Drought Monitoring by the Agricultural Research Council

DROUGHT MONITORING BY THE AGRICULTURAL RESEARCH COUNCIL

Recent drought conditions over the North West Province have revitalized interest in drought monitoring over South Africa. The Agricultural Research Council - Institute for Soil, Climate and Water (ARC-ISCW) monitors climate and vegetation responses operationally and provides near-real time products for the delineation of adversely affected areas. The Institute produces a monthly newsletter (named Umlindi) which provides updates of climate and vegetation conditions throughout the year, contributing to the near-real time understanding of how a specific rainy season unfolds. The maps published in thenewsletter are based on products derived at the ARC-ISCW. These include: total rainfall, derivatives of rainfall totals at various time scales relevant to agriculture, vegetation conditions and cumulative vegetation conditions and derivatives thereof. The maps are also available in JPEG format for separate use. Figure1 is an example of one of the drought monitoring products: a 12-month Standardized Precipitation Index (SPI) map by June 2013, showing severe drought conditions over parts of the North West Province at this time scale.

Figure 1: 12-Month Standardized Precipitation Index (SPI)per quaternary catchment by June 2013.

While operational drought monitoring is an on-going process at the ARC-ISCW, contributions are also made towards other projects involving the phenomenon of drought. The Institute has been involved in the EuropeanUnion-funded African Monitoring of Environment for Sustainable Development (AMESD) project.As part of the project deliverables, the ARC-ISCW developed a Drought Monitoring System (DMS) to be used in SADC with available remotely-sensed data for the area. The DMS is a decision support tool to be used at national or provincial level for drought monitoring and has been employed for the creation of maps used in the SADC Drought Report. The tool is an open source, stand-alone application specifically geared towards allowing the user to choose from a range of drought monitoring indices based on data available over EUMETCast. The data are received via a satellite dish so reception is not necessarily dependent on a good Internet connection. The system was developed for use in a Windows environment. The monitoring system combines the current rainfall estimates and vegetation responses (Normalized Difference Vegetation Index (NDVI), cumulative NDVI) as input. These are used to obtain products such as comparisons with long-term averages and other indices relevant for drought monitoring and possible with available near-real time data with resultant “Drought Maps” as an output product. The Long-Range Forecast of the South African Weather Service(SAWS) has been integrated into the system, and “drought outlooks” are also produced by combining the 3-month rainfall forecast with rainfall and vegetation conditions during the previous few months. The user is guided to apply existing algorithms to input data with freedom to choose areas and periods of interest.

The Disaster Management Act stresses the shift from a reactive to a proactive disaster management approach. Towards enabling a proactive approach, the ARC-ISCW is contributing to drought risk profiles regionally covering the country.The Institute’s contribution entails firstly a historical assessment of drought occurrence over the countryas a whole in terms of various definitions of drought related to intensity, extent, duration and potential impacts. Secondly, it involves the characterization regionally of drought frequency and intensity according to various definitions of drought related to impacts. Operational assessment of climate and vegetation conditions through monitoring products focussing on a range of timescales further assists in early detection of developing drought conditions.

For more information contact:

Johan Malherbe

Tel: +27 12310 2577

E-mail: