“Evolution is the law of nature, everything has to be evolved and those that can’t adopt changes in time will be destroyed”, it’s the promise of nature. Geologically, the Earth’s climate has been changed several times. Land on which we rest is not simple and original, but it is a composition and had been evolved by the operation of second causes. As we are all aware of the fact that snow and ice masses are the major source of fresh water for mountainous population and HKH region has been declared as “Third pole” in terms of fresh water storage. Climate is changing in these Mountains. The impact on cryospheric environment can be recognized as extreme climate events like drought and floods. GLOFs, water scarcity, shift of snow line elevation and changes in the form of precipitation become frequent in the mountains of HKH.
Yala Glacier lies in Central Himalaya Langtang valley, Rasuwa district, Nepal with elevation range of 5749 to 5128 m a.s.l and covers an area of 1.61 km2. Yala Glacier is under observation ofdifferent research groups since 90s as benchmark glacier for the catchment. However, Langtang catchment contains some debris covered glaciers. Layer of debris on the surface of glacier ice can alter behavior of ice beneath it to changes in meteorological variables. Long term observations of meteorological variables in valley have shown continuous increase in temperature. This increase in temperature causes rapid melting of snow and ice. Simultaneously, changes in precipitation cause serious concerns about water storage capacity of catchment in the form of snow and ice. During our recent research expedition to Yala Glacier (Nov 2017). Observation taken from different ablation stakes shows rapid melting of ice. Significant melt of about 6.54m has been observed in stack 1 during last 8 months. Previously in 1990s Yala Glacier was extended to lower elevations but with changes in climatic conditions it retreated back to its current position (5128 m a.s.l), increase in temperature is blamed to be the cause of glacier retreat.
Large number of population directly depends on resources in the catchment that are associated with hydrology. Natural resources are tied to each other and changes in climatic conditions of the region are already having significant effect on cryosphere of the region as shown in the pictorial view of the Yala Glacier. Current changes in climate also threatens ecosystem in catchment by changing total water storage capacity. Increase in mean annual temperature leads to decrease total water storage capacity of catchment in the form of frozen water. Current changes in meteorological variables might be triggered by industrialization in the surrounding regions of HKH. Rapid loss of mass from Himalayan Glaciers has been reported in past (Yamada and others, 1992; Kadota and others, 1993; Bolch and others, 2012). Yala Glacier shows negative mass balance continuously. A negative mass balance of -0.89 m w.e. (Barnal et al., 2014). If it continues to decline soon there will be no more elevated land to hold glacier.
The recent research training expedition to Yala Glacier consisted of 12 members; 2 from Karakoram International University (Pakistan), 5 from Kathmandu University (Nepal), 3 from ICIMOD (Nepal) and 2 from Department of Hydrology and Meteorology (Nepal). The multicultural research experience was quite helpful for regional knowledge sharing and networking, enhancing our understanding on glacier monitoring and learning basic mountaineering skills that can be relevant to glaciologists for self rescue in the mountains.
When we stepped into Langtang village, the site of a devastating avalanche during the 2015 earthquake shocked every one of us. Remanence of that terrible event is still on the floor of that village and the threat is still hanging high above. 7.8-magnitude earthquake triggered vast mass of about 40 million tons estimated mass of snow, ice and debris on the steep sloped mountains. It produced a very high speed wind that flattened every standing structure on its way even on the opposite side of valley several kilometers downstream. 243 people died in this devastating mass flow. Huge mass ofice is still melting beneath a thick debris layer and number of ponds are formed on the surface. On the north-eastern part of village some of the houses are re-built and some are still under rehabilitation.
Our research group climbed up to the maximum elevation of 5500 m a.s.l, established base camp at elevation of 4900 m a.s.l and stayed for 7 days in Yala Base camp. It was very difficult to work in that extreme environment. Temperature usually dropped down below freezing point but the clouds remained calm throughout the field trip. Because of the strong motivation of field members, in the end we all managed to complete our work properly and also enjoyed our stay.
Meanwhile, results of field observations by the recent research expedition to Yala is yet to come. Impact of changes in cryosphere of the regions should be elaborated in more comprehensive way to estimate the stock of natural resources for sustainable life in mountainous terrains and minimize hazards associated with it. Study of the cryospheric science and management of natural resources need more attention of both national and international organizations in order to maintain ecosystem of higher elevations.