Papers by Sheikh Nawaz Ali
Local Perceptions and Trends of Climate Change in the Sikkim Himalaya, North-East India
Journal of Computational Chemistry, 2021
The Himalayan high mountain areas are more vulnerable to climate change and the awareness of its ... more The Himalayan high mountain areas are more vulnerable to climate change and the awareness of its impacts among the natives is very crucial as well as beneficial to stakeholders and policymakers. The impacts of climate change via food security, water availability, natural hazards, agriculture, and livelihoods have a direct relation or threat to the lives of high mountain communities, as these areas are experiencing the immediate and greatest impacts of climate change. Although the tourism industry has become the backbone of the economy in these areas, a significant increase in tourist footfall has also impacted the environment, livelihoods, culture and food habits. To understand the local perceptions of climate change, a binary question-based survey (interview) was conducted in six main subdivisions of North Sikkim, which is a biodiversity and tourism hotspot. The data revealed that irrespective of the locality (urban/rural) people are aware of climate change. Significant coherence i...
Morphometric analysis, being widely used to assess the drainage characteristics of the river basi... more Morphometric analysis, being widely used to assess the drainage characteristics of the river basins, has been found to be a useful tool to delineate the glacial till covered overburden material as well as to identify areas prone to flash floods in present studies. A number of parameters including the stream frequency, drainage density and drainage texture suggest that the unconsolidated, unstratified and highly permeable glacially deposited overburden till material facilitates the infiltration of snowmelt and rainwater in the Pindari glacio-fluvial basin, Eastern Kumaun Himalaya, India. Likewise, other till overburden covered glacial and proglacial areas of Higher Himalayan regions have been contributing to the groundwater budget. The shape parameters further suggest that the sub-basins with higher form factor are more prone to flash floods. Besides this, the anomalies in the morphometric parameters have been found to be a useful tool to delineate zones of active tectonics in such areas.
The timing of glaciation is an important parameter that helps in the understanding of past climat... more The timing of glaciation is an important parameter that helps in the understanding of past climate change and provides valuable information for developing the predictive futuristic models. There are evidences to suggest that during the late Quaternary, Himalayan glaciers fluctuated considerably thus implying their sensitivity to changes in past climatic conditions. Although the Himalayan region is fed by two major weather systems viz. the southwest summer monsoon and the mid-latitude westerlies, however, the existing chronology (mostly exposure ages) indicates that irrespective of the geographical position, glaciers seem to grow during increased insolation and enhanced southwest summer monsoon including the mid-latitude westerly dominated north-western Himalayan glaciers (Ladakh and Karakoram). Considering the limited geographical coverage and the dating uncertainty, the above inferences should be treated as tentative.
Agarwal, K.K., Prakash, C., Nawaz Ali, S. and Jahan, N. (2012). Morphometric analysis of the Ladhiya and Lohawati river basins, Kumaun Lesser Himalaya, India. Zeitschrift für Geomorphologie, NF Volume 56 (2), pp. 201-224
Chronology of late quaternary glaciations in Indian Himalaya: A critical review
Journal of the Geological Society of India, 2013
Goriganga valley, which is located in the transition zone between the dry steppe of the Tibetan p... more Goriganga valley, which is located in the transition zone between the dry steppe of the Tibetan plateau in the north and the sub-humid Himalayan climate in the south, has preserved four events of glaciation with decreasing magnitude. The oldest Stage-I glaciation is represented by a w12.5 km long discontinuous diamictite ridge which terminates north of Rilkot (w3100 m asl). The Stage-II glaciation is represented by sub-rounded and partially eroded lateral moraines and terminates around Martoli village (w3240 m asl). The Stage-III and IV glacial moraines are sharp crested, unstable and terminate proximal to the present day glacier at w3640 m asl and w3740 m asl respectively. The Stage-II moraines have been optically dated between 25 AE 2 ka and 22 AE 1 ka implying that glacier expanded during the global Last Glacial Maximum (LGM). This is contrary to the suggestion that during Last Glacial maximum (LGM) glaciation was limited in extent due to weak Indian Summer Monsoon (ISM) in the monsoon dominated regions of the Himalaya. We ascribe the LGM glaciations to a combination of the lowered temperature and enhanced mid-latitude westerlies. Following the LGM glaciation, Goriganga valley experienced two major pulses of deglaciation. The older event is dated between 16 and 12 ka and is coeval with the initiation of the ISM whereas the younger events (10À8 ka) represent the early to mid-Holocene strengthened ISM. The Stage-III and IV glaciations which terminated proximal to the modern glacier are speculated to occur during the mid-Holocene and Little Ice Age (LIA) respectively.
Asian Journal of Earth Sciences, 2010
Impact of Pollen Rain from the Vegetation of Alpine-Subalpine Belt as a Reliable Measure for Palaeoclimatic Interpretation: A Case Study from Pindari Glacier, Kumaun Himalaya, India
Record of Neotectonic Activity in the Pindari Glacier valley: Study based on Glacio-geomorphic and AMS Fabric evidences
Anisotropy of Magnetic Susceptibility in the Almora Crystalline Zone Lesser Himalaya, India: A Case Study
Is the recessional pattern of Himalayan glaciers suggestive of anthropogenically induced global warming?
Drainage morphometry of Himalayan Glacio-fluvial basin, India: hydrologic and neotectonic implications
Chronology of late Quaternary glaciation in the Pindar valley, Alaknanda basin, Central Himalaya (India)
Palaeoglacial reconstruction based on geomorphological mapping in the Pindari glacier valley, Ala... more Palaeoglacial reconstruction based on geomorphological mapping in the Pindari glacier valley, Alaknanda basin (Central Himalaya), has revealed five glacial stages with decreasing magnitude. The oldest and most extensive stage-I glaciation deposited sediments at ∼2200 masl (Khati village). The stage-II glaciation was around 7 km long and luminescence dated to 25 ± 2 ka, and has deposits at 3200 masl (Phurkia village). Stage-III glaciation is represented by degraded linear moraine ridges and is dated to 6 ± 1 ka and its remnants can be found around 3850 masl. A sharp crested crescentic moraine extending from around 3650 masl to 3900 masl is attributed to stage-IV glaciation and is dated to 3 ± 1 ka. Following this, there appears to have been a gradual recession in Pindari glacier as indicated by four sharp crested unconsolidated moraines (stage-V) on the valley floor which abuts the stage-IV moraine.We suggest that the stage-I glaciation occurred during the cool and wet Marine Isotopic Stage 3/4 (MIS-3/4), stage-II glaciations began with the onset of MIS-2, whereas the stage-III and IV glaciations occurred during the mid-to late Holocene (MIS-1). We speculate that the first sharp crested unconsolidated moraines around 3600 masl correspond to the later phase of the Little Ice Age (LIA). Historical data suggests that the remaining three ridges represent Pindari glacier snout positions at 1906, 1958 and 1965. We argue that the late Quaternary glaciations in the Pindar valley were modulated by changing insolation and summer monsoon intensity including the LIA, whereas the 20th century recessional trends can be attributed to post-LIA warming.► Five events of glaciation recorded from Pindari glacier valley, Central Himalaya. ► Stage-I is attributed to the cool and moist MIS-4, stage-II corresponds to the LGM. ► The stage-III was initiated during the strengthened monsoon around 6 ka. ► Stage-IV glaciation dated to 3 ka indicates a decrease in monsoon strength. ► Observations suggest a strong monsoon–glacier linkages in Central Himalaya.
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Papers by Sheikh Nawaz Ali