Observed trends and changes in daily temperature and precipitation extremes over the Koshi river basin

The Koshi river basin is a sub-basin of the Ganges shared among China, Nepal, and India. The river system has a high potential for investment in hydropower development and for irrigation in downstream areas. The upper part of the basin contains a substantial reserve of freshwater in the form of snow and glaciers. Climate variability, climate change, and climate extremes might impact on these reserves, and in turn impact on systems that support livelihoods, such as agriculture, biodiversity and related ecosystem services. Climatological variability and trends over the Koshi river basin were studied using RClimDex. Daily temperature data (20 stations) and precipitation data (50 stations) from 1975 to 2010 were used in the analysis. The results show that the frequency and intensity of weather extremes are increasing. The daily maximum temperature (TXx) increased by 0.1 °C decade−1 on average between 1975 and 2010 and the minimum (TNn) by 0.3 °C decade−1. The number of warm nights increased at all stations. Most of the extreme temperature indices showed a consistently different pattern in the mountains than in the Indo-Gangetic plains, although not all results were statistically significant. The warm days (TX90p), warm nights (TN90p), warm spell duration (WSDI), and diurnal temperature range (DTR) increased at most of the mountain stations; whereas monthly maximum and minimum values of daily maximum temperature, TX90p, cool nights (TN10p), WSDI, cold spell duration indicator (CSDI), DTR decreased at the stations in the Indo-Gangetic plains, while the number of cold days increased. There was an increase in total annual rainfall and rainfall intensity, although no clear long-term linear trend, whereas the number of consecutive dry days increased at almost all stations. The results indicate that the risk of extreme climate events over the basin is increasing, which will increase people's vulnerability and has strong policy implications

Projected changes in climate over the Indus river basin using a high resolution regional climate model (PRECIS)

A regional climate modelling system, the Providing REgional Climates for Impacts Studies developed by the Hadley Centre for Climate Prediction and Research, has been used to study future climate change scenarios over Indus basin for the impact assessment. In this paper we have examined the three Quantifying Uncertainty in Model Predictions simulations selected from 17-member perturbed physics ensemble generated using Hadley Centre Coupled Module. The climate projections based on IPCC SRES A1B scenario are analysed over three time slices, near future (2011-2040), middle of the twenty first century (2041-2070), and distant future (2071-2098). The baseline simulation (1961-1990) was evaluated with observed data for seasonal and spatial patterns and biases. The model was able to resolve features on finer spatial scales and depict seasonal variations reasonably well, although there were quantitative biases. The model simulations suggest a non-uniform change in precipitation overall, with an increase in precipitation over the upper Indus basin and decrease over the lower Indus basin, and little change in the border area between the upper and lower Indus basins. A decrease in winter precipitation is projected, particularly over the southern part of the basin. Projections indicate greater warming in the upper than the lower Indus, and greater warming in winter than in the other seasons. The simulations suggest an overall increase in the number of rainy days over the basin, but a decrease in the number of rainy days accompanied by an increase in rainfall intensity in the border area between the upper and lower basins, where the rainfall amount is highest

Reconstructing historic Glacial Lake Outburst Floods through numerical modelling and geomorphological assessment:Extreme events in the Himalaya

Recession of high‐mountain glaciers in response to climatic change frequently results in the development of moraine‐dammed glacial lakes. Moraine dam failure is often accompanied by the release of large volumes of water and sediment, termed a Glacial Lake Outburst Flood (GLOF). Chukhung Glacier is a small (~3 km2) receding valley glacier in Mt. Everest (Sagarmatha) National Park, Nepal. Unlike many Himalayan glaciers, which possess a thick mantle of supraglacial debris, its surface is relatively clean. The glacier terminus has receded 1.3 km from its maximum Holocene position, and in doing so provided the space for an ice‐contact moraine‐dammed lake to develop. The lake had a maximum volume of 5.5 × 105 m3 and drained as a result of breaching of the terminal moraine. An estimated 1.3 × 105 m3 of material was removed from the terminal moraine during breach development. Numerical dam‐breach modelling, implemented within a Generalised Likelihood Uncertainty Estimation (GLUE) framework, was used to investigate a range of moraine‐dam failure scenarios. Reconstructed outflow peak discharges, including failure via overtopping and piping mechanisms, are in the range 146–2200 m3 s‐1. Results from two‐dimensional hydrodynamic GLOF modelling indicate that maximum local flow depths may have exceeded 9 m, with maximum flow velocities exceeding 20 m s‐1 within 700 m of the breach. The floodwaters mobilised a significant amount of material, sourced mostly from the expanding breach, forming a 300 m long and 100 m wide debris fan originating at the breach exit. moraine‐dam. These results also suggest that inundation of the entire floodplain may have been achieved within ten minutes of initial breach development, suggesting that debris fan development was rapid. We discuss the key glaciological and geomorphological factors that have determined the evolution of a hazardous moraine‐dammed lake complex and the subsequent generation of a GLOF and its geomorphological impact

Anatomy of terminal moraine segments and implied lake stability on Ngozumpa Glacier, Nepal, from electrical resistivity tomography (ERT)

