Project Overview 

There is inadequate knowledge about the linkages between spatial and temporal variability of non-perennial rivers, the integrity of these ecosystems, and human well-being. These rivers dominate most parts of southern Africa which is largely semi-arid to arid.

Modifications of non-perennial river flows by impoundments and flow abstractions for various purposes has led to degradation of these river systems. Lack of adequate knowledge about the social, cultural and economic values of services derived from these ecosystems results in very little effort being made to sustainably manage them.

Impoundments and flow diversions continue to be developed without adequately providing for environmental flows. Attempts to allocate water for non-perennial rivers have generally not led to the achievement of sustainable management of river systems, because the methods used are not appropriate for these systems.

Water resources managers thus have difficulties in enforcing the provision of environmental flows for non-perennial rivers, since the methods used have low levels of confidence and can be challenged by prospective applicants for licences to impound or divert river water.  The continued lack of provision for environmental flows increases poverty for those communities depending on ecosystems that are being degraded due to river flow modifications. ?

Project Objectives: 

• Understanding of the relationships between river flow, ecosystem characteristics and services provided by non-perennial rivers, and 
• Prediction, decision making and management related to the ecological and social consequences of flow modifications of non-perennial rivers. 

The following are the objectives of the project:

• To determine the nature of the spatial and temporal variability non-perennial river flows and factors accounting for these variations. 
• To establish how interactions between surface water and groundwater affect the quantity and quality of non-perennial river flows in different physiographic settings. 
• ?To examine how landforms and land-forming processes at catchment and channel scales determine the types of physical habitats occurring along non-perennial rivers.
• To identify the factors influencing spatial and temporal variations of the physiochemical characteristics of water in non-perennial rivers, and how these characteristics affect ecosystems and human uses of these rivers. 
• To establish how the spatial and temporal variations of non-perennial river flows influence the composition, distribution and abundance of riparian plants, and their uses by local people.
• To examine factors influencing the composition, abundance and dynamics of riverine fauna of non-perennial rivers or terrestrial fauna dependent upon them, and their uses by local people.
• To identify and evaluate the contributions of river flows and ecosystems along non-perennial rivers to human well-being.

Project Leader 

• Prof. Dominic Mazvimavi

Lead Researchers:

• Prof. Jenny Day 
• Prof. Leslie Petrik 
• Prof. Lincoln Raitt 
• Dr. Michael Grenfell 
• Dr. Suzanne Grenfell 
• Dr. Thokozani Kanyerere 
• Dr. Jaco Nel Dr Kevin Pietersen

Student Researchers:

Research Students 
First Name & Surname » Project » Degree 

• Adeola, Adeneye » Water quality » PhD 
• Errol, Malinjane » Water quality » MSc 
• Curtis, Grootboom » Geomorphology » MSc 
• Keaton, Hattingh » Geomorphology » MSc 
• Nomanesi, Makhonco » Geomorphology » MSc 
• Vincent, Banda » Geohydrology » MSc 
• Phumlani, Mnqondeki » Geohydrology » MSc 
• Raven, Pietersen » Geohydrology » MSc 
• Bernard, Schacht » Hydrology » MSc 
• Dylan, Seaton » Hydrology » MSc

The study is being undertaken on the following four catchments: 

• Verlorenveli River is located along west coast of South Africa with a freshwater lake connected to the sea at the distal end, and highly impacted by groundwater use for potato production, and rainfed grain production. 
• Tankwa River is located in a very arid part and covers most of the Tankwa-Karoo National Park proclaimed in 1986. This area has the succulent karoo ecosystem considered to be one of the biodiversity hotspots in the world. A plan for restoration of natural vegetation in the park is being implemented. However, the potential effects of some of the proposed restoration measures on river health are unknown. Globally, there is limited knowledge about ecologically sound management measures of river flow modifications in such very arid areas. 
• Touws River occurs within the Western Cape Province, in the region referred to as the Klein Karoo with fynbos, succulent karoo, and thickets as the major biomes. Rainfall is spatially highly variable with the mountain parts receiving up to 1000 mm/yr while the western part has very low rainfall, typically 100 mm/yr. This non-perennial river has some very interesting pools that are frequently not connected by river flows. The importance of these pools to supporting aquatic fauna, and livelihoods needs to be established. Extreme large floods that modify channel processes do occasionally occur. The influence of fluvial geomorphological processes on physical habitats is largely unknown.
• Heuningnes Catchment is located on the southern-most part of Africa in the Cape Agulhas and has numerous riparian floodplain wetlands, and temporary and permanent ponds.

