scholarly journals Are General Circulation Models Ready for Operational Streamflow Forecasting for Water Management in the Ganges and Brahmaputra River Basins?

2015 ◽  
Vol 17 (1) ◽  
pp. 195-210 ◽  
Author(s):  
Safat Sikder ◽  
Xiaodong Chen ◽  
Faisal Hossain ◽  
Jason B. Roberts ◽  
Franklin Robertson ◽  
...  
Keyword(s):  
Water Management ◽  
River Basins ◽  
Hydrologic Model ◽  
Streamflow Forecasting ◽  
Management Decisions ◽  
Brahmaputra River ◽  
Ganges Basin ◽  
Monthly Scale ◽  
Brahmaputra Basin ◽  
The Ganges

Abstract This study asks the question of whether GCMs are ready to be operationalized for streamflow forecasting in South Asian river basins, and if so, at what temporal scales and for which water management decisions are they likely to be relevant? The authors focused on the Ganges, Brahmaputra, and Meghna basins for which there is a gridded hydrologic model calibrated for the 2002–10 period. The North American Multimodel Ensemble (NMME) suite of eight GCM hindcasts was applied to generate precipitation forecasts for each month of the 1982–2012 (30 year) period at up to 6 months of lead time, which were then downscaled according to the bias-corrected statistical downscaling (BCSD) procedure to daily time steps. A global retrospective forcing dataset was used for this downscaling procedure. The study clearly revealed that a regionally consistent forcing for BCSD, which is currently unavailable for the region, is one of the primary conditions to realize reasonable skill in streamflow forecasting. In terms of relative RMSE (normalized by reference flow obtained from the global retrospective forcings used in downscaling), streamflow forecast uncertainty (RMSE) was found to be 38%–50% at monthly scale and 22%–35% at seasonal (3 monthly) scale. The Ganges River (regulated) experienced higher uncertainty than the Brahmaputra River (unregulated). In terms of anomaly correlation coefficient (ACC), the streamflow forecasting at seasonal (3 monthly) scale was found to have less uncertainty (>0.3) than at monthly scale (<0.25). The forecast skill in the Brahmaputra basin showed more improvement when the time horizon was aggregated from monthly to seasonal than the Ganges basin. Finally, the skill assessment for the individual seasons revealed that the flow forecasting using NMME data had less uncertainty during monsoon season (July–September) in the Brahmaputra basin and in postmonsoon season (October–December) in the Ganges basin. Overall, the study indicated that GCMs can have value for management decisions only at seasonal or annual water balance applications at best if appropriate historical forcings are used in downscaling. The take-home message of this study is that GCMs are not yet ready for prime-time operationalization for a wide variety of multiscale water management decisions for the Ganges and Brahmaputra River basins.

scholarly journals Spatial and seasonal responses of precipitation in the Ganges and Brahmaputra river basins to ENSO and Indian Ocean dipole modes: implications for flooding and drought

2015 ◽  
Vol 15 (1) ◽  
pp. 147-162 ◽  
Author(s):  
M. S. Pervez ◽  
G. M. Henebry
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
Indian Ocean Dipole ◽  
El Nino ◽  
La Niña ◽  
Ganges Basin ◽  
La Nina ◽  
Brahmaputra Basin ◽  
The Ganges ◽  
Seasonal Responses

Abstract. We evaluated the spatial and seasonal responses of precipitation in the Ganges and Brahmaputra basins as modulated by the El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) modes using Global Precipitation Climatology Centre (GPCC) full data reanalysis of monthly global land-surface precipitation data from 1901 to 2010 with a spatial resolution of 0.5° × 0.5°. The GPCC monthly total precipitation climatology targeting the period 1951–2000 was used to compute gridded monthly anomalies for the entire time period. The gridded monthly anomalies were averaged for the years influenced by combinations of climate modes. Occurrences of El Niño alone significantly reduce (88% of the long-term average (LTA)) precipitation during the monsoon months in the western and southeastern Ganges Basin. In contrast, occurrences of La Niña and co-occurrences of La Niña and negative IOD events significantly enhance (110 and 109% of LTA in the Ganges and Brahmaputra Basin, respectively) precipitation across both basins. When El Niño co-occurs with positive IOD events, the impacts of El Niño on the basins' precipitation diminishes. When there is no active ENSO or IOD events (occurring in 41 out of 110 years), precipitation remains below average (95% of LTA) in the agriculturally intensive areas of Haryana, Uttar Pradesh, Rajasthan, Madhya Pradesh, and Western Nepal in the Ganges Basin, whereas precipitation remains average to above average (104% of LTA) across the Brahmaputra Basin. This pattern implies that a regular water deficit is likely, especially in the Ganges Basin, with implications for the agriculture sector due to its reliance on consistent rainfall for successful production. Historically, major droughts occurred during El Niño and co-occurrences of El Niño and positive IOD events, while major flooding occurred during La Niña and co-occurrences of La Niña and negative IOD events in the basins. This observational analysis will facilitate well-informed decision making in minimizing natural hazard risks and climate impacts on agriculture, and supports development of strategies ensuring optimized use of water resources in best management practice under a changing climate.