This research was supported financially by the European Commission FP7-MC-IEF (PIEF-GA-2012-330805), the University Centre in Svalbard (UNIS), National Geographic Society GRANT #W135-10.Moraine-dammed lakes at debris-covered glaciers are becoming increasingly common and pose significant outburst flood hazards if the dam is breached. While moraine subsurface structure and internal processes are likely to influence dam stability, only few sites have so far been investigated. We conducted electrical resistivity tomography (ERT) surveys at two sites on the terminal moraine complex of the Ngozumpa Glacier, Nepal, to aid assessment of future terminus stability. The resistivity signature of glacier ice at the site (100-15 kΩ m) is more consistent with values measured from cold glacier ice and while this may be feasible, uncertainties in the data inversion introduce ambiguity to this thermal interpretation. However, the ERT data does provide a significant improvement to our knowledge of the subsurface characteristics at these sites, clearly showing the presence (or absence) of glacier ice. Our interpretation is that of a highly complex latero-terminal moraine, resulting from interaction between previous glacier advance, recession and outburst flooding. If the base-level Spillway Lake continues to expand to a fully formed moraine-dammed glacial lake, the degradation of the ice core could have implications for glacial lake outburst risk.Publisher PDFPeer reviewe

Climate change impacts on glacier hydrology and river discharge in the Hindu Kush-Himalayas: a synthesis of the scientific basis

Rising temperatures and changing precipitation patterns across the Hindu Kush–Himalaya (HKH) region resulting from climate change have an influence on water resource availability and food security for the downstream population. This review seeks to objectively assess the available evidence of the impacts of climate change on glacier hydrology and the wider implications upon water resources within the Indus, Ganges, and Brahmaputra basins. Glacier meltwater contribution to river flows is scale dependent and varies considerably across the east–west climatic zones of the HKH. For the Ganges and Brahmaputra this contribution is estimated to be significantly less than for the Indus to the west, with summer monsoon rains dominating flows from central and easterly areas, whereas meltwater remains a significant contributor to downstream flow of westerly basins, which receive most precipitation during winter. No corroborated trends exist in observed discharge for any basin, and such analyses are hindered by a lack of good-quality long-term data. Predicted increases in temperature will drive increased shrinkage of glaciers, leading to initial increases in meltwater produced, followed by subsequent declines with reduced glacier mass. The impacts of such changes are predicted to be minimal for the overall discharge of the Ganges and Brahmaputra, where increases in rainfall may in fact lead to increased flows but with greater variability. Within the Indus basin, reduced meltwater will have significant impacts upon available runoff; however, increased uncertainties surrounding precipitation and socioeconomic changes limit any conclusive assessment of how water availability will be affected; moreover, seasonality of runoff may be a more important factor. Scientific challenges and research recommendations are identified for the region. This review proposes the need for the scientific evidence pertaining to the region's glacier systems to be approached objectively in the future, such that a robust assessment of change can be attained

Insulin autoimmune syndrome as a cause of recurrent hypoglycemia in a carbimazole user: a case report from Nepal

Vivek Pant,1 Bijay Bhandari,2 Suman Baral,3 Sangha Ratna Bajracharya4 1Department of Clinical Biochemistry, Institute of Medicine (IOM), Tribhuvan University Teaching Hospital (TUTH), Kathmandu, Nepal; 2Department of Clinical Pharmacology, Institute of Medicine (IOM), Tribhuvan University Teaching Hospital (TUTH), Kathmandu, Nepal; 3Endocrine Unit, Department of Medicine, Institute of Medicine (IOM), Tribhuvan University Teaching Hospital (TUTH), Kathmandu, Nepal; 4Department of Clinical Pharmacology, Institute of Medicine (IOM), Tribhuvan University Teaching Hospital (TUTH), Kathmandu, Nepal Abstract: Insulin autoimmune syndrome (IAS) is a rare cause of nondiabetic hypoglycemia characterized by hyperinsulinemia and autoantibodies to endogenous insulin without prior exposure to exogenous insulin. We report a drug-induced case of IAS in a 59-year-old Nepalese female. She had been taking carbimazole for Graves’ disease and later presented with recurrent episodes of hypoglycemia, with laboratory findings of low blood glucose, increased molar ratio of insulin to C-peptide, and elevated autoantibodies to insulin. IAS should be considered while evaluating hypoglycemia to prevent unwarranted invasive procedures and surgical interventions. Keywords: insulin autoimmune syndrome, hypoglycemia, carbimazole, Hirata diseas

Prevalence of complications of simple tooth extractions and its comparison between a tertiary center and peripheral centers: a study conducted over 8,455 tooth extractions

This study was conducted to investigate and compare the prevalence of complications of simple tooth extractions in a tertiary centre (BP Koirala Institute of Health Sciences, Dharan) and the peripheral centers (Mechi and Koshi zonal hospitals). This is a prospective descriptive study. Tooth extractions were carried out under local anesthesia in the tertiary and the peripheral centers during one year period (March 15"th 2004 to March H"111 2005). Intraoperative and postoperative complications were recorded and analyzed. Out of 8,455 tooth extractions in 6,639 [male-2,465 (37.12%) and females - 4,174 (62.88%)] patients aged between 5yrs- 65 yrs, 7,152 extractions were done in tertiary center and 1,393 extractions were done in peripheral centers.90 complications (1.06%) were observed. 53(58.89%) complications were intraoperative and 37(41.12%) complications were postoperative. 60(0.84%) complications were observed in the tertiary center and 30 (2.3%) complications were observed in the peripheral centers and the difference was highly significant (P<0.000001). The most frequent complication in the tertiary centre was fracture of tuberosity (0.15%) and in the peripheral centers it was 'roots left' (0.77%). Prevalence of 'roots left', injury to adjacent tooth and postoperative hemorrhage was significantly high (P<0.05) in peripheral centers. The higher prevalence rate of complications of tooth extractions in the peripheral centers should not be overlooked and well equipped and organized extraction procedure with qualified dental practitioner is strongly suggested to minimize the complications. Key Words: Complications; intraoperative; postoperative; tooth extraction