Alexander Gelfan

Russian Academy of Sciences | RAS · Institute of Water Problems

A comprehensive, physically based model of snow accumulation, redistribution, sublimation, and melt for open and forested catchments was assembled, based on algorithms derived from hydrological process research in Russia and Canada. The model was used to evaluate the long-term snow dynamics of a forested and an agricultural catchment in northwester...

The Prediction in Ungauged Basins (PUB) initiative of the International Association of Hydrological Sciences (IAHS), launched in 2003 and concluded by the PUB Symposium 2012 held in Delft (23–25 October 2012), set out to shift the scientific culture of hydrology towards improved scientific understanding of hydrological processes, as well as associa...

A physically based distributed model of snowmelt and rainfall runoff generation in the permafrost regions has been developed. The model describes snow cover formation and snowmelt, thawing of the ground, evaporation, basin water storage dynamics, overland, subsurface and channel flow. An important feature of the model is taking into account influen...

Two procedures to estimate the area-averaged snowmelt and meltwater outflow from a snowpack were compared for a river basin in the south part of European Russia. Both methods are based on the same model of melting snow but use two different methods for computing the snowmelt rate at the surface of the snowpack, the degree-day method and the Kuzmin...

Thirty‐three snowpack models of varying complexity and purpose were evaluated across a wide range of hydrometeorological and forest canopy conditions at five Northern Hemisphere locations, for up to two winter snow seasons. Modeled estimates of snow water equivalent (SWE) or depth were compared to observations at forest and open sites at each locat...

It has been well established that during the late Quaternary, the Khvalynian transgression of the Caspian Sea occurred, when the sea level rose tens of meters above the present one. Here, we evaluate the physical feasibility of the hypothesis that the maximum phase of this extraordinary event (known as the “Early Khvalynian transgression”) could be...

Our study is aimed at detection of directional trends in streamflow data observed in large rivers located in different climatic zones and attribution of the detected changes to climate drivers. We consider detection and attribution as interrelated study stages within a suggested hypothesis testing framework with the use of a hydrological model. Fir...

The Arctic rivers contribute more than one‐third of the total freshwater streamflow into the Arctic Ocean and play an essential role in the heat and mass circulation of the Arctic atmosphere/ocean system. As the Arctic is warming faster than the global average, the streamflow from Arctic basins increases. This study analyzed the streamflow of the t...

The present overview is the second part of the article “Runoff of Russian Rivers Under Current and Projected Climate Change: A Review,” which focuses on modern assessment of possible changes in the runoff characteristics of Russian rivers in the XXI century under projected global climate change. The article considers two assessment groups: based on...

The objective of the study is to verify a hypothesis that a hydrological model, which successfully passed a comprehensive evaluation test (CE-test), is more suitable for climate impact study than that which failed the test. In our study, the CE-test is a specially designed model evaluation procedure, including a set of enhanced tests of model perfo...

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through on-line media, followed by two workshops through which a large number of potential science questions were collated, p...

The study is aimed to evaluate a hydrological simulation model intended for assessing climate change impact. A new test was suggested and applied to evaluate the performance of a physically based model of Selenga River runoff generation. In this test, to calibrate the model, an enhanced Nash–and-Sutcliffe efficiency (NSE) criterion was used, includ...

A regional numerical physico-mathematical model of river runoff formation is used to study the possibility to assess long-term variations of water regime characteristics in the Amur R. in the XXI century. Two methods were used to specify climate projections as boundary conditions in the hydrological model: (1) based on the results of calculations w...

Two approaches can be distinguished in studies of climate change impacts on water resources when accounting for issues related to impact model performance: (1) using a multi-model ensemble disregarding model performance, and (2) using models after their evaluation and considering model performance. We discuss the implications of both approaches in...

This paper considers the main principles and technologies used in developing the operational modeling system for the Ussuri River Basin of 24,400 km² based on the automated system of hydrological monitoring and data management (ASHM), the physical-mathematical model with distributed parameters ECOMAG (ECOlogical Model for Applied Geophysics) and th...

An intercomparison of climate change impacts projected by nine regional‐scale hydrological models for 12 large river basins on all continents was performed, and sources of uncertainty quantified in the framework of the ISIMIP project. The models ECOMAG, HBV, HYMOD, HYPE, mHM, SWAT, SWIM, VIC and WaterGAP3 were applied in the following basins: Rhine...

A long-term forecasting ensemble methodology, applied to water inflows into the Cheboksary Reservoir (Russia), is presented. The methodology is based on a version of the semi-distributed hydrological model ECOMAG (ECOlogical Model for Applied Geophysics) that allows for the calculation of an ensemble of inflow hydrographs using two different sets o...

