidu, G. M.; Stoffberg, G. H.; Tadesse, T. 2017.
Climate change and population growth impacts on surface
water supply and demand of Addis Ababa, Ethiopia.
Climate Risk Management, 18, 21-33.
https://doi.org/10.1016/j.crm.2017.08.004
Barthel, R.; Banzhaf, S. 2016. Groundwater and surface water
interaction at the regional-scaleA review with focus on
regional integrated models. Water Resources
Management, 30, 1-32. https://doi.org/10.1007/s11269-
015-1163-z
Bendito, A.; Twomlow, S. 2015. Promoting climate smart
approaches to post-harvest challenges in Rwanda.
International journal of agricultural sustainability, 13,
222-239. https://doi.org/10.1080/14735903.2014.959329
Bizimana, H.; Sönmez, O. 2015. Landslide occurrences in the
hilly areas of Rwanda, their causes and protection
measures. Disaster Science and Engineering, 1(1), 1-7.
Bizoza, A. R. 2014. Institutions and the adoption of
technologies: Bench terraces in Rwanda. In: Vanlauwe,
B.; van Asten, P.; Blomme, G. (Eds.). Challenges and
opportunities for agricultural intensification of the
humid highland systems of Sub-Saharan Africa.
Springer, Cham, 335-354.
https://doi.org/10.1007/978-3-319-07662-1_26
Bucagu, C.; Mbonigaba, J.; Uwumukiza, B. 2013. Effects of
mineral and organic fertilizers on crop productivity and
nutrient use efficiency in smallholder farms of Southern
Rwanda. Rwanda Journal, 1, 15-34.
Cavallo, E.; Galiani, S.; Noy, I.; Pantano, J. 2013. Catastrophic
natural disasters and economic growth. Review of
Economics and Statistics, 95, 1549-1561.
https://doi.org/10.1162/REST_a_00413
Chae, S.-R.; Chung, J.-H.; Heo, Y.-R.; Kang, S.-T.; Lee, S.-M.;
Shin, H.-S. 2015. Full-scale implementation of a vertical
membrane bioreactor for simultaneous removal of organic
matter and nutrients from municipal wastewater. Water, 7,
1164-1172. https://doi.org/10.3390/w7031164
Consultancy Services for Development of Rwanda National
Water Resources Master Plan. 2014. Rep.
021/RNRA/2011-2012 [online], [cited 21 June 2018].
Available at:
http://www.minirena.gov.rw/uploads/media/Rwanda_Wat
er_Resources_Master_Plan.pdf
Etale, A.; Drake, D. 2013. Industrial pollution and food safety
in Kigali, Rwanda. International Journal of
Environmental Research, 7, 403-406.
Falkenmark, M. 2013. Adapting to climate change: towards
societal water security in dry-climate countries.
International Journal of Water Resources Development,
29, 123-136.
https://doi.org/10.1080/07900627.2012.721714
Fidèle, N.; Pierre, B. J.; Théodomir, M. 2015. Assessment of
mineral fertilizer use in Rwanda. International Journal of
Agriculture Innovations and Research, 3, 1478-1482.
Gerland, P. Raftery, A. E.; Ševčíková, H.; Li, N.; Gu, D.;
Spoorenberg, T.; Alkema, L.; Fosdick, B. K.; Chunn, J.;
Lalic, N.; Bay, G.; Buettner, T.; Heilig, G. K.; Wilmoth, J.
2014. World population stabilization unlikely this century.
Science, 346, 234-237.
https://doi.org/10.1126/science.1257469
Habiyaremye, G.; Ge, J. W.; Mupenzi, J. D. L. P.; Balogun, W.
O.; Jerop, S. A. 2011. Effects of global climate change on
water resources in Rwanda: Lake Kivu case study.
Materials Science & Engeneering, 55-57, 268-271.
https://doi.org/10.4028/www.scientific.net/AMM.55-
57.268
Haggag, M.; Kalisa, J. C.; Abdeldayem, A. W. 2016.
Projections of precipitation, air temperature and potential
evapotranspiration in Rwanda under changing climate
conditions. African Journal of Environmental Science and
Technology, 10, 18-33.
https://doi.org/10.5897/AJEST2015.1997
Hosseini, N.; Johnston, J.; Lindenschmidt, K.-E. 2017. Impacts
of climate change on the water quality of a regulated
prairie river. Water, 9(3), 199.
https://doi.org/10.3390/w9030199
Houghton, J. T.; Albritton, D.; Meira Filho, L.; Cubasch, U.;
Dai, X.; Ding, Y.; Griggs, D.; Hewitson, B.; Isaksen, I.;
Karl, T. 2001. Contribution of Working Group I to the
Third Assessment Report of the Intergovernmental Panel
on Climate Change. United Kingdom: Cambridge
University Press.
