This document discusses ecosystem services in the Senqu River in South Africa. It provides baseline data on hydrology, water quality, geomorphology, riparian vegetation and socioeconomic factors in local communities. It then uses a probabilistic model called PROBFLO to assess how different development scenarios may impact ecosystem services. Scenario 1 models a no development reference state, while Scenario 2 models post-development with implementation of environmental flows to maintain ecosystem functions. The model indicates some services like fish and water availability may decline under development without mitigation, while others like riparian habitat may be maintained with environmental flows.

1. Upscaling aquatic ecosystem
service provision by management
of the drivers of change
Dr. Chris Dickens
&
Dr. Gordon O’Brien

2. WHAT ARE ECOSYSTEM SERVICES?
• Benefits humans obtain from
ecosystems (Costanza et al 1997)
Environmental
Quality
Social Well
Being
Economic
Prosperity
Governance
Figure 11: Sustainability model
in South Africa

4. Phase 2 of the Lesotho Highlands Water Project

5. Photo:DavidBrazier/IWMIPhoto:TomvanCakenberghe/IWMIPhoto:DavidBrazier/IWMIPhoto:DavidBrazier/IWMI
IFR P1
IFR P2
IFR 5
IFR 6

6. Photo:DavidBrazier/IWMIPhoto:TomvanCakenberghe/IWMIPhoto:DavidBrazier/IWMIPhoto:DavidBrazier/IWMI
HYDRO. FOUNDATION
PARAMETERISE THE MODEL

7. LHDA 6001 Baseline Study
Median
25%-75%
Non-Outlier Range
Outliers
Extremes
PWQ1 PWQ2 PWQ3 PWQ4 PWQ5 PWQ6 PWQ7
Monitoring Point
0
5
10
15
20
25
30
35
40
45
ConductivitymS/m
LHDA 6001 Baseline Study
Median
25%-75%
Non-Outlier Range
Outliers
Extremes
PWQ1 PWQ2 PWQ3 PWQ4 PWQ5 PWQ6 PWQ7
Monitoring Point
0
50
100
150
200
250
300
Suspendedsolidsmg/l
WATER QUALITY: Spatial Changes
EC SS
LHDA 6001 Baseline Data
Median
25%-75%
Non-Outlier Range
Outliers
Extremes
5 6 11 12 1 2 3
Month
0
100
200
300
400
500
600
PWQ6conductivity(microS/cm)
Electrical
conductivity

8. The survey data (coloured
points,) model grid and
mapped out roughness areas
at IFR P2.
Velocity modelled for
IFR P1 at 40.08 m3/s, S
(observed in January
2014).
HYDRAULICS
Inundation depth
modelled for IFR P2 At
40.08 m3/s (observed in
January 2014)

9. Geomorphological features at IFR P2
A stylised depiction of the riffle transect
GEOMORPHOLOGY

10. 0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
Marginal Zone: (B/C) Lower Zone: (B/C) Upper Zone: (C)
Cover(%)
Woody Riparian Woody Terrestrial Non-woody (Incl Reeds) Perennial Aliens Open (Alluvium) Open (Bedrock) Open (Water) Other
Aerial cover estimation (%) for vegetation components stratified by sub-zones at IFR P1: woody vegetation
assessment (top), non-woody vegetation assessment (bottom). Letters in brackets e.g. (B/C) indicate ecological
category of the sub-zone
RIPARIAN VEGETATION

11. SOCIO-ECONOMIC BASELINE (1 of 5)
Total Consumption
(Per Household)
Total Consumption
(Population)
Household well-being indicator M 9,519 36,172,613
Water:
All water consumption m3
/a 64 244,623
Senqu River consumption m3
/a 2 8,862
Fish:
All fish caught # 142 538,245
Senqu River catch # 107 405,303
Wild Edible Plants:
All collections Bags/a 220 836,039
Senqu River riparian collection Bags/a 83 316,609
Wild Medicinal Plants:
All collections Bags/a 64 242,896
Senqu River riparian collection Bags/a 37 140,444

12. SOCIO-ECONOMIC BASELINE (3 of 5)
Total Consumption
(Per Household)
Total Consumption
(Population)
Livestock numbers:
Cattle # 1 3,764
Sheep/Goats # 1 2,669
Horse/Donkey # 0 248
Other # - -
6,682
Domestic Energy:
Wood:
All collections Bags/a 477 1,813,264
Senqu River riparian collection Bags/a 357 1,355,255
Bush:
All collections Bags/a 552 2,098,679
Senqu River riparian collection Bags/a 247 940,109
Dung:
All collections # 14,638 55,625,594
Senqu River riparian collection # 4,423 16,808,884

