Remote sensing in disaster management

Natural disasters place humanity at nature's mercy. Thanks to technologies in use by SANSA's Earth Observation team, we have the ability to mitigate their effects.

Technologies like Remote Sensing and Geographic Information Systems allow SANSA to monitor disasters such as drought, Earthquakes, tsunamis, volcanic eruptions, field fires and floods. Satellite images are used to identify vulnerable areas, evacuation routes and suitable locations for warning systems. Optical remote sensing, which uses visible, short-wave infrared sensors to create images of the Earth, contributes to search and rescue operations in areas inaccessible by road. Radar data is useful during oil spills and floods, as it's not affected by atmospheric interference and cloud cover.


RADAR detects objects in the atmosphere using radio waves, and determines their speed, direction and altitude.


In January this year, floods hit the rural town of Matatiele in the Eastern Cape. Satellite images were used by SANSA to identify flooded areas and houses which were built within the flood risk zone. Of the 87 houses built within 100m of the Matatiele River, 12 were at great risk of being flooded. This kind of information is essential in planning settlements to prevent damages and loss of life.

Earth observation has long been important to monitoring floods after they happen. SANSA is now working with the SA Weather Service to anticipate floods before they happen. "It's fairly easy to look at the damage done after a flood," says EO Directorate MD Jane Olwoch. But by working with meteorologists to understand when and where the rain is going to fall, and superimposing data on hydrology, land use, and historic rain and flood patterns, SANSA will build a national map of areas which are more disaster-prone. "Then we can advise the authorities that 'this is a flood area, so don't build roads and houses here,'" says Olwoch.

By anticipating floods, SANSA makes planning much easier for provincial and local disaster management and emergency services.

SANSA is also working closely with the National Disaster Management Centre to ensure a model is developed to identify areas at risk of being flooded. The SERVIR-CREST hydrological model will simulate variations of land surface and subsurface water in specific areas over specific periods of time. It will identify areas likely to be flooded by analysing rainfall and potential evapotranspiration data, a digital elevation model (DEM), river discharge and soil.


Evapotranspiration is the amount of plant transpiration and water evaporation from land and ocean surfaces released into the atmosphere.


SANSA is also a project manager in the International Charter on Space and Major Disasters. SANSA co-ordinates remote sensing data from other space agencies in response to natural disasters in the SADC region. Even archived information about past disasters is instrumental in gaining a better understanding of trends and dynamics which contribute to natural disasters.




Delivering the National Development Plan – the vital role of Earth observation

SANSA is expanding the reach of its Earth Observation (EO) service to the most local level of government, with the placement of EO specialists in municipalities.

"Many municipalities are not yet fully exploiting the EO data which we can make available to them," says Jane Olwoch an environmental scientist and MD of the Earth Observation Directorate at SANSA.

During 2014, EO staff will be embedded as EO champions and extension officers in Tshwane and Mangaung municipalities, with the task of building relationships and championing the use of EO.

"There is a lot of information which municipalities need and which SANSA already has. We just need to inform and educate people about the vast potential available through their national space agency."

Rapid urbanisation and the growth of informal settlements is one of the major challenges facing municipalities. "The view from the top makes it much easier to count houses and to map and understand settlements and the pace of urbanisation, which makes it easier to plan and deliver services," Olwoch says.

She points to recent studies which show housing estates and golf courses built on areas with the highest agricultural potential. "That is very dangerous. SA doesn't have a lot of agricultural land and what little we have is often taken up for non-agricultural use, which has implications for food security, water flow, biodiversity and environmental processes."

Olwoch says EO is also establishing a relationship with the National Planning Commission (NPC). "There are so many ways we can contribute to the work of the NPC," she says. In addition to the use of satellite imagery for infrastructure monitoring and as a planning tool, the EO team also meets National Development Plan (NDP) ambitions for the creation of highly-skilled technology jobs in data systems and software engineering.

"Earth observation enables service delivery," says Olwoch. "We are helping government to use images from space to deliver the NDP."

Imraan Saloojee, who heads stakeholder relations and business development for SANSA, is the eyes and ears of SANSA on the global stage. One of the key international collaborations for the agency is the TIGER project, which looks at how EO products and services can be used for water management in Africa.

SANSA is the central agency through which international Earth observation data is acquired and distributed in SA. "We acquire the data and make it widely available in the national interest," Saloojee says. Among EO data available through SANSA is imagery from the French SPOT (Satellite Pour l'Observation de la Terre) and the US Geological Survey's (USGS) LandSAT satellites. The latter, responding to a global initiative through the Group on Earth Observations (GEO) to make more EO data available without any cost, saw a hundredfold increase in users globally once it was made available free of charge by the USGS.

A key SANSA product is the 'mosaic', a comprehensive EO map of the whole of SA, which provides a very valuable information source for all of government.


What are the impacts of climate change?

climate change

The report, titled Climate Change 2014: Impacts, Adaptation, and Vulnerability, from Working Group II of the IPCC, details the impacts of climate change to date, the future risks from a changing climate, and the opportunities for effective action to reduce risks. A total of 309 coordinating lead authors, lead authors, and review editors, drawn from 70 countries, were selected to produce the report. They enlisted the help of 436 contributing authors, and a total of 1,729 expert and government reviewers.

Today in Yokahama, Japan, The Intergovernmental Panel on Climate Change (IPCC) issued a report that says the effects of climate change are already occurring across all continents and our oceans. The world, in many cases, is ill-prepared for risks from a changing climate. The report also concludes that there are opportunities to respond to such risks, though the risks will be difficult to manage with high levels of warming.

Watch this space: Dr Jane Olwoch, MD for SANSA EO who has been part of the writing team will present on key findings soon


Exploring the limitless applications of the new SPOT6 data in the South African context


Satellite imagery is used to support public sector planning and delivery in areas such as agriculture, human settlements, infrastructure development, and environmental monitoring and conservation. In line with its vision to be a leader in ensuring that satellite Earth observation data benefits society, the environment, the economy and the global community through products and services; research and application development; science advancement and human capital development, the South African National Space Agency (SANSA) is in the process of acquiring SPOT 6 Imagery for South African users.

Spot data has in the past proven to be a valuable data set for the local users and decision makers. However, there is a constant need to further leverage this and other valuable data sets and extend their use in decision making processes in the country. The new technologically enhanced SPOT 6 high-resolution satellite has been qualified by the European Space Agency (ESA) to take part in the Copernicus Earth observation program which showcases the recognition of this satellite and its capability.

Eyes in the Sky inspiring the youth

The South African National Space Agency (SANSA) is today launching an exciting collection of tools for learners in the country, in support of the geography curriculum at high school.

This launch is one of the initiatives SANSA and the Department of Science and Technology (DST) have organised to commemorate World Space Week, an initiative of the United Nations which is celebrated from 04 -10 October annually. The theme for 2013 is 'Exploring Mars, Discovering Earth'.

The Fundisa School Education and Fundisa disc are set to help increase understanding of Earth observations among Grade 10-12 learners. These resources, which include a portal for students, will also help raise awareness about the value satellite imagery adds to Geographic Information Systems (GIS) analysis.

These tools are aligned to SANSA's goal of building intellectual capital through cutting-edge research, development, innovation, technology and applications in the country.

Because many schools do not have computers and computer-based GIS software, the  resources will provide scenes relating to the schools' areas of interest and surrounding communities. SANSA will complement the data with material customised for FET and as much as possible align to the curriculum. By the time the learners graduate in Grade 12 they will have a greater understanding of Earth observation and can proceed to more focused studies at tertiary level.

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