International Lakes Environment Committee (ILEC). 2018
WLDB Lake List in Republic of Rwanda [online], [cited
21 June 2018]. Available at:
http://wldb.ilec.or.jp/Search/LakeListCountryCode/RW.
Isidoro, D.; Grattan, S. 2011. Predicting soil salinity in response
to different irrigation practices, soil types and rainfall
scenarios. Irrigation Science, 29, 197-211.
https://doi.org/10.1007/s00271-010-0223-7
Karamage, F.; Zhang, C.; Ndayisaba, F.; Nahayo, L.;
Kayiranga, A.; Omifolaji, J. K.; Shao, H.; Umuhoza, A.;
Nsengiyumva, J. B.; Liu, T. 2016. The need for awareness
of drinking water loss reduction for sustainable water
resource management in Rwanda. Journal of Geoscience
and Environment Protection, 4, 74.
Karamage, F.; Zhang, C.; Fang X.; Liu, T., Ndayisaba, F.,
Nahayo, L., Kayiranga, A. Nsengiyumva, J. B. 2017.
Modeling rainfall-runoff response to land use and land
cover change in Rwanda (19902016). Water, 9, 147.
https://doi.org/10.3390/w9020147
Kigali Conceptual Master Plan. 2007. Kigali, Republic of
Rwanda.
Kiptum, A. R.; Sang, C. C. 2017. Determinants of groundwater
retention in wells: a case of Keiyo north district, Elgeyo
Marakwet County, Kenya. Journal of Water Security, 3,
jws2017007.
https://doi.org/10.15544/jws.2017.007
Journal of Water Security, 2018, Vol. 4, jws2018003
7
Liu, W.-C.; Chan, W.-T. 2016. Assessment of climate change
impacts on water quality in a tidal estuarine system using
a three-dimensional model. Water, 8, 60.
https://doi.org/10.3390/w8020060
Lovell, E. R.; Tumuri, M. 1999. Provisional Environmental
Impact Assessment for the Extraction of Coral Reef
Products for the Marine Aquarium and Curio Trade. Rep.
Fiji: Government.
Maharjan, B.; Pachel, K.; Loigu, E. 2016. Trends in urban storm
water quality in Tallinn and influences from stormflow
and baseflow. Journal of Water Security, 2, jws2016001.
https://doi.org/10.15544/jws.2016.001
Mahmood, R.; Jia, S.; Babel, M. S. 2016. Potential impacts of
Climate Change on Water Resources in the Kunhar River
Basin, Pakistan. Water, 8, 23.
https://doi.org/10.3390/w8010023
Majaliwa, J.; Bashwira, S.; Tenywa, M.; Kansiime, F.;
Bagalwa, M.; Karume, K.; Adidja, M.; Adipala, E. 2012.
An overview of pollution loading into Lake Kivu basin.
In: Third Biennial Conference RUFORUM, 24-28
September 2012, Entebbe, Uganda, 861-868.
McDonald, R. I.; Weber, K.; Padowski, J.; Flörke, M.;
Schneider, C.; Green, P. A.; Gleeson, T.; Eckman, S.;
Lehner, B.; Balk, D.; Boucher, T.; Grill, G.; Montgomery,
M. 2014. Water on an urban planet: Urbanization and the
reach of urban water infrastructure. Global Environmental
Change, 27, 96-105.
https://doi.org/10.1016/j.gloenvcha.2014.04.022
Mohammed, R.; Scholz, M.; Zounemat-Kermani, M. 2017.
Temporal hydrologic alterations coupled with climate
variability and drought for transboundary river basins.
Water Resources Management, 1-14.
https://doi.org/10.1007/s11269-017-1590-0
Muhirwa, D.; Nhapi, I.; Wali, U.; Banadda, N.; Kashaigili, J.;
Kimwaga, R. 2010. Characterization of wastewater from
an abattoir in Rwanda and the impact on downstream
water quality. International Journal of Ecology &
Development™, 16, 30-46.
