Disaster Response

Disaster Response | New Techniques to Avoid a Kerala like Disaster

By: Giriraj Amarnath, The author is a Research Group Leader at Water Risks and Disasters, International Water Management Institute, Sri Lanka
Kerala has witnessed one of the most devastating floods in history. Many lives and livelihoods were lost in just a few days. To reduce future occurrences and the impact of such calamities, it is important that we focus on implementing and improving the measures that can offer greater resilience.
Magazine Articles Planning n Mitigation

Kerala, with its magnificent natural landscapes and fertile valleys, is often described as ‘God’s own country’. During June to August 2018, unusually heavy summer monsoon rains caused disastrous floods across the state dashing this idyllic image. These were the worst floods Kerala had witnessed since 1924 resulting in the death of more than 324 people and requiring the relocation of at least a million (Babu, 2018). The places that suffered the most severe damage were Chengannur, Pandanad, Aranmula, Aluva, Chalakudy, Kuttanad and Pandalam while all 14 districts of Kerala were placed on red alert (Varghese, 2018; Rajiv, 2018; BBC News, 2018a; Mathrubhumi News, 2018a). According to the Kerala government, one-sixth of its total population was directly affected by the floods and their related incidents (Press Trust of India, 2018). The Indian government declared this a level three calamity, or a ‘calamity of a severe nature’.

In an unprecedented response to the heavy rainfall, floodgates of 35 of Kerala’s 54 dams were opened. At Idukki, for example, all five floodgates of the dam were opened simultaneously for the first time in 26 years. Heavy rains in Wayanad and Idukki caused severe landslides and left the hilly districts isolated (Mathrubhumbi News, 2018b).

Crop damage

Continuous heavy rainfall in Kerala led to extensive flooding of agricultural lands, resulting in crop losses with an estimated value equivalent to INR 150 to 200 billion (Shenoy, 2018). Coffee, rubber, tea and black pepper were amongst the crops most affected. Even so, the extent of damage to coffee, tea, cardamom and rubber plantations is not yet clear. In rural Kerala, many farmers may not be able to harvest at all this season. Also, many lack adequate access to insurance to aid recovery.

Insurers to take a big hit

Insurance claims resulting from the floods have been initially estimated at INR 5,000 million. The situation for insurance companies is not as adverse as it was in the case of floods in Chennai or Jammu and Kashmir where approximately INR 50,000 million and INR 20,000 million were paid, respectively (Sinha, 2018). The Insurance Regulatory and Development Authority (IRDA) of India has instructed the insurance companies to settle all claims expeditiously. Given the magnitude of the tragedy, there is considerable pressure on insurers to provide immediate cash. Health insurance companies could also take a hit due to an increase in waterborne diseases resulting from the floods.

Disaster Response | Responding to future disasters

In addition to examining and managing the immediate consequences of the Kerala floods, the obvious question to ask now is what can be done to cope more effectively with future water related disasters, thus reducing damage and loss of life. Described below are ten measures that could contribute to greater resilience as such threats have become more frequent and severe.

Improved flood forecasting: The first step is to take advantage of recent improvements in flood forecasting. One critical limitation in India and other developing countries is the lack of monitoring networks, which prevents near real-time flood prediction. In response, researchers  at International Water Management Institute  (IWMI) and elsewhere are developing new techniques that use increasingly available satellite sensors to forecast floods based on river discharge. Radar altimetry, for example, accurately estimates water levels and river discharge showing much potential for places where there is no river monitoring network (Tarpanelli et al. 2017, 2018). This technique is limited, however, by the low revisit time of the satellite, leading to delays in flood prediction. To overcome this, researchers have used the artificial neural network technique to merge data from multiple sources including different satellite missions and optical sensors as well as radar altimetry. In a study, researchers found this multi-mission approach to be the most reliable tool for estimating river discharge (ibid).

