scholarly journals Improvements in Sub-Catchment Fractional Snowpack and Snowmelt Parameterizations and Hydrologic Modeling for Climate Change Assessments in the Western Himalayas

Hydrology ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 179
Author(s):  
Vishal Singh ◽  
Francisco Muñoz-Arriola
Keyword(s):  
Assessment Tool ◽  
Circulation Model ◽  
High Elevation ◽  
Primary Objective ◽  
Lapse Rate ◽  
Western Himalayas ◽  
Global Circulation Model ◽  
Catchment Scale ◽  
Hydrological Parameters ◽  
Satluj River

The present work proposes to improve estimates of snowpack and snowmelt and their assessment in the steep Himalayan ranges at the sub-catchment scale. Temporal variability of streamflow and the associated distribution of accumulated snow in catchments with glacier presence in the Himalayas illustrates how changes in snowpack and snowmelt can affect the water supply for local water management. The primary objective of this study is to assess the role of elevation, temperature lapse rate (TLR), and precipitation lapse rate (PLR) in the computation of snowpack (or snowfall) and snowmelt in sub-catchments of the Satluj River basin. Modeling of snowpack and snowmelt was constructed using the Soil Water Assessment Tool (SWAT) in both historical (1991–2008) and near-time scenarios (2011–2030) by implementing real-time hydrometeorological, snow-hydrological parameters, and Global Circulation Model (GCM) datasets. The modeled snowmelt-induced streamflow showed a good agreement with the observed streamflow (~60%), calibrated and validated at three gauges. A Sequential Uncertainty Parameter Fitting (SUFI2) method (SUFI2) resulted that the curve number (CN2) was found to be significantly sensitive during calibration. The snowmelt hydrological parameters such as snowmelt factor maximum (SMFMX) and snow coverage (SNO50COV) significantly affected objective functions, such as R2 and NSE, during the model optimization. For the validation of snowpack and snowmelt, the results have been contrasted with previous studies and found comparable. The computed snowpack and snowmelt were found highly variable over the Himalayan sub-catchments, as also reported by previous researchers. The magnitude of snowpack change consistently decreases across all the sub-catchments of the Satluj river catchment (varying between 4% and 42%). The highest percentage of changes in the snowpack was observed over high-elevation sub-catchments.

scholarly journals Sub catchment Assessment of snowpack and snowmelt change by analyzing elevation bands and parameter sensitivity in the high Himalayas

2017 ◽  
Author(s):  
Vishal Singh ◽  
Manish Kumar Goyal ◽  
Rao Y. Surampalli ◽  
Francisco Munoz-Arriola
Keyword(s):  
Assessment Tool ◽  
Swat Model ◽  
Circulation Model ◽  
Parameter Sensitivity ◽  
Snow Accumulation ◽  
Sensitivity Analyses ◽  
River Catchment ◽  
Hydrological Parameters ◽  
Streamflow Generation ◽  
Satluj River

Abstract. The present work proposes to improve estimates of how much streamflow is generated by snow in the watersheds of the steep Himalayas. Half of the earth’s glacial catchments in nonpolar areas are in the Himalayas, and they generate almost a third of the streamflows in India. In River catchments with glacier presence in the region, temporal variability in streamflow generation and the associated distribution of accumulated snow illustrate how changes in snowmelt and precipitation can affect water supplies to a growing population of 1.3 billion people. Estimations of snowpack and snowmelt in watersheds are critical for understanding streamflow generation and sources of catchments. However, estimating precipitation and snow accumulation is constrained by the difficulties complex terrain poses to data collection. The primary objective of this study is to assess the role of elevations in the computation of snowfall (snowpack) and snowmelt in sub-catchments. The study area is the Satluj River Catchment (up to Kasol gauge) with moderate (e.g., 526 m) to very high elevations (e.g., 7429 m) dominated by snow covers and glaciers. The Satluj River Catchment was divided into 14 sub-catchments. Snowpack and snowmelt variations in the sub-catchments in both historical and projected near-term (2011–2130) periods were analyzed using observed and Global Circulation Model (GCM) data sets. Both hydrological scenarios used elevation bands and parameter-sensitivity analyses built in the Soil Water Assessment Tool (SWAT) model. For model calibration/validation and parameter sensitivity analysis, an advanced optimization method — namely, Sequential Uncertainty Fitting (SUFI2) approach was used with multiple hydrological parameters. Among all parameters, the curve number (CN2) was found significantly sensitive for computations. The snowmelt hydrological parameters such as snowmelt factor maximum (SMFMX) and snow coverage (SNO50COV) significantly affected objective functions such as R2 and NSE during the model optimization process. The computed snowpack and snowmelt were found highly variable over the Himalayan sub-catchments as also reported by previous researchers in other regions. The magnitude of snowpack change consistently decreases across all the sub-catchments of the Satluj River Catchment (varying between 4 % and 42 %). The highest percentage of changes in snowpack was observed over high-elevation subcatchments.

