Posted on Thursday, March 8th, 2018 in Use cases

The Dutch are famous for their history of fighting and protecting themselves against water. And they continue to do well. It’s been 65 years since the last major flood, best known as the great North Sea flood of 1953. But despite their excellent work, high water levels occur frequently, and their recurrence has increased lately due to changing weather conditions. What would happen if their dikes could no longer protect them from water? How would this affect daily life? And how can they prepare for this?

In 1953, the great North Sea flood was caused by a spring tide in the North Sea, combined with a storm surge. Besides the sea, rivers can be a cause of major flooding, as was the case in 1993 when extremely high water levels were registered in the Meuse, and the villages of Borgharen and Itteren in the province of Limburg were inundated. Another source of floodwater is heavy rainfall. Luckily, no large-scale floods due to rainfall have occurred recently in the Netherlands, but numerous examples exist from other European countries, such as France and the United Kingdom, as well as the heavy floods in Houston in the United States last year.

Floods can be extremely disruptive to daily life and activities in the city, and will typically result in a high level of damage. One of the main dilemmas for governments facing a flood is whether to evacuate, as it can be complicated due to flooded roads. Insight into how floods will develop and how critical infrastructures will be affected is key during decision-making.

Cascading effects

High water levels can cause damage to the infrastructure resulting in power outages and other disruptive factors. For example, in 2015 in Perthshire, Scotland, heavy rain lead to serious flooding and a bridge carrying power grids was washed away. The power outages contributed to the already dramatic situation for people in the affected area, leaving them without heating, lighting and hot water, and causing refrigerated food to spoil.

The lack of power also affects the ability of hospitals to care for their patients. Besides that, flood water can cause unhygienic conditions, in which case evacuation of the hospital may be necessary. The power outages will cascade to mobile phone services. Even though telecom towers have back-up batteries to overcome short power cuts, once the battery runs empty the mobile service will ultimately be interrupted.

 

Understanding the effects of a flood

Flooded homes, power and mobile communication outages, and limited access to medical care are just some examples of what people may have to anticipate. Home heating, public transportation, police and fire services, and financial services may be affected as well. The severity of the situation will depend on the severity of the flood itself, the design of the infrastructures, the community’s preparation and the response of the emergency services.

 

SIM-CI offers insight and foresight

SIM-CI gains insight and foresight in these events by simulating the cascading effects, starting with the flood itself and ending with the number of people in areas affected by a power outage. Floods are simulated by making use of height maps, buildings and waterway data. The cause of the flood can be chosen, for example, a dike breakage or high river water. The water heights in the region are calculated whilst critical infrastructures are simulated and examined, for instance, checking high water levels in electrical substations as they might flood, causing failures in electricity networks. If and when this happens, the electricity networks are recalculated and used as input for determining possible cascading effects. Checking whether telecom towers are up and running could be one of the examples.

Besides providing insight into floods and their cascading effects, SIM-CI’s products can be used for decision-making in crisis situations and mitigating risks, such as providing evacuation routes when roads are flooded, or designing robust critical network infrastructures.