Better insurance products: Flood insurance for crop damage and insurance pooling for extreme flood events is a must. IWMI and the Consortium of International Agricultural Research Center’s (CGIARs) Research Programme on Climate Change, Agriculture and Food Security (CCAFS) developed the index based flood insurance (IBFI) for Bihar in collaboration with global reinsurer Swiss Re (Amarnath and Sikka, 2018). Scientists first examined past satellite images to identify historic floods and prepare a flood risk map. Villages in three locations were selected for the pilot: one in an area at high risk of flooding, one in a place with medium risk and one with low risk of inundation. The scheme went live in July 2018 with a total insured sum of around INR 5 million (approx. USD 78,000). For the pilot, the Agriculture Insurance Company of India (AICI) agreed to pay out money to farmers based on scientific data indicating the actual depth and the duration of flood waters in the paddy fields. In the initial stage of the pilot, which covered rice crops for the 2017 monsoon season (from early July until the end of October), the insurance product was fully subsidised with the project making premium payments on behalf of the farmers for a total insured value of INR 4,600,000 (Amarnath and Sikka, 2018). Crop insurance has become critical, particularly in view of increased agricultural shocks due to the vagaries of nature and it is not only vital for smallholders’ wellbeing, but also for national food security and stability.

Giving the floodplain back to nature: Much of the damage caused by floods in Kerala and Chennai was a direct consequence of indiscriminate human encroachment on the river and other water bodies. As long as primary economic activity continues on the floodplain, measures such as improved forecasting may be of little help. To fundamentally reduce vulnerability in the face of future disasters, government authorities need to delineate the 100-year floodplain—the area in which there is atleast 1 per cent chance of flooding in any given year—and strictly regulate development in this area.

Climate screening of development projects: To better manage current and future risks in these areas, the government and its development partners can resort to strict use of climate screening tools to clear development projects for implementation, based on the risks they pose in terms of land, water and ecosystems. Projects involving a higher risk level, given increasing climate variability, would require further innovation in order to proceed. There is a clear need for a more holistic approach to agri-food systems that takes into account the impacts and interactions between nature, humans, and agri-food systems. Currently, CGIAR Research Programme on Water, Land and Ecosystems is conducting studies to understand these systems (ibid).

Healing the ecosystem: Over time, settlements must be shifted out of the floodplain, giving it back to nature. Sound plans need to be implemented for helping to heal the river basin ecosystem. These plans should include measures such as strict regulation of sand mining and other activities that directly affect river flow. Also important are planned flooding of the river downstream, which mimics the annual flood cycle to manage fluvial sediment in the river and the reservoir. Encroachment of roads, houses and other structures onto the floodplain as well as various types of land use (such as high-value agriculture) may limit the scope for controlled flooding, although some degree of high-flow restoration should still be possible. Enhanced water releases from dams are sometimes used to dilute downstream discharge of wastewater. In these cases, restoring naturally low levels of flow can be quite difficult, if not impossible, due to human health concerns (Yoon et. al., 2015).

More built infrastructure: Reservoirs constructed at the centre of river basins, based on feasibility studies, are vital to reduce the risk of water-related disasters through increased capacity for storing surface water. Dams provide numerous economic benefits and can mitigate the adverse impacts of water variability and extreme climate events. However, such large-scale water infrastructure has also caused significant social and environmental costs prompting calls for alternative, nature-based solutions. The solution to this dichotomy is not to forego investment in built infrastructure, which remains essential for socio-economic development, but to give greater consideration to the role of nature in planning and operating large, built infrastructure.

Managing difficult tradeoffs:  Sediment trapping in reservoirs may modify to a large degree the sediment transport downstream of the dam. This often results in modified channel and floodplain geometry, which in many cases represents a fundamentally different physical habitat to support native ecosystems. It may prove impossible to maintain some semblance of natural flow and sediment transport including connections between the river and its floodplain. In that case, one must ask whether the ecosystem and species that can be supported through dam re-operation actually justify the social and economic costs.

Dam re-operation:  Dam operation contributed at least partly to the flooding in Kerala (BBC, 2018b). Physical constraints posed by dam infrastructure, especially the design of outlet works, can severely limit the rate at which controlled water releases from a dam can be managed, making it difficult or impossible to release water of variable amounts, ranging from low-flow to flood-flow rates (Richter and Thomas, 2007; Mul et al. 2015).In contrast to the large sums of money being invested in new dam construction, financiers and international development organisations have not adequately supported dam re-operation, i.e., the modification of dam operations. Correcting this imbalance is critical to better enable low-income counties to operate dams as an integrated system rather than in isolation (Richter and Thomas, 2007).

