Draft Climate Change Plan
Key Climate Hazards
The figure below shows projected changes in annual average temperatures, highlighting increasing temperatures throughout the district for the period 2021-2050 under the RCP 8.5 scenario. By 2050, the district is projected to be affected by higher annual average temperatures, which will adversely affect water and food security. Evaporation rates will also likely increase and agricultural outputs may reduce.
Increasing rainfall variability
The figure below shows projected shifts in annual average rainfall throughout the district between 2021-2050 under the RCP 8.5 scenario. Annual average rainfall amounts vary across the district. There is uncertainty regarding projected future rainfall.
Increasing storms and flooding events
The figure below shows projected changes in the annual average number of extreme rainfall days throughout the district over the period 2021-2050 under the RCP 8.5 scenario. Increases in the number of rainfall days are likely to result in an increase in intense storms, and flooding events across the district.
The current delineation of biomes is depicted in the figure below, with the predicted shift in biomes shown in the following figure based on a high-risk scenario. The biomes have varying sensitivities to the projected impacts of climate change which are further exacerbated by issues such as the fragmentation of natural areas and unsustainable water usage rates.
Climate Change Vulnerability
A climate change vulnerability assessment is a way of identifying and prioritising impacts from climate change. The IPCC defines vulnerability as:
"Vulnerability to climate change is the degree to which geophysical, biological and socio-economic systems are susceptible to, and unable to cope with, adverse impacts of climate change"
Summary of Climate Change Response Plan
A vulnerability assessment lets you identify these adverse impacts of climate change that are most important to your area. The climate change vulnerability assessment process that is used in this toolkit identified the following indicators in the table below.
Adaptive Capacity Comment
|Agriculture||Reduced food security||Yes||Elim|
|High||Recent droughts have caused food price increase with some households unable to afford to sustain their livelihoods.||Low||Agri Parks|
|Biodiversity and Environment||Increased impacts on threatened ecosystems||Yes||Overberg|
|High||The District is covered by a substantial number of threatened ecosystems. The ‘Kogelberg Sandstone Fynbos’, ‘Elgin Shale Fynbos’, ‘Western Ruens Shale Renosterveld’, ‘Elim Ferricrete Fynbos’, ‘Overberg Sandstone Fynbos’, ‘Central Ruens Shale Renosterveld’, ‘Eastern Ruens Shale Renosterveld’, ‘Ruens Silcrete Renosterveld’ and ‘Cape Lowland Alluvial Vegetation’ are all categorised as critically endangered ecosystem types||Low||CapeNature|
NGO's - ICLEI, ABI - KBRC
|Biodiversity and Environment||Increased impacts on environment due to land-use change||Yes||Invasive alien species|
|High||Land use change in the District is due to increase spread of invasive alien species, land degradation, soil erosion, coastal erosion, unsustainable harvesting of natural resources, increased pollution, poor waste management, poor stormwater management, population growth, spatial development.||Low||DEA/ Conservation Entities|
Municipalities - Town Planning
|Coastal and Marine||Loss of land due to sea level rise||Yes||Struisbaai|
|High||At 260 km2 in total, the Overberg District Municipal Area contains the second largest area of coastal land with less than a 5.5 m elevation in South Africa||Low||Cape Agulhas|
|Coastal and Marine||Increased damage to property from sea level rise||Yes||Cape Agulhas|
|High||Coastal property along the coast line is bound to be damaged due to sea level rise.||Low||Cape Agulhas|
|Human Health||Increased heat stress||Yes||Grootstrand|
|High||The young (<5yrs age group) and elderly (>64yrs age group) constitute 17.17% of the total population||Low||District and local Municipalities|
Department of Health
|Human Settlements, Infrastructure and Disaster Management||Increased impacts on strategic infrastructure||Yes||There are several strategic infrastructures found within the District Municipality||High||N2, R43 and R44|
Air Force base in Overberg
District and its local municipalities
|Human Settlements, Infrastructure and Disaster Management||Increased risk of wildfires||Yes||Increased biomass due to invasive species|
|High||The Districts’ veld fire risk is high. Veld fire prevalence is high during the summer months in the district.||Low||District Municipality|
DEA and DP
|Water||Decreased water quality in ecosystem due to floods and droughts||Yes||Rivers - (Swellendam, TWK)|
|High||2011 Green Drop scores of each local municipality within the Overberg District Municipality: The Cape Agulhas Local Municipality scored 51.90%, the Overstrand Local Municipality scored 43.30%, the Swellendam Municipality scored 26.60% and the Theewaterskloof Local Municipality scored 31.20%||Low||The District and local municipalities|
Water and Sanitation
|Water||Less water available for irrigation and drinking||Yes||TWK - Dam 25%|
|High||The entire Western Cape is and has been experiencing severe drought cases.||Low||Municipalities|
Water and Sanitation
The CSIR Greenbook has also developed and refined a vulnerability assessment framework by collating relevant data into composite vulnerability indicators. Four local municipality level vulnerability indices were computed and are shown spatially below.
Social inequalities are the factors that affect the susceptibility and coping mechanisms of communities and households. Indicators for social vulnerability attempt to consider the sensitivity, response and recovery from the impacts of natural hazards. The CSIR Green Book has developed a socio-economic vulnerability index that is measured on a scale from 1 (low vulnerability) to 10 (high vulnerability). The map below shows the Socio-Economic vulnerability score of each municipality in the district visually.
Environmental vulnerability describes the vulnerability and risk to the natural environment and the impacts on the ecological infrastructure of which surrounding settlements are dependent. The environmental risk of an area includes ecosystems, habitats, physical and biological processes (reproduction, diversity, energy ﬂows, etc). The CSIR Green Book has developed an Environmental Vulnerability Index that is measured on a scale from 1 (low vulnerability) to 10 (high vulnerability). The map below shows the environmental vulnerability score of each municipality in the district visually.
Physical vulnerability describes the physical fabric and connectedness of settlements (buildings and infrastructure) and focuses mainly on the conditions that exist before a hazard occurs and the expected level of resulting loss. The CSIR Green Book has developed a physical vulnerability index that is measured on a scale from 1 (low vulnerability) to 10 (high vulnerability). The map below shows the physical vulnerability score of each municipality in the district visually.
Economic vulnerability describes the potential risks posed by hazards on economic assets and processes. Potential hazards can include job losses, increased poverty and interruptions in business activities. The CSIR Green Book has developed an economic vulnerability index that is measured on a scale from 1 (low vulnerability) to 10 (high vulnerability). The map below shows the economic vulnerability score of each municipality in the district visually.
- CSIR. 2019. ‘Green Book | Adapting South African Settlements to Climate Change’. Green Book | Adapting South African Settlements to Climate Change. 2019. www.greenbook.co.za.
- Le Roux, A, E van Huyssteen, K Arnold, and C Ludick. 2019. ‘The Vulnerabilities of South Africa’s Settlements’. Green Book. 2019. https://pta-gis-2-web1.csir.co.za/portal/apps/GBCascade/index.html?appid=280ff54e54c145a5a765f736ac5e68f8.
SANParks. 2011a. ‘CCAB - Current Biome Delineations 2011 [Vector Geospatial Dataset]’. Available from the Biodiversity GIS website. http://bgis.sanbi.org/SpatialDataset/Detail/484
SANParks. 2011b. ‘CCAB - High Risk Scenarios - Biome Delineations 2011 [Vector Geospatial Dataset]’. Available from the Biodiversity GIS website. http://bgis.sanbi.org/SpatialDataset/Detail/486.