Rising cloudburst events in the Himalayas: Causes and consequences

Introduction

In recent years, there has been a notable increase in the frequency of reported occurrences of atmospheric phenomena known as “cloudburst” events. While in the past many politicians have made the public aware of cloud bursts via the lens of a “foreign conspiracy,” the scientific explanation for the phenomenon has remained largely unknown to the general public. The majority of the cloudburst events are linked to unforeseen intense precipitation. The topography of the Himalayas, characterized by its steep and unstable slopes, provides an ideal setting for the occurrence of cloudburst events, which can result in the rapid onset of flash floods or landslides. However, it is still difficult to foresee the exact location, amplitude, and severity of such catastrophic events. 

Characteristics of cloudburst events

A cloudburst refers to a significant volume of precipitation occurring within a brief timeframe, often accompanied by the occurrence of hail and thunder. Indian metrological department also defines cloudburst as a meteorological event characterized by unanticipated precipitation surpassing 100mm/h within a geographic area spanning approximately 20-30 Km2. This meteorological phenomenon possesses the potential to induce flood-like conditions. One such major consequence of cloudbursts in the form of floods was witnessed in J&K in 2014. Research scholars have proposed that the convergence of low-level westward moving monsoonal systems and eastward moving mid-tropospheric westerly troughs was a significant factor contributing to the occurrence of the devastating flood of 2014. 

Factors contributing to cloudbursts

Over the past few years, there has been an increased occurrence of lethal convergence between moist warm monsoon winds and cool dry western winds, commonly referred to as western disturbance. This convergence has resulted in the formation of a low-pressure system over J&K. Also, due to the phenomenon of climate change, rising temperatures have led to a notable increase in oceanic warming. Consequently, this warming trend has facilitated the transportation of moisture-laden air towards the Himalayan region.  These warm winds vertically uplift saturated clouds which are unable to precipitate due to these upward vertical motions of an exceptionally warm air current. Raindrops, in contrast to descending, are transported in an upward direction by the prevailing air current. New droplets are created while preexisting raindrops undergo growth. Once a certain threshold is reached, the raindrops attain a mass that exceeds the cloud’s capacity to retain them, resulting in their rapid descent in unison. The vertical motion of clouds supplies the necessary energy for the occurrence of a cloudburst. Typically, this phenomenon occurs at elevations ranging from 1,000 to 2,500 meters above sea level. 

Frequency and impact of cloudbursts in Jammu and Kashmir

The most well-known cloud burst incident occurred on July 8 2022, just upstream from Amarnath Shrine, during the height of the pilgrimage season. Because of this, a large amount of rubble and rocks rushed downstream, sweeping away three lungars and 40 camps which were established up within and along the drainage channel. 17 pilgrims were killed in the incident, injuring 60 pilgrims while 30 were reported missing. However, this devastation could be blamed more on human actions as authorities despite being acquainted with the fact that the area is prone to natural disasters, permitted the establishment of camps along the water course. 

Based on a report compiled by the State Disaster Management Authority, it has been observed that a significant number of flash floods and cloudbursts have occurred in Jammu and Kashmir since 2010, leading to a loss of human lives amounting to approximately 300 individuals. In the year 2022, a significant number of fatalities, amounting to nearly 40 individuals, were recorded as a result of cloud bursts in the region of Jammu and Kashmir. Additionally, numerous individuals sustained injuries during these incidents. The majority of the cloudburst incidents have been reported in pre-monsoon months unlike the states of Himachal Pradesh and Uttarakhand where such incidents occur from the month of September-October. 

The cloud burst disaster has had a devastating effect on public and private infrastructures and properties across the entire territory of both UTs (J&K and Ladakh), including interior roadways, highways, tunnels, bridges, water and power supply lines, farmland, crops, and orchards. The quantity and severity of cloud burst disasters are rising, yet the systems in place to track them and lessen their impact are woefully insufficient. Most often, uncontrolled construction and encroachment on drainage systems are to blame for the devastation. The number of deaths in Amarnath is evidence of official indifference. In many instances, the government tends to attribute climate change as the primary cause of various issues, thereby implying a sense of incapacity. While this assertion cannot be disregarded, it is important to acknowledge that there exists significant potential for proactive measures in the areas of cloud burst monitoring, forecasting, and management. Regrettably, these aspects are currently absent from the government’s disaster management strategies and initiatives. 

Proactive measures and disaster management

The escalation of climate change’s repercussions is becoming more pronounced, necessitating proactive measures to mitigate its intensifying impact. Policymakers, as well as humanitarian and development organizations, have to effectively address, proactively prevent, and mitigate the potentially catastrophic consequences of climate change in a timely manner, in order to avert irreparable damage. First and foremost, it is imperative to identify specific locations where flash floods resulting from cloud bursts have the potential to cause catastrophic events. Consequently, it is crucial to map and closely monitor human settlements situated in close proximity to these vulnerable areas in order to mitigate the associated risks. 

The implementation of mitigation measures, such as relocating residents from low-lying areas to higher ground, elevating infrastructure, homes, and businesses above floodplains, and relocating them far from rivers and streams can reduce the lethal losses by cloud burst events. Better management of watersheds is required to prevent landslides, flash floods, mudflows, and cave-ins on hilly terrain. Extensive deliberation and proactive measures are necessary to address the feasibility of establishing Doppler Radars capable of forecasting cloud bursts with a lead time of several hours. The utilization of such predictions can prove highly advantageous in terms of preserving human lives, provided that comprehensive disaster management strategies are established with clearly delineated responsibilities assigned to specific roles. Regrettably, there has been minimal advancement in the establishment of radar systems at designated susceptible sites, particularly in a limited number of locations where our available resources permit initial implementation. That’s a big fat failure on the part of the present Union and related state administrations. The issue necessitates immediate attention.

References

Das, S., R. Ashrit, and M. W. Moncrieff (2006), Simulation of a Himalayan cloudburst event, J. Earth Syst. Sci., 115(3), 299-313, doi:10.1007/BF02702044.

IMD, Climatology of the Himalayas and neighbourhood, 2003, Published by India Meteorological Department, NCC, ADGM(r) office, Pune.

Juyal, N., (2010), Cloudburst-triggered debris flows around Leh, Current Science, 99, 1166 1167.

Medina, S., R.A. Houze Jr., A. Kumar, and D. Niyogi (2010), Summer monsoon convection in the Himalayan region: terrain and land cover effects, Quart. J. Roy. Meteorol. Soc.,136, 593 616., doi: 10.1002/qj.601.

Roe, G. H. (2005). Orographic precipitation. Annu. Rev. Earth Planet. Sci., 33, 645-671.

Romatschke, U., and R.A. Houze Jr (2011), Characteristics of precipitating convective systems in the South Asian Monsoon, J. Hydrometeorol., 12, 3–26,doi: 10.1175/2010JHM1289.1.

J&K gets third X-Band Doppler Weather Radar for better, timely forecasts (business-standard.com)

Amarnath Yatra: Amarnath Cloudburst Live Updates: Rescue Operations Underway Near Amarnath Shrine (ndtv.com)