Water Scarcity
Water supply not constrained by resource limitations. Malawi, vast freshwater lake
alongside is ‘water stressed’ (Cairncross, 2003).
Variation Spatio-temporal
Precipitation
Climate
precipitation corresponds with position of ITCTZ:
ICTZ=convergence of 2 ‘Hadley Cells’ where warmer air rises, cools, sheds precipitation,
moves poleward, & descends delivering little precipitation.
Seasonal variation: rainy season in July (northern hemisphere summer) rainy season in
January (southern hemisphere summer) (Ziegler ea 2013). Bimodal/ unimodal rainy seasons
by latitude (Taylor, 2004).
(Goulden ea, 2009) Central Africa = 37% of total precipitation.
NA - Similar area, but 3% of precipitation.
41% Africa = dry regime (<400mm/a).
25% = Intermediate (400 -> 1000mm/a)
Relief development compels rainfall. Orographic rainfall (relief) (Taylor, 2004).
Coastal areas more temperate. Ocean moderates temp. Reduced seasonal and daily temp
variations. Cool dry summer, mild wet winter. Higher rainfall (Taylor, 2004).
Resources
Context.
What determines presence of surface water? Rainfall ≠ surface water. Different access (De
Wit ea, 2006).
• Precipitation / relief (topography runoff-tectonics-lakes; grabens or warping) and
critically… evapotranspiration consuming 70 to 90% of precipitation (UNEP, 2012).
Landscape and climate defines spatio-temporal distribution of resources (Taylor, 2004).
40% of state borders are rivers or basin watersheds.
Every major river traverses one or more international boundary (Goulden ea, 2009).
What happens to P (Taylor, 2004).
Almost all rain, some snow over Rwenzori or Kilimanjaro.
Interception-vegetation.
Reduces intensity. Intercepted P either E or soil (stemflow), or leaf drip.
Infiltration continues till soil saturated. Then HOF (Hortonian). Low relief = ponding.
ET or infiltration. low->high relief more HOF.
Infiltrated water T (thru roots), E (shallow soil depth), percolate beyond root zone
(enhanced by gaps from soil dessication, roots or animals). Hard to work out E and T vols
back to atomsphere, hence ET.
Percolated - GW recharge, to surface drainage as interflow via gradient (diverted by
saturated soils, impermeable rocks). Then goes overground as saturated overland flow
1
(SOF). Increases discharge volumes, flooding risk.
2 equations
Precipitation = Evapotranspiration + RunOff (HOF, SOF) + Groundwater Recharge
RunOff = Hortonian Overland Flow + Interflow + Saturated Overland Flow
Surface Water
Runoff disproportional to P. Defined by land use, topography, geology, GW discharges.
Change in runoff disproportional to change in P (more than GW) (Taylor 2004).
Africa has v variable surface water (McMahon ea, 2007). highest co-efficients of variation
(σ/μ)in river discharge.
Groundwater
groundwater resources defined by geology and climate (MacDonald ea, 2012).
Africa GW in ~40 transboundary systems (Goulden ea, 2009).
- Non renewable. Widely used in NA. IE Great Man-Made River Project in Libya (Goulden ea,
2009).
2,820KM of pipes from Nubian Sandstone Aquifer System (fossil) (3.68Mm3/day).
1,300 wells, most >500m deep (Allan, 1988).
(Goulden ea, 2009)
Renewable resources
Sustainability of resource dependent on balance of input to withdrawals (Shiklomanov,
2000). Estimation hard, poor data, expertees, capital for research and hydrological/ political
boundary discrepancy.
Many just use MARR. With MARR DRC has 2% of global renewable freshwater MARR misses
PET, soil water (rain-fed), GW recharge, fossil GW, assumes equitable sharing of
transboundary resources (Shiklomanov, 2000). Also hides inter/intra annual variation (the
key issue). Also based on poor/ incomplete data (Taylor, 2004).
Water Scarcity
SSA
Category
Change 2000-2015
Av % access to
'improved'.
45-58
Rural % improved
Urban
29-42
78-82
(UN-UNICEF, 2017).
