scholarly journals Finding the Optimal Multimodel Averaging Method for Global Hydrological Simulations

2021 ◽  
Vol 13 (13) ◽  
pp. 2574
Author(s):  
Wenyan Qi ◽  
Jie Chen ◽  
Chongyu Xu ◽  
Yongjing Wan
Keyword(s):  
Hydrological Modeling ◽  
Averaging Method ◽  
Hydrological Models ◽  
Hydrological Simulation ◽  
Climate Conditions ◽  
Averaging Methods ◽  
Model Driven ◽  
Climatic Regions ◽  
Arctic Regions ◽  
The World

Global gridded precipitations have been extensively considered as the input of hydrological models for runoff simulations around the world. However, the limitations of hydrologic models and the inaccuracies of the precipitation datasets could result in large uncertainty in hydrological forecasts and water resource estimations. Therefore, it is of great importance to investigate the hydrological value of a weighted combination of hydrological models driven by different precipitation datasets. In addition, due to the diversities of combination members and climate conditions, hydrological simulation for watersheds under different climate conditions may show various sensitivities to the weighted combinations. This study undertakes a comprehensive analysis of various multimodel averaging methods and schemes (i.e., the combination of the members in averaging) to identify the most skillful and reliable multimodel averaging application. To achieve this, four hydrological models driven by six precipitation datasets were used as averaging members. The behaviors of 9 averaging methods and 11 averaging schemes in hydrological simulations were tested over 2277 watersheds distributed in different climate regions in the world. The results show the following: (1) The multi-input averaging schemes (i.e., members consist of one model driven by multiple precipitation datasets) generally perform better than the multimodel averaging schemes (i.e., members consist of multiple models driven by the same precipitation dataset) for each averaging method; (2) The use of multiple members can improve the averaging performances. Six averaging members are found to be necessary and advisable, since using more than six members only imrpoves the estimation results slightly, as compared with using all 24 members; (3) The advantage of using averaging methods for hydrological modeling is region dependent. The averaging methods, in general, produced the best results in the warm temperate region, followed by the snow and equatorial regions, while a large difference among various averaging methods is found in arid and arctic regions. This is mainly due to the different averaging methods being affected to a different extent by the poorly performed members in the arid and arctic regions; (4) the multimodel superensemble method (MMSE) is recommended for its robust and outstanding performance among various climatic regions.

scholarly journals Can Precipitation and Temperature from Meteorological Reanalyses Be Used for Hydrological Modeling?

2016 ◽  
Vol 17 (7) ◽  
pp. 1929-1950 ◽  
Author(s):  
Gilles R. C. Essou ◽  
Florent Sabarly ◽  
Philippe Lucas-Picher ◽  
François Brissette ◽  
Annie Poulin
Keyword(s):  
United States ◽  
Hydrological Modeling ◽  
The United States ◽  
Hydrological Models ◽  
River Flows ◽  
Surface Precipitation ◽  
Climatic Regions ◽  
Precipitation Seasonality ◽  
Regional Reanalysis ◽  
Precipitation And Temperature

Abstract This paper investigates the potential of reanalyses as proxies of observed surface precipitation and temperature to force hydrological models. Three global atmospheric reanalyses (ERA-Interim, CFSR, and MERRA), one regional reanalysis (NARR), and one global meteorological forcing dataset obtained by bias-correcting ERA-Interim [Water and Global Change (WATCH) Forcing Data ERA-Interim (WFDEI)] were compared to one gridded observation database over the contiguous United States. Results showed that all temperature datasets were similar to the gridded observation over most of the United States. On the other hand, precipitation from all three global reanalyses was biased, especially in summer and winter in the southeastern United States. The regional reanalysis precipitation was closer to observations since it indirectly assimilates surface precipitation. The WFDEI dataset was generally less biased than the reanalysis datasets. All datasets were then used to force a global conceptual hydrological model on 370 watersheds of the Model Parameter Estimation Experiment (MOPEX) database. River flows were computed for each watershed, and results showed that the flows simulated using NARR and gridded observations forcings were very similar to the observed flows. The simulated flows forced by the global reanalysis datasets were also similar to the observations, except in the humid continental and subtropical climatic regions, where precipitation seasonality biases degraded river flow simulations. The WFDEI dataset led to better river flows than reanalysis in the humid continental and subtropical climatic regions but was no better than reanalysis—and sometimes worse—in other climatic zones. Overall, the results indicate that global reanalyses have good potential to be used as proxies to observations to force hydrological models, especially in regions with few weather stations.