Mupenzi, J. P.; Ge, J.; Habiyaremye, G. 2009. Major Elements
in Lake Muhazi, Rwanda, East Africa. Acta Geologica
Sinica (English Edition), 83, 927-931.
https://doi.org/10.1111/j.1755-6724.2009.00114.x
Mupenzi, C.; Li, L.; Nahayoa, L.; Amanambua, A. C.;
Kayirangaa, A.; Karamageb, F.; Ndayisabaa, F.;
Nyeshejaa, E. M.; Nsengiyumvaa, J. B. 2017. Spatial
pattern assessment of Lake Kivu basin rivers water quality
using National Sanitation Foundation water quality and
rivers pollution indices. Desalination and Water
treatment, 95, 118-127.
https://doi.org/10.5004/dwt.2017.21566
Myhre, G.; Shindell, D.; Bréon, F.-M.; Collins, W.; Fuglestvedt,
J.; Huang, J.; Koch, D.; Lamarque, J.-F.; Lee, D.;
Mendoza, B.; Nakajima, T.; Robock, A.; Stephens, G.;
Takemura, T.; Zhang, H. 2013. Anthropogenic and natural
radiative forcing. In: Stocker, T. F.; Qin, D.; Plattner, G.-
K.; Tignor, M.; Allen, S. K.; Doschung, J. Nauels, A.;
Xia, Y.; Bex, V.; Midgley, P. M. (Eds.). Climate Change
2013: The Physical Science Basis. Contribution of
Working Group I to the Fifth Assessment Report of the
Intergovernmental Panel on Climate Change. Cambridge
University Press. 659-740.
https://doi.org/10.1017/CBO9781107415324.018
National Institute of Statistics of Rwanda (NISR). 2014.
Rwanda fourth populiation and housing census 2012.
[online], [cited 21 June 2018]. Available at:
http://www.statistics.gov.rw/survey-period/fourth-
population-and-housing-census-2012
Nahayo, L.; Li, L.; Kayiranga, A.; Karamage, F.; Mupenzi, C.;
Ndayisaba, F.; Nyesheja, E. M. 2016. Agricultural impact
on environment and counter measures in Rwanda. African
Journal of Agricultural Research, 11, 2205-2212.
https://doi.org/10.5897/AJAR2016.10899
Nahayo, L.; Mupenzi, C.; Kalisa, E.; Mukanyandwi, V.,
Gasirabo, A.; Hakorimana, E. 2018. Seasonal drinking
water quality monitoring for the Community Wellbeing in
the Eastern Rwanda. Journal of Environment Protection
and Sustainable Development, 4, 1-6.
Nahayo, L.; Mupenzi, C.; Kayiranga, A.; Karamage, F.;
Ndayisaba, F.; Nyesheja, E. M.; LI, L. 2017. Early alert
and community involvement: approach for disaster risk
reduction in Rwanda. Natural Hazards, 86, 505-517.
https://doi.org/10.1007/s11069-016-2702-5
Ndayisaba, F.; Guo, H.; Bao, A.; Guo, H.; Karamage, F.;
Kayiranga, A. 2016. Understanding the spatial temporal
vegetation dynamics in Rwanda. Remote Sensing, 8, 129.
https://doi.org/10.3390/rs8020129
Nhapi, I.; Wali, U.; Uwonkunda, B.; Nsengimana, H.; Banadda,
N.; Kimwaga, R. 2011. Assessment of water pollution
levels in the Nyabugogo Catchment, Rwanda. Open
Environmental Engineering Journal, 4, 40-53.
https://doi.org/10.2174/1874829501104010040
Nigatu, W.; Kangeli, S. G.; Nsengimana, J.; Nsabimana, A.
2015. Microbiological safety assessment of groundwater
wells in Bugesera and Muhanga districts of Rwanda.
Journal of Applied & Environmental Microbiology, 3,
106-111.
https://doi.org/10.12691/jaem-3-4-3
Nsengimana, H.; Masengesho, F.; Nyirimbibi, D. K. 2012.
Some physico-chemical characteristics of ground water in
Rwanda. Rwanda Journal, 25, 101-109.
https://doi.org/10.4314/rj.v25i1.7
Nshimiyimana, F.; Nhapi, I.; Wali, U.; Nsengimana, H.;
Banadda, N.; Nansubuga, I.; Kansiime, F. 2010.
Assessment of heavy metal pollution in a trans-boundary
river: The case of the Akagera River. International
Journal of Mathematics & Computation, 9, 26-45.
