Sumit Rai

Assessment of snowmelt runoff modelling and isotope analysis: a case study from the western Himalaya, India

Abstract The major river systems of India, i.e. the Indus, Ganga and Brahmaputra river systems originating in the Himalayan region, are considered the lifeline of the Indian subcontinent. The main sources maintaining the flow of the Himalayan rivers are snow/glacial melt runoff, rainfall runoff and base flow. The Beas River originates from Beas Kund Glacier in the Himalayan region and flows down to join the Sutlej River, which is a tributary of the Indus River system. In the present study two approaches, namely hydrologic modelling and isotope analysis, have been applied to estimate the contribution of snow and glacier melt. Samples of streamflow, rainfall and snow for isotopic analysis were collected daily from April to September and weekly from October to March during 2010 and 2011. The isotope analysis of samples reveals that the snow/glacier melt contribution to the Beas River at Manali is 50% of the total flow during these 2 years. Snowmelt runoff modelling has been carried out using the SNOWMOD model, and the snow/glacier melt runoff contribution is calculated to be 52% of the total flow during the same period. These findings indicate that the results obtained from the two approaches are similar.

Efficient Conjunctive Use of Surface and Groundwater Can Prevent Seasonal Death of Non-Glacial Linked Rivers in Groundwater Stressed Areas

The surface and groundwater system is an interdependent system. In the case of alluvial plains, they are best manifested by the relationship between a river and groundwater system. This relationship is vibrant and dynamic in rain-fed rivers or the non-glacial linked rivers. It has been typically observed that many a case such rivers originate from lesser elevation and in downstream stretches; during summers, their flow is maintained by groundwater contribution. In groundwater stressed regions, often these rivers get disconnected from aquifer. Thus there could be different levels of stream-aquifer interaction during monsoon and non monsoon seasons. In this context, the article examines effect of long-term groundwater abstraction on such river flows in a conceptual framework. It also proposes efficient conjunctive use of surface and groundwater to prevent death of such rivers.

Effect of Integrated Nutrient Management on Physico-chemical Soil Properties Under Rice Crop in Hot Sub Humid Ecoregion of Middle Gangetic Plains of India

A field experiment was conducted during Kharif season (2010) to find out the effect of integrated use of urea, zinc, poultry manure and Azotobacter on physico-chemical properties, available NPKS content of soil under rice crop (Oryza sativa L.). The experiment was laid out in Randomized Block Design (RBD) during kharif seasons with seven treatments and three replications. The details of various treatments applied to rice crop are as follows: T1 (Control); T2 (100% RDF); T3(100% RDF+ Zn); T4 (50 % RDF + 50 % N through urea); T5 (50 % N through poultry manure + 50 % N through urea + Zn); T6 (50 % N through poultry manure + 25 % N through urea+ Azotobacter); T7 (50 % N through poultry manure + 25 % N through urea + Azotobacter + Zn). The integrated use of poultry manure along with urea, zinc and Azotobacter were found to build up in organic carbon, available N, P, K and S content of soil under rice plants significantly over the sole use of chemical fertilizer. The plots which had received poultry manure and chemical fertilizers with Azotobacter showed significant improvement in residual soil fertility. It could also be concluded that the application of poultry manure with Azotobacter has good performance over sole application of manure.