The ECOlogical Model for Applied Geophysics (ECOMAG) and the HYdrological Predictions for the Environment (HYPE) process-based hydrological models were set up to assess possible impacts of climate change on the hydrological regime of two pan-Arctic great drainage basins of the Lena and the Mackenzie Rivers. We firstly assessed the reliability of th...

In regional climate impact studies, good performance of regional models under present/historical climate conditions is a prerequisite for reliable future projections. This study aims to investigate the overall performance of 9 hydrological models for 12 large-scale river basins worldwide driven by the reanalysis climate data from the Water and Glob...

The original publication includes the following sentence in the Results section: “In general, both types of regional models, conceptual and process-based, have similar performances for the 12 large-scale basins, and HBVand SWIM perform slightly better than other models in terms of monthly hydrographs, seasonal dynamics and high flows for most basin...

A large number of hydrological forecasting systems exist across the globe. Recent advances have pushed the limits of predictability of discharge and other hydrological variables from a few hours to several days or even months. In this chapter, we aim to give an overview of Hydrological Ensemble Prediction Systems across the globe. It provides brief...

Adv. Meteorol.ISI Document Delivery No.: DQ2TQTimes Cited: 0Cited Reference Count: 38Cudennec, Christophe Gelfan, Alexander Ren, Liliang Slimani, AndmohamedHindawi publishing corpNew york

In 2013, the IAHS launched the hydrological decade 2013–2022 with the theme “Panta Rhei: Change in Hydrology and Society”. The decade recognises the urgency of hydrological research to understand and predict the interactions of society and water, to support sustainable water resource use under changing climatic and environmental conditions. This pa...

There are more than 700 cities and towns, thousands of villages and settlements, and more than seven million hectares of agricultural land of the Russian territory are exposed to a risk of flooding. Results of flood modeling for three cities located in different parts of Russia: Veliky Ustyug at Northern Dvina river (Europe); Yakutsk at the Lena ri...

In 2013, the International Association of Hydrological Sciences (IAHS) launched the hydrological decade 2013–2022 with the theme “Panta Rhei: Change in Hydrology and Society”. The decade recognizes the urgency of hydrological research to understand and predict the interactions of society and water, to support sustainable water resource use under ch...

Possibilities to investigate the spatial structure of snow cover by means of dynamic-stochastic model are discussed in this article. Basin of the Cheboksary reservoir (area of 376 500 sq.km) was used as an example. Results of numerical experiments show that our dynamic-stochastic model of the snow cover formation reproduces a snow field structure w...

An approach has been proposed to analyze the simulated hydrological extreme uncertainty related to the internal variability of the atmosphere ("climate noise"), which is inherent to the climate system and considered as the lowest level of uncertainty achievable in climate impact studies. To assess the climate noise effect, numerical experiments wer...

An approach to seasonal ensemble forecast of unregulated water inflow into a large reservoir was developed. The approach is founded on a physically-based semi-distributed hydrological model ECOMAG driven by Monte-Carlo generated ensembles of weather scenarios for a specified lead-time of the forecast (3 months ahead in this study). Case study was c...

An approach is proposed to assess hydrological simulation uncertainty originating from internal atmospheric variability. The latter is one of three major factors contributing to uncertainty of simulated climate change projections (along with so-called “forcing” and “climate model” uncertainties). Importantly, the role of internal atmospheric variab...

A dynamic-stochastic model, which combines a deterministic model of snow cover formation with a stochastic weather generator, has been developed. The deterministic snow model describes temporal change of the snow depth, content of ice and liquid water, snow density, snowmelt, sublimation, re-freezing of melt water, and snow metamorphism. The model...

An approach is proposed to assess hydrological simulation uncertainty originating from internal atmospheric variability. The latter is one of three major factors contributing to the uncertainty of simulated climate change projections (along with so-called "forcing" and "climate model" uncertainties). Importantly, the role of the internal atmospheri...

The flood of 2013 in the Amur River basin was the heaviest in that region for the past few decades. It embraced all rivers of the basin, including the Chinese part. This disaster had catastrophic consequences despite the fact that the Zeyan and Bureyan reservoirs mitigated the impact of floodwaters on the level regime of the Middle Amur. The paper...

The paper deals with evaluation of robustness of the physically-based semi- distributed hydrological model ECOMAG with respect to changing (by either climatic or land- use cases) conditions. Case study has been carried out for two basins considered within the modelling experiment held in the frame of the 2013 IAHS conference in Göteborg, Sweden....

The major formation factors of a disastrous flood in the Amur basin in July–September 2013 are discussed. The role of the Zeya and Bureya reservoirs in reducing the flood hazard is discussed. Preliminary estimates of the recurrence of peak flood discharge are given. It is shown that, considering the deficiency of data on water discharges along the...

