Center for Environmental Sciences & Engineering

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

Global Positioning Systems (GPS) in Agriculture: applications, challenges and future trends

Sediment particles entrainment from the channel bed is influenced by flow turbulence which creates fluctuating shear stress at the bed. Sweep quadrant event is considered to be most important for entrainment of sediment particles as it exerts forces in the flow direction resulting in rolling and sliding of sediment particle. Similarly, the ejection event has been considered important for sediment transport since these events maintain the sediment particles in suspension. In this paper, the nature of bursting events and in particular, the sweep events were studied in a model of braided river with a central island. The instantaneous velocities of flow were measured using the ADV. The turbulent stresses were determined from these instantaneous velocities. Box–Cox transformation is applied to transform the original data into a normally distributed data. The velocity measurements near the braided bar were made at 12 vertical sections using an ADV. The maximum value of turbulent kinetic energy and the Reynolds shear stress was found to occur near the bed level. These turbulent parameters have greater values for scouring points, this shows that these parameters are related with the scouring near the braided bar. © 2016 Indian Society for Hydraulics.

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Civil Engineering

(SoE) School of Engineering

ISH Journal of Hydraulic Engineering

Experimental study on bursting events around a bar in physical model of a braided channel

Spatial precipitation is a major input to distributed hydrological models, and the accuracy of runoff predictions greatly depends on its accuracy. Satellite-based precipitation products are expected to offer an alternative to ground-based rainfall estimates in the present and the foreseeable future. In the present study, the suitability of tropical rainfall measuring mission (TRMM) multisatellite precipitation analysis (TMPA) rainfall in driving a distributed hydrological model for runoff prediction was evaluated. For this purpose, a hydrological model from the literature was calibrated and validated using raingauge data on daily time step for simulation of runoff in Kopili River basin (=7,198 km2) during 2003-2010. The calibrated model was then used for simulation of runoff employing specialized software and compared with the observed discharge at Kherunighat gauging site. Evaluation criteria, i.e., coefficient of correlation (CC), Nash-Sutcliffe coefficient (NSE), percent bias (PBIAS) and root mean square error (RMSE)-observations standard deviation ratio (RSR) were adopted to judge the performance of the model under different rainfall datasets. Simulation using gauge precipitation, the values of CC, NSE, PBIAS, and RSR were found to be 0.85, 0.67, 4.73, and 0.45 respectively during calibration and 092, 0.85, -1.50, and 0.29, respectively, during validation indicating overall good model performance. Furthermore, using the raw TMPA precipitation, the values of CC, NSE, PBIAS, and RSR were found to be 0.90, -5.21, 141.55, and 2.01, respectively during the period 2004 to 2007 and 0.85, -13.49, 179.89, and 2.80, respectively during simulation time period from 2008 to 2010. The moderate value of RSR indicates that the raw TMPA precipitation-based simulation represents the low flow, including rising and recession limbs fairly well, however, in case of the high-flow periods, overpredictions for all years were observed. The evaluation result concluded that the raw TRMM precipitation data are heavily biased from observed precipitation and are incompatible for daily runoff simulation in the study area and bias correction is essential for TRMM precipitation correction. However, after employing adequate bias-correction techniques, the TRMM precipitation performed well with higher degree of accuracy and can be used as an alternative to measured rainfall data due to its high spatial resolution where data are insufficient for runoff prediction, i.e., for ungauged basins. Moreover, performance of the TRMM precipitation improved when simulated in combination with the gauge precipitation. Therefore, along with the efforts to improve satellite-based precipitation-estimation techniques, it is also important to develop more-effective near-real-time precipitation bias-adjustment techniques for hydrological applications. © 2015 American Society of Civil Engineers.

Journal of Hydrologic Engineering

Evaluation of TRMM-precipitation with rain-gauge observation using hydrological model J2000