Ouyang, T.; Zhu, Z.; Kuang, Y. 2006. Assessing impact of
urbanization on river water quality in the Pearl River
Delta Economic Zone, China. Environmental Monitoring
and Assessment, 120, 313-325.
https://doi.org/10.1007/s10661-005-9064-x
Piao, S.; Ciais, P.; Huang, Y.; Shen, Z.; Peng, S.; Li, J.; Zhou,
L.; Liu, H.; Ma, Y.; Ding, Y. 2010. The impacts of
climate change on water resources and agriculture in
China. Nature, 467, 43-51.
https://doi.org/10.1038/nature09364
Rugigana, E.; Nyirazinyoye, L.; Umubyeyi, A.; Nsengiyumva,
J.; Kanyandekwe, C.; Ntahobakulira, I. 2013.
Prioritization of disasters and their management in
Rwanda. East African Journal of Public Health, 10, 429-
439.
Rutanga, J. 2014. Assessment of microbiological and
physicochemical parameters of ground water: A case
study of Gikondo Industrial Park, Kigali, Rwanda.
Ethiopian Journal of Environmental Studies and
Management, 7, 153-159.
https://doi.org/10.4314/ejesm.v7i2.6
Sekomo, C. B.; Nkuranga, E.; Rousseau, D. P.; Lens, P. N.
2011. Fate of heavy metals in an urban natural wetland:
Journal of Water Security, 2018, Vol. 4, jws2018003
8
the Nyabugogo Swamp (Rwanda). Water, Air, & Soil
Pollution, 214, 321-333.
https://doi.org/10.1007/s11270-010-0426-9
United Nations (UN), Department of Economic and Social
Affairs, Population Division. 2014. World Urbanization
Prospects: The 2014 Revision, Highlights
(ST/ESA/SER.A/352).
Urama, K. C.; Ozor, N. 2010. Impacts of climate change on
water resources in Africa: the role of adaptation. African
Technology Policy Studies Network, 29, 1-29.
Usanzineza, D.; Nhapi, I.; Wali, U.; Kashaigili, J.; Banadda, N.
2011. Nutrients inflow and levels in lakes: A case study of
Lake Muhazi, Rwanda. Ecology & Development Sum, 19,
53-62.
Uwimbabazi, P.; Lawrence, R. 2011. Compelling factors of
urbanization and rural-urban migration in Rwanda.
Rwanda Journal, 22, 9-26.
Uwimpuhwe, M.; Reddy, P.; Barratt, G.; Bux, F. 2014. The
impact of hygiene and localised treatment on the quality
of drinking water in Masaka, Rwanda. Journal of
Environmental Science and Health, Part A, 49, 434-440.
https://doi.org/10.1080/10934529.2014.854674
Uzamukunda, S. 2015. Improving the existing farming systems
toward a climate smart agriculture in Musanze district of
Rwanda. Master’s Thesis in Agricultural
Science/Agroecology. Swedish University of Agricultural
Sciences.
Veraart, J. A.; Van Duinen, R.; Vreke, J. 2017. Evaluation of
socio-economic factors that determine adoption of climate
compatible freshwater supply measures at farm level: a
case study in the southwest Netherlands. Water resources
management, 31, 587-608.
https://doi.org/10.1007/s11269-016-1399-2
Vörösmarty, C. J.; Green, P.; Salisbury, J.; Lammers, R. B.
2000. Global water resources: vulnerability from climate
change and population growth. Science, 289, 284-288.
https://doi.org/10.1126/science.289.5477.284
Wronski, T.; Dusabe, M. C.; Apio, A.; Hausdorf, B.; Albrecht,
C. 2015. Biological assessment of water quality and
biodiversity in Rwandan rivers draining Into Lake Kivu.
Aquatic Ecology, 49, 309-320.
https://doi.org/10.1007/s10452-015-9525-4
... revolution and is expected to reach 9.7 billion by 2050 [4]. The current population of Rwanda stands at 12 million (population density of 470.6 people per km 2 ) and is expected to double by 2050 [5]. This implies that the country is densely populated in comparison to other East African countries [6,7]. ...
... It shares common frontiers with Uganda to the North, Burundi to the South, Tanzania to the East and the Democratic Republic of the Congo (DRC) to the West. Like other East African countries, Rwanda is relatively rich in water resources (Figure 1) [5]. The current study was done in Nyabarongo (Nyawarungu) and Nyabugogo rivers which form part of the Rwandese drainage system. ...