Collaborating Partners 

Project Overview 

Sustainable management of water requires knowledge of the temporal and spatial variations of this resource, and factors influencing both the quality and quantity of water. This knowledge has traditionally been derived from data collected from ground-based observation stations. The network of ground-based stations is declining throughout Africa partly due to inadequate funding, while at the same time the demands for data are increasing due to competing water uses.

Space-based sensors (satellite and radar) capture the temporal and spatial changes in the earth system affecting water resources. Earth observation data enables estimation of rainfall, evaporation, transpiration, floods and droughts, monitoring water quality in large water bodies, identification of groundwater recharge and discharge areas, assessment of plant water relationships, and coverage of aquatic weeds.

There are several products being produced from earth observation data, e.g. rainfall estimates, evapotranspiration rates, and soil moisture. However, the utility of these products, including their accuracy, needs to be assessed in different environments. This project is investigating how representative the following products are in parts of South Africa:

a) Precipitation from the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) http://chg.geog.ucsb.edu/data/chirps/ 
b) Precipitation estimates from the Tropical Applications of Meteorology using SATellite (TAMSAT), http://www.tamsat.org.uk/ 
c) MOD16 global evapotranspiration, https://modis.gsfc.nasa.gov/data/dataprod/mod16.php d)     Soil moisture estimates derived from the Advanced SCATterometer (ASCAT) http://www.eumetsat.int/

Project Leader 

• Prof Nebo Jovanovic

Lead Researchers 

• Dr Michael Grenfell 
• Prof Dominic Mazvimavi

Research Students 

First Name & Surname » Year

• Jason, Moller » 2012-2014
• Eugune, Maswanganye » 2015-Present 
• Nolusindiso, Ndara » 2015-Present

 

Collaborating Partners

Project Overview 

The project is developing an integrated decision support system for the Lake Manyara Basin. This involves considering sustainable multi-sector water allocations in this basin. 
The project aims to contribute to sustainable development of ecotourism and irrigation in the basin. The decision-support system includes aquatic ecosystems, hydrological systems, soils, and land uses.

Project Leader 

• Dr Thokozani Kanyerere

Lead Researchers 

• Prof Lincoln Raitt 
• Dr Michael Grenfell 
• Dr Maryke Malan 
• Mr Henock Solomon 

Research Students

• None

Collaborating Partners

  

Project Overview 

The project is developing an integrated decision support system for the Lake Manyara Basin. This involves considering sustainable multi-sector water allocations in this basin. The project aims to contribute to sustainable development of ecotourism and irrigation in the basin. 
The decision-support system includes aquatic ecosystems, hydrological systems, soils, and land uses.

Project Leader 

• Prof Yongxin Xu 

Lead Researchers 

• Dr Thokozani Kanyerere 

Research Students 

• Mr Siyamthanda Gxokwe 
• Ms Danica Carnow 
• Mr Nangamso Tuswa

Collaborating Partners

  

Project Overview

The project aims to have an improved understanding of the groundwater system along the West Coast of South Africa. Data is being analysed to establish the hydrogeological characteristics of this study area.

Groundwater recharge areas are being delineated using data collected at existing boreholes. A conceptual model of the groundwater system is being developed. Geophysical techniques such as electrical resistivity tomography are being utilised to delineate aquifers.
A groundwater management plan that takes into account recharge rates and water uses is being developed. The project is also exploring best approaches for protecting wellfields from contamination, taking into account land uses and groundwater dependent ecosystems.

Project Leader

• Dr Sumaya Israel

Lead Researchers

• Dr Thokozani Kanyerere
• Prof Nebo Jovanovic
• Dr Richard Bugan
• Dr Gideon Tredoux

Research Students

• Mr Fanus Fourie (MSc)
• Ms Odwa (MSc)
• Ms Van der Schyff (MSc)
• Mr Clinton Andries (MSc)
• Mr Zaheed Gaffoor (MSc)
• Ms Nicolette Vermaak (PhD)

Collaborating Partners