Rouf A. Shah

Estimation of snow and glacier melt contribution to Liddar stream in a mountainous catchment, western Himalaya: an isotopic approach

ABSTRACT Snow- and glacier-dominated catchments in the Himalayas are important sources of fresh water to more than one billion people. However, the contribution of snowmelt and glacier melt to stream flow remains largely unquantified in most parts of the Himalayas. We used environmental isotopes and geochemical tracers to determine the source water and flow paths of stream flow draining the snow- and glacier-dominated mountainous catchment of the western Himalaya. The study suggested that the stream flow in the spring season is dominated by the snowmelt released from low altitudes and becomes isotopically depleted as the melt season progressed. The tracer-based mixing models suggested that snowmelt contributed a significant proportion (5–66 %) to stream flow throughout the year with the maximum contribution in spring and summer seasons (from March to July). In 2013 a large and persistent snowpack contributed significantly (∼51 %) to stream flow in autumn (September and October) as well. The average annual contribution of glacier melt to stream flow is little (5 %). However, the monthly contribution of glacier melt to stream flow reaches up to 19 % in September during years of less persistent snow pack.

Influence of southwest monsoons in the Kashmir Valley, western Himalayas

ABSTRACT The regional climate of the Himalayas is predominated by the southwest monsoons and the western disturbances. The uplift of the Pir Panjal to its present height is believed to restrict the southwest monsoons from entering into the Kashmir Valley in the western Himalayas. In the present study, monthly precipitation samples were collected across the Kashmir Valley from June 2013 to May 2014 for δ18O and δ2H analyses to constrain the influence of southwest monsoons in the valley. Except in August, the precipitation is enriched in 18O and 2H from June to September and depleted from October to May. The sharp depletion of 18O in precipitation along with the decrease in d-excess in August confirm the maximum intrusion of southwest monsoons into the valley. A significant temperature – δ18O relationship was found during October and May (westerlies period) decreasing during June and September (southwest monsoon period). The local meteoric water line for the whole Kashmir Valley based on the precipitation-weighted monthly samples is . Higher intercept of the regression equation suggested dominant contribution of precipitation from western disturbances. The study suggested that the southwest monsoons enter the Kashmir Valley from southwest through the mountainous passes.

Hydrogeochemical assessment of groundwater in Kashmir Valley, India

Groundwater samples (n = 163) were collected across Kashmir Valley in 2010 to assess the hydrogeochemistry of the groundwater in shallow and deep aquifers and its suitability for domestic, agriculture, horticulture, and livestock purposes. The groundwater is generally alkaline in nature. The electrical conductivity (EC) which is an index to represent the total concentration of soluble salts in water was used to measure the salinity hazard to crops as it reflects the TDS in groundwater ranging from 97 to 1385 μS/cm, except one well in Sopore. The average concentration of major ions was higher in shallow aquifers than in deeper aquifers. In general, Ca2+ is the dominant cation and HCO3−

Delineation of Point Sources of Recharge in Karst Settings

_{3}^{-}

Estimating mean residence time of karst groundwater in mountainous catchments of Western Himalaya, India

the dominant anion. Ca–HCO3, Mg–HCO3, Ca–Mg–HCO3, Na–HCO3 were the dominant hydrogeochemical facies. High concentration of HCO3 and pH less than 8.8 clearly indicated that intense chemical weathering processes have taken place in the study area. The groundwater flow pattern in the area follows the local surface topography which not only modifies the hydrogeochemical facies but also controls their distribution. The groundwater in valley flows into four directions, i.e., SW–NE, NE–W, SE-NW and SE–NE directions. The results suggest that carbonate dissolution is the dominant source of major ions followed by silicate weathering and ion-exchange processes. The concentrations of all the major ions determined in the present study are within the permissible limits of WHO and BIS standards. The results of Total Hardness, SAR, Na%, Kelly Index, USDA classification, Magnesium absorption ratio, residual sodium carbonate, and PI suggested that groundwater is good for drinking, livestock, and irrigation purposes.

Hydrological processes in glacierized high-altitude basins of the western Himalayas