“Access to resources, particularly by poor people, is controlled by a complex web of
political, economic, cultural, social and physical factors. Nevertheless, narratives of resource
availability are often dominated by reductionist, physical evaluations of resources that
embrace the ‘scarcity paradigm’ in which access or availability is inferred to be controlled
predominantly or exclusively by its physical characteristics.” (Damjkaer & Taylor, 2017).
2
Seasonal supply. Not an issue of volume, its distribution in time and space, influenced by
infrastructure, coping and climate.
Variable rainfall and river flows across spatio-temporal scales has management
consequences. ~69% African pop in relative water abundance. Not = poor access to water
and sanitation. (Damjkaer & Taylor, 2017).
Largest challenges are social/ econ/ political, not physical.
Also groundwater, soil water, water recycling etc.
Topography, steepness, drainage routes.
Consumers
Also water use, how many people, what uses, per capita use? variation inter/intra annual
variation in use? Technology to get water? Corruption and inequity?
Future scarcity
Interplay between human and climate changes influencing water scarcity (Goulden ea,
2009).
Climate
Trends
3
projecting changes in the direction and magnitude of climate extremes depends on many
factors, including the type of extreme, the region and season, the amount and quality of
observational data, the level of understanding of the underlying processes, and the
reliability of their simulation in models (IPCC, 2012).
substantial warming in temperature extremes by the end of the 21st century (IPCC, 2012).
Precipitation
Projections more uncertain and show higher spatio-temporal variance than temp (Niang ea,
2012).
global warming intensifies precipitation
• fewer, low and medium intensity precipitation events
• more, very heavy precipitation events (i.e., “extreme events”). (Allan et al. 2010).
frequency of heavy precipitation or the proportion of total rainfall from heavy falls will
increase in the 21st century over many areas of the globe (IPCC, 2012).
medium confidence that droughts will intensify in the 21st century in some seasons and
4
areas, due to reduced precipitation and/or increased evapotranspiration (IPCC, 2012).
North Africa reduction likely by 22ndC (Niang ea, 2014).
NA region drying and warming (including North of Morocco,Algeria, Libya, Egypt, and
Tunisia) consistent in the global and regional projections under the A1B and A2
scenarios.(Niang ea, 2014).
West Africa variation. Intermodel variation in direction and magnitude of change. Wetter
wet season with a small delay to rainy season by the end of the 21st century. (Niang ea,
2014).
E Africa. End 21c wetter climate, intense wet seasons, weaker droughts october to
december and march to may. Wide range of spatial rainfall changes (Niang ea, 2014).
S Africa. Drying annual mean over southwest (Namibia to Botswana). Dry summers (Niang
ea, 2014).
Extreme events
Eastern Africa extreme events experienced more frequently during the last 30 to 60 years
(Funk et al., 2008).
More frequent droughts due to warming Indian Pacific warm pool (Niang ea, 2014).
SA. More droughts. Higher prob heatwave related to deficient precipitation during el Nino
(Niang ea, 2014).
NW Sharaha, More drought.
Water Resources
Changes in precipitation in intermediate = serious changes in surface and GW supply. High
seasonality, covers 3 densely pop areas - Southern Africa (inc Limpopo and Orange Basins).
-Most of E Africa (inc most of upper Nile basin).
-East-West band (basically Sahel). Covers big basins ie. Chad, Niger, Upper Volta, Senegal.
West Africa Niger and Volta basins increased runoff during 21st century,
Central and Eastern models disagree on direction and magnitude of change.
Southern- decreased surface runoff
(Goulden ea, 2009).
Precipitation changes have refracted impacts.
Studies combine climate change models and hydrological models to include river flow
response to changes in temperature, potential evaporation (PE) and rainfall.
Greater proportional changes in river flows than in precipitation and fairly modest
responses to increasing temperature or PE.
River flows- range of outcomes, even the same rivers.
Due to inter-model range in future precipitation.
Rarely represent PE, soil moisture dynamics and land cover, or a focus on changes in the
5
frequency/magnitude of extreme events.
High ET losses in many of Africa’s most socio-economically important basins, likely to
increase (assuming little change in everything else) (Goulden ea, 2009).
