use of groundwater data in lusaka, zambia alison parker, david nussbaumer, afua owusu, ian sutton
TRANSCRIPT
Use of groundwater data in Lusaka, Zambia
Alison Parker, David Nussbaumer, Afua Owusu, Ian Sutton
Understanding long-term changes in Lusaka’s groundwater levels
Method
Collect long-term data on:– Groundwater levels– Climate– Groundwater abstraction
Analyse using – Sen’s Nonparametric Estimator of Slope– Seasonal Mann Kendall
Data
Data type Location Length of record
Groundwater levels Sheki Sheki 1 borehole 12 years
Climate City AirportKenneth Kaunda Airport
Since 1950
Abstraction Ngwerere 4 years
Borehole commission dates Lusaka Since 1960
Analysis19
60-1
964
1965
-196
9
1970
-197
4
1975
-197
9
1980
-198
4
1985
-198
9
1990
-199
4
1995
-199
9
2000
-200
4
2005
-200
9
2010
-201
4
0
5
10
15
20
25
30
Years
Cum
ulati
ve n
umbe
r of b
oreh
oles
in o
pera
-tio
n
Jan-02 Jul-07 Dec-121265.51266.01266.51267.01267.51268.01268.51269.01269.51270.01270.5
Sheki 1 BH
Time
Grou
ndw
ater
leve
l (m
-am
sl)
Dec-66 Oct-73 Aug-80 Jun-87 May-94 Mar-01 Jan-08 Nov-140
100
200
300
400
500
600
KK Airport Monthly Rainfall
Time
Rain
fall
(mm
)
Groundwater:
Rainfall:
Number of boreholes:
Fallen 1.7m since 2002
Decreasing significantly
Other data
Private users, irrigation, industry, Water Trusts – could be up to 48% of Lusaka’s water (Shaboko-Mbale 2012)
So how and why is Lusaka's groundwater changing?
• Water levels are declining• Both abstraction and climate change may be playing a part…..• ….. but insufficient data to fully support this hypothesis.
Understand data needs of decision makers and how to improve data management
Method
Interviews with– 4 senior engineers from LWSC– 1 chemist from LWSC– All 10 Water Trust managers
Capacity
Lack of capacity to understand hydrogeological information• Only two Water Trust managers have a background in water
management• SGwR helping to address this
Data collection
• Last year none of the then Water Trusts collected water level date– Four started recently– Four plan to
• All monitor chlorine residuals• LWSC periodically monitors
pH, turbidity, nitrates• Little data sharing or feedback
Conclusion
• Capacity building in groundwater needed for all decision makers• Better data management systems required
Alison Parker
01234 758120