scholarly journals Numerical modelling of dynamic flood topographies in the Terai region, Nepal.

2020 ◽  
Author(s):  
Maggie J. Creed ◽  
Elizabeth H. Dingle ◽  
Hugh D. Sinclair ◽  
Dilip Gautam ◽  
Noel Gourmelen ◽  
...  
Keyword(s):  
Prediction Models ◽  
Flood Hazard ◽  
Field Measurements ◽  
Channel Switching ◽  
Gangetic Plain ◽  
Flood Prediction ◽  
Bed Elevation ◽  
Inundation Extent ◽  
Indo Gangetic Plain ◽  
Global Population

<p>Rivers sourced from the Himalayas support ~10% of the global population living on the Indo-Gangetic Plain. These rivers can be a source of devastating floods. Flood hazard maps used to inform early warnings systems in the Terai region in southern Nepal are based on static, outdated DEMs, which may not reflect the current river and floodplain topography. Sediment dynamics can change the river course and the distribution of flow down large bifurcation nodes, affecting flood inundation extent. These processes are rarely considered in flood prediction models for this region. In this study, using a 2D depth-averaged hydrodynamic model, several flood scenarios for the Karnali River are investigated, including different DEMs, variable bed elevations, and a scenario with bed levels modified at an important bifurcation node to reflect field observations. Inundation extent varied by upto 14% between scenarios for a 1-in-20 year flood discharge. Our results suggest that combining regular field measurements of bed elevation, with updated DEMs, could help to improve future flood prediction maps. Updating model input parameters is particularly important following large flood events and/or large landslides in the upstream catchment, which could increase bed aggradation and provoke channel switching in highly mobile, alluvial river systems.</p>

scholarly journals FLOOD HAZARD ASSESSMENT AND DELIMITATION OF THE LIKELY FLOOD HAZARD ZONES OF THE UPPER PART IN GALLIKOS RIVER BASIN

2017 ◽  
Vol 50 (2) ◽  
pp. 995 ◽  
Author(s):  
I. Tsitroulis ◽  
K. Voudouris ◽  
A. Vasileiou ◽  
C. Mattas ◽  
Μ. Sapountzis ◽  
...  
Keyword(s):  
River Basin ◽  
Prediction Models ◽  
Flood Hazard ◽  
Human Life ◽  
Meteorological Data ◽  
Flood Management ◽  
Flood Prediction ◽  
Management Framework ◽  
Inundation Maps ◽  
Software Packages

Floods are one of the most common natural hazards in global range and could threat the human life, health, environment and infrastructure. The aim of this paper is the estimation and the delimitation of the likely flood hazard zones, for different rainfall intensities in the upper part of Gallikos river basin (central Macedonia) according to the European directive 2007/60. For the analysis of the meteorological data and the construction of flood zone maps, HYDROGNOMON, HEC-HMS, HEC-RAS free software packages were used. The thematic maps were constructed with ESRI GIS. The results are depicted in flood inundation maps, delimitating and visualizing the scale of the flood hazard effect in the area. The construction of flood prediction models is a very useful tool towards the direction of the design of an efficient flood management framework.

scholarly journals Geomorphology, sedimentology, and hazard assessment of the Sapta Koshi alluvial fan in eastern Nepal

2002 ◽  
Vol 27 ◽  
Author(s):  
Pramod Kumar Thakur ◽  
Naresh Kazi Tamrakar
Keyword(s):  
Hazard Assessment ◽  
Flood Hazard ◽  
Fine Sand ◽  
Alluvial Fan ◽  
Gangetic Plain ◽  
Radial Length ◽  
Channel Shifting ◽  
Hazard Level ◽  
Geomorphic Surfaces ◽  
Indo Gangetic Plain

The Sapta Koshi River that is known for exceptionally high sediment-carrying and channel-shifting nature forms a broad alluvial fan into the Indo-Gangetic Plain after its emergence from the Siwalik Hills. The Sapta Koshi alluvial fan has a radial length of about 45 km and width of about 15 km in the Nepalese territory, where it forms a proximal to midfan segment extending from NE to SW, showing various geomorphic surfaces characterised by gravel to fine sand and mud lithofacies associations. The alluvial fan deposits are of Holocene epoch, and are unconsolidated and vulnerable to rapid erosion. Flooding, river oscillation and soil erosion are the main environmental problems in the alluvial fan region. The flood hazard assessment was made using criteria such as slope, relative relief, distance from the active channel and its shifting pattern, engineering protection-structures, and man-induced activities. The alluvial fan region was zoned into three hazard levels such as high, medium and low. The western bank of the Sapta Koshi River, around Balardaha. Bhardaha, and HanumanNagar are identified to be highly prone to flooding and waterlogging. Man-induced activities play important role in increasing the hazard level in these areas. Therefore, short- and long-termed preventive measures have been suggested.

scholarly journals Seasonal distribution and drivers of surface fine particulate matterand organic aerosol over the Indo-Gangetic Plain

2021 ◽  
Author(s):  
Caterina Mogno ◽  
Paul I. Palmer ◽  
Christoph Knote ◽  
Fei Yao ◽  
Timothy J. Wallington
Keyword(s):  
Crop Production ◽  
Large Fraction ◽  
Fine Particulate Matter ◽  
Organic Aerosol ◽  
Seasonal Distribution ◽  
Agricultural Crop ◽  
Gangetic Plain ◽  
Fine Particulate ◽  
Indo Gangetic Plain ◽  
Global Population