Preprint
Water is an indispensable natural resource that is often prodigiously threatened by anthropomorphic activities. This study evaluated the physicochemical properties of water and selected heavy metals in edible muscles of a piscivorous fish (Protopterus annectens) from Nyabarongo and Nyabugogo rivers of Rwanda. Edibility health risk was evaluated using the target hazard quotient method. Water samples were taken in triplicate from Ruliba station and Kirinda bridge on Nyabarongo river and Giticyinyoni on Nyabugogo river. Fish samples were obtained from the sampling stations on Nyabarongo river. All samples were analyzed following standard methods and analytical results indicated that the average temperature, pH, total dissolved solids and electrolytic conductivity of water from the rivers were within WHO acceptable limits. The statistical mean concentrations of the ionic components of the water samples were 1.61 ± 0.03, 0.53 ± 0.002, 0.24 ± 0.02 and 0.051 ± 0.01 mg/L for Fe, Mn, Cu and Pb respectively at Ruliba station and 0.63 ± 0.02, 0.02 ± 0.002, 0.09 ± 0.01, 0.06 ± 0.002 and 0.75 ± 0.02 mg/L for Fe, Mn, Zn, Cr and Pb respectively at Kirinda bridge. Water from Giticyinyoni had 1.57 ± 0.02, 0.49 ± 0.03, 0.29 ± 0.058, 0.43 ± 0.058, 0.15 ± 0.00 and 0.59 ± 0.058 mg/L of Fe, Mn, Cu, Zn, Cr and Pb respectively. Zinc, Cu, Cr and Cd were below detection limits in samples from Ruliba station and Kirinda bridge (Nyabarongo river). Edible muscles of P. annectens from Nyabarongo river contained 272.8 ± 0.36, 292.2 ± 0.25, 8.8 ± 0.36, 135.2 ± 0.15, 148.0 ± 0.21 and 432. 0 ± 0.50 mgkg-1 for Fe, Mn, Cu, Zn, Cr and Pb at Ruliba station and 336.0 ± 0.70, 302.6 ± 1.22, 6.4 ± 0.26, 44.7 ± 0.20, 138.2 ± 0.17 and 302.4 ± 1.50 mgkg-1 for Fe, Mn, Cu, Zn, Cr and Pb respectively at Kirinda bridge. Health risk assessment indicated that consumption of the edible muscles of P. annectens may lead to deleterious health effects as reflected by values of target hazard quotients being greater than one. Therefore, the Rwandese government should lay strategies to reduce pollution of the rivers. Further research should evaluate the heavy metal content of metabolically active organs of P. annectens from Nyabarongo river as well as the microbiological profile of water from the rivers.
... Global population registered a sharp increase to 7.8 billion in 2020 following the industrial revolution and is expected to reach 9.7 billion by 2050 (Akresh et al., 2011). With 13.03 million inhabitants occupying about 26,336 km 2 area (495 inhabitants per km 2 ), Rwanda has the second-highest population density in Africa (Imasiku & Ntagwirumugara, 2020;Mukanyandwi et al., 2018). In East Africa, it is the most densely populated country (Karamage et al., 2016a;UN, 2015). ...
Article
Full-text available
Heavy metal pollution and accumulation in aquatic ecosystems present serious threats to sustainability. In the current study, the heavy metal content of water and edible muscles of a piscivorous fish (Protopterus annectens) as well as bioaccumulation of the heavy metals in fish tissues were evaluated. Samples of water (n = 6) and fish (n = 6) were taken from Kirinda bridge and Ruliba station on Nyabarongo river and analyzed by UV spectroscopy and atomic absorption spectrometry respectively. The heavy metal concentrations in water were: iron (0.63 ± 0.02 and 1.61 ± 0.03 mg/kg), manganese (0.53 ± 0.002 mg/kg at Ruliba station), chromium (0.06 ± 0.002 mg/kg at Kirinda bridge), cadmium (0.106 ± 0.002 mg/kg at Ruliba station) and lead (0.75 ± 0.02 and 0.051 ± 0.01 mg/kg). Edible muscles of Protopterus annectens contained 336.0 ± 0.70, 302.6 ± 1.22, 6.4 ± 0.26, 44.7 ± 0.20, 138.2 ± 0.17 and 302.4 ± 1.50 mg/kg of iron, manganese, copper, zinc, chromium and lead at Kirinda bridge and 272.8 ± 0.36, 292.2 ± 0.25, 8.8 ± 0.36, 135.2 ± 0.15, 148.0 ± 0.21 and 432. 0 ± 0.50 mg/kg of iron, manganese, copper, zinc, chromium and lead respectively at Ruliba station. Most of the heavy metal contents were above the recommended levels. Bioaccumulation factors recorded in Protopterus annectens ranged from 403.2 to 15,130 L/kg, implying that consumption of this fish could pose deleterious health risks. The study suggested that P. annectens could be used as a sentinel organism for biomonitoring of aquatic ecosystems.