Modeling the response of non-perennial streams to climate change impact: The Bouregreg watershed in Morocco

2021 ◽  
Author(s):  
Anna Maria De Girolamo ◽  
Youssef Brouziyne ◽  
Lahcen Benaabidate ◽  
Aziz Aboubdillah ◽  
Ali El Bilali ◽  
...  
Keyword(s):  
Climate Change ◽  
Assessment Tool ◽  
Swat Model ◽  
Circulation Model ◽  
Hybrid Modeling ◽  
Climate Data ◽  
Global Circulation Model ◽  
Stream Network ◽  
Modeling Framework ◽  
Modeling Approach

<p>The non-perennial streams and rivers are predominant in the Mediterranean region and play an important ecological role in the ecosystem diversity in this region. This class of streams is particularly vulnerable to climate change effects that are expected to amplify further under most climatic projections. Understanding the potential response of the hydrologic regime attributes to climatic stress helps in planning better conservation and management strategies. Bouregreg watershed (BW) in Morocco, is a strategic watershed for the region with a developed non-perennial stream network, and with typical assets and challenges of most Mediterranean watersheds. In this study, a hybrid modeling approach, based on the Soil and Water Assessment Tool (SWAT) model and Indicator of Hydrologic Alteration (IHA) program, was used to simulate the response of BW's stream network to climate change during the period: 2035-2050. Downscaled daily climate data from the global circulation model CNRM-CM5 were used to force the hybrid modeling framework over the study area. Results showed that, under the changing climate, the magnitude of the alteration will be different across the stream network; however, almost the entire flow regime attributes will be affected. Under the RCP8.5 scenario, the average number of zero-flow days will rise up from 3 to 17.5 days per year in some streams, the timing of the maximum flow was calculated to occur earlier by 17 days than in baseline, and the timing of the minimal flow should occur later by 170 days in some streams. The used modeling approach in this study contributed in identifying the most vulnerable streams in the BW to climate change for potential prioritization in conservation plans.</p>

scholarly journals Future streamflow simulation in a snow-dominated Rocky Mountain headwater catchment

2017 ◽  
Vol 49 (4) ◽  
pp. 1172-1190
Author(s):  
Ram P. Neupane ◽  
Jan F. Adamowski ◽  
Joseph D. White ◽  
Sandeep Kumar
Keyword(s):  
Assessment Tool ◽  
Circulation Model ◽  
Rocky Mountain ◽  
Baseline Period ◽  
Global Circulation Model ◽  
Global Circulation ◽  
Seasonal Flow ◽  
The Future ◽  
Variable Precipitation ◽  
Headwater Catchment