Throughout its historical development, hydrology as an earth science, but especially as a problem-centred engineering discipline has largely relied (quite successfully) on the assumption of stationarity. This includes assuming time invariance of boundary conditions such as climate, system configurations such as land use, topography and morphology,...

A physicomathematical model of the hydrological cycle in a forested catchment was constructed. This model describes the interception of liquid and solid precipitation by tree crowns; snow accumulation and melting; vertical transfer of moisture in soil and its evaporation; and surface, subsurface, and channeled runoffs. The model was calibrated and...

Predicting water runoff in ungauged water catchment areas is vital to practical applications such as the design of drainage infrastructure and flooding defences, runoff forecasting, and for catchment management tasks such as water allocation and climate impact analysis. This full colour book offers an impressive synthesis of decades of internationa...

Climatic and basin factors affecting the extreme snowmelt floods have been investigated on the basis of a dynamic-stochastic model, which combines a physically based model of snowmelt runoff generation with a stochastic weather generator. The investigations have been carried out for the Seim River basin (catchment area is 7460 km2) in the European...

The potential role of rural land use in mitigating flood risk and protecting water supplies continues to be of great interest to regulators and planners. The ability of hydrologists to quantify the impact of rural land use change on the water cycle is however limited and we are not able to provide consistently reliable evidence to support planning...

An overview of water resources in Russia is presented in terms of the problem of water scarcity. It is shown that physical water scarcity, defined as insufficient resources to satisfy demand, is a feature of water security in very few regions of Russia, whereas most regions have enough water to meet industrial, agricultural and household needs, as...

Empirical and modelling approaches to assessing runoff sensitivity to climate change are presented by the example of the large rivers of the Arctic basin. The empirical approach has been carried out for seven large Arctic rivers. It is based on comparing the climatic mean of runoff estimated for the "warm" years of observations with the correspondi...

This chapter deals with predicting the entire runoff hydrograph in ungauded basins. Runoff hydrographs form the basis for a wide range of hydrological investigations and water resources management tasks. From a scientific perspective one may be interested in predicting hydrographs in ungauged basins in order to understand how the individual process...

A technique for satellite-data-based modeling water and heat regimes of a large scale area has been developed and applied for the 227,300 km2 agricultural region in the European Russia. The core component of the technique is the physically based distributed Remote Sensing Based Land Surface Model (RSBLSM) intended for simulating transpiration by ve...

An approach for flood risk assessment in a poorly gauged basin has been proposed and tested for the Sosna River basin in the European Russia. The approach involves searching a data-rich small proxy-basin which is hydrologically similar to the poorly gauged study basin, developing a physically based model of flood generation in the proxy-basin, and...

A spatial model is proposed of snowmelt-rainfall runoff formation of the mountain river enabling to take account of spatial inhomogeneity of the river catchment and vertical zoning of physiographic and meteorological conditions. The model describes the processes of snow cover formation at various altitudes and snow melting, infiltration into the so...

A technique is proposed of precomputing the snowmelt runoff hydrograph on the basis of physical and mathematical models of river runoff formation, available standard data of surface hydrometeorological measurements, and satellite measurements of Earth’s surface conditions. The computations were carried out for two regions including the basins of th...

A dynamic-stochastic model of flood generation consisting of a distributed physically based model of snowmelt runoff genesis and a stochastic weather generator has been used for the assessment of extreme flood risk. Coupling this model with Monte-Carlo simulations of meteorological series allows one to calculate long series of runoff hydrographs an...

A physically-based, distributed model of runoff generation in the permafrost regions is presented. The model describes processes of snow cover formation, taking into account blowing snow sublimation, snowmelt, freezing and thawing of the ground, water detention by a basin storage, infiltration, evaporation, overland, subsurface and channel flow. An...

A dynamic-stochastic model, which combines a physically based model of snowmelt runoff formation with a stochastic weather generator, has been proposed. The physically based model describes snow accumulation and melt, vertical heat and moisture transfer in a soil, detention of melt water by the depressions at the catchment surface, overland and cha...

The method of the plotting of probabilistic distributions of maximum runoff characteristics on the base of the dynamic-stochastic model of the river runoff formation, enabling to take account of the changes in runoff formation conditions caused by the anthropogenic activity at the river catchment, is described. To approximate the plotted distributi...

The distributed physically based model of snowmelt runoff generation for a mountainous river basin which allows for taking into account horisontal and vertical heterogeneity of hydrological processes has been developed. The model is based on a finite-element schematization of the river basin and includes the description of processes of snow cover f...

A physically based model of runoff generation is presented which is founded on the finite-element schematization of a catchment area and describes processes of interception of liquid and solid precipitation by vegetation, snow accumulation and melt, soil freezing and thawing, infiltration of rainfall and melt water into the frozen and unfrozen soil...