13. SOCIO-ECONOMIC BASELINE (5 of 5)
• Cultural services:
– Cultural diversity, spiritual and religious
values, aesthetic values, recreation and
ecotourism
Cultural Ecosystem
Service activity
Average time
spent per trip
Senqu River
Dependence
Average trips to
Senqu River
Hours/trip % Trips per year
Swimming 4.4 85% 17.1
Baptism 3.5 92% 4.5
Cultural Activities 4.8 88% 3.2
Spiritual Activities 4.4 74% 2.2
Initiation Activities 2.4 90% 1.6
Church 5.3 100% 0.3

14. Photo:DavidBrazier/IWMIPhoto:TomvanCakenberghe/IWMIPhoto:DavidBrazier/IWMIPhoto:DavidBrazier/IWMI
Historical flows
Current flows
Future flows
Hydrology
Geomorphology
Hydraulics
Water quality
RIVER TYPE
HYDROLOGICAL
STATISTICS
SOURCES/STRESSORS
(Location of multiple
source/stressors)
ENVIRONMENT
PEOPLE
LOCAL COMMUNITIES
OTHER BENEFICIARIES
BIOLOGICAL
COMPONENT
PHYSICAL CONTENT
HABITATS
(Location of multiple
receptors)
SOCIO-ECOLOGICAL ENDPOINTS
(Location of ranked impacts to endpoints)
Floodplain non-woody plants (grazing)
Medicinal plants for people
Edible plants for people
Protection of fish for the ecosystem
Reeds
Protection of the riparian ecosystem
Protection of the river benthos
Domestic water (drinking and washing)
Fish stocks as food for people
Recreational/spiritual use
Woody plants (fuel, construction)
Building sand supply from instream
CONCEPTUAL MODEL CONSTRUCTION

15. Photo:DavidBrazier/IWMIPhoto:TomvanCakenberghe/IWMIPhoto:DavidBrazier/IWMIPhoto:DavidBrazier/IWMI
CONCEPTUAL MODEL CONSTRUCTION

16. PROBFLO: EXPANSION OF EXAMPLE
S3
RIPARIAN PLANTS
(FOOD, FUEL AND
BUILDING MATERIALS)
SUPPLY FROM
ENVIRONMENT
DEMAND: LOCAL
COMMUNITIES
LOCAL
COMMUNITIES
OTHER
BENEFICIARIES
DEMAND FOR
LIVESTOCK
DEMAND
RIPARIAN PLANT
COMMUNITIES
ABUNDANCE
RIPARIAN
COMMUNITY
INTEGRITY
ENVIRONMENTAL
REQUIREMENTS
HYDROLOGY
GEOMORPHOLOGY
HYDRAULICS
WATER QUALITY
HABITAT
FLOW
STANDARD

17. PROBFLO: Conditional Probability Tables
Output Node
Possible
states by
defined
ranks
Likelihood
of
outcomes
given input
states
Conditional Probability Table
S2

18. Abundance
zero
low
medium
high
30.0
60.0
10.0
0
1.6 ± 1.2
Riparian_Com_Integrity
zero
low
medium
high
35.0
55.0
10.0
0
1.5 ± 1.2
Riparian_Plant_Communities
zero
low
med
high
31.4
59.7
8.90
0
1.55 ± 1.2
Environment_Supply
zero
low
med
high
46.9
45.4
7.18
0.52
1.23 ± 1.3
Demand_by_People
zero
low
medium
high
51.8
46.4
1.82
0
1 ± 1.1
Demand_for_Lifestock
zero
low
medium
high
35.0
60.0
5.00
0
1.4 ± 1.1
Environmental_Requirements
zero
low
med
high
65.5
25.6
7.32
1.62
0.902 ± 1.4
Habitat
zero
low
medium
high
57.1
26.5
10.5
5.91
1.3 ± 1.8
Water_Quality
zero
low
medium
high
80.0
15.0
5.00
0
0.5 ± 1.1
Hydraulics
zero
low
medium
high
45.0
30.0
15.0
10.0
1.8 ± 2
Geomorphology
zero
low
medium
high
75.0
15.0
7.00
3.00
0.76 ± 1.5
Hydrology
zero
low
medium
high
70.0
20.0
5.00
5.00
0.9 ± 1.6
Local_Communities
zero
low
medium
high
25.0
70.0
5.00
0
1.6 ± 1
Other_Beneficiaries
zero
low
medium
high
80.0
20.0
0
0
0.4 ± 0.8
Demand
zero
low
medium
high
42.9
54.3
2.86
0
1.2 ± 1.1
Riparian_Vegitation
zero
low
medium
high
44.1
51.3
4.42
0.16
1.21 ± 1.2
RIPARIAN PLANTS
(FOOD, FUEL AND
BUILDING MATERIALS)
SCENARIO 1: NO
DEVELOPMENT,
REFERENCE STATE.
SC 1