Surface
10% drop in precipitation reduces river discharge by 17 to 50% (de Wit and Stankiewicz,
2006).
Ground
Uncertainties in estimates of renewable groundwater resources and groundwater recharge.
Monitoring inadequate (Goulden ea, 2009).
GW demand to increase as total water use increases. Also increase in response to surface
water availability. GW responds slower to CC than surface, but impacts recharge rates and
renewable GW resource (Goulden ea, 2009).
Dry Regions GW recharge impacts equal from climate and land use/ management (Goulden
ea, 2009).
I.E River Bani (Niger basin, wetter) v Nakambe (Upper Volta, drier).
Bani reduced rainfall = reduced GW and river discharge. Nakambe rain down, GW down
but discharge up due to land use.
Storage
Dam construction. Reservoir storage equated to ‘development’ (Grey & Sadoff 2007).
Rainwater harvesting: roof-top collection, sand dams.
Vulnerability
Slow MDGs reduces resilience and adaptive capabilities of African individuals, communities,
states, and nations.
high levels of spatial and group disparities. In addition, progress on all MDG indicators is
skewed in favor of higher-income groups and urban populations,which means further
marginalization of already excluded groups (Niang ea, 2014).
Scarcity
high spatial and temporal variability of water resource availability and its uneven spatial
distribution means that water scarcity is a major concern in some parts of Africa. Climate
change threatens to put further pressure on water resources already under pressure
(Goulden ea, 2009).
Most effective adaptation and disaster risk reduction actions are those that offer
development benefits in the relatively near term, as well as reductions in vulnerability over
the longer term (high agreement, medium evidence) (IPCC, 2012).
Seasonal
Adaptability; econ, institutional and behavioural resilience. What crops? Virtual water?
6
Recent water section adaption. building adaptive capacity and no-regret type activities in
response to multiple factors. Due to uncertainty and adaption necessary for non-climate
factors. Careful applying western policy in Africa, different institutional capacity and
practical application context (Goulden ea, 2009).
Long Term
Vulnerability dynamic, varying across temporal and spatial scales, and depend on economic,
social, geographic, demographic, cultural, institutional, governance, and environmental
factors (IPCC, 2012).
Cooperation
Equitable allocation? right to ‘beneficial use’ of water, rather than to water per
se. ‘reasonable and equitable use’ within each watercourse State, “with a view to attaining
optimal utilization thereof and benefits therefrom”, is balanced with an obligation not to
cause significant harm
Basin scale litigation infringes on sovereignty? given the complexities and uniqueness of
each watershed, general codification should not even be attempted? Watershed most
rational?
(Wolf, 1999).
GW. Ballagio Draft Treaty.
“the weight to be given to each factor is to be determined by its importance in
comparison with that of the other relevant factors”. uniqueness of each basin and its
riparian States suggest that any universal set of principles must, by necessity, be fairly
general (Wolf, 1999).
Different adaptive capacity (water spatio-temporal distribution, nature and volume of
resources and distribution tech, nature and volume of consumption) of riparian states.
(IPCC, 2012).
Economic resources, social vulnerability, institutional arrangements.
One country benefit, other loses? Need for cooperation (Sadoff & Grey, 2002).
7
Metrics- measuring scarcity
Damkjaer & Taylor, 2017.
(1) be redefined physically in terms of the freshwater storage required to address
imbalances in intra- and inter-annual fluxes of freshwater supply and demand;
(2) abandons subjective quantifications of human environments
(3) be used to inform participatory decision-making processes that explore a wide range
of options for addressing freshwater storage requirements beyond dams that include use of
renewable groundwater, soil water and trading in virtual water.
Use of MARR
MARR = mean ‘blue water’.
P-ET=MARR.
assuming changes in freshwater storage are negligible.
‘river runoff’’ equating renewable freshwater resources to mean annual river runoff
(MARR).
-implicitly assumes changes in soil moisture storage (DSMS) and groundwater storage
(DGWS) are negligible, and MARR represents the net contribution of precipitation (P) to the
terrestrial water balance accounting for outflows derived from evapotranspiration (ET).
Temporal variation
-(Taylor 2009) MARR masks intra- and inter-annual variabilities in freshwater resources
SSA big variation (McMahon et al. 2007).