scholarly journals When do institutions work? A comparison of two water disputes over the Ganges, Brahmaputra and Meghna river basins

Water Policy ◽  
2017 ◽  
Vol 20 (2) ◽  
pp. 308-322 ◽  
Author(s):  
Lei Xie ◽  
Muhammad Mizanur Rahaman ◽  
Wei Shen
Keyword(s):  
Water Management ◽  
Foreign Relations ◽  
River Basins ◽  
Institutional Arrangements ◽  
Environmental Agreements ◽  
Building Trust ◽  
Institutional Cooperation ◽  
Water Management Institutions ◽  
Management Institutions ◽  
The Ganges

Abstract This article investigates the motives and incentives that drive countries' diplomatic efforts in water disputes. It aims to identify links between the formation of water management institutions (WMIs) and the outcomes of such institutional cooperation. Three features have been identified as key to the effectiveness of WMIs: (1) the development of trust; (2) sanctions aimed at curbing cheating; and (3) the balancing of different countries’ interests over shared waters. This article conducts a comparative analysis of the formation of institutional arrangements among three riparian states by focusing on two cases: water interactions between China and India, and between India and Bangladesh. It argues that India, China and Bangladesh have exhibited different preferences in regard to their participation in WMIs. The two cases illustrate how different WMIs are formed and also how, in proportion to variations in the level of competition over water quantity, diplomatic cooperation through environmental agreements can lead to different outcomes with varying degrees of success. This article concludes that in the context of the global South, where foreign relations are unstable and countries’ reliance on river basins varied, building trust and balancing interests over water management are especially important to the formation of effective institutional arrangements.

scholarly journals Spatial and seasonal responses of precipitation in the Ganges and Brahmaputra river basins to ENSO and Indian Ocean dipole modes: implications for flooding and drought

2014 ◽  
Vol 2 (2) ◽  
pp. 1671-1692
Author(s):  
M. S. Pervez ◽  
G. M. Henebry
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Climate Impacts ◽  
Climate Modes ◽  
Ganges Basin ◽  
Brahmaputra Basin ◽  
Precipitation Records ◽  
The Ganges

Abstract. We evaluated the spatial and temporal responses of precipitation in the basins as modulated by the El Niño Southern Oscillation (ENSO) and Indian Ocean (IO) dipole modes using observed precipitation records at 43 stations across the Ganges and Brahmaputra basins from 1982 to 2010. Daily observed precipitation records were extracted from Global Surface Summary of the Day dataset and spatial and monthly anomalies were computed. The anomalies were averaged for the years influenced by climate modes combinations. Occurrences of El Niño alone significantly reduced (60% and 88% of baseline in the Ganges and Brahmaputra basins, respectively) precipitation during the monsoon months in the northwestern and central Ganges basin and across the Brahmaputra basin. In contrast, co-occurrence of La Niña and a positive IO dipole mode significantly enhanced (135% and 160% of baseline, respectively) precipitation across both basins. During the co-occurrence of neutral phases in both climate modes (occurring 13 out of 28 yr), precipitation remained below average to average in the agriculturally extensive areas of Haryana, Uttar Pradesh, Bihar, eastern Nepal, and the Rajshahi district in Bangladesh in the Ganges basin and northern Bangladesh, Meghalaya, Assam, and Arunachal Pradesh in the Brahmaputra basin. This pattern implies that a regular water deficit is likely in these areas with implications for the agriculture sector due to its reliance on consistent rainfall for successful production. Major flooding and drought occurred as a consequence of the interactive effects of the ENSO and IO dipole modes, with the sole exception of extreme precipitation and flooding during El Niño events. This observational analysis will facilitate well informed decision making in minimizing natural hazard risks and climate impacts on agriculture, and supports development of strategies ensuring optimized use of water resources in best management practice under changing climate.