Application of the physically based model of runoff generation developed at Water Problems Institute of RAS is presented. The model is based on the finite-element schematization of the river basin. To describe the subgrid effects, we proposed that some parameters inside of finite elements are gamma-distributed. To assign the coefficient of spatial...

A technique of using satellite-derived data for constructing continuous snow characteristics fields for distributed snowmelt runoff simulation is presented. The satellite-derived data and the available ground-based meteorological measurements are incorporated in a physically based snowpack model. The snowpack model describes temporal changes of the...

A technique of constructing spatial fields of snow characteristics based on assimilation of satellite land surface monitoring data and available ground-based hydrometeorological measurements in a physical based snowpack model is presented. The constructed snow characteristics fields are used as inputs of distributed physically based model of runoff...

A new technique for constructing spatial fields of snow characteristics for runoff simulation and forecasting is presented. The technique incorporates satellite land surface monitoring data and available ground-based hydrometeorological measurements in a physical based snowpack model. The snowpack model provides simulation of temporal changes of th...

The influence of long-term snow accumulation on the runoff conditions several months afterwards is a distinct hydrological characteristic of cold regions, which creates opportunities for long-term (seasonal and subseasonal) hydrological forecasting in these regions. We consider evolution of the long-term forecasting approaches from the deterministi...

In this paper, possible ways to increase effectiveness of the long-term ensemble spring floods forecasting and to assess their uncertainty based on the physical-mathematical model of the runoff formation (for the Vyatka River case study) are studied. It is shown that deterministic forecasts issued by using this approach are more accurate than those...

The possibility of using a priori information to reduce the amount of hydrological observation series data needed for the calibration of physically-based models of runoff generation has been studied. It is shown that by using measurements and runoff generation models in proxy-basins, the number of parameters requiring calibration can be limited to...

Improvement of long-range forecasts of snowmelt flood volume is one of key hydrological problems in Northern Russia. Accurate quantitative characterization of snow cover properties required in snowmelt runoff models is challenging in this region since the existing network of hydrometeorological stations is sparse. Application of satellite data for...

Applicability of the physically based models of runoff generation has been shown for the long-term ensemble forecasts of snowmelt runoff volumes and peak discharges. For the deterministic forecast, the ensembles of runoff hydrographs have been modeled by different combinations of measured and calculated indices of the basin conditions on the date o...

A physically-based model of the hydrothermal regime of frozen soil has been developed. This model describes the process of coupled heat and moisture transfer through homogeneous, unsaturated frozen soil and accounts for the influence of phase changes on water flow. The process is formulated as one-dimensional partial differential equations, which a...

Detailed long-term observations in small Kontaktny Creek basin were used to estimate the parameters of a physically based model through a rigorous parameterisation-calibration procedure. This small basin is considered typical, i.e. a proxy-basin for the surrounding large basin of the Upper Kolyma River from the viewpoint of substantial conditions o...

The possibility of using a priori information to reduce hydrological observation series needed for calibration of physically based models of runoff generation has been studied. It is shown that using measurements and runoff generation models in proxy-basins allows one to limit the number of calibrated parameters to 3-4; from 2 to 3 years of runoff...

A physicomathematical model of snow accumulation and melt is developed. The model takes into account the influence of forest canopy on snow processes. Parameters of the model are measurable canopy characteristics. The model is tested on the long-term data of the Valdai experimental station and describes dynamics of the snow water equivalent without...

A physically based model of runoff generation is coupled with Monte Carlo simulations of the model inputs to estimate flood peak frequency distributions. The runoff generation model represents the following hydro-logical processes: snow cover formation and snowmelt, freezing and thawing of soil, vertical soil moisture transfer and evaporation, over...

A physically based distributed model of runoff generation, including the description of snow processes, soil freezing and thawing, formation of runoff losses and infiltration, evaporation, overland and subsurface flow, water movement in the river channel system, has been applied to investigate capability of assigning a priori values of the model pa...

There are two main schools of estimation of extreme flood characteristics in the world hydrological practice. The first approach is based on fitting a statistical distribution to available measurements of flood peak discharges and extrapolating this distribution to estimate the floods of needed low exceedance probabilities. The second one uses the...

The model is based on the finite-element schematization of river basin and includes the description of the following hydrological processes: snow cover formation and snowmelt, freezing and thawing of soil, vertical soil moisture transfer and evapotran- spiration, water retention in basin storage, overland and channel flow. Stochastic sub- grid vari...

A dynamic-stochastic model of snowmelt and rainfall runoff generation has been developed. The dynamic part of the model is based on the finite-element schematization of a catchment area and includes descriptions of snow cover formation and snow melting, infiltration into the soil, soil freezing and soil thawing, evaporation, overland and channel fl...