Abstract The Rocky Mountains in North America are comprised of headwater snow catchments that provide sustained seasonal flow downstream. Changes in streamflow over the last half century in these basins may be associated with changing climate with increased temperature and variable precipitation, shifting seasonal hydrology. We investigated potential changes in future hydrology in a Rocky Mountain headwater catchment by simulating water budgets of the Athabasca River located in Jasper National Park, Canada. Potential hydrologic changes were predicted using a calibrated version of the Soil and Water Assessment Tool (SWAT). Future discharge and other parts of the catchment water budget were projected based on the global circulation model (GCM) derived from the Special Report on Emission Scenarios (SRES) for the latter part of the century (2081–2099). A projected decrease in future precipitation resulted in reduced mean annual streamflow, by up to 86%, compared to the baseline period for the catchment. Projected summer streamflow decreased from 58 to 39%. Streamflow increased from 13 to 26% during the spring, dampening the dominance of summer peak-flow hydrology. Colder winters for the future scenarios increase the overall proportion of precipitation as winter snowfall. However, dramatically lower precipitation estimated for this basin will drive water limits for the future.

scholarly journals Assessing Hydrological Vulnerability to Future Droughts in a Mediterranean Watershed: Combined Indices-Based and Distributed Modeling Approaches

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2333
Author(s):  
Youssef Brouziyne ◽  
Aziz Abouabdillah ◽  
Abdelghani Chehbouni ◽  
Lahoucine Hanich ◽  
Karim Bergaoui ◽  
...  
Keyword(s):  
Water Resource Management ◽  
Assessment Tool ◽  
Swat Model ◽  
Circulation Model ◽  
Distributed Model ◽  
Drought Indices ◽  
Global Circulation Model ◽  
Distributed Modeling ◽  
Combined Indices ◽  
Annual Water

Understanding the spatiotemporal distribution of future droughts is essential for effective water resource management, especially in the Mediterranean region where water resources are expected to be scarcer in the future. In this study, we combined meteorological and hydrological drought indices with the Soil and Water Assessment Tool (SWAT) model to predict future dry years during two periods (2035–2050and 2085–2100) in a typical Mediterranean watershed in Northern Morocco, namely, Bouregreg watershed. The developed methodology was then used to evaluate drought impact on annual water yields and to identify the most vulnerable sub-basins within the study watershed. Two emission scenarios (RCP4.5 and RCP8.5) of a downscaled global circulation model were used to force the calibrated SWAT model. Results indicated that Bouregreg watershed will experience several dry years with higher frequency especially at the end of current century. Significant decreases of annual water yields were simulated during dry years, ranging from −45.6% to −76.7% under RCP4.5, and from −66.7% to −95.6% under RCP8.5, compared to baseline. Overall, hydrologic systems in sub-basins under the ocean or high-altitude influence appear to be more resilient to drought. The combination of drought indices and the semi-distributed model offer a comprehensive tool to understand potential future droughts in Bouregreg watershed.

scholarly journals Impact of climate change on the hydrology of a semi-arid river basin of India under hypothetical and projected climate change scenarios

2020 ◽  
Author(s):  
Sujeet Desai ◽  
D. K. Singh ◽  
Adlul Islam ◽  
A. Sarangi
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Assessment Tool ◽  
Circulation Model ◽  
Central India ◽  
Coefficient Of Determination ◽  
Climate Change Scenarios ◽  
Global Circulation Model ◽  
Calibration And Validation ◽  
Semi Arid

Abstract Climate change impact on the hydrology of the Betwa river basin, located in the semi-arid region of Central India, was assessed using the Soil and Water Assessment Tool (SWAT), driven by hypothetical scenarios and Model of Interdisciplinary Research on Climate version 5 (MIROC5) Global Circulation Model projections. SWAT-Calibration and Uncertainty Programs (SWAT-CUP) was used for calibration and validation of SWAT using multi-site streamflow data. The coefficient of determination, Nash–Sutcliffe efficiency, RMSE-observations standard deviation ratio and percent bias during calibration and validation period varied from 0.83–0.92, 0.6–0.91, 0.3–0.63 and −19.8–19.3, respectively. MIROC5 projections revealed an increase in annual mean temperature in the range of 0.7–0.9 °C, 1.2–2.0 °C and 1.1–3.1 °C during the 2020s, 2050s, and 2080s, respectively. Rainfall is likely to increase in the range of 0.4–9.1% and 5.7–15.3% during the 2050s and 2080s, respectively. Simulation results indicated 3.8–29% and 12–48% increase in mean annual surface runoff during the 2050s and 2080s, respectively. Similarly, an increase of 0.2–3.0%, 2.6–4.2% and 3.5–6.2% in mean annual evapotranspiration is likely during the 2020s, 2050s and 2080s, respectively. These results could be used for developing suitable climate change adaptation plans for the river basin.