scholarly journals Catchment Scale Evaluation of Multiple Global Hydrological Models from ISIMIP2a over North America

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3112
Author(s):  
Magali Troin ◽  
Richard Arsenault ◽  
Elyse Fournier ◽  
François Brissette
Keyword(s):  
Hydrological Modeling ◽  
Model Performance ◽  
Second Phase ◽  
Hydrological Models ◽  
Catchment Scale ◽  
Meteorological Forcing ◽  
Climate Conditions ◽  
Seasonal Flow ◽  
Operational Decision Making ◽  
Climate Change Impact Study

A satisfactory performance of hydrological models under historical climate conditions is considered a prerequisite step in any hydrological climate change impact study. Despite the significant interest in global hydrological modeling, few systematic evaluations of global hydrological models (gHMs) at the catchment scale have been carried out. This study investigates the performance of 4 gHMs driven by 4 global observation-based meteorological inputs at simulating weekly discharges over 198 large-sized North American catchments for the 1971–2010 period. The 16 discharge simulations serve as the basis for evaluating gHM accuracy at the catchment scale within the second phase of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP2a). The simulated discharges by the four gHMs are compared against observed and simulated weekly discharge values by two regional hydrological models (rHMs) driven by a global meteorological dataset for the same period. We discuss the implications of both modeling approaches as well as the influence of catchment characteristics and global meteorological forcing in terms of model performance through statistical criteria and visual hydrograph comparison for catchment-scale hydrological studies. Overall, the gHM discharge statistics exhibit poor agreement with observations at the catchment scale and manifest considerable bias and errors in seasonal flow simulations. We confirm that the gHM approach, as experimentally implemented through the ISIMIP2a, must be used with caution for regional studies. We find the rHM approach to be more trustworthy and recommend using it for hydrological studies, especially if findings are intended to support operational decision-making.

North Atlantic Oscillation; a Climatic Indicator to Predict Hydropower Availability in Scandinavia

2002 ◽  
Vol 33 (5) ◽  
pp. 415-424 ◽  
Author(s):  
Cintia B. Uvo ◽  
Ronny Berndtsson
Keyword(s):  
Climate Change ◽  
Spatial Distribution ◽  
Climate Variability ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Winter Precipitation ◽  
Model Driven ◽  
The World ◽  
Hydropower Production ◽  
Precipitation And Temperature

Climate variability and climate change are of great concern to economists and energy producers as well as environmentalists as both affect the precipitation and temperature in many regions of the world. Among those affected by climate variability is the Scandinavian Peninsula. Particularly, its winter precipitation and temperature are affected by the variations of the so-called North Atlantic Oscillation (NAO). The objective of this paper is to analyze the spatial distribution of the influence of NAO over Scandinavia. This analysis is a first step to establishing a predictive model, driven by a climatic indicator such as NAO, for the available water resources of different regions in Scandinavia. Such a tool would be valuable for predicting potential of hydropower production one or more seasons in advance.

scholarly journals Multi-source data assimilation for physically-based hydrological modeling of an experimental hillslope

2018 ◽  
Author(s):  
Anna Botto ◽  
Enrica Belluco ◽  
Matteo Camporese
Keyword(s):  
Soil Moisture ◽  
Data Assimilation ◽  
Hydrological Modeling ◽  
Nonlinear Models ◽  
Pressure Head ◽  
Richards Equation ◽  
Hydrological Models ◽  
Filter Performance ◽  
Trade Offs ◽  
Source Data

