Gh Jeelani

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.

Delineation of the recharge areas and distinguishing the sources of karst springs in Bringi watershed, Kashmir Himalayas using hydrochemistry and environmental isotopes

Water samples were collected from precipitation, streams and karst springs of the mountainous Bringi catchment of Kashmir Himalayas for major ions, stable isotopes (δ18O and δD) and 3H analysis. The main objective is to identify the potential recharge area for karst springs. The water in the Triassic limestone aquifer of the Bringi watershed is characterized by low levels of mineralization with TDS of the spring water samples ranging between 99 and 222 mg/l except the Kongamnag spring, which contained TDS up to 425 mg/l. As expected in an area with dominant carbonate lithology, Ca–HCO 3 and Ca–Mg–HCO 3 hydrochemical facies were found. Based on the amount weighed monthly averages (n = 6), the local meteoric water line (LMWL) for Bringi watershed is δD = 7.7 ×δ18O + 11.1 (r2 = 0.99). The isotopic signature of winter precipitation is reflected in stream and spring water in late spring and is therefore, a representative of snow melting. The spring waters in September bear the δ2H and δ18O enriched isotopic signatures of summer rainfall. With the help of the local vertical isotopic gradient of precipitation (δ18O=−0.27‰ per 100 m increase in elevation), the mean elevation of precipitation that recharged the aquifer is estimated and ranges about 2500–2900 m amsl. There is a very strong correlation (r2 = 0.97) between the seasonal isotope composition of streams and springs, indicating that streams and springs either share similar catchments or the springs are recharged by the streams.

Delineation of Point Sources of Recharge in Karst Settings

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).

Textural characteristics of sediments and weathering in the Jhelum river basin located in Kashmir Valley, Western Himalaya

This study presents a detailed textural and geochemical study of sediments of river Jhelum and its tributaries of Kashmir valley. The textural studies clearly established that the sediments were dominantly of medium grain size, moderately sorted and very positively skewed. The kurtosis suggested dominantly leptokurtic nature of sediments. The sediments were deposited under moderate to low energy conditions with dominant rolling processes. The statistical parameters showed little spatial as well as temporal variations. The observations are supported by the frequency curves and bivariate plots between various textural parameters, confirming the polymodal nature of sediments with dominant to moderate sand fraction. The bimodal and unimodal nature of the sediments was also present at certain locations. The major oxide elemental chemistry of the sediments indicated that the dominant elemental oxide was SiO2 followed by Al2O3 in all the sediments. The Chemical Index Alteration (CIA) and Resistant Index of Maturity (RM) reflected moderate weathering and immaturity of the sediments in the basin.