scholarly journals A Comparative Evaluation of a Mesoscale Model and Atmospheric Global Circulation Model for Air Quality Simulation: A Multiscale, Multisite Evaluation

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
P. Goswami ◽  
J. Baruah
Keyword(s):  
High Resolution ◽  
Mesoscale Model ◽  
Large City ◽  
Circulation Model ◽  
Urban Pollution ◽  
Atmospheric Pollutants ◽  
Scale Model ◽  
Global Circulation Model ◽  
Global Circulation ◽  
Meso Scale

Concentrations of atmospheric pollutants are strongly influenced by meteorological parameters like rainfall, relative humidity and wind advection. Thus accurate specifications of the meteorological fields, and their effects on pollutants, are critical requirements for successful modelling of air pollution. In terms of their applications, pollutant concentration models can be used in different ways; in one, short term high resolution forecasts are generated to predict and manage urban pollution. Another application of dynamical pollution models is to generate outlook for a given airbasin, such as over a large city. An important question is application-specific model configuration for the meteorological simulations. While a meso-scale model provides a high-resolution configuration, a global model allows better simulation of large-sale fields through its global environment. Our objective is to comparatively evaluate a meso-scale atmospheric model (MM5) and atmospheric global circulation model (AGCM) in simulating different species of pollutants over different airbasins. In this study we consider four locations: ITO (Central Delhi), Sirifort (South Delhi), Bandra (Mumbai) and Karve Road (Pune). The results show that both the model configurations provide comparable skills in simulation of monthly and annual loads, although the skill of the meso-scale model is somewhat higher, especially at shorter time scales.

scholarly journals THOR: A NEW AND FLEXIBLE GLOBAL CIRCULATION MODEL TO EXPLORE PLANETARY ATMOSPHERES

2016 ◽  
Vol 829 (2) ◽  
pp. 115 ◽  
Author(s):  
João M. Mendonça ◽  
Simon L. Grimm ◽  
Luc Grosheintz ◽  
Kevin Heng
Keyword(s):  
Circulation Model ◽  
Planetary Atmospheres ◽  
Global Circulation Model ◽  
Global Circulation

scholarly journals True dipole wander

2018 ◽  
Vol 215 (3) ◽  
pp. 1523-1529
Author(s):  
Peter Olson ◽  
Maylis Landeau ◽  
Evan Reynolds
Keyword(s):  
Circulation Model ◽  
Global Circulation Model ◽  
Polar Wander ◽  
Global Circulation ◽  
True Polar Wander ◽  
Symmetric Pattern ◽  
Asymmetric Pattern ◽  
Heterogeneous Mantle ◽  
Geocentric Axial Dipole ◽  
Geomagnetic Dipole

SUMMARY A fundamental assumption in palaeomagnetism is that the geomagnetic field closely approximates a geocentric axial dipole in time average. Here we use numerical dynamos driven by heterogeneous core–mantle boundary heat flux from a mantle global circulation model to demonstrate how mantle convection produces true dipole wander, rotation of the geomagnetic dipole on geologic timescales. Our heterogeneous mantle-driven dynamos show a dipole rotation about a near-equatorial axis in response to the transition in lower mantle heterogeneity from a highly asymmetric pattern at the time of supercontinent Pangea to a more symmetric pattern today. This predicted dipole rotation overlaps with a palaeomagnetically inferred rotation in the opposite direction and suggests that some events previously interpreted as true polar wander also include true dipole wander.

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