Investigation of the relation between the return periods of major drought characteristics using copula functions

Afsar, Mehdi Husami
Şorman, Ali Ünal
Yılmaz, Mustafa Tuğrul
Different drought characteristics (e.g. duration, average severity, and average areal extent) often have monotonic relation that increased magnitude of one often follows a similar increase in the magnitude of the other drought characteristic. Hence it is viable to establish a relationship between different drought characteristics with the goal of predicting one using other ones. Copula functions that relate different variables using their joint and conditional cumulative probability distributions are often used to statistically model the drought characteristics. In this study bivariate and trivariate joint probabilities of these characteristics are obtained over Ankara (Turkey) between 1960 and 2013. Copula-based return period estimation of drought characteristics of duration, average severity, and average areal extent show joint probabilities of these characteristics can be satisfactorily achieved. Among different copula families investigated in this study, elliptical family (i.e. including normal and t-student copula functions) resulted in the lowest root mean square error.


The importance of allochthonous organic matter quality when investigating pulse disturbance events in freshwater lakes: a mesocosm experiment
Caldero-Pascual, Maria; Yildiz, Dilvin; Yalçın, Gülce; Metin, Melisa; Yetim, Sinem; Fiorentin, Claudia; Andersen, Mikkel Rene; Jennings, Eleanor; Jeppesen, Erik; Ger, Kemal Ali; Beklioğlu, Meryem; McCarthy, Valerie (2021-11-01)
Extreme precipitation is occurring with greater frequency and intensity as a result of climate change. Such events boost the transport of allochthonous organic matter (allo-OM) to freshwater ecosystems, yet little is known about the impacts on dissolved organic matter (DOM) quality and seston elemental stoichiometry, especially for lakes in warm climates. A mesocosm experiment located in a Turkish freshwater lake was designed to simulate a pulse event leading to increased inputs of allo-OM by examining the ...
Determination of geostatistically representative sampling locations in Porsuk Dam Reservoir Turkey
Aksoy, Ayşegül; Düzgün, Hafize Şebnem (2013-09-13)
Several factors such as wind action, bathymetry and shape of a lake/reservoir, inflows, outflows, point and diffuse pollution sources result in spatial and temporal variations in water quality of lakes and reservoirs. The guides by the United Nations Environment Programme and the World Health Organization to design and implement water quality monitoring programs suggest that even a single monitoring station near the center or at the deepest part of a lake will be sufficient to observe long-term trends if th...
Investigation of rain erosion on germanium by using finite element method
Salman, Hüseyin Anıl; Yıldırım, Raif Orhan; Department of Mechanical Engineering (2011)
Impact of rain drops at relatively high velocities, which is known as rain erosion, causes severe damages on various materials. Every material can withstand the rain erosion up to a specific impact velocity. However, this damage is critical for optical windows which are very important components for Electro-Optical (EO) systems such as thermal camera. Even a small scratch may affect the transmission capability of the optical window adversely and leads to some functional problems in the device due to insuffi...
Analysis of the Integrated Intensity of the Central Peaks Calculated as a Function of Temperature in the Ferroelectric Phase of Lithium Tantalate.
Kiracı, Ali; Yurtseven, Hasan Hamit (null; 2017-04-29)
The integrated intensity of the central peak is calculated as a function of temperature in the ferroelectric phase (T<TC) of nearly stoichiometric LiTaO3. This calculation is performed using the temperature dependence of the order parameter obtained from the mean field theory (MFT) at temperatures lower than the transition temperature TC (TC= 963 K) of this crystal. The calculated values of the order parameter (squared) are fitted to the integrated intensity of 92 the central peaks as observed from the Ram...
Analysis of the 2007 and 2013 Droughts in Turkey by NOAH Hydrological Model
Bulut, Burak; Yılmaz, Mustafa Tuğrul (2016-10-01)
Analysis of drought, which is classified as a natural disaster, is globally considering the damage it gives. As a result detection of its characteristics is essential for understanding and reducing the effects of this natural disaster and for imminent prediction. In this study, soil moisture estimates obtained from NOAH hydrological model and normalized difference vegetation index obtained from MODIS observations are used to analysis the recent droughts in Turkey. With the utilization of these parameters th...
Citation Formats
M. H. Afsar, A. Ü. Şorman, and M. T. Yılmaz, “Investigation of the relation between the return periods of major drought characteristics using copula functions,” presented at the EGU General Assembly 2016, Viyana, Avusturya, 2016, Accessed: 00, 2021. [Online]. Available: