Disaster Profile of Himachal Pradesh

Introduction

Himachal is prone to very diverse disaster Profile.Total Area of Himachal Pradesh is about 55673 sq Km with Population around 70 Lakh. The overall density as census 2011 was 123 person per square Km, which now must be around 125 person per Sq Km. Physiography of State range from Plain to Higher Himalaya to Cold Desert, which pose wide diversity of threat. ( Details of Whole Disaster Plan can be sen here https://hpsdma.nic.in/)

Factors Affecting the Disaster Profile of Himachal Pradesh.

1. Geology: It include Major Thrust , fault, Rocks strata, Slopes etc.
2. Climate: It include intense rainfall, snowfall , Flood and Draught.
3. Vegetation:- Like Forest, which is liked with slide and forest fire.
4. Industrial:- Like Factory fire, Gas Leaks, Blasts in factory premises.

1) Geology of Himachal Pradesh and Disaster:

Himalaya are the youngest Mountain range of world, with many active Thrust and Fault. ( see full Geology of Himachal Pradesh Basic Geology of Himachal Pradesh .)

• Main Frontal Thurst– It separate the Indian Shivalik from the Indian Plains.
• Main Boundary Thrust: This Thrust separate the Shivalik range form Lesser Himalaya.
• Main Centran Thrust; This thrust separate the lesser Himalaya and Greater Himalaya. Its passes close to Main Boundary thrust and passes through center of Himachal Pradesh.

Above mention Thrust are major one, there are many local Thrust and Fault such as Kaurik–Chango Fault, Kangra Fault Zone etc , which can case intense earthquakes and landsliding. Specially the area which is near Main Boundary Thrust and Main Central Thrust are very prone to Disaster.

Date	Location Affected	Magnitude	Damage	Geological Notes
4 April 1905	Kangra	7.8	20,000 people died; 53,000 domestic animals perished; 1,00,000 houses destroyed; economic loss: 2.9 million rupees	One of the deadliest Himalayan earthquakes; linked to the Main Boundary Thrust (MBT); rupture extended across Kangra–Dharamshala zone; caused major surface deformation and landslides.
1 June 1945	Chamba	6.5	NA	Occurred in the highly stressed Pir Panjal region; associated with the Himalayan Frontal fault system; moderate crustal movement but limited surface damage due to low population density.
19 January 1975	Kinnaur	6.8	60 people died; 100 injured; 2000 dwellings devastated; 2500 people homeless	Known as the Kinnaur Earthquake; linked to activity along the Kaurik Fault zone near Indo-Tibetan border; triggered large rockfalls and slope failures typical of high-altitude brittle geology.
26 April 1986	Dharamshala	5.5	6 people died; major building damage; loss around 65 crore	Occurred on the MBT system; shallow focus caused severe local shaking; weak sedimentary formations in the Siwalik foothills amplified ground motion.
1 April 1994	Chamba	4.5	NA	Small but felt widely; linked to local readjustments in the Higher Himalaya; part of ongoing strain accumulation along the Main Central Thrust (MCT).
24 March 1995	Chamba	4.9	Strong shaking; over 70% houses developed cracks	Indicates active micro-seismicity around the Ravi River valley; old masonry structures cracked due to repeated stress cycles in the Chamba–Bharmaur tectonic segment.
29 July 1997	Sundernagar	5	Damage to around 1000 houses	Occurred in the Mandi fault cluster near the Pandoh region; presence of soft sediments and reservoir-induced stress may have increased local shaking.

Real Life Example of Thrust Linked Sliding Zones in Himachal Pradesh:-

There many active Sliding zone near Chowari Chamba, along the Dhauladhar and Hathi Dhar.(See the Pic). Similarly there are many active sliding zone in Himachal Pradesh, Marking them and extensive geological studies and associated construction guideline can mitigate disaster risk.

