25-Comparative study of water chemistry in two morphologically dissimilar rural lakes of Kashmir Himalayas

Abstract

The present paper describes the work carried out on two morphologically dissimilar Lakes of Kashmir Himalaya. The physco-chemical parameters assessed, shows considerable variation. It has been recorded that Mansbal, an open drainage type of lake, flashes out an equal volume of water in one and a quarter of year. While as Bod-sar is closed type of lake, on contrary does not flash much water (no flashing rate) has maximum detention period, so nutrient retention period is high which support the metabolic phenomenon within the lake. Mansbal is a warm monometic lake and develops summer stratification while no such phenomenon is evident in Bod-sar (Wanganeo et. al. 2006). Mansbal Lake shows vertical stratification profile of dissolve oxygen that is of clinograde type, it has been also observed that there is a gradual reduction in Hypolimic oxygen in lake while no such phenomenon was observed in the Bod-sar Lake because of shallow depth. (Wanganeo et. al. 2006). The concentration of free carbon dioxide supports the decomposition rate at the sediment water interface in the Bod-sar. While in Mansbal, the free carbon dioxide concentration is very less. Free carbon dioxide tension being under the direct influence of photosynthetic action, and high metabolic process drives the pH from acidity towards the alkalinity in Bod-sar. In Mansbal, pH is driven from neutrality towards the alkalinity. Conductance being principal function of ions, witness seasonal trend in both the lakes. Fall in salt concentration during summer is conceptive with least electrically conductivity of water. Nutrients in both the lakes are highly dynamic because it may be utilized, stored transformed and excreted repeatly by various aquatic organisms. The variations in phosphorous content are likely to be the influence of catchments interaction and other autochthonous phenomenon (When sediment water interface becomes anoxic in such type of productive ecosystem the oxidized micro zone formed below is lost which induce the phosphorus release in both lake waters at rapid rate). In Bod-sar the bacterial metabolism of organic matter is the primary mechanism by which orthophosphrous is converted in to phosphate. All forms of nitrogen show seasonal trend. Magnesium and sodium are relatively conservative in nature, concentration are abundant because it is relative unaffected by metabolically alternate reduction and oxidation concentration of waters. Silicate has marked influence on the productivity and succession of algal population. The amount of silicates is less in Mansbal and high in Bod-sar, hence supporting the ecological succession and productivity of Bod-sar. The data on the water chemistry clearly reveals that there were great temporal variations in most of the parameters while few parameters fluctuated between the narrow ranges in both the lake there is insignificant spatial fluctuation in the study.