... In addition to the mentioned causes of the water quality changes, climate change is another factor accelerating the change in water quality (Bondarenko et al., 2019). Like in other parts of the world, pollution from human activities is also a threat to water bodies in Rwanda, especially lakes (Mukanyandwi et al., 2018). ...
Article
Full-text available
Rwanda possesses multiple lakes, whose properties were rarely described. The present study assessed physico-chemical characteristics of water in Burera and Ruhondo lakes located in highly populated area with steep slopes, which are under extensive agriculture, thus water quality monitoring is important. Both lakes were alkaline with high content of Mg, while Ruhondo had higher electrical conductivity than Burera. Phosphorus and nitrogen exceeded Class III EPA standards indicating that both lakes are at risk of eutrophication. Keywords: water quality, lakes Burera and Ruhondo, Rwanda
... Furthermore, this will reduce the cost of water treatment and enhance community's wellness and natural resources management as well. Many researchers focused on seasonal evaluation of the assessment of metals in lakes and rivers (Low et al. 2016;Mukanyandwi et al. 2018;Rajeshkumar et al. 2018) but they did not work on the springs which are used with numerous people especially in developing countries. The accessibility of water supply is still inadequate in Rwanda; more than 38% of Rwandan people use natural sources including springs and the information about water quality of those springs was unknown. ...
Article
Full-text available
The quality of drinking water source remains as a major concern in areas of developing and underdeveloped countries worldwide. The treatment and supply of drinking water in Rwanda are carried out by Water and Sanitation Corporation, a state-owned public company. However, it is not able to supply water to all households. Consequently, the non-serviced households depend on natural water sources, like springs, to meet their water requirements. Nevertheless, the water quality in these springs is scarcely known. Therefore, this study assessed and compared metal elements in drinking water sources in the dry and rainy seasons in 2017 using the contamination degree, metal index, and geographic information systems to reveal the spatial distribution of water quality within the considered water sources of springs in Rwanda. The samples were collected monthly from nine water sources of springs and the measured elements are aluminium, calcium, copper, iron, manganese, and zinc. The metal index indicated that during the dry season and rainy season, the sites of Kibungo (1.10 and 1.26) and Kinigi (1.01 and 1.54) have assessed a metal index which is higher than 1. Thus, the water quality of those sites was getting the threshold of warning. The analysis indicated that pollutants are easily transported into water bodies during the rainy season in urban and rural areas to a greater extent than during the dry season .
Article
The landscape surrounding protected areas (PAs) plays a big role in supporting the achievement of conservation goals. This paper examines demographic dynamics in the vicinity of Akagera National Park (ANP) both in time and space, considers its implication on land-use/land-cover (LULC) change of one of its neighboring districts, and involves the existing environmental planning policies to anticipate the fate of the ANP. Data retrieved from Rwanda Land Management and Use Authority (RLMUA) and from the National Institute of Statistics of Rwanda (NISR) were reinforced with field observation and Global Positioning System (GPS) measurements taken within Gatsibo district where the study was conducted and injected into a Geographic Information System (GIS) for mapping and analysis. Findings revealed that in the next 50 years, the increasing human settlement and associated social-economic needs will erase any remnant wildlife hotspots in the ‘Unrestricted zone’ of the district and reclaim intrusion in its ‘Restricted zone’ of which ANP is part. This raises imminent fear of growing cases of encroachment of human activities into illegal and high-risk zones and a possible second de-gazettement of the park. The reversal of this trend requires the implementation of the local LULC plan and the promotion of the ecological lifestyle.