scholarly journals Hydrological modeling as a tool for water resources management of the data-scarce Brahmaputra basin

2020 ◽  
Author(s):  
Pulendra Dutta ◽  
Arup Kumar Sarma
Keyword(s):  
Water Resources ◽  
River Basin ◽  
Hydrological Modeling ◽  
Assessment Tool ◽  
Swat Model ◽  
Fair Value ◽  
Hydrologic Model ◽  
Statistical Parameters ◽  
Brahmaputra River ◽  
Brahmaputra Basin

Abstract A robust hydrological assessment is a challenging task in regions of limited hydro-climatological information. This level of uncertainty is further augmented in studies of flood hydrology for regions like the Brahmaputra River basin, where spatial variations of topography, land use, soil, and weather components are very high. The present study describes the development of a suitable hydrologic model for the data-scarce transboundary Brahmaputra River basin occupying an area of more than 5,42,000 km2. The main objective is to provide hydrologic assessment of the Brahmaputra River basin, even at locations having hardly any historical records. The Soil and Water Assessment Tool (SWAT) model is calibrated and validated using observed discharge of three sections located on the main stem. The results show a fair strength of the statistical parameters. Moreover, the model has been found to produce a satisfactory replica of historical flows at the tributaries with a fair value of correlation (R2 = 0.77) at Golaghat. The results of this model would facilitate the ability of the local authorities with science-based elements to carry out decisions on the management of water resources at the main basin, and even at the sub-basin level.

How model selection can determine flood risk estimates – a case study in the Ganges basin using the GLOFRIM framework

2020 ◽  
Author(s):  
Jannis Hoch ◽  
Dirk Eilander ◽  
Hiroaki Ikeuchi
Keyword(s):  
Model Selection ◽  
Flood Risk ◽  
Hydrologic Model ◽  
Order Estimate ◽  
Hydrodynamic Models ◽  
Ganges Basin ◽  
Risk Estimates ◽  
Selection For ◽  
The Ganges ◽  
Flood Maps

<p>Fluvial flood events are a major threat to people and infrastructure. To compute flood risk estimates, modelling cascades are often applied. Therein, flood hazard is driven by hydrologic or river routing and floodplain flow processes. As such, model selection within such a cascade can determine how well some of these processes can be simulated. Depending on the selection made, obtained flood maps can vary and, in turn, can have major implications for the analysis of how many people, buildings, economic values and so forth is at risk. Understanding the role of model selection in the flood risk modelling process is thus of great importance.</p><p>By means of GLOFRIM 2.0, we coupled the global hydrologic model PCR-GLOBWB with the hydrodynamic models CaMa-Flood and LISFLOOD-FP for the delta region of the Ganges-Brahmaputra basin. Applying the model-coupling framework GLOFRIM facilitates forcing various models with identical boundary conditions and thus transparent and objective inter-comparison of flood models.</p><p>While replacing the kinematic wave approximation of the hydrologic model with the local inertia equation of hydrodynamic models does not yield better discharge estimates in the Ganges basin, flood maps obtained with LISFLOOD-FP improved representation of observed flood extent. Compared to downscaled products of PCR-GLOBWB and CaMa-Flood, the critical success index increases by around 50 %.</p><p>Combining the obtained flood maps with actual exposure maps gives then a first-order estimate how the selection for one specific model set-ups translates into varying flood risk estimates. The research thus shows how those model selections, deliberately made or not, are an important driver of simulated flood risk. As such, it is detrimental that the various specifics of a model are known to facilitate the optimal model selection for objective-specific modelling requirements.</p>

A Simple Streamflow Forecasting Scheme for the Ganges Basin

2016 ◽  
pp. 399-420 ◽  
Author(s):  
Y. Jiang ◽  
W. Palash ◽  
A.S. Akanda ◽  
D.L. Small ◽  
S. Islam
Keyword(s):  
Streamflow Forecasting ◽  
Ganges Basin ◽  
The Ganges

scholarly journals Hydrological recurrence as a measure for large river basin classification and process understanding

