Analytical and numerical study of the salinity intrusion in the Sebou river estuary (Morocco) – effect of the “Super Blood Moon” (total lunar eclipse) of 2015

Abstract

Abstract. The longitudinal variation of salinity and the maximum salinity intrusion length in an alluvial estuary are important environmental concerns for policy makers and managers since they influence water quality, water utilization and agricultural development in estuarine environments and the potential use of water resources in general. The supermoon total lunar eclipse is a rare event. According to NASA, they have only occurred 5 times in the 1900s – in 1910, 1928, 1946, 1964 and 1982. After the 28 September 2015 total lunar eclipse, a Super Blood Moon eclipse will not recur before 8 October 2033. In this paper, for the first time, the impact of the combination of a supermoon and a total lunar eclipse on the salinity intrusion along an estuary is studied. The 28 September 2015 supermoon total lunar eclipse is the focus of this study and the Sebou river estuary (Morocco) is used as an application area. The Sebou estuary is an area with high agricultural potential, is becoming one of the most important industrial zones in Morocco and it is experiencing a salt intrusion problem. Hydrodynamic equations for tidal wave propagation coupled with the Savenije theory and a numerical salinity transport model (HEC-RAS software "Hydrologic Engineering Center River Analysis System") are applied to study the impact of the supermoon total lunar eclipse on the salinity intrusion. Intensive salinity measurements during this extreme event were recorded along the Sebou estuary. Measurements showed a modification of the shape of axial salinity profiles and a notable water elevation rise, compared with normal situations. The two optimization parameters (Van der Burgh's and dispersion coefficients) of the analytical model are estimated based on the Levenberg–Marquardt's algorithm (i.e., solving nonlinear least-squares problems). The salinity transport model was calibrated and validated using field data. The results show that the two models described very well the salt intrusion during the supermoon total lunar eclipse day. A good fit between computed salinity and measurements is obtained, as verified by statistical performance tests. These two models can give a rapid assessment of salinity distribution and consequently help to ensure the safety of the water supply, even during such infrequent astronomical phenomenon.

Effects of Extreme Events on Arsenic Cycling in Salt Marshes

“…10.1002/2017JG004259 environmental contaminants, such as As (Thomson & Rose, 2011), but few studies have been published about the direct effects of extreme phenomena on water quality (Haddout et al, 2016). Both the supermoon and hurricane-induced storm and surge extreme events that we examined increased water inundation at our field site but affected pore water chemistry in different ways.…”

Monitoramento de salinidade e modelagem de intrusão salina no Rio Cubatão, São Paulo.

“…The acquired data were compared to the temperature and salinity data from the industrial sensor HOBO U24-002-C Water Conductivity Data Logger. This temperature and salinity accuracy is in consonance with others water quality sensor applied in recent researches in estuarine environments (YU et al, 2014;HADDOUT et al, 2016, ABDULLAH et al, 2016, LOCKRIDGE et al, 2016 Salinity is calculated using the dimensionless Practical Salinity Scale 1978 (PSS-78) (IOC; SCOR; IAPSO, 2010), which depends on temperature and pressure values (Eq. 3 to Eq.…”

“…Seawater intrusion in estuaries is a complex phenomenon and depends directly on many environmental conditions, such as the estuary geometry, tidal processes and fresh water inputs. This process may cause high salinity concentration in upstream parts of estuarine rivers, affecting multiple uses of water (MARTIN;MCCUTCHEON, 1999;ETEMAD-SHAHIDI et al, 2015;MASLOUHI, 2016;JI, 2017). Considering that each estuary has specific salinity patterns, it is crucial to develop a better understanding on its local behavior, principally in estuaries with high density population or industrial areas, where water resources demand is decisive for several activities KJERFVE, 2012;ETEMAD-SHAHIDI et al, 2015).…”

“…several studies have been conducted to investigate estuarine responses to climate change effects, such as alteration of freshwater discharge and SLR, and their relation with seawater intrusion Haddout, Igouzal and Maslouhi (2016). applied the 1D HEC-RAS model to study the seawater dynamics in the Sebou River estuary (Morroco) under different tide and freshwater discharge forcing conditions.…”

Thermal response of Moroccan lakes to climatic warming: first results

“…To evaluate FLake model performance, we used a number of statistical metrics: root mean squared error (RMSE); mean absolute error (ABSERR); the Nash Sutcliffe modelling efficiency index (EF); the goodness-of-fit (R 2 ) and the % of deviation from observed (PBIAS) (see Moriasi et al, 2007;Stehr et al, 2008;Conversa et al, 2015;Haddout et al, 2016Haddout et al, , 2017a. The closer the values of RMSE and ABSERR to zero, and the R 2 to unity, the better the model performance is evaluated (El-Nasr et al, 2005).…”