Article
Full-text available
Spatial variation of water quality in rivers is a function of the surrounding environment and land, the reason why water indices are important to reduce the bulk of information into a simplified and understandable manner for specific purposes. This study aimed at assessing the spatial distribution of water quality of 23 Rwandan rivers that drain into the Lake Kivu by using the National Sanitation Foundation Water Quality Index (NSFWQI) and the River Pollution Index (RPI). The study collected field data and analyzed the parameters of the NSFWQI and RPI including suspended solids, turbidity, biological oxygen demand, nitrate, temperature, total phosphorus, pH, fecal coliform and dissolved oxygen. For gathering details related to entities adjacent to rivers, land use and land cover, topography and rainfall have been analyzed. The results showed that good water quality (negligibly polluted) was located in areas dominated by forestland while bad and very bad (39%, 26%) classes of rivers (severely polluted) were influenced by the dominance of farmland. Moreover, 22% of rivers in medium class were equivalent to 26% moderately polluted due to the disturbance of other land use types and other factors such as slope and tropical rainfall.
Article
Full-text available
Continuous degradation of biophysical factors and over utilisation of available water through unsustainable consumptive means, tend to threaten the existence of groundwater supply. The aim of this study was to examine the influence of human activities and biophysical factors on groundwater retention in wells in Keiyo North District, Elgeyo Marakwet County, Kenya. Structured questionnaires were used to obtain primary data. Systematic simple random sampling technique was applied in the study. Excel and Statistical Package for Social Sciences (SPSS) were used for data analysis. The results of the study showed that biophysical factors had significant influence on groundwater level and/or retention capacity during dry season and no association during rainy season. Altitude and land use were insignificant in influencing groundwater retention during both dry and wet seasons. The logit model showed that nearness to the forest, swamp, river had high probability to influence groundwater retention in the wells. However, the random factor in the regression model showed significant difference in influencing groundwater retention, which explains more on the impact of other parameters that were beyond the scope of this study such as soil characteristics and climate on water retention capability. The findings of this study will inform policy and decision makers as they develop sustainable conservation strategies that will ensure continuous groundwater supply.
Article
Full-text available
Study region: Rwanda is a landlocked country in Africa with precipitation ranging from 800 mm yr−1 in the east to 1500 mm yr−1 in high-altitude regions in the north and west. Study focus: Streamflow estimation is an important task that is required in water resource assessments due to its importance in planning, decision-making and economic development. In this study, streamflow characteristics of ungauged catchments in Rwanda were calculated using a regionalization approach based on climate similarity and stepwise multiple-regression analysis. One climatic homogeneous region was identified and datasets of nine gauged stations and general available catchment characteristics were used to develop non-transformed and log-transformed regression models. New hydrological insights for the region: Results of this study show that climate, physiography and land cover strongly influence the hydrology of catchments in Rwanda. Using leave-one-out cross-validation, the log-transformed models were found to predict the flow parameters more suitably. These models can be used for estimating the flow parameters in ungauged catchments in Rwanda and the methodology can be applied in any other region, as long as sufficient and good quality streamflow data is available.
Article
Full-text available
Addis Ababa is expected to experience water supply stress as a result of complex interaction of urbanization and climate change. The aim of this study is to investigate water demand and supply prospects for the City of Addis Ababa by applying the Water Evaluation and Planning (WEAP) hydrological model and using scenarios of population growth trends and climate change. The study includes analysis of water consumption, hydrological information and climate data which is statistically downscaled using approach used to generate climate data available at the Worldclim data center. Bias corrected climate model data of NIMR-HadGEM2-AO under a midrange RCP 4.5 scenario and RCP8.5, high emissions scenario was used for the study. The result shows that the projected population of Addis Ababa city using high population growth rate (3.3%) will be about 7 million by the year 2039. The climate change projections result under RCP 4.5 and RCP 8.5 scenarios on surface water supply shows that the level of reservoirs volume both at Legedadi/Dire and Gefersa reservoirs will be reduced in the projected years between the years 2023 and 2039. The result of the RCP 8.5 scenario with low population growth shows that the unmet water demand will be 257.28 million m3 in 2037. The result of the RCP 4.5 scenario with low population growth shows that the unmet water demand will be 314.91 million m3 in 2037. This indicates that the unmet water demand with the dry climate of RCP 4.5 climate change scenario is higher than RCP 8.5 scenario. Under the RCP 4.5 scenario with high population growth (3.3%) the unmet water demand is 87.42 million m3 in 2030, 158.38 million m3 in 2035 and 380.72 million m3 in 2037. This indicates that the unmet water demand in both high population growth and the dry climate of RCP 4.5 climate change scenario will lead to severe shortage of water in the city. The most effective management options are water tariff increasing, domestic water use technology efficiency improvement and water harvesting which give satisfactory result in mitigating unmet demand of climate change and population growth in the city.
