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

For 2-D simulation of curvilinear flow field, use of momentum equations involves flow dispersion stress terms. Dispersion Stress terms take into account the effect of secondary flow variation arisen due to integration of the product of discrepancy between depth averaged velocity and the true velocity distributions. The objective of this paper is to present empirical mathematical functions to evaluate these terms. These terms can be incorporated in the 2D depth averaged flow equations as an additional source/sink term. In this work, the derivation is done to get revised set of empirical relations are later used in development of enhanced 2D numerical model. When compared with earlier investigations, the proposed formulations are simplified and numerically compatible. It is expected that modified formulation for flow dispersion stress tensor will lead to more realistic and improved simulation of flow field in curved flow domain. © 2019 IOP Publishing Ltd. All rights reserved.

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IOP Conference Series: Materials Science and Engineering

Mathematical model development of modified flow dispersion stress tensor in 2-D curvilinear flow domain

Forests are the potential source for managing carbon sequestration, regulating climate variations and balancing universal carbon equilibrium between sources and sinks. Further, assessment of biomass, carbon stock, and its spatial distribution is prerequisite for monitoring the health of forest ecosystem. Moreover, vegetation field inventories are valuable source of data for estimating aboveground biomass (AGB), density, and the carbon stored in biomass of forest vegetation. In view of the importance of biomass, the present study makes an attempt to estimate temporal AGB of Tripura State, India, using Moderate Resolution Imaging Spectroradiometer (MODIS), normalized difference vegetation index (NDVI), leaf area index (LAI) and the field inventory data through geospatial techniques. A model was developed for establishing the relationship between biomass, LAI, and NDVI in the selected study site. The study also aimed to improve method for quantifying and verifying inventory-based biomass stock estimation. The results demonstrate the correlation value obtained between LAI and NDVI were 0.87 and 0.53 for the years 2011 and 2014, respectively. The correlation value between estimated AGB with LAI were found as 0.66 and 0.69, while with NDVI, the values were obtained as 0.64 and 0.94 for the years 2011 and 2014, respectively. The regression model of measured biomass with MODIS NDVI and LAI was developed for the data obtained during the period 2011–2014. The developed model was used to estimate the spatial distribution of biomass and its relationship between LAI and NDVI. The R2 values obtained were 0.832 for estimated and the measured AGB during the training and 0.826 for the validation. The results indicate that the methodology adopted in this study can help in selecting best fit model for analyzing relationship between AGB and NDVI/LAI and for estimating biomass using allometric equation at various spatial scales. The developed output thematic map showed an average biomass distribution of 32–94 Mg ha−1. The highest biomass values (72–95 Mg ha −1) was confined to the dense region of the forest while the lowest biomass values (32–46 Mg ha−1) was identified in the outer regions of the study site. © 2019, Springer Nature Switzerland AG.

Environmental Monitoring and Assessment

Forest biomass estimation using remote sensing and field inventory: a case study of Tripura, India

Farmers, agencies, agricultural research community and firms require access to tools to analyze and estimate stressed and productive regions to obtain higher yield. At present, this is performed manually using visual interpretation. Recently there has been some development in the detection and mapping of the stressed crop by use of hyperspectral analysis; but, there is an information gap between farmers and information about the location of the crop under stress in the given area. There is an urgent need to provide a robust solution to identify the stressed region in the agricultural area. To address this, a unique application called as VegNet (Vegetative-Network) has been developed, which aims to provide the necessary tools to detect stressed crop locations using the spectral images obtained from UAVs, and provide stressed crops condition, location and area covered by those stressed crops. In this paper, a combination of spectral vegetation indices techniques has been highlighted to produce a comprehensive solution for precision agriculture using a UAV and VegNet. This incorporates several algorithms; segmentation, Canny-edge detector, dilation, gap-filling, image extraction and locating the stressed region using spectral modelling based Graphical User Interface (GUI) application for precision agriculture, societal benefit and Environmental research. © 2019 Elsevier B.V.

Remote Sensing Applications: Society and Environment

UAVs technology for the development of GUI based application for precision agriculture and environmental research

The very geography of Nepal and India is such that these two countries must engage with each other in social, economic, and political spheres; water resources is one of the most important spheres. This study reviews the experience of cooperation in the Kosi basin between India and Nepal, focusing on the perceptions of risks and opportunities by decision makers. The following five categories of risk are examined at four tipping points, 1954, 1966, 1991, and 2015: capacity and knowledge, accountability and voice, sovereignty and autonomy, equity and access, and stability and support. The study provides deeper insights about the perceived risks as far as negotiations on the proposed Kosi high dam are considered. The perceived risks have grown significantly from 1954 to 2015 for Nepal as compared to India. In 2015, Nepal has all five categories of perceived risks. The study also proposes risk reduction strategies to reduce the level of perceived risks for both Nepal and India, which is an area of future research. The study may facilitate the negotiation process for the Kosi High Dam Project leading to mutually agreed win-win solutions for both riparian countries. © 2019 American Society of Civil Engineers.

Journal of Water Resources Planning and Management

Perceived Risk of Cooperation between India and Nepal on the Kosi River

Environment and Ecology 37 (3B)

Gregarious colonization of Tribulus terrestris L.(Puncture Vine): Ecological implications

Modern Phytomorphology

Occurrence of Symphyotrichum squamatum ( Spreng .) G . L . Nesom in Uttar Pradesh , India : A new record

Soil moisture represents a vital component of the ecosystem, sustaining life-supporting activities at micro and mega scales. It is a highly required parameter that may vary significantly both spatially and temporally. Due to this fact, its estimation is challenging and often hard to obtain especially over large, heterogeneous surfaces. This study aimed at comparing the performance of four widely used interpolation methods in estimating soil moisture using GPS-aided information and remote sensing. The DistanceWeighting (IDW), Spline, Ordinary Kriging models and Kriging with External Drift (KED) interpolation techniques were employed to estimate soil moisture using 82 soil moisture field-measured values. Of those measurements, data from 54 soil moisture locations were used for calibration and the remaining data for validation purposes. The study area selected was Varanasi City, India covering an area of 1535 km2. The soil moisture distribution results demonstrate the lowest RMSE (root mean square error, 8.69\%) for KED, in comparison to the other approaches. For KED, the soil organic carbon information was incorporated as a secondary variable. The study results contribute towards efforts to overcome the issue of scarcity of soil moisture information at local and regional scales. It also provides an understandable method to generate and produce reliable spatial continuous datasets of this parameter, demonstrating the added value of geospatial analysis techniques for this purpose. © 2019 by the authors.

Resources

GIS and remote sensing aided information for soil moisture estimation: A comparative study of interpolation techniques

Turbulent flow characteristics around the braid bar are not thoroughly studied till now. In the current paper, the quadrant method is used to analyze the turbulence characteristics of flow around the island in a braided river model. An attempt has been made herein to relate the depositional characteristics around the island in the braided river model to the sweep and ejection events. The new parameter bursting ratio is defined in this paper; it is observed that the bursting ratio is strongly related with the erosion/deposition characteristics around the island in a braided river model. The transition probability of 16 possible bursting movements are computed for four different experimental condition, the results shows that the, movements are closely related with the erosion/deposition magnitude around the bar in a braided river model. The values of sweep ratio and ejection ratio at 12 different points around the island for four different experimental conditions are computed using Box Cox analysis. The results found that the sweep and ejection ratio have positive linear correlation with scouring/ deposition magnitude, thus sweep and ejection ratio are important parameters which are related to the scouring/ deposition magnitude around the island in a braided river model. © 2017 Indian Society for Hydraulics.