Therefore characteristics of water resources defined by variability. Masked by MARR
EG Great Ruaha River catchment.
SW Tanzania. Semi arid.
December-March short intense wet season. Long dry season.
Huge variation in mean monthly discharge.
Dec-Martch - up to 414 Mm3 (160m3s-1).
July-Nov - 6Mm3 (4m3s-1).
Recently discharge = 0 at end of some dry seasons (Kashaigili, 2008).
MARR = 146Mm3 (55m3s-1). Nearly half the year average freshwater renewable
resources = 1/10th of this.
-does not indicate the proportion of river discharge that occurs episodically as stormflow
and that which occurs throughout the year as baseflow; the latter often results from
groundwater discharge.
Other water
-does not account for soil water (‘‘green water’’).
sustains almost all food production in Sub-Saharan Africa (Taylor, 2009).
Can play a critical role in determining agricultural demand the sector that globally
accounts for the majority of freshwater withdrawals and influences the amount of available
blue water resources (Rockstro¨m and Falkenmark 2015).
Groundwater.
only considered as river discharge.
8
GW important.
Estimated at more than 100xMARR for many African countries (MacDonald ea, 2012).
Spatio temporal distribution of GW.
sustaining river discharge during dry periods.
Access to freshwater away from river channels.
Virtual water
Allan, 2003.
Because of this, MARR scarcity assessments overestimate demand and underestimate
renewable freshwater resources (Taylor 2009).
Ratio freshwater availability:demand monthly shows previously masked water stressed
areas.
But, rise in food prices, especially recently. (Niang ea, 2014).
Water scarcity metrics inherent issues
Water scarcity = practical scarcity?
a) the data on water resources availability do not take into account how much of it could be
made available for human use;
b) water withdrawal data do not take into account: PET, water recycling/ return flows.
c) the indicators do not take into account a society’s adaptive capacity to cope with stress.
Water Stress Index (WSI).
Sudano-Sahel droughts 1980s. (Falkenmark 1989).
conceived during famines across Sudano-Sahel in 1980s, water scarcity occurs when >1000
people that compete for a single flow unit of water 1 000 000 m3 /year - equivalent to 1000
m3 /person/year
9
Water scarcity = access to safe water.
Basis was context specific. industrialised country in a semi-arid zone has a gross water
demand1 of approximately 500 m3 capita-1 year-1 , equivalent to 2000 people/flow unit.
This value was set as the threshold at the time for operating a modern semi-arid society
using extremely sophisticated water management and […] half of this value [1000
people/flow unit] could be considered as relatively water-stressed.
does not specify an amount required to meet agricultural, industrial and energy demands
but instead argue that in order to assure adequate health, people need a minimum of about
100 L of water per day for drinking, cooking and washing. Of course many times this amount
is necessary to carry out the activities necessary to sustain an economic base in the
community. Although what constitutes ‘‘many times’’ is not specified
Withdrawal to Availability Ratio (WTA)
water scarcity in terms of the ratio or percentage of total annual withdrawals to annual
freshwater supply.
Domestic, industrial and agricultural sectors.
Withdrawals/a:supply/a
-‘water stressed’- 20% (0.2) and 40% (0.4)
-‘severely stressed’ 40% (0.4)
Uses MARR hence issues as above.
WTA approach can employ spatially and temporally variable freshwater demand functions
but their estimation has their own conceptual challenges
Water Scarcity does not equal access to safe water
Measured water scarcity is unrelated to measured coverage of access to safe water.
(WWAP, 2003). WRONG:
at present many developing states cannot supply the minimum water/cap/a of 1,700 M3
of drinking water necessary for ‘healthy and active life'.
WHY:
-Ignores minimum water/cap/a includes industry and agriculture (by far the largest users).
-Assumes access to safe drinking is relative to freshwater availability.
-no evidence to say 1.7M3/cap/a to sustain a 'healthy and active life’.
Cannot give absolute thresholds that apply to all countries. Therefore application of WSI &
WTA stress and scarcity thresholds is unclear.