A holistic approach:  Individual measures aimed at mitigating flood risk and ecosystem impacts should form part of a holistic approach based on an understanding of the various components of the urban water system as well as upstream and downstream relationships. Referred to as integrated urban water management (IUWM), the approach not only relies on flood models and the use of embankments to divert water, but also encompasses the entire water cycle—water sources and supplies as well as wastewater (e.g., its use for urban cropping) and storm water—viewing urban water in the wider basin context.

Institutional reforms:  Better management of disaster risks, with the ultimate aim of achieving water security can be a key driver for sustainable growth. To foster quicker progress toward this aim, responsibility for water management should lie with a single institution which is able to take high-level decisions on water use, implement measures to reduce disparities in water resources and respond to water-related disasters.

Disaster Response | Using nature for climate change adaptation in urban areas

In the wake of disasters like the floods in Kerala, the standard response is to boost expenditures on dams and other ‘grey’ or built infrastructure. To achieve water security, however, societies need to invest as well in ‘green’ or natural infrastructure such as wetlands, watersheds and floodplains (Eline et. al, 2017).These nature-based solutions have a proven ability to mitigate the impacts of water-related disasters while also delivering other developments such as food production and biodiversity preservation (Nesshöver et. al, 2017).

Nature-based solutions promoting green and blue urban areas have significant potential to decrease the vulnerability and enhance the resilience of cities in light of climatic change. Building on existing evidence and needs for future science and policy agendas when dealing with nature-based solutions are about: (i) producing stronger evidence on nature-based solutions for climate change adaptation and mitigation and raising awareness by increasing implementation; (ii) adapting for governance challenges in implementing nature-based solutions by using reflexive approaches which implies bringing together new networks of society, nature-based solution ambassadors, and practitioners; and (iii) considering socio-environmental justice and social cohesion when implementing nature-based solutions by using integrated governance approaches that take into account an integrative and transdisciplinary participation of diverse actors. Taking these needs into account, nature-based solutions can serve as climate mitigation and adaptation tools that produce additional co-benefits for societal well-being, thereby serving as strong investment options for sustainable urban planning (Kabisch et al. 2016).

The solutions are often implemented in an ad-hoc manner as is the case with conventional built infrastructure. Moreover, while there have been significant advances in the design and testing of nature-based solutions for risk mitigation, they have yet to be fully evaluated and standardised. As a result, some nature-based projects for climate adaptation and disaster risk reduction have been improperly designed, leading to unsatisfactory and unsustainable results.

There can be no ‘one-size-fits-all’ approach, given that weather hazards as well as the wider climatic and ecological conditions are variable and often poorly understood. Nonetheless, the conventional engineering sector has a long history of fully developed protocols and standards from which there is much to learn. Such guidance can aid project development and implementation while also helping to achieve a common understanding of the likely effectiveness of such solutions in reducing risks.


The recent incidents of floods across Kerala have shed light on the severe problems induced by flood events. Given the reality of climate change, these flood disasters will escalate until some proactive measures are taken to mitigate them. There are several natural and anthropogenic ways to reduce the impact of these disasters and ensure societal well-being.

Sponge Cities:

Flooding is widely considered to be the most serious water-related problem affecting many large south Asian cities. Rapid urbanisation; land-use change and socio-economic development are making an already sizeable problem steadily worse. To solve the problems of increasing flooding, water shortage and pollution caused by the traditional model of urban development, a new model—the Sponge City, is being developed. The concept is based on natural and ecological flows that allow storm water to be managed with natural infiltration, natural retention and detention, and natural cleaning facilities. It reflects new thinking about how to tackle surface-water flooding as well as related issues in urban water management, such as the purification of urban runoff, reduction of peak run-off and water conservation. The idea is to make better use of ‘blue’ and ‘green’ spaces in the urban environment for storm water management and control. This and related practices enhance natural ecosystems and provide more aesthetically pleasing surroundings for people living and working in urban environments, in addition to enhancing urban habitats for birds and other organisms. China has already begun to implement this approach in several cities, with the aim of achieving sustainable water use and better flood control (Fig. 6).



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