About
31
Publications
11,153
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
482
Citations
Citations since 2017
Introduction
Skills and Expertise
Publications
Publications (31)
Hydrological models have traditionally been calibrated and evaluated against point-scale observations, such as streamflow, emphasizing the temporal, but not necessarily the spatial component of a model. The main goal of this study is to improve the spatial pattern performance of simulated actual evapotranspiration (AET), a key variable in the land-...
Spatial patterns in long-term average evapotranspiration (ET) represent a unique source of information for evaluating the spatial pattern performance of distributed hydrological models on a river basin to continental scale. This kind of model evaluation is getting increased attention, acknowledging the shortcomings of traditional aggregated or time...
This study aims to improve the standard water balance evapotranspiration (WB ET) estimate, which is typically used as benchmark data for catchment-scale ET estimation, by accounting for net intercatchment groundwater flow in the ET calculation. Using the modified WB ET approach, we examine errors and shortcomings associated with the long-term annua...
The interactions of hydrological variables in the terrestrial hydrological cycle are complex. To better predict the variables, distributed and physically based models are used as they account for the complexity of interactions. In this study, we addressed the joint simulation of water- and energy fluxes and the potential benefit of flux measurement...
Global change has triggered a number of changes, such as alterations in climate, land productivity, water resources and atmospheric chemistry with far reaching impacts on ecosystem functions and services. Finding solutions to climate and land use change driven impacts on our terrestrial environment is one of the most important scientific challenges...
The temporal multiscale variability of the surface heat fluxes is assessed by the analysis of the turbulent heat and moisture fluxes using the eddy covariance (EC) technique at the TERrestrial ENvironmental Observatories (TERENO) prealpine region. The fast and slow response variables from three EC sites located at Fendt, Rottenbuch, and Graswang ar...
The spatial variations of water and energy budgets are highly influenced by the heterogeneity of land-surface characteristics. We investigate the spatiotemporal variability and dependence structure patterns of water and energy fluxes along an elevation gradient. Our analysis is based on the application of the GEOtop model and empirical Copulas. It...
Non-closure of the surface energy balance is a frequently observed phenomenon of hydrometeorological field measurements, when using the eddy-covariance method, which can be ascribed to an underestimation of the turbulent fluxes. Several approaches have been proposed in order to adjust the measured fluxes for this apparent systematic error. However,...
This paper describes the results of an analysis of extreme rainfall events in the central plateau of
Iran. To study the extreme events, daily records of eighteen stations’ rainfalls in the region for
different initial dates up to 2005 gathered from the bureau of meteorology. Then, the extreme
rainfall threshold was calculated for each individual st...
The southern coasts of Caspian Sea is subjected to synoptic/mesoscale weather systems
ranging from locally enhanced sea breeze formation and small local front systems to synoptic scale cyclones.
This study presents climatology of cyclones over the southern coasts of Caspian Sea covering a ten year period
1996-2005. Altogether 57 cyclones were forme...
In this study, changes in the spatial and temporal patterns of climate extreme indices were analyzed. Daily maximum and minimum air temperature, precipitation, and their association with climate change were used as the basis for tracking changes at 50 meteorological stations in Iran over the period 1975–2010. Sixteen indices of extreme temperature...
The southern coasts of Caspian Sea is subjected to synoptic/mesoscale weather systems
ranging from locally enhanced sea breeze formation and small local front systems to synoptic scale cyclones.
This study presents climatology of cyclones over the southern coasts of Caspian Sea covering a ten year period
1996-2005. Altogether 57 cyclones were forme...
The southern coasts of Caspian Sea is subjected to synoptic/mesoscale weather systems ranging from locally enhanced sea breeze formation and small local front systems to synoptic scale cyclones. This study presents climatology of cyclones over the southern coasts of Caspian Sea covering a ten year period 1996-2005. Altogether 57 cyclones were forme...
The southern coasts of Caspian Sea is subject to synoptic/mesoscale weather systems ranging from locally enhanced sea breeze formation and small local front systems to synoptic scale cyclones. The intensity and structure of these weather systems cover a wide spectrum, which include cold-cored weather systems from the Siberian highs as well as warm-...