Some new holistic measures include socio-economic and political factors influencing actual
water scarcity. Can these factors be meaningfully, universally quantified? HDI, GDP/cap etc
not quite the right thing.
Other metrics
Water Depletion Indicator (WDI).
10
% of annual average renewable water (surface + GW) consumed by humans within a
watershed.
Annually, seasonally, and dry years.
Importance of seasonality. Watersheds that are depleted on annual scale can be heavily
depleted seasonally/ dry years.
Redefine scarcity by storage.
groundwater, green water (soil and plants), lakes, dams, reservoirs.
Scarcity then = extent to which required freshwater storage is available and used to inform
adaptive responses reducing freshwater demand and/or increasing access to freshwater
storage.
Advantages
1)GW particularly problematic. (Taylor ea, 2013).
Largest distributed source of freshwater and actual supply.
40% of all irrigation and access to safe water.
Including small scale storage is challenging.
GW mapping is better, but needs improving, especially in Africa (MacDonald ea, 2012).
Reducing freshwater demand affects discharge. Effects vary.
increasing use of green water,
increasing storage infrastructure (dams, pumping wells)
Recognises problematic quantification of human environments.
2)Socio-economic and political factors do play a role in access to water (Zeitoun ea, 2016).
Seen in absence of relationship between ‘water scarcity’ and ‘access to safe water’.
3)Applied to wide range of adaptive strategies, not just large dams, reservoirs etc.
Make use of renewable GW, rainwater harvesting, reducing freshwater storage
requirements through virtual water and consumption efficiencies.
11
Global Change and African water
Key themes:
• Global Change (climate, land use, consumption (patio-temporal patterns, volumes,
sectors).
• hydrological variability
• vulnerability to change
Summary
• high intrinsic variability in renewable freshwater resources across Africa is projected to
increase
• non-linear hydrological responses to the intensification of precipitation and warming
(increased ET).
• very substantial changes in freshwater demand projected associated with the proposed
expansion of land under irrigation and rapid urbanisation.
impacts of climate change on human rights. right of peoples to a “general satisfactory
environment favorable to their development” (Niang ea, 2014).
CC harm MDGs
increase the pressure on economic activities, such as agriculture and fishing, also
adversely affect urban areas located in coastal zones. Slow progress in attaining most MDGs
(Niang ea, 2014)
Climate
Warming. PET up.
12
Inter and intra-annually.
Malawi intra-annual variation coefficient 93%!!
Rain-fed agriculture. Plant ur crops then no rain for a month = dead crops. Irrigation sorts
out temporal distribution. (98% rain fed in SSA (Niang ea, 2014).
Variable rainfall makes even more variable river discharge.
median CoVs in annual river discharge:
• 82% southern Africa
• 24% Europe
• 31% global median McMahon et al. (2007)
Adapting to existing variability a big part of adapting to global change (wide ranging
predictions)
Variability most damaging element of CC predictions.
13
Co2 and warming mean faster and more PET (Conway ea, 2009).
Weak models
No national diversity in values. Variation or actual.
Not even touching terrestrial hydrology. Weak data behind them in Africa too.
IPCC AR5
• substantial uncertainty in water resource projections under 2°C rise in global mean air
temperature IPCC AR5 Kingston and Taylor (2010)
Basically no idea. Could be 20% up or down. None better than one another. Plateau in
progress.
Inequity in impacts is certain.
14
P Intensification
Warming world - intenser P. Now observable.
1. warmer air holds more water – amount rises exponentially with temperature.
2. heavy rainfalls tend to deplete air of all of its available moisture.
• air temperature rises in the tropics lead to greater relative increases in waterholding
capacity. Greatest P intensification predicted in Tropics.
“It is likely that the frequency of heavy P… will increase in the 20th century over many areas
of the globe. This is particularly the case in… tropical regions.” IPCC SREX (2011)
Fewer low/ med intensity events. More, infrequent heavy events and droughts (Allan,
2010).
Impacts
Therefore more frequent and intense floods/ droughts (IPCC, 2017).
Increased discharge variability (Niang ea, 2014).