1.1) Rocks of Himachal Pradesh

Rocks of Himachal range from early Quaternary to Pre Cambrian age. Igneous rocks and meta sedimentary rocks are stable than Sedimentary rocks. However underlying thrust and Fault define the stability of a region. Below is simple classification of rocks. (see full Geology here:Simplified Geological Map)

• Higher Himalaya: Oldest crystalline rocks (Precambrian gneiss, schist) + Palaeozoic sediments.
• Tethys Himalaya (Spiti–Kinnaur belt): Marine sedimentary rocks from Palaeozoic to Mesozoic (limestone, shale, sandstone).
• Lesser Himalaya: Meta sediments (slates, phyllites, quartzites) and Subathu Formation.
• Siwalik Foothills: Youngest fluvial deposits (Miocene–Pliocene conglomerates, sandstones).
• Valley Fills: Quaternary alluvium, moraines, loess.

Rocks Link with Disaster

Rocks which are sedimentary in nature are very unstable and can cause major landslide events. In contrast igneours rocks and meta sedimentary rocks are relatively stable and are less porus. For example Shivalik is composed of sedimentary rocks like sandstone, madstone and silt stone etc thus it cause splash erosion.

Real Life Example:

In 2017 , mudflow in Shivalik hills in District Mandi caused massive landslide and killed 46 People. If rocks Data is studied with underlying thrust , this kind of disaster can easily be aborted.

1.2) Slope and Disaster Profile of Himachal Pradesh.

Slope region define the intensity of landslide. Underlying Thrust/Faults, Forest cover, Rocks and Rainfall are major factors defining the intensity of Landslide. Thus we can say:

Landslide= F(Thrust, Forest, Rocks and Rainfall)

Where are Slope are unstable:

Slope are Generally unstable where Thrust are active. In case of Himachal Pradesh, you will be find Lesser Himalaya and Greater Himalaya has very unstable Slope due to on going collision of Himalaya.

Unstable Slope=F( Thrust, Rocks, Rivers and Infrastructure Like Highways)

Real life Example

Four Lanes construction has destablized the slope along the Chandigarh Shimla highways causing serious threat to commuter.

2. Climate Related Disaster

In included heavy rainfall, snowfall, cold and hot winds ,Draught and GOLF events. In recent years monsoon days has been decreased with intensity of monsoon has significantly increased, similarly mountain are experience Dry , snowless winter spell all this impacting the fragile Ecological system. Climate change has also increased the intenstiy of GOLF events in Himacha Pradesh.

Latest Modeling and Use of AI in GOLF events

Researcher has will automated system to detect glacial lakes in Himachal Pradesh using satellite images and machine learning. It combines data from Sentinel-1, Sentinel-2, SRTM DEM and high-resolution Planet Scope images. A Random Forest model identifies glacial lakes with high accuracy (up to 94.44%).

Sr No	Region / State / UT	Number of Expanding Glacial Lakes	Key Notes
1	Arunachal Pradesh	197	Highest number of expanding lakes in India
2	Ladakh	120	Second-highest; major part of cold-desert zone
3	Jammu & Kashmir	57	High-risk river basins; Chenab, Jhelum catchments
4	Sikkim	47	Located in glacial valleys feeding Teesta basin
5	Himachal Pradesh	6	Includes sensitive lakes like Ghepan Lake
6	Uttarakhand	5	Linked to flood-prone Ganga basin tributaries
	Total (within India)	432	Out of 681 lakes monitored within India
	Total (entire Himalayan region)	1,435	Out of 2,843 lakes and water bodies monitored

Source – Indian Express-June 2025.

3.Vegetation

Forest cover 27.99 % area of Himachal Pradesh. Plant roots bind soil, making slopes more stable and lowering the chances of landslides in hilly regions. Forests act as natural barriers by slowing runoff, reducing floods and improving water infiltration.

Thick vegetation also protects riverbanks from erosion and prevents the widening of rivers during heavy rain. In dry areas, vegetation shields the land from wind erosion and dust storms. When forests are cut or degraded, these protective functions disappear, turning small hazards into big disasters. Healthy vegetation, therefore, acts like a natural defense system that protects both people and landscapes.

Real life Example:

Channelisatio and afforestation under the JICA project has reduce the flood potential in Swan river catchment area in district UNA. Similarly people of Kullu protesting the cutting of tress for Bijli Mahdev project, highlist role vegetation in Disaster. Similarly pine leaf needle in hot summer make many region fire prone.

4. Industrial Factors

Like Factory Fires, Current , Blast, release of chemicals etc pose serious threat in industrialist and urban zone. District Una, Solan,Sirmaur and part of Kangra are prone to this kind of disaster.