Karst, a geomorphic landscape that arises from the combination of high rock solubility and well developed subsurface drainage networks on rock types that are easily dissolved by water notably carbonate rocks such as limestone, dolomite or marble (Bretz 1942; Sweeting 1981; Jennings 1985; Palmer 1991, 2007; Bloom 1998; Klimchouk et al. 2000; Gunn 2004; Culver and White 2005; Ford and Williams 2007) and to a lesser extent evaporites such as gypsum, anhydrite and halite (Kozary et al. 1968; Klimchouk 2002; Johnson and Neal 2003; Ford and Williams 2007), constitutes 20–25 % of the earth’s land surface (Ford and William 2007; Bakalowicz 2005). These areas are regraded to represent the earth’s most diverse, scenic and resource-rich terrains with much of their wealth hidden underground including minerals, oil and natural gas, limestone quarries, apart from beautiful housing sites for urban development (Lamoreaux et al. 1993; Schmitz and Schroeder 2006). It is worldwide observed that nearly 40–50 % of the human population utilizes drinking water derived from karst aquifer systems, either directly or indirectly (Cost 1995; Ford and Williams 2007; Cooper et al. 2011; Brinkmann and Parise 2012). However, the unique hydrologic, geomorphologic and hydrogeologic features of karst (White 1988; Ford and Williams 2007; Palmer 2007; Parise and Gunn 2007) make these aquifers more vulnerable to pollution and contaminants (Drew and Hotzl 1999; Bohlke 2002; Parise and Pascali 2003; Bonacci 2004; Kovacic and Ravbar 2005; Ford and Williams 2007; Parise 2010).

Assessment of Groundwater in Karst System of Kashmir Himalayas, India

ABSTRACT The mean residence time (MRT) of karst groundwater in three mountainous catchments of the Western Himalaya was estimated using multiple approaches: the tritium method, the sine wave model and tracer tests. Water samples were collected from precipitation, glacier melt, streams and karst springs for δ2H and tritium analysis during 2012 and 2013. High tritium values were observed in winter precipitation and low values in summer precipitation. The variation of tritium in karst springs was similar to that of the streams, whereas glacier melt showed lower tritium values. The MRT of cold karst springs was shorter than that of warm karst springs. The tracer breakthrough curves (TBC) retrieved for different springs suggested a short travel time for groundwater and possibly conduit flow. Deterioration of water quality and variation in flux magnitude are the two main practical consequences of the short travel time of karst groundwater in the region. EDITOR D. Koutsoyiannis ASSOCIATE EDITOR K. Heal

Weathering and anthropogenic influences on the water and sediment chemistry of Wular Lake, Kashmir Himalaya