A heavy rainfall event during the period from 30th of March to 2nd of April 2009 has been studied using upper air and surface data as well as NOAA HYSPLIT model. This observational study attempts to determine factors responsible for the occurrence of heavy rainfall over Iran induced by Mediterranean cyclone, a western severe sub-tropical storm that...
Atmospheric blocking plays an important role in the mid-latitude climate variability and can be responsible for anomalies and / or extreme climates. This study investigates the effects of blocking phenomenon on the rainfall in northwestern Iran. In addition to the occurrence of atmospheric blocking , the climatology of the characteristics of blocki...
In order to study the extreme precipitation events , daily records of 12 sites in Kerman province of Iran , from their establishment up to the year 2005 , were gathered from the I. R. of Iran Meteorological Organization (IRIMO). From these data rainfall records which occurred during the periods from 21st of June to 21st of September were extracted...
Atmospheric blocking plays an important role in the mid-latitude climate variability and can
be responsible for anomalies and/or extreme climates. This study investigates the effects of
blocking phenomenon on the rainfall in northwestern Iran. In addition to the occurrence of
atmospheric blocking, the climatology of the characteristics of blocking...
Drought is a natural disaster that gives a lot of damage every year. It is one of the most dangerous natural hazards because it is very difficult to identify its onset. In this paper the Standard Precipitation Index (SPI) has been used to monitor drought in Iran. The SPI index is a powerful tool, requiring only rainfall data for its calculation, an...
A stochastic weather generator is a model capable of generating daily weather patterns that are statistically similar to the observed patterns. Since the frequency and the magnitude of extreme weather events especially temperature and precipitation are likely to increase under climate change, there is a growing need to investigate how well weather...
During the period from 12 to 15 April, 2009 nearly the entire Iran, apart from the southern border, experienced an advective cooling event. While winter freezing concerns are typical, the nature of this freezing event was unusual with respect to its date of occurrence and accompanying synoptic meteorological situation. To analyze the freezing event...
The results of the zonal and meridional wind components from NCEP dataset are presented to study three heavy rainfall events (12–13 April 2009, 22–23 May 2001, and 23–24 April 1995) over the southern coasts of Caspian Sea. The 6-hourly NCEP/NCAR reanalysis data of zonal and meridional wind components at different pressure levels, the daily precipit...
An exceptional southerly Foehn in the Alborz Mountains in northern Iran is investigated by using a combination of observations, reanalysis, and simulation data. A synoptic analysis is used as well as a high-resolution numerical modeling to clarify the Foehn event at different scales. The event resulted in an extensive and high-intensity fire in the...
In this study, the spatial and temporal patterns of changes in the indices of precipitation extremes, on the basis of daily data and its association with climate change at twenty meteorological stations in northwest Iran over the period 1988–2012 were analyzed. Ten indices of extreme precipitation, which have been quality controlled, tested for hom...
This study aims to analyze the long-term precipitation series using nonparametric methods (i.e. the Mann–Kendall and Time Series techniques) spanning from 1956 to 2005 in Gorgan station. The monthly total of precipitation data collected from the Bureau of Meteorology and then the time series plots produced using AnClim software.The outputs indicate...
Projects
Project (1)
http://www.space.geus.dk/
The aim of this project is to develop a theoretical framework and new methodologies for spatial hydrological model evaluation that are required to enable a paradigm shift towards truly science based water management. Currently, hydrological models remain focused on comparing simulations to a single spatially aggregated catchment scale observation in the form of river discharge, with the conviction that it provides some inherent insight into the internal hydrological behaviour of the river basin. This notion is outdated and limits the use of models for science based and differentiated water management. Therefore, a paradigm shift it required, moving away from the aggregated evaluation of hydrological models towards a spatially distributed approach. Recent advances in fully distributed and grid based model codes, computational power and spatial data availability have prepared the ground for bringing the science forward. However, hydrological model evaluation and calibration severely lack methodologies for incorporating spatial pattern information.