Abstract. Data assimilation has been recently the focus of much attention for integrated surface-subsurface hydrological models, whereby joint assimilation of water table, soil moisture, and river discharge measurements with the ensemble Kalman filter (EnKF) have been extensively applied. Although the EnKF has been specifically developed to deal with nonlinear models, integrated hydrological models based on the Richards equation still represent a challenge, due to strong nonlinearities that may significantly affect the filter performance. Thus, more studies are needed to investigate the capabilities of the EnKF to correct the system state and identify parameters in cases where the unsaturated zone dynamics are dominant, as well as to quantify possible tradeoffs associated with assimilation of multi-source data. Here, the model CATHY (CATchment HYdrology) is applied to reproduce the hydrological dynamics observed in an experimental two-layered hillslope, equipped with tensiometers, water content reflectometer probes, and tipping bucket flow gages to monitor the hillslope response to a series of artificial rainfall events. Pressure head, soil moisture, and subsurface outflow are assimilated with the EnKF in a number of scenarios and the challenges and issues arising from the assimilation of multi-source data in this real-world test case are discussed. Our results demonstrate that the EnKF is able to effectively correct states and parameters even in a real application characterized by strong nonlinearities. However, multi-source data assimilation may lead to significant trade-offs: the assimilation of additional variables can lead to degradation of model predictions for other variables that were otherwise well reproduced. Furthermore, we show that integrated observations such as outflow discharge cannot compensate for the lack of well-distributed data in heterogeneous hillslopes.

scholarly journals Hydrological Modeling of the Paligad Watershed (India) Using HSFP Model

2019 ◽  
pp. 217-228
Author(s):  
Aamir Ishaq Shah ◽  
Sumit Sen ◽  
Anurag Mishra
Keyword(s):  
Hydrological Modeling ◽  
Simulation Program ◽  
Expert Advice ◽  
Coefficient Of Determination ◽  
Hydrological Simulation ◽  
Hspf Model ◽  
Hydrological System ◽  
Set Up

For hydrological studies, it is well known that each hydrological system behaves differently and in order to effectively manage those systems, it is necessary to understand their behavior. The hydrological component of Hydrological Simulation Program – FORTRAN (HSPF) model was set up and calibrated for Paligad watershed which is a sub-basin of Aglar watershed in the Uttarakhand state of India. The calibration of the model was done manually and an expert advice system called as HSPEXP+ was used to aid calibration. The values of evaluation indicators such as coefficient of determination (

Comparison between dynamic and static sensitivity analysis approaches for impact assessment of different potential evapotranspiration methods on hydrological models performance

2021 ◽  
Author(s):  
Rodric Mérimé Nonki ◽  
André Lenouo ◽  
Christopher J. Lennard ◽  
Raphael M. Tshimanga ◽  
Clément Tchawoua
Keyword(s):  
Sensitivity Analysis ◽  
Impact Assessment ◽  
Hydrological Modeling ◽  
Potential Evapotranspiration ◽  
Model Performance ◽  
Estimation Methods ◽  
Model Parameters ◽  
Hydrological Models ◽  
Sensitivity Approach ◽  
Static Sensitivity