Significant subregional variability. Particularly in water stressed regions ie. NA, SA. Models
do not capture inter/ intra annual and interdecadal variability which can impact surface
water positively or negatively. Need better understanding of relationships between PET, soil
moisture and land use change to understand dynamics under T and P projections (Goulden
ea, 2009; Niang ea, 2014).
GW
-Tanzania: semi-arid. longest, published record of groundwater levels in the tropics.
-recharge episodic.
disproportionately from extreme (>80th percentile) seasonal rainfall.
Happens after heavy rainfall - currently linked to El Nino.
-dependence upon extreme rainfall associated with modes of large-scale climate
variability (e.g. El Niño) observed across tropical Africa
(Taylor ea, 2013).
Deeper aquifers more at risk of solidification due to higher density salt water. IE Morocco
(Niang ea, 2014).
Urban GW quality impacts
Heavy P events -> pathogenic contamination of GW and disease outbreaks (Taylor ea,
2009).
Non-climactic factors (pop growth, urbanisation, irrigation, land use change) more impact
than climate (Niang ea, 2014).
Extended drought drys up shallow wells. Access/ availability different. Drought and source
failure link not clear cut (Calow ea, 2010).
15
Dakar Example (Re ea, 2011).
Public supply GW 46% (local and imported) and imported surface water
Household sceptic tanks for sanitation.
Poorly sealed (spill). Drain into shallow subsurface (into urban aquifer).
High flood risk too.
- shallow groundwater lens (on seawater)
- imported water and urban wastewater leak to shallow subsurface.
Flood management
- pump flood water to retention ponds
- eutrophication (nitrate > 500 mg/l)
- pump collected water to sea
Pumps fail?
Retention pond overflow where?
Grim water, direct health impacts and indirect.
Dense, infected sea water goes into urban aquifer.
Surface water
Decrease in water abundance. Multi factors tho. Climate issues in SA and NA. Zambezi basin
pop and econ growth, more irrigation and water transfers likely causes (Niang ea, 2014).
NA in 2050 CC accounts for 22% of water shortages, 78% socio-economic. Reduced atlas
mountain snowpack (warming and less P), rapid spring melting. Less water, uneven in time
for morrocco (Droogers ea, 2012).
EA. blue nile flows down long term (end of 21C) (PET up, P down, HEP/ irrigation upstream),
but up medium term. Less water for irrigation downstream at High Aswan Dam (Niang ea,
2014; Kingston & Taylor 2010).
WA. significant uncertainty in rainfall, and practical impacts on resources. Itiveh & Bigg 2008
say P up in Niger basin, others say down but strong seasonal component with increased dry
season P, decreased wet season P. Volta basin slight increase (Kuntsmann ea, 2008).
(Niang ea, 2014).
Human
Demographic and economic trends.
Pop up >100% since 1980. 2010 - Over 1b. 2050 - 3b (if fertility rates remain).
global economic crisis is adding additional constraints on economic development efforts,
leading to increased loss of livelihood andwidespread poverty.
% below poverty line. 1990 56.5%, 2008 47.5% (SSA). Bare man still below. Especially
rural. SSA: 1998 64.9%, 2008 61.8%. double the average in other developing countries
(Niang ea, 2014).
What use is sustainable?
Future per capita use/ used for what/ used were.
16
Population up, changing use patters and increasing urban concentration of pop and econ
activities will further pressurise freshwater resources.
(Goulden ea, 2009).
population growth, and changes in per capita and agricultural water demand. Economicallyand demographically-driven growth in demand generally leads to large changes in per capita
water availability and often outweighs climatically-induced changes (Goulden ea, 2009).
Land use
changes in land cover and land use, the construction of upstream reservoirs, and pollution
from domestic, industrial and agricultural sources will exacerbate problems related to
timing and quality of water supplies (Goulden ea, 2009).
Sahelian paradox. land use change from perennial grasslands -> cultivation = increased
runoff and GW with reduced rain (Favreau ea, 2009).
Likely due to soil and vegetation cover changes (Gal ea, 2009).
17
(UN, 2007).
Cities pop x7 between 1950 to 1980: Kinshasa (DRC), Lagos (Nigeria), Nairobi (Kenya).
