According to the millennium ecosystem assessment, ecosystem services are continuously being degraded or transformed around the world with negative consequences on human well-being. At the centre of this degradation is the changing land cover due to unsustainable land use. Ecological infrastructure (EI) as defined by the South African National Biodiversity Institute (SANBI) refers to naturally functioning ecosystems that deliver valuable services to people, such as water and climate regulation, soil formation and disaster risk reduction. Monitoring the long term impacts of land cover change on ecosystem services (ES) and EI should provide useful starting point for understanding how EI support ES over time and space.
In South Africa, there are few studies, if any, that focuses on how EI can be built, enhanced, protected and maintained, and how this contributes to ES. It is also unclear how EI and ES contributes to alleviating the wellbeing of rural people dependent on livelihoods that may be directly linked to ES or exposed to adverse effects of ES failures. This study focuses on mapping EI and assesses its links with water based ES (also referred to as hydrological ecosystem services, (HES)). The study quantifies the impacts of land cover change and climate change on EI and HES for the past seven decades in a rural catchment.
The Duiwenhoks catchment in Southern Cape in the Eden district, Western Cape Province in South Africa provides an example of increasing risks due to extreme weather events that may be a result of land transformation and depletion of EI. The catchment has seen increasing land cover change and associated environmental impacts (Tshindane 2016, & Nzonda 2016). A recent study by Nel et al. (2014) declared the Eden district a disaster area as a result of frequent natural hazards such as flash floods and drought. The Eden district is also subject to a natural fire regime that may be intensified due to alien invasive plant species which result in increased fuel loads (Nel et al., 2014). This has resulted in the degradation of some areas of the catchment which may compromise the delivery of HES.
This study provides a thorough assessment and mapping of HES and EI based on Tshindane (2016), who conducted a fine scale land cover change data derived from grey scale & infrared aerial photographs from 1940-2010 using an automated process in Erdas Remote Sensing and ArcGIS software. Mapping the spatial extent of HES and EI will be achieved through the use of advanced GIS technologies using ArcGIS 10.3 and Remote Sensing software, Erdas Imagine 2016. The key EI to be mapped are: (EI for areas supporting Ecosystem based Adaptation (EbA), EI for areas supporting corridors or connectivity, EI for water production and flow augmentation, EI for flood attenuation, EI for resilience of ecosystem to extreme events and EI for water quality). The study will also map certain ecosystem services such as areas important for carbon sequestration. The output will assist in quantifying the extent to which historical land use/cover changes determines the current state of HES and EI which is lacking the most in our current literature in South Africa and also complements the MSc study by Bhengu, 2016.
1. Tshindane, M. 2016. Quantifying decadal changes in land cover in the Duiwenhoks catchment using spatial analysis techniques. MSc thesis. School of Agricultural, Earth and Environmental Sciences. University of KwaZulu-Natal.
2. Nzonda, G. 2016. Characterising historical land cover change and understanding trends in the Goukou catchment, Western Cape, South Africa. MSc thesis. School of Agricultural, Earth and Environmental Sciences. University of KwaZulu-Natal.
3. Bhengu, S. 2016. Mapping ecosystem services in Umngeni catchment. MSc thesis. School of Agricultural, Earth and Environmental Sciences. University of KwaZulu-Natal.
4. Nel, J.L., Le Maitre D.C., Nel D.C., Reyers B., Archibald S., et al. (2014) Natural Hazards in a Changing World: A Case for Ecosystem-Based Management. PLoS ONE 9(5): e95942.