AbstractPotential Evapotranspiration (PET) plays a crucial role in water management, including irrigation systems design and management. It is an essential input to hydrological models. Direct measurement of PET is difficult, time-consuming and costly, therefore a number of different methods are used to compute this variable. This study compares the two sensitivity analysis approaches generally used for PET impact assessment on hydrological model performance. We conducted the study in the Upper Benue River Basin (UBRB) located in northern Cameroon using two lumped-conceptual rainfall-runoff models and nineteen PET estimation methods. A Monte-Carlo procedure was implemented to calibrate the hydrological models for each PET input while considering similar objective functions. Although there were notable differences between PET estimation methods, the hydrological models performance was satisfactory for each PET input in the calibration and validation periods. The optimized model parameters were significantly affected by the PET-inputs, especially the parameter responsible to transform PET into actual ET. The hydrological models performance was insensitive to the PET input using a dynamic sensitivity approach, while he was significantly affected using a static sensitivity approach. This means that the over-or under-estimation of PET is compensated by the model parameters during the model recalibration. The model performance was insensitive to the rescaling PET input for both dynamic and static sensitivities approaches. These results demonstrate that the effect of PET input to model performance is necessarily dependent on the sensitivity analysis approach used and suggest that the dynamic approach is more effective for hydrological modeling perspectives.

Pruning residues incorporation and reduced tillage improve soil organic matter stabilization and structure of salt-affected soils in Citrus tree orchard under semi-arid climate conditions 

2021 ◽  
Author(s):  
Noelia Garcia-Franco ◽  
Martin Wiesmeier ◽  
Luis Carlos Colocho Hurtarte ◽  
Franziska Fella ◽  
María Martínez-Mena ◽  
...  
Keyword(s):  
Organic Matter ◽  
Drip Irrigation ◽  
Management Practices ◽  
Reduced Tillage ◽  
Citrus Tree ◽  
Climate Conditions ◽  
The World ◽  
Pruning Residues ◽  
Salt Affected Soils ◽  
Semi Arid

<p>Arid and semiarid regions represent about 47% of the total land area of the world and around 40% of the world’s food is produced there. In these areas, soil salinization is an emerging problem due to unsustainable land management practices and climate change. However, the use of sustainable land management practices in salt-affected soils can offset the negative effects of salinization and increase soil carbon stocks. In a Citrus tree orchard under semi-arid climate conditions, we evaluated the effect of (i) intensive tillage along with flood irrigation (IT); (ii) combination of no-tillage with pruning residues (branches and leaves) as mulch, and drip-irrigation (NT+PM); and (iii) combination of reduced tillage with the incorporation of pruning residues and drip-irrigation (RT+PI), on aggregate stability, amount and quality of organic matter fractions and soil organic carbon (OC) sequestration. Our results showed that the incorporation of pruning residues through reduced tillage decreased bulk density and salinity while soil porosity, soil OC and N stocks, and percentage of OC-rich macroaggregates increased compared to the IT system.  However, the positive effects of the NT+PM system on soil properties were limited to the topsoil. The IT management system showed the highest values of bulk density and salinity and lower amounts of macroaggregates and soil OC stocks. In conclusion, the combination of pruning residues through the reduced tillage and drip-irrigation was the most effective systems to improve soil structure and OC sequestration and reduced the salt content under Citrus tree orchard in semi-arid soils</p>

World Meteorological Organization and Agricultural Droughts

2005 ◽  
Author(s):  
Mannava V.K. Sivakumar
Keyword(s):  
Human Activities ◽  
Regional Climate ◽  
Climatic Conditions ◽  
World Meteorological Organization ◽  
Atmospheric Composition ◽  
Transfer Of Knowledge ◽  
Climate Conditions ◽  
Surface Features ◽  
The World ◽  
Hydrological Services

