SAR Data: Gamechanger for Flood Management
One of the most commonly occurring natural disasters is floods, caused due to extreme rainfall, #cloudbursts Coastal #storm surges from tropical #cyclones or #tsunami , poor #drainage , or quick snowmelt.
Floods can be of three types: -
Flash Flood: This type of phenomenon takes place as a consequence of extreme rainfall that is more than what #soil can absorb.
Fluvial floods: Also known as river floods caused when the level of #water in #lakes , #rivers , or #streams rises above the normal level and can affect the surrounding areas.
Coastal Floods: They’re the result of #tropical cyclones or tsunamis.
?From 1990 to 2019, a total of 9,924 natural #disasters occurred globally, of which 42 percent were floods. In 2021, a total of 432 catastrophic episodes were recorded that were higher than the average 357 annual disastrous events. These events were dominated by floods with 223 flood disasters recorded #globally , more than the average of 163 annual flood occurrences recorded from 2001-2020. Though 2006 has the record for the greatest number of #floods with 226 flood disasters registered worldwide.
If we look at India at a glance between 1980 and 2017, India witnessed 278 floods. According to NDMA out of the total geographical area of 329 million hectares (mha), more than 40 mha is flood-prone.
Some flood-prone zone in #india includes: -
flood-prone zones or areas in India: -?
Impacts of Human-activities on Floods
Flood is a #natural phenomenon, however, increased anthropogenic activities are intensifying it and causing them more frequent. Activities like #deforestation , unplanned urbanization, and poor #agriculture practices are some of the reasons for increased floods. “The number of weather, climate, and water extremes are increasing and will become more frequent and severe in many parts of the world as a result of climate change,” says WMO Secretary-General Prof. Petteri Taalas. According to Prof. Taalas the #world has more water vapors in the #environment which is aggravating extreme #rainfall and deadly #flooding .
Why Flood requires monitoring?
According to a WHO report, between 1998-2017, floods affected more than 2 billion people worldwide. Drowning accounts for 75% of deaths in flood disasters.
According to the World Bank 2.2 billion people, or 29% of the world population, live in locations that are estimated to experience some level of inundation during a 1-in-100-year flood event.
Flood-related catastrophes have increased by?134 percent since 2000 , compared with the two previous decades, according to the World Meteorological Organization (WMO).
As per Rentschler, J., Salhab, M. & Jafino, B.A. (2022), 1.81 billion people (23% of the world population) are directly exposed to 1-in-100-year floods. Out of which, 1.24 billion are located in South and East Asia, where China (395 million) and India (390 million) account for over one-third of global exposure.
Not only this flood also causes severe damage to #infrastructure , loss of lively stock, #destruction of crops, and much more. Additionally, it also gives rise to various diseases like #cholera , Dengue, and other #waterborne diseases.
Disclaimer: This map is only for representation purposes and does not indicate the actual international boundaries.
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How were problems used to be addressed in the past?
Traditionally, there were very few ways to counteract, which led to the loss of lives, damage of resources, and diseases. Furthermore, the aftereffects were more severe. To #restore the properties, considerable #financialresources , time, and effort are invested.
Before the year 2000, Governments across the world were focused more on Disaster response, Natural, and Engineered #floodmanagement .
Although all of them are important aspects of flood management, #monitoring via #satellite is crucial as it can facilitate pre-planning and effective management.
Earth observation through #satelliteimagery has various applications in the field of disaster management, some of them are: -
1.??Monitoring: ?Through satellite images, we can #monitor any anomalous #weather patterns that can be a sign of impending disaster(s).
2.???Pre-Planning: ?Satellite image data will help you in mitigation measures against future floods that might take place shortly. It will help you prepare for events such as Bangladesh's 1998 flood, where over 75% of the total area of the country was flooded, including half of Dhaka. Another example can be the 1993 flood in Northern India where heavy #monsoon caused #flashfloods and #landslides , that lead to huge damage to human lives, #crops , livestock, and housing across the seven to eight states in India.
3.??Search and Rescue: ?In flood-like situations, it is difficult to find out the people who need to be rescued, this can be easily enabled by the use of #satellitedata .
4.??Flood Mapping: ?Image data can help you accurately map flood-inundated regions that can help in effective #restoration and infrastructure planning.
Why Flood is still causing so much damage.
Natural disasters like floods cannot be prevented but managed. Even so, various Earth observation satellites, satellite-communication have made it easier to manage and preplan for floods, but it continues to cause extreme losses one such example is the Pakistan floods of 2022 that killed around 1739 people and caused Rs 3.2 trillion ($14.9 billion) of damage and ? 3.3 trillion ($15.2 billion) of economic losses
These might be can be the result of: -
1.??Timely access to high-resolution data: During alarming situations like floods, the data needs to be available on time as the situation demands timely actions and planning, to prevent severe damage. Earlier, there were fewer sensors, so the #image was not always available as a result the data cannot be presented leading to delayed #operations and inadequate planning.
2.??Affordability: Earth observation data is a powerful monitoring solution. In the past, the data was extremely expensive and less feasible. fortunately, recent #technical improvements allowed the capturing of a vast region in high resolution while also making this solution economical and practical.?
3.??Clouds: In case of flood events the areas were usually covered with clouds that hamper optical imaging, as they cannot penetrate the clouds, also at night Optical imaging is not feasible. On the other hand, SAR #constellations such as ICEYE can monitor the area day and night in all weather conditions. Rather than waiting for the clouds to get clear optical images, SAR can capture and deliver images in a few hours. This gives power to decision-makers to strategically plan, and optimize operations effectively and efficiently. ?
Suhora as a #solutionprovider understands the problem, technology, and its applications. To address the flood problems, we work with our partners ICEYE to deliver affordable flood solutions using high-resolution SAR along with intraday revisits, which can aid in disaster management.