2015 ◽  
Vol 19 (4) ◽  
pp. 1919-1942 ◽  
Author(s):  
R. Fernandez ◽  
T. Sayama
Keyword(s):  
River Basin ◽  
River Basins ◽  
Global Scale ◽  
Hydrologic Model ◽  
Surface Model ◽  
Data Set ◽  
Arctic Regions ◽  
Monthly Scale ◽  
Monsoon Area ◽  
Hydrological Variable

Abstract. Hydrological functions of river basins are summarized as collection, storage and discharge, which can be characterized by the dynamics of hydrological variables including precipitation, evaporation, storage and runoff. The temporal patterns of each variable can be indicators of the functionality of a basin. In this paper we introduce a measure to quantify the degree of similarity in intra-annual variations at monthly scale at different years for the four main variables. We introduce this measure under the term of recurrence and define it as the degree to which a monthly hydrological variable returns to the same state in subsequent years. The degree of recurrence in runoff is important not only for the management of water resources but also for the understanding of hydrologic processes, especially in terms of how the other three variables determine the recurrence in runoff. The main objective of this paper is to propose a simple hydrologic classification framework applicable to large basins at global scale based on the combinations of recurrence in the four variables using a monthly scale time series. We evaluate it with lagged autocorrelation (AC), fast Fourier transforms (FFT) and Colwell's indices of variables obtained from the EU-WATCH data set, which is composed of eight global hydrologic model (GHM) and land surface model (LSM) outputs. By setting a threshold to define high or low recurrence in the four variables, we classify each river basin into 16 possible classes. The overview of recurrence patterns at global scale suggested that precipitation is recurrent mainly in the humid tropics, Asian monsoon area and part of higher latitudes with an oceanic influence. Recurrence in evaporation was mainly dependent on the seasonality of energy availability, typically high in the tropics, temperate and sub-arctic regions. Recurrence in storage at higher latitudes depends on energy/water balances and snow, while that in runoff is mostly affected by the different combinations of these three variables. According to the river basin classification, 10 out of the 16 possible classes were present in the 35 largest river basins in the world. In the humid tropic region, the basins belong to a class with high recurrence in all the variables, while in the subtropical region many of the river basins have low recurrence. In the temperate region, the energy limited or water limited in summer characterizes the recurrence in storage, but runoff exhibits generally low recurrence due to the low recurrence in precipitation. In the sub-arctic and arctic regions, the amount of snow also influences the classes; more snow yields higher recurrence in storage and runoff. Our proposed framework follows a simple methodology that can aid in grouping river basins with similar characteristics of water, energy and storage cycles. The framework is applicable at different scales with different data sets to provide useful insights into the understanding of hydrologic regimes based on the classification.

MODERN HYDROGRAPHIC AND WATER MANAGEMENT ZONING OF UKRAINE’S TERRITORY – IMPLEMENTATION OF THE WFD-2000/60/EC

2020 ◽  
Author(s):  
V.K. Khilchevskyi ◽  
Keyword(s):  
Water Management ◽  
Water Resources ◽  
River Basins ◽  
River Basin Management ◽  
The Black Sea ◽  
Main Function ◽  
River Basin Management Plans ◽  
Management Plans ◽  
The Crimea ◽  
Sea Coast

In contrast to the hydrological and hydrochemical zoning, hydrographic and water management zoning of Ukraine (2016) was created on a basin basis, taking into account the boundaries of river basins, and not physiographic zoning. The main function of hydrographic and water management zoning is water management. Primary is hydrographic zoning, and water management - based on it. The description of modern hydrographic zoning of the territory of Ukraine, approved in 2016 by the Verkhovna Rada of Ukraine and included in the Water Code of Ukraine is given. Hydrographic zoning is carried out for the development and implementation of river basin management plans. On the territory of Ukraine nine areas of river basins are allocated: Dnipro; Dnister; Danube; Southern Bug; Don; Vistula; rivers of the Crimea; rivers of the Black Sea coast; rivers of the Azov Sea coast 13 sub-basins are allocated in four river basins district. The water management zoning is described - the division of hydrographic units into water management areas, which is carried out for the development of water management balances. In the regions of the river basins in the territory of Ukraine allocated 132 water management areas, 59 of which are located in the Dnipro basin. About 9,000 bodies of surface water allocated for monitoring in Ukraine. Approved zoning is the implementation of the provisions of the EU Water Framework Directive 2000/60 / EC in the management of water resources in Ukraine. Modern hydrographic and water management zoning of the territory of Ukraine approximates the management of water resources of the state to European requirements.

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