Adaptation strategies for coping with agricultural droughts must be based on a better understanding of the climatic conditions of the location or region under consideration. As the United Nations’ specialized agency with responsibility for meteorology and operational hydrology, the World Meteorological Organization (WMO), since its inception, has been addressing the issue of agricultural droughts. This chapter presents a short overview of the various initiatives undertaken by WMO in this respect. The fight against drought receives a high priority in the long-term plan of WMO, particularly under the Agricultural Meteorology Programme, the Hydrology and Water Resources Programme, and the Technical Cooperation Programme. WMO actively involves the National Meteorological and Hydrological Services (NMHSs), regional and subregional meteorological centers, and other bodies in the improvement of hydrological and meteorological networks for systematic observation, exchange and analysis of data for better monitoring of droughts, and use of medium- and long-range weather forecasts, and assists in the transfer of knowledge and technology. Following is a brief description of various activities undertaken by WMO in the combat against drought. WMO has been in the forefront of research on interactions of climate, drought, and desertification from its beginnings in the mid-1970s, when it was suggested that human activities in drylands could alter surface features that would lead to an intensification of desertification processes and trends. WMO has been in the forefront of research on interactions of climate, drought, and desertification from its beginnings in the mid-1970s, when it was suggested that human activities in drylands could alter surface features that would lead to an intensification of desertification processes and trends. Human-induced changes in dryland surface conditions and atmospheric composition can certainly have an impact on local and regional climate conditions because they directly affect the energy budget of the surface and the overlying atmospheric column. These changes to the energy balance have been simulated in many numerical modeling studies covering almost all dryland areas of the world.

Camel Meat Nutrient Content and Potential Health Benefits

2020 ◽  
pp. 285-305
Author(s):  
Isam Tawfik Kadim ◽  
Roger Purchas ◽  
Issa Al-Amri ◽  
Abdulaziz Alkindi ◽  
Ghulam Abbas
Keyword(s):  
Functional Food ◽  
Meat Products ◽  
Nutrient Content ◽  
Potential Health ◽  
Climatic Regions ◽  
Health And Wellbeing ◽  
The World ◽  
Camel Meat ◽  
National Economies ◽  
Red Meats

Camels are an important source of nutritious meat and meat products for people, and therefore play a major role in the national economies of many countries. In comparison with other red meats, camel meat generally contains less fat and ash, more moisture, and similar protein content. Camel meat products are receiving worldwide interest owing to its unique healthy features and the ability of camels to thrive in climatic regions of the world that may be a challenge to many other meat-producing species. Camel meat products contain many essential nutrients and some components with potential bioactive properties that could be beneficial for human health and wellbeing. Continued improvements in the understanding and optimization of the production processes of camel meat are required for successful industrial implementation and marketing. Advances in ingredient systems may be used to manufacture new meat products from camel meat where higher levels of nutrition are required to enhance consumer health and wellbeing. Camel meat as a functional food is one area that can be exploited.

scholarly journals Improving Meteorological Seasonal Forecasts for Hydrological Modeling in European Winter

2020 ◽  
Vol 59 (2) ◽  
pp. 317-332
Author(s):  
Nicky Stringer ◽  
Jeff Knight ◽  
Hazel Thornton
Keyword(s):  
North Atlantic ◽  
Large Scale ◽  
Hydrological Modeling ◽  
Strongly Correlated ◽  
Hydrological Models ◽  
Seasonal Forecasts ◽  
The North ◽  
Ensemble Mean ◽  
The North Atlantic Oscillation ◽  
Correlation Skill

AbstractRecent advances in the skill of seasonal forecasts in the extratropics during winter mean they could offer improvements to seasonal hydrological forecasts. However, the signal-to-noise paradox, whereby the variability in the ensemble mean signal is lower than would be expected given its correlation skill, prevents their use to force hydrological models directly. We describe a postprocessing method to adjust for this problem, increasing the size of the predicted signal in the large-scale circulation. This reduces the ratio of predictable components in the North Atlantic Oscillation (NAO) from 3 to 1. We then derive a large ensemble of daily sequences of spatially gridded rainfall that are consistent with the seasonal mean NAO prediction by selecting historical observations conditioned on the adjusted NAO forecasts. Over northern and southwestern Europe, where the NAO is strongly correlated with winter mean rainfall, the variability of the predicted signal in the adjusted rainfall forecasts is consistent with the correlation skill (they have a ratio of predictable components of ~1) and are as skillful as the unadjusted forecasts. The adjusted forecasts show larger predicted deviations from climatology and can be used to better assess the risk of extreme seasonal mean precipitation as well as to force hydrological models.

Sign in / Sign up

Export Citation Format

Share Document