19. Abundance
zero
low
medium
high
50.0
30.0
5.00
15.0
1.7 ± 2.1
Riparian_Com_Integrity
zero
low
medium
high
30.0
30.0
15.0
25.0
2.7 ± 2.3
Riparian_Plant_Communities
zero
low
med
high
34.2
35.3
16.8
13.7
2.2 ± 2
Environment_Supply
zero
low
med
high
19.6
38.9
28.8
12.7
2.69 ± 1.9
Demand_by_People
zero
low
medium
high
53.0
38.9
8.05
0
1.1 ± 1.3
Demand_for_Lifestock
zero
low
medium
high
40.0
30.0
15.0
15.0
2.1 ± 2.1
Environmental_Requirements
zero
low
med
high
14.1
32.7
33.2
20.0
3.18 ± 1.9
Habitat
zero
low
medium
high
20.9
24.2
30.4
24.5
3.17 ± 2.1
Water_Quality
zero
low
medium
high
15.0
35.0
25.0
25.0
3.2 ± 2
Hydraulics
zero
low
medium
high
45.0
15.0
30.0
10.0
2.1 ± 2.1
Geomorphology
zero
low
medium
high
30.0
15.0
45.0
10.0
2.7 ± 2
Hydrology
zero
low
medium
high
5.00
20.0
5.00
70.0
4.8 ± 1.9
Local_Communities
zero
low
medium
high
60.0
35.0
5.00
0
0.9 ± 1.2
Other_Beneficiaries
zero
low
medium
high
50.0
35.0
15.0
0
1.3 ± 1.5
Demand
zero
low
medium
high
42.6
39.3
13.6
4.52
1.6 ± 1.7
Riparian_Vegitation
zero
low
medium
high
27.0
44.6
22.5
5.89
2.15 ± 1.7
RIPARIAN PLANTS
(FOOD, FUEL AND
BUILDING MATERIALS)
SCENARIO 2: POST
DEVELOPMENT,
WITH IFR
IMPLEMENTATION.
SC 2

20. Photo:DavidBrazier/IWMIPhoto:TomvanCakenberghe/IWMIPhoto:DavidBrazier/IWMIPhoto:DavidBrazier/IWMI
RIPARIAN PLANTS
(FOOD, FUEL AND
BUILDING MATERIALS)
SUPPLY FROM
ENVIRONMENT
ENVIRONMENTAL
REQUIREMENTS
HYDROLOGY HABITAT
MAINTAIN EXISTING
MACROINVERTEBRATE
COMMUNITY
STRUCTURES
ENVIRONMENTAL
REQUIREMENTS
HYDROLOGY
HABITAT
(HYDRAULICS)
ECOLOGICAL
CUES
HYDROLOGY
MAINTAIN VIABILITY OF
RHEOPHILIC RVER FISH
GUILDECOLOGICAL CUE
FLOWS
ENVIRONMENTAL
REQUIREMENTS
HYDROLOGY
HABITAT
(HYDRAULICS)
WATER FOR LIFE
(PEOPLE AND
LIVESTOCK)
SUPPLY FROM
ENVIRONMENT
QUANTITY
FISH (SUBSISTENCE
FISHERY)
SUPPLY FROM
ENVIRONMENT
ENVIRONMENTAL
REQUIREMENTS
HYDROLOGY HABITAT
QUANTITY
FORMAL WATER
ABSTRACTION
MONITORING EWRs

21. SCENARIO INTERPRETATION – CHANGE IN ECOSYSTEM SERVICES
PD-3 PD-4 PD-5 PD-LMH PD-3 PD-4 PD-5 PD-LMH
Hydro:
Water -95.00% -2.50% -3.00% 0.00% 0.00% 0.00% 0.00% 0.00%
Fish:
Fish -65.00% -25.00% -25.00% -5.00% -55.00% -20.00% -30.00% -55.00%
Geomorphology:
Sand -10.00% -50.00% -20.00% -15.00% 50.00% 10.00% 35.00% 30.00%
Riparian Area -5.00% -15.00% -5.00% -10.00% 30.00% 10.00% 15.00% 40.00%
Veg:
Rip Habitat Health -48.00% 0.00% -20.00% 0.00% -5.00% 0.00% -5.00% -10.00%
Wood -40.00% 0.00% 5.00% 5.00% 5.00% 0.00% 5.00% 0.00%
Floodplain Grazing -30.00% 0.00% -30.00% -5.00% -10.00% 0.00% -10.00% -15.00%
Reeds -44.00% 0.00% -15.00% -5.00% -10.00% 0.00% -10.00% -15.00%
Medicinal -43.00% 0.00% -5.00% -5.00% -10.00% 0.00% -10.00% -15.00%
Food -40.00% 0.00% -5.00% -5.00% -10.00% 0.00% -10.00% -15.00%
IFR-P1 IFR-P2
CALCULATE THE RELATIVE AND INTEGRATED RISK