How a high-tech approach to drought management can help halt desertification and achieve global goals

By Giriraj Amarnath 

Unsustainable land-use practices, such as deforestation, the excessive use of agricultural fertilizers and pesticides, and the over exploitation of water resources all contribute to desertification, which, in turn, is exacerbated by drought. With climate change already increasing the frequency, duration and severity of droughts, the stresses placed on our ecosystems are becoming ever greater. Unless rapid action is taken to restore land to vitality, economic losses will mount. According to the global disaster database, between 1950 and 2020, 487 droughts occurred in Africa and Asia – where the world’s drylands are primarily concentrated – affecting more than 2.5 billion people and costing more than $64 billion.

Harnessing technology

At the International Water Management Institute, we promote integrated drought-risk management as a way to help nations minimize the impacts of drought. This involves using state-of-the-art satellite technology to develop drought-monitoring and early-warning systems; undertaking vulnerability assessments; and supporting governments to use the information generated to shape effective mitigation and response plans. We are currently working on such projects within South Asia, Africa and the Middle East.

Creating drought early-warning systems involves examining satellite data on aspects such as rainfall, snowfall, snow cover, soil moisture, vegetation health and crop yield. A dry spell in which precipitation is lower than normal for more than a few days leads to a ‘meteorological drought’. If this dry period continues to the extent it reduces water levels in rivers and reservoirs, a ‘hydrological drought’ occurs. And if soil moisture levels fall – causing plants to wilt – an ‘agricultural drought’ results. Mapping these satellite-based signals can show early on if a drought is emerging – even before its effects are visible on the ground. Satellite observations of soil moisture can be particularly useful for predicting declines in yield that may threaten food security.

Our scientists used satellite technology to develop the award-winning South Asia Drought Monitoring System (SADMS). Through this system, authorities responsible for drought can access a weekly map of drought conditions, as well as a 15-day drought forecast. When drought struck South Asia in 2020, two southern states of India used SADMS to develop real-time contingency planning measures (including provision of drought-tolerant seed varieties, rainwater harvesting and spraying of potassium nitrate to alleviate drought stress). The areas in which the measures were enacted were later found to have had significantly higher yields and financial returns than those where they were not. Meanwhile in Sri Lanka, the World Food Programme and national partners used the system to produce a climate and food security bulletin.

Our success with SADMS led to our developing a drought early-warning system for the Afghanistan government, as part of its World Bank-funded Early Warning, Early Finance and Early Action Project. This program was launched to strengthen the country’s drought planning and response, following a severe drought in 2018 that caused widespread crop failures and hunger. Our scientists created the Afghanistan Drought Early Warning Decision Support (AF-DEWS) Tool to provide early indications of drought (so authorities could take timely action to mitigate impacts) and forecasts on how the drought might evolve (to inform the provision of financing). With drought once again progressing in the country – and with the pandemic ongoing – the tool is assisting policymakers to implement appropriate drought-response strategies and ensure millions of farmers have sufficient food.

As climate change disrupts historical weather patterns, droughts are increasingly likely to have detrimental impacts on water and food security in the Middle East and North Africa (MENA) region. Under the USAID-funded MENA drought program, we are working with partners to empower Morocco, Lebanon and Jordan with the tools to anticipate, prepare for and mitigate the worst impacts of drought. There are four main aspects to this work: developing map-based drought-monitoring systems; creating early-warning systems with built-in triggers for actions such as declaring a drought, directing pastoral farmers to take their herds to alternative grazing lands or increasing grain imports; undertaking assessments to identify country-specific vulnerabilities to drought; and supporting the development of mitigation policies and responses.

Across all parts of Africa, limited data on water makes managing precious resources a challenge. In response, IWMI launched the Water Secure Africa (WASA) initiative. Involving African and international partners, WASA is employing the latest advances in earth observation, information and communications technologies to strengthen water security across the continent. In 2020, the initiative helped to prepare sub-national drought-risk assessments for Ethiopia, Ghana, Burkina Faso and Zambia. And, currently, WASA partner Digital Earth Africa is organizing decades of satellite data so it can be easily analyzed, with IWMI developing tools to translate the data into information to support effective decision-making around water management.

An invaluable tool

As the projects outlined above show, satellite technology can be an invaluable tool for monitoring and mitigating the worst impacts of drought. By integrating its use into early-warning systems and preparedness planning processes, authorities can minimize negative impacts on ecosystems, livelihoods and economies. Not only can this help to combat further desertification of the world’s already fragile drylands, it can support progress towards meeting the United Nations Sustainable Development Goals and the Sendai Framework on Disaster Risk Reduction.