Upload
katlyn-heckle
View
219
Download
2
Tags:
Embed Size (px)
Citation preview
EXAMINING THE POTENTIAL OF USING SPRING WATERS FOR DOMESTIC AND IRRIGATION FARMING ACTIVITIES:
CASE STUDY OF LIWONDE, MALAWI.
A Russel C.G. Chidya (MSc)Prof Wapulumuka O. MulwafuAss Prof Samson S.M.I Sajidu
A Corresponding author: E-mail: [email protected]
University of Malawi – Chancellor College
Date: 31st Oct – 2nd Nov 2012
13th WaterNet/WARSFSA/GWP-SA International Symposium on IWRM 1
NEPAD SANWATCEwww.nepadwatercoe.org
AMCOW
Presentation Outline
2NEPAD SANWATCEwww.nepadwatercoe.org
1. Introduction & Literature Review
2. Aim and Objectives
3. Methods and Materials
4. Results & Discussion
5. Conclusion & Recommendations
6. Acknowledgements
1. Introduction & Literature review
3NEPAD SANWATCEwww.nepadwatercoe.org
Water is a finite natural resource essential for the well being of mankind (GWP, 2010).Important water sources:
a. surface water i.e. springs, streams and rivers ponds, lakes &seas.
b. ground water i.e.: located in aquifers – related to wells, boreholes &springs
In Malawi, existence of rivers, springs, L. Malawi, L. Chilwa and other smaller lakes provide fresh water resources.
However, climate variability, poor agricultural practices, poor waste disposal, poor water use and poor management of catchment areas etc pose daunting challenges which could result in quality & access to water resources being strained in the near future (Kass et al, 2005; GWP, 2010).
Intr‘d cont.../...
4NEPAD SANWATCEwww.nepadwatercoe.org
Springs are an important source of water for various purposes i.e. domestic, irrigation, & fishing (Spechler &Schiffer, 1995; WHO, 2008).
Previous studies by UNEP & GPF showed that Liwonde is one the areas in Malawi that have both hot and cold spring water sources.
However, there is no established data on the exact location & capacity of these springs. No attempt has been made to assess the socio-economic use, management & governance systems of these springs.
Further, no data is available on the physico-chemical characteristics of the spring waters and their implications for domestic and irrigation use.
2. Aim & specific objectives
5NEPAD SANWATCEwww.nepadwatercoe.org
Main Aim:To examine the potential of using cold and hot spring waters for domestic and irrigation farming activities in Liwonde, Malawi.
Specific Objectives
1. To assess the socio-economic use and governance systems of spring water resources.
2. To study the physico-chemical characteristics of spring water resources and their implications for domestic and irrigation use.
3. To examine the water discharge and capacity of springs to support large-scale domestic and irrigational farming activities.
3. Methods & Materials
6
3.1 Description of the study area – Liwonde
Situated in Southern Malawi & lies at 470 – 531 m above sea level. experiences tropical climate, &receives a relatively low rainfall. Is one of the hottest areas (mean max T of 39 °C). Lies in Shire R plain & is partly surrounded by Mts.
Fig 1A: Map of Africa & Malawi showing location of Study Area
SW1
N
SW10
Liwonde Township
To Lilongwe
From Blantyre
SW2
SW3
SW4
SW11
SW12
SW5
SW6
SW7SW8
SW9SHIRE RIVER
Mts
Fig 1B: Location of sampling sites
7NEPAD SANWATCEwww.nepadwatercoe.org
13 Hot & cold springs were identified, most connected to boreholes.
3.2 Water sample collection
BoreholeSpring water flow thru borehole
Aquifer system
Fig 2: Schematic diagram of a borehole connected to a spring
Water samples collected in triplicate using 0.5 L cleaned plastic bottles; transported &preserved in accordance with std methods (APHA, 1998; WII, 2008).
Fig 3: A hot spring in Liwonde
3.3 Physico-chemical & discharge analyses
8NEPAD SANWATCEwww.nepadwatercoe.org
Table 1: Water Quality parameters & analytical methods used
Parameter Site MethodpH, water T, EC, & TDS On site Field digital meters
Alkalinity, (as CO32- &HCO3
- ) LAB Titration (WII, 2008)
Total hardness (due to Ca2+ & Mg2+) LAB EDTA titrimetric (APHA, 1998; WHO, 1999).
Cl- LAB ISE method (APHA, 1998; NICO, 2000)
SO42- LAB Turbidmetric (UV/Vis spectrophotometer, model #. 6405,
England )
PO43- LAB Vanadomolybdophosphoric acid Colorimetric
(UV/Vis, model #. 6405, England)
Ca, Mg, K, Na, Cd, Zn, Cu, & Mn LAB AES (Agilent 4100 MP-AES, USA)
Discharge of springs flowing through boreholes
On-site Volumetric method with a bucket at an average height of about 70 cm.
9NEPAD SANWATCEwww.nepadwatercoe.org
3.4 Irrigational water quality indices
100)22(
)(%
KNaMgCa
KNaNa
100)22(
)2(MHR
MgCa
Mg
223
23 MgCaHCOCORSC
2221 MgCa
NaSAR
The following equations were used to determine: SAR, %Na, MHR, & RSC (Bauder et al., 2008):
- - - - - - - - - - [1]
- - - - - - - - - - [2]
- - - - - - - - - - [3]
- - - - - - - - - - [4]
3.5 Socio-economic data collection
10NEPAD SANWATCEwww.nepadwatercoe.org
The socio-economic activities making use of springs in the study area investigated thru:
Field visits, Observations, key informant interviews literature review
3.6 Statistical AnalysisSocial-economic data evaluated by repeated reading &content analysis. Water quality &discharge data analysed by Microsoft Excel (Windows 2007) to compute means, standard deviations & Pearson Correlation C (2-tailed at 95%)
4. Results & Discussion
11NEPAD SANWATCEwww.nepadwatercoe.org
Fig 4 (A, B, C): Pictures showing spring flow through boreholes in Liwonde. (Photos: Russel Chidya)
4.1 The socio-economic activities and spring water management 12 cold & hot springs identified & most (75%, n=12) were associated with boreholes.
A
B
C
Results & Discussion cont‘d
12
Preliminary results revealed that spring waters in the area are used for:
1. domestic purposes. i.e. washing, bathing, cooking & drinking.
2. small-scale subsistence &commercial farming (vegetables, rice, sugarcane, & maize).
3. moulding of bricks, 4. fish ponds
Fig 5: Pictures showing multiple uses of spring waters. (Photos: Russel Chidya)
NEPAD SANWATCE 13
Watering of nursery & tree seedlings
Growing of vegetables
Fig 6: Photos showing multiple use of springs waters. (photos: R Chidya)
Results & Discussion cont‘d
14NEPAD SANWATCEwww.nepadwatercoe.org
Major problems observed
Congestion (>300 households)Poor management
Lack of maintenance
Poor Sanitation (photo by Russel Chidya)
ANY POSSIBLE INTERVENTION?
Integrated approach in spring water usage and management, hence IWRM i.e. to address:
oHygiene & SanitationoWater quality & quantityoAccess to water
4.2 Physico-chemical characteristics
15NEPAD SANWATCEwww.nepadwatercoe.org
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
SW9
SW10
SW11
SW12
0
2
4
6
8
10
12
14 pH
Sampling point
pH
WHO limit (6.5 – 8.5)
Spring waters slightly basic; pH range 7.7 – 9.1
Most sites (67%, n=12) registered pH > upper WHO (2008) limit, hence deemed not suitable for consumption
0100200300400500600700800900
1000 EC (range 555 - 948 uS/cm)
Sampling point
EC
Both EC &TDS were within MBS (2005) limit (EC 700 – 1500 (µS/cm).
However, springs near Shire R showed slightly higher EC & TDS, hence depict high ionisation and dissolution of minerals.
4.2 Physico-chemical characteristics ... cont’d
16NEPAD SANWATCEwww.nepadwatercoe.org
Site Turbidity (FNU)
T (ºC) Discharge (cm3/s)
CO32-
(mg/L)
HCO3-
(mg/L)
SO42-
(mg/L)
PO43-
(mg/L)
Cl-
(mg/L)
SW1 0.18 27.73 296.88 13.8 329.22 32.36 bdl 72.44SW2 0.13 29.00 309.33 14.32 225.58 36.85 bdl 117.35SW3 0.14 28.33 824.08 16.88 250.04 32.93 0.33 191.36SW4 0.09 27.00 296.88 12.36 332.98 26.09 bdl 135.48SW5 0.12 28.47 433.94 48.04 165.15 33.88 bdl 103.40SW6 1.06 38.00 Nd 42.8 175.60 25.92 0.33 105.87SW7 0.25 26.40 134.12 41.24 177.06 39.62 0.67 129.56SW8 1.30 30.33 Nd 42.76 172.91 37.72 1.17 120.92SW9 0.26 25.80 29.41 26.28 180.15 32.61 bdl 77.99
SW10 0.24 39.70 Nd 25.44 151.85 115.80 bdl 19.52SW11 12.83 41.33 Nd 27.12 145.00 84.95 1.67 62.08SW12 10.58 40.33 Nd 26.68 146.89 88.91 1.17 112.41MBS
(2005)≤5.0 NA NA NA NA 200-
400NA 100-200
WHO (2008)
0.1-1.0 NA NA NA NA 500* NA 250
T: water temperature. Nd: not determined. bdl: below detection level. MBS: Malawi Bureau of standards. WHO: World Health Organisation. NA: not available. Nh: not of health concern at levels found in drinking water. *taste threshold value
Table 2: Results on physico-chemical characteristics of the spring water
Results & Discussion – cont‘d
17NEPAD SANWATCEwww.nepadwatercoe.org
Based on WHO (2008) hardness classification, all samples registered ‘soft class’ (0-70 mg/L CaCO3).
SO42-, Cl-, Mg, Ca, Na, Cu, & Mn were below WHO (2008) limits at all sites,
hence water generally safe for domestic use. However, due to presence of Cd & relatively high levels of Na at some sites, further water quality studies needed to justify this claim.
Suitability of water for irrigation: Based on SAR, 4 sites fell under excellent ‘S1 class’ (0-10); 2 sites registered
‘good’ (SAR 10-18), 1 site doubtful (SAR 18-26) and 5 sites ‘unsuitable classes’ (SAR>26).
But, based on RSC & %Na by Bauder et al., (2008) all sites were unsuitable for irrigation due to elevated CO3
2-, HCO3- and Na+ ions that tend to affect
irrigable soil properties.
This study has shown that the springs have both socio-economic value and capacity to support large-scale farming & domestic use.
However, major challenges faced include poor sanitation, governance & management systems. Further, water quality analyses indicated that some springs are of poor quality.
RECOMMENDATIONS & FURTHER STUDIES
Integrated approaches (i.e. IWRM) are needed for sustainable use, governance &proper management of the springs.
Further studies are needed on hydrology and aquifer systems of the area, microbiological tests & human health; & soil analysis for sustainable farming.
5. Conclusion
18NEPAD SANWATCEwww.nepadwatercoe.org
6. Acknowledgements
19NEPAD SANWATCEwww.nepadwatercoe.org
Authors would like to express their sincerely gratitude to the following:
NEPAD SANWATCE– for sponsorship towards the student’s expenses to attend the conference.
SADC WaterNet-Malawi Chapter for partially sponsoring the research study.
13th WaterNet/WARFSA/GWP-SA Secretariat for accepting our abstract & manuscript
Department of Chemistry – Chancellor College (University of Malawi) – for provision of lab space
THE ENDTHANK YOU!!
ZIKOMO
20NEPAD SANWATCEwww.nepadwatercoe.org
“Let there be work, bread, water & salt for
all”-Nelson Mandela-
(Adapted from: Water, Energy & Development 2012 by ESKOM)