Time to be Prepared
Current situation:
- Recent heavy rains caused flash floods and damage in some areas of North India. Rain led to landslides, which further harmed people and property.
What initiated the rain’s onset?
There are three main causes for the region’s and the Himalaya’s excessive precipitation.
- first, a monsoon that is active and has high winds at the lowest altitudes.
- It brings moisture into the area from the Arabian Sea or the Bay of Bengal.
- The second factor is a strong atmospheric force that sweeps eastward through mid-latitude troughs and manifests as outflows in the upper atmosphere.
- The Himalaya can receive moisture from these troughs as well.
- Third, the Himalaya’s hard terrain and orographic uplift caused deep convection.
- Over the weekend, each of these components was present. The synoptic conditions called for significant rainfall.
- A mid-latitude trough was moving eastward in the top layers of the sky, and the monsoon was in full swing with strong, wet easterly winds approaching the area. In addition, moisture started to seep in from the North Arabian Sea.
- Similar synoptic circumstances in 2013 contributed to the floods in Uttarakhand. The floods that hit Pakistan in 2010 are another notable instance.
Recognize the fundamental traits of the monsoons in this region:
- India experiences most of its precipitation from June to September, during the rainy season.
- Only a minor portion (80 to 100 cm) of the season’s total rainfall occurs in this area in a span of just 130 to 150 hours. Only 30–40 hours have elapsed before the seasonal rainfall (40–50 cm) is cut in half. During the second half of the season, the region only experiences light to moderate rainfall.
- This graph demonstrates how the seasonal total is impacted by periods of heavy rainfall. The majority of rainwater drains out when it rains strongly, especially if the soil is already saturated.
- Additionally, the area has seen a three-fold rise in the frequency of extreme rainfall events (greater than 15 cm in 24 hours).
- According to statistics, there are less monsoon wet days and hours overall. This suggests that when it rains, it does so fairly frequently and heavily.
- Extreme rainfall events are prevalent in the Himalayan region due to its complicated topography and diverse climate.
One of the main reasons for high rainfall is the climate:
- These heavy and frequent downpours are regarded to have several fundamental reasons, one of which being climate change. Warmer temperatures cause more evaporation, which increases the air’s moisture content.
- When weather systems and the region’s unique terrain collide, the excess moisture creates tremendous rains.
- Changes in land use and cover appear to be a second factor that is having an impact on the increase of monsoon extreme rainfall, particularly its severity.
- According to the IPCC’s climate change estimates, these patterns will persist. Future floods are predicted to become more frequent than one-day events, which could have unfavorable effects.
- The Arctic is warming and the sea ice is melting as a result of human activity.
- Evidence for the influence of Arctic warming on the monsoon climate via mid-latitude circulation is growing.
- Models and observations suggest that blocking highs and deep mid-latitude troughs (like the one that occurred last weekend) will occur more frequently as a result of Arctic warming.
It is necessary to take action to reduce flooding. To lessen floods, a multi-pronged strategy that combines proactive and reactive tactics is required. These consist of:
- One is a reliable early warning system that warns people of dangerous flash floods and impending severe rain.
- This system might use high-resolution numerical weather prediction models as well as meteorological readings from a Doppler weather radar (DWR). The DWR and forecast data could be evaluated using contemporary techniques like AI and ML.
- Two: steady river levels, seasonal precipitation patterns, and a sophisticated flood warning system.
- Three: maps of flood risk that assess susceptibility, identify high-risk areas, and focus efforts while taking into consideration geography, historical flood data, and hydrological modeling.
- Four: enhancing and maintaining climate-resilient infrastructure, such as channels and drainage systems, to prevent waterlogging.
- Five: Strictly follow land use and zoning restrictions.
- For instance, in locations that are vulnerable to flash floods, access to or the designation of a location as non-residential may be restricted.
- The preservation and restoration of natural ecosystems, such as wetlands and forests, is the sixth issue. As a natural barrier, vegetation absorbs precipitation and lowers runoff.
- Seventh, when there is flooding, awareness campaigns may encourage people to establish evacuation preparations, administer first aid, and seek out dependable information sources.
Conclusion:
- India can thus improve its ability to handle extreme weather by taking preparations and becoming aware of the rising likelihood of extreme precipitation.
