The website www.GrapeLook.co.za assists grape farmers in Western Cape, South Africa, with the daily management of scarce irrigation water resources and on-farm nitrogen in order to promote sustainable optimal resource utilization, reduce input costs, and protect the environment by means of operational satellite remote sensing technologies. The study areas include the areas around Somerset West (Heldenberg), Stellenbosch, Paarl, Wellington, Worcester, De Doorns, Citrusdal and Vredendal.
In 2010 a one-year demonstration project started, with the purpose of providing real-time information on grape production, irrigation water demands and crop nitrogen status to producers in order to improve the water use efficiency on their own farms on a week-to-week basis. The satellite data is available to all stakeholders, i.e. farmers, irrigation advisors, the Irrigation Boards, and the WUAs.
Water use surveillance and ecological economic modeling of Agro-Ecosystems
The project aimed at providing spatial information to assist local, regional and national authorities as well as private land owners with water and associated land use planning. Specific objectives were to determine the impact of land and water resources practices in the Olifants-Doring water management area (WMA) on ecosystem functions using remote sensing technologies and to determine the economics of bulk water allocations and land-use decision-making in order to inform the environmental / socio-economic trade-offs.
A major component of this project is estimating the actual crop water use of agricultural crops and fruit trees cultivated in the Sandveld and surrounding areas, spatially. This information can be used when determining a water balance for the Olifants-Doring WMA and assessing the impact of different land uses on water availability in the WMA, as well as analyzing the contribution of different crops/land uses to the economy of that area. The dominant agricultural ‘crops’ produced in this greater Sandveld region include potatoes, citrus and grapes (wine and table), of which all are produced under irrigation. Since the Water Act was instituted in 1998, the area under cultivation of potatoes has increased significantly, and there is therefore great interest to determine the impact of this change in land use on available water resources.
Coping with competing water claims in the Incomati Basin through Interactive Science (WIBIS)
This project aimed at supporting inter-sector and inter-state policy development and sustainable use of the Incomati basin water through building capacity with respect to water valuation and innovative water monitoring. In order to be able to assess the implications of water reallocations among activities, sectors and states (i.e. for making trade-offs) insight is required in the relationship between land- and water use and benefits that water generates for land use activities in the Basin, main sectors in the Basin and the various states. A discussion support tool was developed and tested to assess the implications of water reallocation policies on different stakeholders. WaterWatch provided actual water consumption and biomass production maps of the Incomati basin using SEBAL for a dry year (2002-03), a wet year (2005-06) and an average year (2003-04).
Monitoring hydrological benefits of the removal of invasive species
The Working for Water program aims at protecting the water resources of South Africa through controlling alien invasive plants. The SEBAL technology offers a method to assess the past, present and future impact of invasive species on the water resources. The goal of this project was to assess the water consumption over an 8-year period in KwaZulu-Natal and Western Cape.
A methodology for near-real time spatial estimation of evaporation
Many of the conventional methods to estimate evaporation can only be applied at field scale which is insufficient for basin-wide analysis. Remote sensing data to estimate evaporation holds great potential. This study aims at determining the best methodology to estimate evaporation using remote sensing images.
Water use efficiency of table and wine grapes in Western Cape
The Western Cape faces an increasing demand for water while water resources area scarce. The challenge for the grape industry is to reduce its water consumption whilst maintaining its economic sustainability. Information on the water use efficiency of different crops, farms and irrigation is required to suggest improvement in the water utilization.
Combining remote sensing and economic analysis to assess water productivity
The project was to demonstrate that remote sensing analysis in combination with a surface energy balance model (SEBAL) can be used to calculate actual water consumption and can be combined with a set of social and economic indicators. The analysis consisted out of two parts: (1) a technical analysis of the hydrology using remote sensing data, and (2) an interpretation of the technical data using social and economic indicators.