Article
Full-text available
Flows along the upper Qu'Appelle River are expected to increase in the future via increased discharge from Lake Diefenbaker to meet the demands of increased agricultural and industrial activity and population growth in southern Saskatchewan. This increased discharge and increased air temperature due to climate change are both expected to have an impact on the water quality of the river. The Water Quality Analysis Simulation Program (WASP7) was used to model current and future water quality of the upper Qu'Appelle River. The model was calibrated and validated to characterize the current state of the water quality of the river. The model was then used to predict water quality [nutrient (nitrogen and phosphorus) concentrations and oxygen dynamics] for the years 2050-2055 and 2080-2085. The modelling results indicate that global warming will result in a decrease in ice thickness, a shorter ice cover period, and decreased nutrient concentrations in 2050 or 2080 relative to 2010, with a greater decrease of nutrient concentrations in open water. In contrast to the effect of warmer water temperatures, increased flow through water management may cause increases in ammonium, nitrate, and dissolved oxygen concentrations and decreases in orthophosphate concentrations in summer.
Article
Full-text available
Stormwater runoffposes serious environmental problems and public health issues in Rwanda, a tropical country that is increasingly suffering from severe floods, landslides, soil erosion and water pollution. Using the WetSpa Extension model, this study assessed the changes in rainfall runoffdepth in Rwanda from 1990 to 2016 in response to precipitation and land use changes. Our results show that Rwanda has experienced a significant conversion of natural forest and grassland to cropland and built-up areas. During the period 1990-2016, 7090.02 km² (64.5%) and 1715.26 km² (32.1%) of forest and grassland covers were lost, respectively, while the cropland and built-up areas increased by 135.3% (8503.75 km²) and 304.3% (355.02 km²), respectively. According to our estimates, the land use change effect resulted in a national mean runoffdepth increase of 2.33 mm/year (0.38%). Although precipitation change affected the inter-annual fluctuation of runoff, the long-term trend of runoffwas dominated by land use change. The top five districts that experienced the annual runoffdepth increase (all >3.8 mm/year) are Rubavu, Nyabihu, Ngororero, Gakenke, and Musanze. Their annual runoffdepths increased at a rate of >3.8 mm/year during the past 27 years, due to severe deforestation (ranging from 62% to 85%) and cropland expansion (ranging from 123% to 293%). These areas require high priority in runoffcontrol using terracing in croplands and rainwater harvesting systems such as dam/reservoirs, percolation tanks, storage tanks, etc. The wet season runoffwas three times higher than the dry season runoffin Rwanda; appropriate rainwater management and reservation could provide valuable irrigation water for the dry season or drought years (late rainfall onsets or early rainfall cessations). It was estimated that a reservation of 30.5% (3.99 km³) of the runoffin the wet season could meet the cropland irrigation water gap during the dry season in 2016.
Article
The rapid population growth, climate change and inappropriate natural resources use and management are predominantly limiting the community's access to safe drinking water. This record is high in poor regions compared to developed countries due to lack of awareness and/or financial capabilities. The objective of this study was to compare changes on drinking water quality during dry and rain seasons for the quality management and community wellness. The measured heavy metals were Calcium, Iron, Manganese, Copper, Aluminium and Zinc between July 2016 and February 2017 in the Eastern province of Rwanda. The samples were collected from three sites randomly selected among the water sources available in the study area. The monthly water samples were analysed in the laboratory of the water treatment plants neighbouring each sampling site. The results showed higher values of heavy metals during the rainy season than that in dry season. The mean of Manganese (0.25, 0.25 and 0.19 mg/L) at all sampling sites exceeded the drinking water guidelines (0.1 mg/L) of the World Health Organization. In addition, it was noted that the mean of Iron (0.35 mg/L) and Aluminium (0.95 mg/L) at Nyagatare site was higher than the WHO standards, 0.3 and 0.1 mg/L for the Iron and Aluminium, respectively. Thus, to ensure safe drinking water, it is good to initiate the rain harvest, agroforestry and bench terraces approaches to minimize the runoff, envisage appropriate wastes and wastewater management, and to approach and involve the community in managing water sources.