Using GIS in Site Suitability for
Aquaculture: Green Economy
Solutions
DEA GIS Day 2014
18 November 2014
Using GIS in site suitability for aquaculture: Green economy solutions
Celéste Dekker
Agricultural Research Council Institute for Soil, Climate and Water,
Pretoria South Africa. [email protected]
Presentation Structure
The challenge
GIS solution
Site suitability for Aquaculture
Spatial analysis options
Climate change
GIS future is Green
The ChallengeAnthropogenic influence
Population growth
Increase in pressure on land and ocean
Food insecurity & Poverty
Natural fish resources nearing depletion
Alternative food (protein) source to capture fisheries: Fish farming -
inland
African aquaculture 2% of global aquaculture production (5% of
Africa's fish)
GIS Solution
Aquaculture fastest growing agricultural sector globally
(>50% of fish)
Increase protein production
Reduce poverty
Increase food security
Existing resources (water, manure, food processing
mills, available land, smallholdings, dams)
Sustainability
Affordability (relatively low cost)
Small-scale farmer benefit
GIS Solution
Gauteng Department of Agriculture and Rural
Development (GDARD)
Phase 1: “Low cost Integrated Aquaculture
and Layer Hen’s Production Unit”
Pond, cage but not recirculating tank
production systems
Edible fish considered
Perception: Gauteng too cold/warm for
aquaculture
Site Suitability for Aquaculture
Fish species considered
Cold water fish:
Rainbow trout (Oncorhynchus mykiss)
Warm water fish:
Common carp (Cyprinus carpio)
African catfish (Clarias gariepinus)
Tilapia (Rendali, Oreochromis niloticus & mossambicus)
Site Suitability for Aquaculture
Mozambique tilapia
(Oreochromis Mossambicus)
Earth ponds (low cost)
Rivers, springs & boreholes
Cage culture
Dams, perennial pans
Current network of irrigation
systems in SA
60 000 ha of water
Large % might be suitable
Site Suitability for Aquaculture
Site suitability of Gauteng for inland fish farming
Spatial data integration concept
Spatial modelling in ArcGIS 10.1
Variables and thresholds - limiting or economic:
Water sources
Water temperature
Restricted areas
Infrastructure
Topography factors
Soil factors
Distance to processors
Site security
Spatial Analysis
Single expert knowledge in choosing parameters
Thresholds assigned to parameters
Parameters combined
Areas where all criteria were met
Yes/No answer
MSc thesis by Steer (2005)
Spatial AnalysisBuffering:
Distance from water source
Distance from substantial roads
Masks:
Wetlands
Built up areas
Eskom lines and substations
Water temperature
Slope
Population density and unemployment
High risk / Low risk (controversial)
Economic viability
Soil clay %
Soil pH
Distance to power lines
Distance from processors
Site Suitability for Aquaculture
Many other factors:
Sources of pollution
Water table heights
Occurrence of fish predators
Water quality
Proximity to chicken farms (manure), food
processing plants and waste (sewerage) water
Legislation
Distance to markets
Dam levels
Aspect
Land ownership
Flood zones
Seepage rates
Competition: other uses
Salinity
Input Criteria
Name of variable layer Source Threshold
Water sources SANBI, DWA, CDSM <= 1 km
Water Temperature
Grids
FAO AWRD database 20 - 30 oC
Tolerate 15 - 42 oC
Ideal 28 - 30 oC
Slope (for Ponds) Derived from SRTM
DEM, ARC-ISCW
0.5% – 2.5%
Population density Derived from
STATSSA census
data
>= 5000 p/km2
Unemployment rate Derived from
STATSSA census
data
>= 30%
Substantial roads Combination of
several road shape
files
<= 200 m
Fish processors Collected from
Google Earth
addresses and phone
calls
<= 100 km
GIS AnalysisModel Builder in ArcMap 10.1
Site Suitability for Aquaculture
Analysis Options
Multi Criteria Evaluation (MCE)
Weighting
Levels of suitability (classes)
Associated Yields
Multiple experts choosing
parameters
Delphi method
Based on Land-Types
Thematic layering in MS Access
Funding Options
Budget
Investment
Data and Tool OptionsFAO African Water Resource Database (AWRD)
Inland aquatic resource management
Spatial data archive and GIS-based tools:
Datasets covering the African continent: Surface water bodies, watersheds,
aquatic species, rivers, political boundaries, population density, soils,
satellite imagery, physiographic and climatological data
Custom-designed applications and tools programmed to run in GIS
software environment (ArcView 3.x)
Integration of different types of information in a GIS analytical
framework
To display and analyse
“Valuable instrument to promote food security”
Continental scale
Species DistributionMozambique tilapia endemic
Nile tilapia invasive species
Naturally occurring in coastal rivers of
Israel, Nile basin, various Ethiopian
lakes, West Africa other lakes and
river systems across Africa
Faster grower
Hybrids accumulate more Nile tilapia
genes over generations
Protect Mozambique tilapia from Nile
tilapia invaders
Preserving Pure O. Mossambicus
International Union for Conservation of Nature (IUCN) status of
Mozambique tilapia
2010 Least concern to near threatened as result of exotic Nile tilapia
introduction/invasion
No active steps by authorities in either Zimbabwe or South Africa to
protect established genetically unpolluted populations in reservoirs
No programmes to control established hybrid populations
Controversial zoning system proposed to allow Nile tilapia farming in
those regions where already present but not in regions where not
Environmental protection of local biodiversity
Promotion of the Mozambique tilapia as suited to small-scale
aquaculture in southern Africa
Climate ChangeGeophysical Fluid Dynamics
Laboratory (GFDL) Climate
model
Increase in water temperature
leads to increase in growth
Above 30 oC growth slows
down, death
Climate change adaptation of
the different species
Factors affecting water temp:
Air Temperature
ET (Potential
evapotranspiration)
Wind
Solar radiation
Future tilapia occurrence
Modelling Options
Model future species distribution
Ecological risk assessment
Based on feed & environment
Ecopath with Ecosim (EWE), Ecospace
MaxEnt
SANBI NFEPA fish sanctuaries
Sub-quaternary catchments
Characteristics of a Mozambique tilapia
sanctuary
Future fish sanctuary delineation
GIS Future is GreenSolving future problems now
GeoDesign: Integration of design tools with existing GIS functionality
Design for Anthropogenic elements of Earth systems
Understand the dynamics of the various systems
Develop robust models and tools
Planning framework that incorporates technology, science and nature
Choose the best alternative futures
Earth Systems Engineering and Management (ESEM)
ESEM: Design, engineering, analysis, and
management of complex Earth systems
ESEM takes a holistic view of multiple issues affecting
our Earth
Environmental, social and other considerations taken
into account up front in the design process
Adaptive systems approach: Ongoing analysis feeds
back into the continual management of the system
GIS and the emerging field of GeoDesign are critical
to the success of approaches such as ESEM and
other logical and rational models for dealing with the
environmental and planning problems of our and
future generations (Braden Allenby, "Biomass
Management Systems" in Reconstructing Earth,
2013)
Ethical practice of social studies moral imperative
GIS Green Solutions
Thank You
Celéste Dekker
(012) 310-2622
ARC-ISCW
GeoInformation Division
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