1. Genetic variability among individuals, populations and species represents the basic level of biodiversity and is a prerequisite of adaptive evolution. 2. Adaptive evolution is driven by natural selection that acts at the level of individual phenotypes. 3. Genetic variation can also be used as a tool to study the history of species and populations and to explore their current structure and reproductive strategies. 4. Genetic markers that are presumably neutral to selection are used in measuring connectivity among Baltic populations and their uniqueness compared to those in the neighbouring marine or freshwater habitats. Genetic markers have often revealed the presence of previously unknown cryptic species that are much older than the Baltic Sea. 5. In most taxa studied, some genetic differentiation has arisen post-glacially between the Baltic Sea and North Sea populations, e.g. In the Atlantic herring Clupea harengus and the Atlantic cod Gadus morhua. 6. Despite such differentiation, few of the Baltic organisms are considered as locally evolved endemic taxa. An exception is the partly asexually reproducing brown algal species Fucus radicans, which has evolved locally and now coexists with its ancestor Fucus vesiculosus in the northern Baltic Sea. 7. The unique blue mussel and Baltic clam populations in the Baltic Sea are closely related to Pacific lineages (Mytilus trossulus and Macoma balthica balthica) but are distinct from the neighbouring North Sea populations (Mytilus edulis and Macoma balthica rubra). They have been modified by interbreeding in the transition zone between the Baltic Sea and the North Sea and now constitute hybrid swarms. 8. A current methodological shift from single-gene approaches to genome-wide studies will help in distinguishing genes and patterns of variation that are affected by selection from those that merely reflect population structure and in identifying characters that account for the adaptations to the unique Baltic Sea environment.

Biological Oceanography of the Baltic Sea

Genetic diversity and evolution

India and Nepal not only share common borders and cultures, but also share precious freshwater sources, i.e., rivers. Rivers have been discussed often in the political corridors because they cross international borders, which transform water reserves into a competitive resource and lead to hydropolitical dynamics between riparian countries. Nepal and India are two of the major riparian nations that share the mighty and complex Ganges Basin. The objective here was to study the more-than-a-century-old hydro-diplomacy between India and Nepal, passing through tumultuous political scenarios to understand how water relations have been shaped and reshaped with time. For this, a database of historical individual events/actions of water cooperation and conflict from 1874 to 2014 was compiled. These events/actions were ranked by intensity, using precise definitions of conflict and cooperation as suggested by the Transboundary Freshwater Dispute Database under the Basins at Risk project formulated at Oregon State University. Statistical analyses indicated cooperative events greatly outnumbered conflictive events. Out of 351 events, only 4% were conflictive, 92% were cooperative, and the remaining 4% were neutral. The study revealed an abundance of cooperative events; however, when seen through the lens of conflict-cooperation levels, the findings indicated a moderately positive cooperation, without much concrete action. © IWA Publishing 2017.

Fulltext

Water Policy

Hydropolitics and hydropolitical dynamics between India and Nepal: An event-based study

Studies of annual peak discharge and its temporal variations are widely used in the planning and decision making process of water resources management. Very recently, soft computing techniques are gaining ground for time series analysis of hydrological events such as rainfall and runoff. In this study Artificial Neural Network (ANN) has been used in combination with wavelet to model the annual maximum flow discharge of rivers. The results of ANN-Wavelet (WANN) model indicate overall low coherence (R2 = 0.39) better than ANN (R2 = 0.31) in isolation. In the present analysis, the authors also conceded a probabilistic distributional analysis of river flow time series which has greater potential to better reflect peak flow dynamics. The results highlight that the overall performance of probability distribution models is superior to WANN model. Instead of that WANN is better than probabilistic models to find the global maxima of the series. © 2015 Faculty of Engineering, Ain Shams University

Ain Shams Engineering Journal

Computational approaches for annual maximum river flow series

Turbulent phenomenon in braided rivers is much more complex as compared to the straight and meandering rivers. Turbulent flow characteristics around the braid bar are not thoroughly studied till now. The results of measurements of three-dimensional velocities carried out in a laboratory model of braided river are presented in this paper. Velocity is measured with the help of acoustic Doppler velocimeter. The main purpose of the study is the recognition of structure of Reynolds stresses in turbulent flow near the bar. Sweep quadrant event is considered to be the most important for entrainment of sediment particles as it exerts forces in the flow direction resulting in rolling and sliding of sediment particle. Similarly, the ejection event has been considered important for sediment transport since these events maintain the sediment particles in suspension. Special attention has been given to sweep and ejection bursting events due to their relation with the sediment entrainment and transport. The fractional Reynolds stresses are examined by a quadrant technique with an arbitrarily chosen hole size. It has been observed near the bed, the largest fractional Reynolds stress contribution comes from the second quadrant and the fourth quadrant. Angle of sweep and ejection events was plotted against the flow depth, in order to relate the sweep and ejection events with the scouring/depositional pattern around the bar. The maximum residence time of each event is also computed. From computation, it was found that the maximum residence time of the even events is much greater than for the odd events near the bed. In order to examine the depth-wise distribution of turbulent flow, Reynolds stress and higher moment Fku are plotted against the flow depth. These parameters assess the sediment characteristics in the vicinity of the bar. Results show that the Fku parameter better assesses the sediment characteristics of flow around the bar. © 2017 Indian Society for Hydraulics.

