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The Urgos watershed is situated in the rain shadow zone of the Pir Panjal Range of the Lahul Himalaya, where western disturbances dominate with solid precipitation. Consequently ice, permafrost and snow meltwater is the main source of the Urgos Nala (stream), which supports agriculture and replenishes drinking water sources downstream in the watersheds. The effect of small amount of glacier retreat and changes in seasonal snow cover is critical for the functioning of meltwater and high natural resources dependent mountain communities. Agriculture, vegetation, fodder and pasture land in the watershed are all entirely dependent on meltwater. Therefore, the study aims to make a quantitative and large-scale map of the study area in relation to rural livelihood. Resource mapping (1:5000) and quantitative characterization of Urgos watershed are achieved using high-resolution satellite images, digital elevation models, Total Station mapping, differential Global Positioning System and collection of field evidences. The landform evolution in the watershed is a result of intense glaciofluvial processes in the past as well as present. The geomorphic features mapped in the area reveal multiple glacial advances in the watershed, in the past. This has direct links with climatic fluctuations and its impact on agriculture and allied activities for the sustenance of people. The analysis shows 22.49% area under glacier and only 1.04% area of the entire watershed under agriculture, fodder, pasture and vegetation land. This 1.04% area of the watershed plays a significant role in the livelihood of the people.

Glacier ice-thickness measurement and distribution is one of the essential variables to assess present status of glacier-water equivalent and its volumetric reserve as well as to model the future glacier dynamics under the climate changing scenario. Yet, substantial gaps in ice thickness information exist for the Himalayan glaciers. The present study provides a long-term assessment (1965–2016) of recessional and area change patterns, as well as the detailed field-based (2016–2017) Ground Penetrating Radar(GPR), derived ice-thickness measurement of the Menthosa Glacier, Lahaul Himalaya. Additionally, the study examines whether the modelled ice thickness from remote sensing data is consistent with the field-based GPR measurement and how can it be improved. The extensive field surveys coupled with the multi-temporal high (Corona KH-4A) to medium resolution (Landsat Enhanced Thematic Mapper+ (ETM+)/Operational Land Imager (OLI), Sentinel 2A-Multispectral Instrument (MSI)) remote sensing data and cross-sectional GPR surveyed profile measurements have been used to examine past half a century (1965–2016) glacier fluctuation and the recent ice-thickness estimations, respectively. The results show that the Menthosa Glacier receded by 301.5 ± 19.2 m during the past half a century (1965–2016) with an average annual retreat of 5.9 ± 0.4 m a−1, whereas glacier lost 0.09 km2 ice in the frontal section. Field measurement over the past one decade (2006–2017) also conforms to a continuous recessional pattern and substantial glacier degeneration particularly the extensive surface lowering and significant appearance of ice-cliffs in the ablation and lateral zones over this period. The GPR measurements (2017) show the minimum glacier ice thickness of 24 meters at 4691 m a.s.l. (in the lower part of ablation area) and maximum glacier ice thickness of 55 meters measured at 4758 m a.s.l. (in the upper left-side tributary part of ablation area). Moreover, the modelled ice thickness derived from remotely sensed data is having Root Mean Square Error (RMSE) between 38 to 72 ± 10 m as compared with GPR measured ice thickness.

This chapter deals with the present status of glaciers in the state of Himachal Pradesh, north-western Himalaya (India). It portrays a detailed and comprehensive review of the literature on glaciers dynamics with specific examples from poorly observed glaciers and basins in the area. It highlights the irregularities in available glacier inventories and its usability, observations related to glacier terminus retreat and area vacated since the post-Little Ice Age (LIA) to contemporary period, glacier mass balance observations since last four decades (1970s–2010s) and identifies the poorly observed basins in terms of glacier research. An emphasis has been placed, of necessity, on what has been the response of glaciers to climate (e.g. temperature and precipitation) and non-climatic (e.g. debris-cover, morphology and catchment relief) factors. The review reveals overall glacier recession trends and thinning with heterogeneity from one glacier to another since end of LIA acorss the Himachal Himalaya.

Detailed field mapping of glacial and paraglacial landforms and optical dating from these landforms are used to reconstruct the early Holocene glaciation in the semi-arid region of Miyar basin, Lahaul Himalaya. The study identifies three stages of glaciation, of decreasing magnitude and termed, from oldest to youngest, the Miyar stage (MR-I), Khanjar stage (KH-II), and Menthosa advance (M-III). The oldest glacial stage (MR-I) has been established on the basis of detailed geomorphological evidence such as U-shaped valley morphology, trimlines, and truncated spurs. It is speculated to be older than the global Last Glacial Maximum (gLGM) based on the magnitude of ΔELA (Equilibrium-Line Altitude, 606m). No evidence of glacier expansion recorded from the basin correlates with the period of the gLGM. The second stage (KH-II) is well represented by extensive depositional features such as lateral and terminal moraines, drumlins, and lacustrine fills that have been constrained within 10 ± 1 to 6.6 ± 1.0 ka (Optically stimulated luminescence—OSL—ages), dating it to the early Holocene advance following the Younger Dryas cooling event. Exceptionally young glacial records of expansion are limited within a few hundred meters of the present termini of tributary glaciers and correlates with the 18th-century cooling event. Records of this glacial advance, termed the Menthosa advance, are clearly noticed in some tributary valleys.

This study presents glacio-archaeological evidence from the Miyar basin, Lahaul Himalaya, that points towards the former presence of a well settled agricultural society, within a glacier end moraine complex. Three high altitude villages (Tharang, Phundang and Patam, now in ruins) with elaborate irrigation networks thrived within the end moraine complex of Tharang glacier at 3700 m a.s.l. Evidence exists in the form of dilapidated houses which had an organised internal space, chronologically constrained by radiocarbon (14C) dating. These settlements occupied the end moraine complex between 980 and 1840 CE, thereby encompassing the majority of Little Ice Age period (1300–1600 CE), as defined elsewhere. The existence of settlements along with an irrigation system and associate fields at ∼3700-3800 m a.s.l. for almost ∼860 years during the late 10th to early 19th centuries suggests more favourable climatic (warm) conditions that at present. By contrast, present habitation is restricted to areas below ∼3500 m a.s.l. However, the slope controlled irrigation system also suggests moisture stressed conditions during the 980–1840 CE period, similar to present. The available temperature and snowfall proxies for the region support our proposed timing, and suggest favourable climatic conditions for the survival of these settlements.

Impressive glacio-archaeological evidence is described from the Miyar basin, Lahul Himalaya, India. Three ruins, namely Tharang, Phundang and Patam are identified along with evidence for past settlement and rich irrigation practices in the basin. These ruins are located in the end moraine complex of Tharang glacier, just ~ 2–3 km from the present glacier snout. Reconstruction of these ruins was undertaken based on mapping and radiocarbon (14C) dating. The radiocarbon dates (9 samples were dated) indicate that the settlement was occupied between cal AD ~ 1170 and cal AD ~ 1730, thereby encompassing the majority of Little Ice Age period. The settlement’s occupation at ~ 3700 m a.s.l. (whereas present habitation is restricted to areas below ~ 3500 m  a.s.l.) for almost ~ 550 years during the 12th to 17th centuries suggest warmer conditions than today. Moreover, the study finds no evidence to suggest any noticeable glacier advance during this period.