Surface Seiche Formation on a Shallow Reservoir in Complex Terrain

[1] This paper explores the use of a mixture model for determining the marginal distribution of hydrological variables, consisting of a truncated central distribution that is representative of the central or main-mass regime, which for the cases studied is a lognormal distribution, and of two generalized Pareto distributions for the maximum and minimum regimes, representing the upper and lower tails, respectively. The thresholds defining the limits between these regimes and the central regime are parameters of the model and are calculated together with the remaining parameters by maximum likelihood. After testing the model with a simulation study we concluded that the upper threshold of the model can be used when applying the peak over threshold method. This will yield an automatic and objective identification of the threshold presenting an alternative to existing methods. The model was also applied to four hydrological data series: two mean daily flow series, the Thames at Kingston (United Kingdom), and the Guadalfeo River at Orgiva (Spain); and two daily precipitation series, Fort Collins (CO, USA), and Orgiva (Spain). It was observed that the model improved the fit of the data series with respect to the fit obtained with the lognormal (LN) and, in particular, provided a good fit for the upper tail. Moreover, we concluded that the proposed model is able to accommodate the entire range of values of some significant hydrological variables.Citation: Solari, S., and M. A. Losada (2012), A unified statistical model for hydrological variables including the selection of threshold for the peak over threshold method, Water Resour. Res., 48, W10541,

show abstract

“…Daily precipitation and mean daily flow data series from Orgiva, Spain (coordinates

36 ° 54' N

3 ° 25' W

) were used. A description of the characteristics of this basin can be found by Herrero et al [2009], Millares et al [2009], and Mans et al [2011].…”

Section: Applicationmentioning

confidence: 99%

A unified statistical model for hydrological variables including the selection of threshold for the peak over threshold method

Solari

Losada

2012

Water Resources Research

View full text Add to dashboard Cite

show abstract

“…The first detailed description thereof was presented by Mortimer (1952). In these systems, wind is the main force affecting the surface and isotherms (Wiegand and Chamberlain, 1987), which produces a set of periodic oscillations and circulation cells throughout the water column that may contribute to internal mixing of the basin (Thorpe, 1974;Monismith, 1985;Wiegand and Chamberlain, 1987;Münnich et al, 1992;Mans et al, 2011;Simpson et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Seiche excitation in a highly stratified fjord of southern Chile: the Reloncaví fjord

et al. 2017

View full text Add to dashboard Cite

Abstract. We describe a seiche process based on current, temperature, and sea-level data obtained from the Reloncaví fjord (41.6° S, 72.5° W) in southern Chile. We combined 4 months of acoustic Doppler current profiler (ADCP) data with sea-level, temperature, and wind time series to analyze the dynamics of low-frequency (periods > 1 day) internal oscillations in the fjord. Additionally, seasonal conductivity, temperature, and depth (CTD) data from 19 along-fjord stations were used to characterize the seasonality of the density field. The density profiles were used to estimate the internal long-wave phase speed (c) using two approximations: (1) a simple reduced gravity model (RGM) and (2) a continuously stratified model (CSM). No major seasonal changes in c were observed using either approximation (e.g., the CSM yielded 0.73 < c < 0.87 m s−1 for mode 1). The natural internal periods (TN) were estimated using Merian's formula for a simple fjord-like basin and the above phase speeds. Estimated values of TN varied between 2.9 and 3.5 days and were highly consistent with spectral peaks observed in the along-fjord currents and temperature time series. We conclude that these oscillations were forced by the wind stress, despite the moderate wind energy. Wind conditions at the end of winter gave us an excellent opportunity to explore the damping process. The observed damping time (Td) was relatively long (Td =  9.1 days).

show abstract

“…Current hydrodynamic modeling of wetlands and shallow reservoirs is normally taken into account using 2D depth averaged models based on either wastewater treatment or overseas experience [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

“…Wind stress modeling over the wetland surface ranges from simple formulations using a constant wind drag coefficient [17] to more theoretically sounded complex formulations [20]. Despite wind being usually presumed as the major driver of water movement and studied phenomena such as seiche formation [17] or water turbidity [21], little discussion is found in the freshwater modeling literature about the choice of the wind stress formulation.…”

Section: Introductionmentioning

confidence: 99%

“…Despite wind being usually presumed as the major driver of water movement and studied phenomena such as seiche formation [17] or water turbidity [21], little discussion is found in the freshwater modeling literature about the choice of the wind stress formulation. However, wind drag modeling is still an ongoing discussion in coastal and marine engineering [22].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Envisat/ASAR Images for the Calibration of Wind Drag Action in the Doñana Wetlands 2D Hydrodynamic Model

et al. 2013

View full text Add to dashboard Cite

Doñana National Park wetlands are located in southwest Spain, on the right bank of the Guadalquivir River, near the Atlantic Ocean coast. The wetlands dry out completely every summer and progressively flood again throughout the fall and winter seasons. Given the flatness of Doñana's topography, the wind drag action can induce the flooding or emergence of extensive areas, detectable in remote sensing images. Envisat/ASAR scenes acquired before and during strong and persistent wind episodes enabled the spatial delineation of the wind-induced water displacement. A two-dimensional hydrodynamic model of Doñana wetlands was built in 2006 with the aim to predict the effect of proposed hydrologic restoration actions within Doñana's basin. In this work, on-site wind records and concurrent ASAR scenes are used for the calibration of the wind-drag modeling by assessing different formulations. Results show a good adjustment between the modeled and observed wind drag effect. Displacements of up to 2 km in the wind direction are satisfactorily reproduced by the hydrodynamic model, while including an atmospheric stability parameter led to no significant improvement of the results. Such evidence will contribute to a more accurate simulation of hypothetic or design scenarios, when no information is available for the atmospheric stability assessment.

show abstract

Surface Seiche Formation on a Shallow Reservoir in Complex Terrain

Cited by 4 publications

References 18 publications

A unified statistical model for hydrological variables including the selection of threshold for the peak over threshold method

A unified statistical model for hydrological variables including the selection of threshold for the peak over threshold method

Seiche excitation in a highly stratified fjord of southern Chile: the Reloncaví fjord

Envisat/ASAR Images for the Calibration of Wind Drag Action in the Doñana Wetlands 2D Hydrodynamic Model

Contact Info

Product

Resources

About