(London 1800, 0.86m-1900, 6.5m for same proportion increase )
Characterised by large, unplanned settlements. historical urbanisation in London - 7 fold
increase in population from 1800 (0.86 million) to 1900 (6.5 million)
Infrastructure over capacity
- piped water
- sewerage
- waste disposal
Accommodating growth and urbanisation impossible
- limited (~70%) or intermittent access to
safe water
- limited access (~60%) to sanitation
- reduced per capita usage
-Practical access even worse. UN data is source 200m from dwelling. Doesn’t account for
queues or costs.
Agriculture
Gendered impacts. Women shoulder vast but poorly recorded proportion of responsibility
of water collection and subsistence farming.
Longer queues for water. Overexploited soil. Financial crises causes formal job losses and
men compete for same jobs? (niang ea, 2014).
Negative impact on cereal. except for EA maize. Benefit from T up in high altitude. Currently
most maize at low altitude, maybe shift. SA maize systems vulnerable (Niang ea, 2014).
Biofuels and land use change (Niang ea, 2014).
Rain fed
Variable P -> variable soil moisture. (P fed agriculture).
Impacts yields disproportionately to P volume.
(Challinor ea, 2006).
Frequency of wet days negative for rained agricultural (Niang ea, 2014).
Irrigated
Irrigation down - climate and competition for resources (Niang ea, 2014).
Livestock
Livestock communities stressors. Rangeland degradation, variable water access,
fragmentation of grazing areas, sedentarization, land tenure change from community to
private, in-migration of non pastoralists into grazing areas, lack of opportunities to diversify
livlihoods, conflict/ political crises, weak social safety nets, insecure access to capital land
and markets. Loss of livestock under prolonged drought.
Cost of livestock water from boreholes in Botswana up 23% by 2050 (more pumping hours
under higher T lower P means inc production costs). Feed production and drinking water
18
impacted. Feed costs up due to lack of supply, maize per cattle head down by 2050
(Thornton ea, 2010).
High altitude EA maybe better from T up (IBID).
(Niang ea, 2014).
Fisheries
Close link between climate variability and fishery production. Coastal WA annual production
value down 21% = 50% decline in fishery employment and US$311m loss regionally (Niang
ea, 2014).
Adaptation.
capacity is considered low in Africa because of economic, demographic, health, education,
infrastructure, governance, and natural factors, levels vary within countries and across subregions, with some indication of higher adaptive capacity in North Africa and some other
countries; individual or household level adaptive capacity depends, in addition to functional
institutions and access to assets, on the ability of people to make informed decisions to
respond to climatic and other changes (Niang ea, 2014).
19
Strengths: wealth in natural resources, well-developed social networks, and longstanding
traditional mechanisms of managing variability through, for example,crop and livelihood
diversification, migration, and small-scale enterprises, all ofwhich are underpinned by local
or indigenous knowledge systems for sustainable resource management.
Hard to quantify ability of systems for adaptation. (Niang ea, 2014).
Policy
early warning systems, emerging risk transfer schemes, socialsafety nets, disaster risk
contingency funds and budgeting, livelihood diversification, and migration (World Bank,
2010).
Calow ea, 2010: Policy recommendations.
• Target GW programs in high vulnerability/ relatively high GW potential areas.
• Target specific water security policy (e.g., water point rehabilitation and repair, well
deepening, and spring protection/excavation).
• Highlight key monitoring areas
At risk GW sources,
Existing systems widened (eg food security) to include water stress indicators
(livelihood indicators).
Practice
Institution.
Early Warning Systems (EWS). Local level. Insecurity varies over v short distances.
Boreholes, alternative sources (small dam), well deepening, pump repair/ relocation, water
tankering (Calow ea, 2010).
20
Individual
Behavioural change required. CC info and education required. Lack of in country expertise
and institutional capacity for planning. capacity of civil society and government
organizationsto access, interpret, and use climate information for planning and decision
making. economic dependence on natural resources, most research on strengthening
adaptive capacity in Africa is focused on agriculture forestry-, or fisheries-based
livelihoods. e rural emphasis is now being expanded through a growing focus on
requirements for enhancing peri-urban and urban adaptive capacity. (Niang ea, 2014).