Western Himalaya is a strategically important region, where the water resources are shared by China, India and Pakistan. The economy of the region is largely dependent on the water resources delivered by snow and glacier melt. The presented study used stable isotopes of water to further understand the basin-scale hydro-meteorological, hydrological and recharge processes in three high-altitude mountainous basins of the western Himalayas. The study provided new insights in understanding the dominant factors affecting the isotopic composition of the precipitation, snowpack, glacier melt, streams and springs. It was observed that elevation-dependent post-depositional processes and snowpack evolution resulted in the higher isotopic altitude gradient in snowpacks. The similar temporal trends of isotopic signals in rivers and karst springs reflect the rapid flow transfer due to karstification of the carbonate aquifers. The attenuation of the extreme isotopic input signal in karst springs appears to be due to the mixing of source waters with the underground karst reservoirs. Basin-wise, the input–output response demonstrates the vital role of winter precipitation in maintaining the perennial flow in streams and karst springs in the region. Isotopic data were also used to estimate the mean recharge altitude of the springs.RésuméL’Himalaya occidental est une région stratégiquement importante, où les ressources en eau sont partagées entre la Chine, l’Inde et le Pakistan. L’économie de la région dépend en grande partie des ressources en eau apportées par la fonte des neiges et des glaciers. La présente étude a utilisé les isotopes stables de l’eau pour mieux comprendre les processus hydro-météorologiques, hydrologiques et de recharge à l’échelle du bassin de trois bassins montagneux de haute altitude dans l’Himalaya occidental. L’étude a fourni de nouvelles perspectives pour la compréhension des facteurs dominants affectant la composition isotopique des précipitations, des manteaux neigeux, de la fonte des glaciers, des cours d’eau et des sources. On a observé que les processus postérieurs au dépôt dépendant de l’altitude et l’évolution du manteau neigeux engendrent un gradient d’altitude isotopique plus élevé dans les manteaux neigeux. Les tendances temporelles similaires des signaux isotopiques dans les rivières et les sources karstiques reflètent le transfert de flux rapide en raison de la karstification des aquifères carbonatés. L’atténuation du signal isotopique d’entrée des sources karstiques semble être due au mélange d’eau des sources avec les réservoirs souterrains karstiques. En ce qui concerne le bassin, la réponse entrée-sortie démontre le rôle important des précipitations hivernales dans le maintien de l’écoulement pérenne dans les cours d’eau et les sources karstiques dans la région. Les données isotopiques ont également été utilisées pour estimer l’altitude moyenne de recharge des sources.ResumenEl Himalaya occidental es una región estratégicamente importante, donde los recursos hídricos son compartidos por China, India y Pakistán. La economía de la región depende en gran medida de los recursos hídricos aportados por la nieve y la fusión de los glaciares. El presente estudio utilizó isótopos estables del agua para comprender mejor los procesos hidrometeorológicos, hidrológicos y de recarga a escaña de cuenca hidrográfica en tres cuencas montañosas de altura en el Himalaya occidental. El estudio proporcionó nuevas perspectivas para comprender los factores dominantes que afectan a la composición isotópica de la precipitación, la capa de nieve, la fusión de los glaciares, las corrientes y los manantiales. Se observó que los procesos post-deposicionales dependientes de la altura y la evolución de la capa de nieve resultaron en un mayor gradiente isotópico en altura de las capas de nieve. Las tendencias temporales similares de las señales isotópicas en ríos y manantiales kársticos reflejan la rápida transferencia de flujo debida a la karstificación de los acuíferos carbonatados. La atenuación de la señal de entrada isotópica extrema en los manantiales kársticos parece ser debido a la mezcla de las aguas de la fuente con los depósitos kársticos subterráneos. En la cuenca, la respuesta de ingresos y egresos demuestra el papel vital de la precipitación invernal en el mantenimiento del flujo perenne en arroyos y manantiales kársticos en la región. También se utilizaron datos isotópicos para estimar la altura media de recarga de los manantiales.摘要喜马拉雅山脉西部是一个战略重地, 那里的水资源由中国、印度和巴基斯坦共同分享。该地区的经济主要依赖于积雪和冰川融化的水资源。本研究使用水的稳定同位素进一步了解喜马拉雅山脉西部三个高海拔盆地中盆地尺度的水文气象、水文和补给过程。该研究在了解影响降水、积雪层、冰川融化、河流和泉中同位素组分主要因素方面提供了新的认识。发现依赖于海拔的后沉积过程及积雪层演化导致积雪层中较高的同位素海拔坡度。河流和岩溶泉中同位素信号的类似时间上的趋势反映了由于碳酸盐含水层的岩溶化致使快速的水流转移。岩溶泉中极端同位素输入信号出现衰减是由于源水和地下岩溶水库的水混合造成的。盆地方面输入和输出响应展示了冬季降水在保持本地区河流和岩溶泉常年流水中的重要作用。同位素资料还用于估算泉的平均补给高度。ResumoO Himalaia ocidental é uma região estrategicamente importante, onde os recursos hídricos são compartilhados pela China, Índia e Paquistão. A economia da região é altamente dependente dos recursos hídricos fornecidos pelo derretimento da neve e da geleira. O estudo apresentado usou isótopos estáveis da água para compreender melhor os processos hidrometeorológicos, hidrológicos e de recarga na escala da bacia em três bacias montanhosas de alta altitude do Himalaia ocidental. O estudo forneceu novos conhecimentos sobre a compreensão dos fatores dominantes que afetam a composição isotópica da precipitação, neve, derretimento da geleira, córregos e nascentes. Foi observado que os processos pós-deposicionais dependentes da elevação e a evolução das camadas de neve resultaram no gradiente isotópico mais alto em camadas de neve. As tendências temporais semelhantes de sinais isotópicos em rios e nas nascentes do carste refletem a rápida transferência de fluxo devido a carstificação dos aquíferos carbonático. A atenuação do sinal de entrada isotópico extremo em nascentes cársticas parece ser devido à mistura das águas de fonte com reservatórios cársticos subterrâneos. Com base na bacia, a resposta entrada-saída demonstra o papel vital da precipitação de inverno na manutenção do fluxo perene em córregos e nascentes cársticas na região. Dados isotópicos também foram utilizados para estimar a altitude média de recarga das nascentes.

Hydrogeochemistry of Dal Lake and the potential for present, future management by using facies, ionic ratios, and statistical analysis

In Kashmir Valley, the carbonate rocks cover an area of about 1100 km2, of which 58% lie towards the southern part. Carbonate lithology in the form of Triassic Limestone constitutes significant karst geomorphologic imprints including solution features, swallow holes, conduits, shafts, caves and large springs. Hydrochemical data of major springs of Kashmir Valley indicate that the spring water chemistry is dominantly contributed from weathering of carbonate rocks. The karst spring waters are undersaturated with respect to calcite and dolomite, and PCO2 of the spring water is more than atmosphere, suggesting the groundwater in karst system is highly aggressive and capable of dissolving the host rock in most of the seasons. During winters, when there is negligible recharge, the spring waters are not aggressive as the carbonic acid is consumed and not replenished, leaving the waters saturated with respect to calcite and dolomite. The observed large fluctuations of spring discharges from daily or seasonal to annual scales reflect the quick flushing of groundwater and the extent of development of subsurface karstification in the region. The karst springs were found to respond immediately to ambient temperature, which causes snow/ice melting, and rainfall, which increases the recharge. Given the high relief of the Kashmir Valley and strong isotopic variability, the vertical isotopic gradients were estimated in different mountainous catchments. Keeping in view the high permeability, short transit times and multifaceted importance of karst springs in the region, effective approaches are required for the management and protection of these vital groundwater resources.