Abstract. The Indo-Gangetic Plain (IGP) is home to 6 % of the global population and is responsible for a large fraction of agricultural crop production in Pakistan, India, and Bangladesh. Levels of fine particulate matter (mean diameter

Severe air pollution and characteristics of light-absorbing particles in a typical rural area of the Indo-Gangetic Plain

2020 ◽  
Vol 27 (10) ◽  
pp. 10617-10628 ◽  
Author(s):  
Pengfei Chen ◽  
Shichang Kang ◽  
Lekhendra Tripathee ◽  
Arnico K. Panday ◽  
Maheswar Rupakheti ◽  
...  
Keyword(s):  
Air Pollution ◽  
Rural Area ◽  
Gangetic Plain ◽  
Indo Gangetic Plain

scholarly journals Observations of Tidal Flat Sedimentation within a Native and an Exotic Spartina Species

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1566
Author(s):  
Barbara Proença ◽  
Florian Ganthy ◽  
Richard Michalet ◽  
Aldo Sottolichio
Keyword(s):  
Single Point ◽  
Field Measurements ◽  
Species Variation ◽  
Storm Events ◽  
Level Variation ◽  
Wave Forcing ◽  
Bed Elevation ◽  
Sediment Stabilization ◽  
Consistent Response

Field measurements of bed elevation and related wave events were performed within a tidal marsh, on two cordgrass species, Spartina anglica (exotic) and Spartina maritima (native), in the Bay of Arcachon (SW France). Bed- and water-level time series were used to infer on the sediment behavior patterns from short to long term. A consistent response was found between the bed-level variation and the wave forcing, with erosion occurring during storms and accretion during low energy periods. Such behavior was observed within the two species, but the magnitude of bed-level variation was higher within the native than the exotic Spartina. These differences, in the order of millimeters, were explained by the opposite allocation of biomass of the two species. On the long term, the sedimentation/erosion patterns were dominated by episodic storm events. A general sediment deficit was observed on the site, suggested by an overall bed-level decrease registered within both species. However, further verification of within species variation needs to be considered when drawing conclusions. Despite possible qualitative limitations of the experimental design, due to single point survey, this work provides original and considerable field data to the understanding the different species ability to influence bed sediment stabilization and their potential to build marsh from the mudflat pioneer stage. Such information is valuable for coastal management in the context of global change.

scholarly journals Comparing and Evaluating Macao Flood Prediction Models

2021 ◽  
Vol 769 (2) ◽  
pp. 022001
Author(s):  
Zeyu Zhang ◽  
Jiayue Qiu ◽  
Xuefei Huang ◽  
Zhiming Cai ◽  
Linkai Zhu ◽  
...  
Keyword(s):  
Prediction Models ◽  
Flood Prediction

scholarly journals Impact of Integrated Agronomic Practices on Soil Fertility and Respiration on the Indo-Gangetic Plain of North India

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 402
Author(s):  
Rama Kant Dubey ◽  
Pradeep Kumar Dubey ◽  
Rajan Chaurasia ◽  
Ch Srinivasa Rao ◽  
Purushothaman Chirakkuzhyil Abhilash
Keyword(s):  
Soil Respiration ◽  
Soil Quality ◽  
Mycorrhizal Fungi ◽  
Field Experiments ◽  
Block Design ◽  
North India ◽  
Gangetic Plain ◽  
Agronomic Practices ◽  
Soil Sustainability ◽  
Indo Gangetic Plain

Global agricultural production is accountable for the emission of ~30% of greenhouse gases. Therefore, the wide-scale adoptions of low-input, soil-friendly, and resource-conserving agronomic practices are imperative for the ‘planet healthy food production’ and also for reducing the carbon emissions from agricultural soil. In this context, the present study aimed to analyze the impacts of integrated agronomic interventions i.e., the application of arbuscular mycorrhizal fungi (AMF) + reduced tillage (RT), biochar + RT, and AMF + biochar + RT, on spatiotemporal variations in soil-quality and soil-sustainability indicators, including microbial and soil respiration, in the Indo-Gangetic Plain (IGP) of North India. For this, field experiments on the above-mentioned agronomic interventions were employed using three different staple crops (Zea mays, Vigna mungo, and Brassica juncea) growing in three different agro-climatic zones of IGP (Varanasi, Sultanpur, and Gorakhpur) in a randomized block design. Periodic data collection was done to analyze the changes in physiochemical, biological, and biochemical properties of the soil, and statistical analyses were done accordingly. Irrespective of the sites, the experimental results proved that the integrated application of AMF + biochar + RT in V. mungo resulted in the highest soil organic carbon (i.e., 135% increment over the control) and microbial biomass carbon (24%), whereas the same application (i.e., AMF + biochar + RT) in Z. mays had the maximum reduction in microbial (32%) and soil (44%) respiration. On the other hand, enhanced occurrence of glomalin activity (98%) was noted in Z. mays cropping for all the sites. Significant negative correlation between soil respiration and glomalin activity under AMF + biochar + RT (−0.85), AMF + RT (−0.82), and biochar + RT (−0.62) was an indication of glomalin’s role in the reduced rate of soil respiration. The research results proved that the combined application of AMF + biochar + RT was the best practice for enhancing soil quality while reducing respiration. Therefore, the development of suitable packages of integrated agronomic practices is essential for agricultural sustainability.

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