MUST BE COUNTRY/ REGION SPECIFIC. Adaptation through holistic, multi sector
improvements (desertification, water management, irrigation, economic diversification).
sustainable agricultural practices and appropriate techs for shorter growing seasons, T, and
extreme P. Alternate energy, and approaches to cope with water/ food insecurity and
livelihood loss (UNFCCC, 2007; Niang ea, 2014).
Differentiated social impacts so differentiated priorities across scales (gender, age,
disability, ethnicity, location, livelihood, migrant status). Attention to equity in sustainability
(IPCC, 2012; Niang ea, 2014).
Many appropriate techs based on indigenous/ community knowledge (Nyong ea, 2007).
More dynamic and robust than acknowledged (Mortimore, 2010) Supported by IPCC 2012,
integrate western and local science.
issues with local knowledge:decline in intergenerational transmission; a perceived decline
in the reliability of local indicators for variability and change, as a result of sociocultural,
environmental, and climate changes ; and challenges of the emerging and anticipated
climatic changes seeming to overrun indigenous knowledge and coping mechanisms of
farmers (Niang ea, 2014).
Mixed crop livestock to more livestock. Reduced growing season for annual crops means
more failed seasons. Especially West Sahel, coastal and mid-altitude EA and SEA (currently
35 million people and chronically food insecure) by 2050. (Niang ea, 2014).
Cattle over dairy cows? cattle-> sheep and goats, fewer poultry. (Niang ea, 2014).
Water Security
Research must serve policy. intended target of the ‘security?’; remove variability in the
(impossible) pursuit of water security ‘for all’,
market-driven reliability for the most efficient use or user,
or social justice for the marginalised.
Prevailing reductionist approach - GDP linked to hydro-climate causes.
Ignores diversity and practicality of water access.
Limits policy makers to interventions which reproduce inequality, and too rigid to adapt.
Integrative approach embraces the complexity of water-society relationships. Power
relations embedded in water use and access. Political and economic systems corruption,
and transparency influence all
As such ‘water security’ must be rooted, expanded, and attuned to social justice.
Also system considers food trade and transboundary.
‘water tenure security’
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Food security.
Different areas physical and human elements require different inputs for ‘food security’.
Climate, soil, seeds, practices, access/ availability of technology.
Agricultural intensification.
more cultivation -> clear deep-rooted vegetation, replacement with staples -> increased soil
erosion. -> increased nutrient mining -> more cultivation.
international institutions calling for increased irrigation to improve production and
livelihoods, increasing climate resilience.
world’s most vulnerable because of extensive reliance on rainfed crop production, high
intra- and inter-seasonal climate variability, recurrent droughts and floods that affect both
crops and livestock, and persistent poverty that limits the capacity to adapt (Niang ea,
2014).
Near term risk management helps climate adaptability (Funk ea, 2008).
Diminished yield potential due to negative impacts of high T increasing (Niang ea, 2014).
Price spikes in food 2007-2008. Price volatility and higher overall prices undercut gains in
food security. Urban poor impacted most, over 50% of income on food. Smallholder farms
(net food buyers) over 50% in many countries (Jayne ea, 2006). hence rural security also at
risk. Especially female headed households (fewer assets). (Niang ea, 2014).
Urbanisation means security requires adaptation in food processing, marketing and
consumption patterns. increased reliance on purchased food. Higher T = higher spoilage risk
(poor infrastructure). Increased flooding risks food transport infrastructure. IE higher post
harvest losses from poor infrastructure and storage (Niang ea, 2014).
Trade/ food (Allan, 2003; Cairncross, 2003).
1 ton of wheat imported = removing stress of mobilising 1,000m3 of water.
by 2000 MENA importing 50m tons of grain/a. = 50km3(50bm3) of water = entire annual
flow volume of Nile into Egypt = 30% of total MENA water resources. Unimaginable
challenge to mobilise this much water.
Economise soil water.
Issues
Rising prices? niang ea, 2014.
virtual water threatens farming livlihoods.
Linking water and food security poses high political risks for water policy makers.
Ethics - markets inherently economically discriminate. Social right to food access, rely on
markets?
Transport and market infrastructure required too. Especially increased food spoilage with
higher T.
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