Analysis of turbulent flow characteristics in the vicinity of the bar in a braided river model

To support the GPM mission which is homologous to its predecessor, the Tropical Rainfall Measuring Mission (TRMM), this study has been undertaken to evaluate the accuracy of Tropical Rainfall Measuring Mission multi-satellite precipitation analysis (TMPA) daily-accumulated precipitation products for 5 years (2008–2012) using the statistical methods and contingency table method. The analysis was performed on daily, monthly, seasonal and yearly basis. The TMPA precipitation estimates were also evaluated for each grid point i.e. 0.25° × 0.25° and for 18 rain gauge stations of the Betwa River basin, India. Results indicated that TMPA precipitation overestimates the daily and monthly precipitation in general, particularly for the middle sub-basin in the non-monsoon season. Furthermore, precision of TMPA precipitation estimates declines with the decrease of altitude at both grid and sub-basin scale. The study also revealed that TMPA precipitation estimates provide better accuracy in the upstream of the basin compared to downstream basin. Nevertheless, the detection capability of daily TMPA precipitation improves with increase in altitude for drizzle rain events. However, the detection capability decreases during non-monsoon and monsoon seasons when capturing moderate and heavy rain events, respectively. The veracity of TMPA precipitation estimates was improved during the rainy season than during the dry season at all scenarios investigated. The analyses suggest that there is a need for better precipitation estimation algorithm and extensive accuracy verification against terrestrial precipitation measurement to capture the different types of rain events more reliably over the sub-humid tropical regions of India. © 2016, Springer-Verlag Wien.

Theoretical and Applied Climatology

Evaluation of TRMM multi-satellite precipitation analysis (TMPA) against terrestrial measurement over a humid sub-tropical basin, India

23rd Canadian Hydrotechnical Conference, Held as part of the Canadian Society for Civil Engineering Annual Conference and General Meeting 2017

Development and field application of the RCC Jack Jetty for river training

Rapid increases in demand for food and energy as a result of population growth and economic development is placing ever increasing demands on limited water resources in South Asia, and climate change is expected further complicate water resource management. In spite of important reductions in poverty levels in recent decades the region is still home to a very large number of poor whose quality of life is directly affected by the availability and quality of water and water services. A significant fraction of the water resources of the region and a significant fraction of the poor are associated with major Himalayan transboundary rivers, and given growing water demand it is likely that the already significant sensitivity around water cooperation amongst co-riparians will increase. Understanding the risks and opportunities for transboundary cooperation in the river systems in South Asia is thus important for guiding sustainable transboundary basin management in the region. This study refines a novel method for a rapid assessment of these cooperation risks and opportunities and applies it to the Brahmaputra, Ganges and Indus river basins to test its utility. The method employs a fuzzy synthetic evaluation technique that combines fuzzy logic and an analytical hierarchy process to assess cooperation risk and opportunity in terms of a Risk-Opportunity Index (ROI). The ROI is a function of four composite development variables and three hegemony variables that indicate the various pressures on the basin water resource and the different control strategies riparians could adopt given existing power asymmetries. In the absence of a clear rationale for differential weighting, equal weights were assigned to all seven variables for this application. A “defuzzification” scoring method is used to define compromising, risk-averse and risk-taking variants of ROI for riparian pairs within each basin. Overall, the results for the compromising ROI suggest that the opportunities for bilateral cooperation are highest (and risks the lowest) in the Brahmaputra Basin and the opportunities are lowest (and the risks highest) in the Indus Basin. This overall assessment is consistent with current common perception. Within the basins the compromising ROI values suggest a few instances of high risk and/or low opportunity, as well as an approximately equal number of instances of medium risk/opportunity and low risk/high opportunity. The study demonstrates that the fuzzy synthetic evaluation technique has utility for rapidly identifying potential opportunities for riparian cooperation in transboundary basins, in order to guide dialogue processes and more detailed analyzes. The study also however, reveals some aspects of the method where further refinement would likely yield more reliable assessments of cooperation risks and opportunities. Specifically, further refinements could consider the relative geographic position of co-riparians within a basin, and the relative resource access of different riparians. The method only considers bilateral riparian interactions and not more complex multi-lateral interactions. The results of study may contribute to various ongoing regional and basin dialogues on water cooperation in South Asia. © 2017, Springer Science+Business Media Dordrecht.