水文学: 現在の研究

Flood plain morphology is intimately related to hydraulic characteristics of channel and rate of channel migration which involves in the evolution of the flood plain as well as the channel pattern. Channel migration is a complex geomorphological process driven by the interaction between fluid flow, alluvial channel beds and banks. Channel migration in alluvial flood plains involves in continuous shifting of channel position horizontaly i.e., oscillation of channel in meander belt, which can be distinguished from abrupt changes occurred by avulsion or by tectonic and climatic events. Increasing channel sinuosity results into channel migration which inturn affect the hydraulic geometry of the channel by changing the gradient, depth and width and flow velocity. Channel interchanges its plaimetry from straight to meandering with higher to a lower discharge in alluvial flood plain. Full bank discharge may have the capacity for maximum down cuts. In the upstream direction Nagar River has an average bed to bank depth 4m and in lower reaches it increases upto 5.5 m having a water depth 30cm to 1.6m respectively during pre-monsoon. Therefore, during the monsoon discharge may increase more than 3 times, which may cause valley deeping and migration too. To understand the channel shifting behaviour hydraulic properties of the river is to be explored. This paper attempts to present a detailed account of river hydraulics and channel migration to evaluate the present scenario of the Nagar River.

In the potable water sector, many decisions are based on the actual test measurement results. It is thus critical that such test results are consistently accurate, valid and reliable. From the various drinking water quality tests data, four chemical tests results and ratios, collected over a 2-year period, were evaluated for any significant correlation: Alkalinity (total) vs. Hardness, Total dissolved solids (TDS) vs. Conductivity (EC), Conductivity vs. Sodium [Na+], and Conductivity vs. Chloride [Cl-]. Of the 9 water works investigated in this preliminary study, 3 sites showed a significant correlation for all 4 comparisons, two other sites had 3 significant water quality relationships, one other site had 2 significant water quality relationships, and two other sites had 1 significant water quality relationships. The average (range) ratios were: Alkalinity/Hardness = 0.9 (0.7-1.1), TDS/EC = 6.3 (5.5-8.5), EC/ [Na+] = 1.1 (0.7-2.0) and EC/ [Cl-] = 0.8 (0.5-1.3). The derived regression equations were used to calculate the water quality parameters (Hardness using Alkalinity, Conductivity using: TDS, [Na] and [Cl-]), which were evaluated for accuracy; the percentage error was generally within ± 10% for 91% of the calculated water quality test parameters. The observed trends (ratios), per site, can be used as an additional accuracy check for the individual, analytically measured, regulatory drinking water quality tests data to facilitate decision making.

Without continual growth and progress, such words as improvement, achievement, and success have no meaning. Founded in 2010 Hydrology Current Research (ISSN: 2157-7587) is growing continuously. It is our pleasure to announce that during year 2019, all issues of volume 10 were published online on time and the print issues were also brought out and dispatched within 30 days of publishing the issue online. It is a rapid peer reviewed Journal which have a key concerns over the Environmental Sciences by exploring the best water oriented clinical research and by exhibiting this information both directly, as clinical findings, and in practice oriented formats of direct application in day-to-day situations.