List of CBEs Spatially Distributed in UGB

Sl. No.	Administrative districts	Area falling in UGB in sq km (% area w.r.t total basin area)	Number of recorded EREs/ CBEs	No. of blocks with EREs/ CBEs	ERSs/CBEs density
1	Chamoli	7455 (34%)	23	6	0.003
2	Rudraprayag	1987 (9%)	8	3	0.004
3	Tehri Garhwal	3280 (15%)	13	5	0.0039
4	Uttarkashi,	4934 (23%)	5	2	0.001
5	Pauri Garhwal	2687 (12%)	7	5	0.002
6	Bageshwar	566 (3%)	1	1	0.0017
7	Pithoragarh	392 (2%)	-	-	-
8	Kinnaur (H. P.)	313 (1%)	-	-	-
	Total	21614 (100%)	57	22	0.0026

Elevation-wise Number of EREs/ CBEs, Villages, and Population in The UGB

Elevation (m)	No. of villages	Population	EREs/ CBEs
< 1000	958	207705	6
1000 - 2000	4269	1084468	38
2000 - 3000	412	147174	4
> 3000	63	12420	9
Total	5702	1451767	57

Distribution of EREs/ CBEs W.R.T Elevation, Village, and Population Across UGB.

Plot Showing EREs/CBEs W.R.T Regional High/Low Elevation, Precipitation, Temperature, and Villages for UGB, Band 1, Band 2, and Band 3. Vertical Pink Lines Show Rainfall Zones Based on Two-step Topography by Bookhagen and Burbank, 2010.

The spatial distribution of extreme events and their recurrence in the UGB was studied to identify vulnerable administrative blocks. The vulnerability and associated risk was assessed using hazard, exposure, vulnerability and adaptive capacity. Four categories of blocks were identified in the populated areas of the basin. Blocks which experienced more than five events during the past ten years are classified as severely vulnerable blocks. Two blocks, Bhilangana in Tehri Garhwal district and Joshimath block in Chamoli district are under this category. Joshimath, Bhilangana, Bhatwari are classified as highly vulnerable blocks followed by Ukhimath, Dasholi, Deoprayag, Jakholi, Tharali, and Narayanbagad having moderate to low vulnerability. The total population of 3,35,750 (23% of UGB) in the severe to high vulnerability blocks are under severe risk. The 75% population of UGB living in the elevation band of 1000-2000 m a.s.l. is also under higher risk as compared to other regions of the basin as discussed earlier. These findings will help the government in prioritizing its policy interventions and formulate targeted block level implementation for disaster risk reduction (DRR). UGB has large high elevation uninhabited area covered by glacier and snow cover with low risk areas.

Vulnerability = (Exposure - Adaptive Capacity) x Sensitivity ..............................(1)
Risk = Hazard x Vulnerability .......................................................................(2)

Map Showing a. Hazard, b. Exposure, c. Adaptive Capacity, and d. Vulnerability in The UGB.

Extent of Risk Associated of EREs/ CBEs in Different Blocks in UGB