Applying EFDC Explorer model in the Gallinas River, Mexico to estimate its assimilation capacity for water quality protection

Abstract

Sanitary and industrial wastewater discharged into rivers, is a general problem that occurs in most of the world and Mexico is not the exception, the main goal of this research is to determine based on simulations of pollutants concentrations, the assimilation capacity of the Gallinas River against discharges of agricultural and industrial wastewater from the cultivation and processing of sugar cane under two different hypothetical simulation scenarios, based on reproducing two well know scenarios. In sugarcane cultivation, large quantities of fertilizers are used whose main active components are based on nitrogen or phosphorus compounds, therefore, the wastewater resulting from sugarcane processing contains a high organic content from 20 to 40% of inorganic compounds, such as nitrogenous substances, organic acids, and phosphorous sulfates. For this reason, the physical–chemical variables of interest analyzed in this work are the PO$$_4$$ 4 (phosphate), NO$$_3$$ 3 (nitrate), and DO (dissolved oxygen). With the simulation results according to each scenery, it can be determined, that despite the continuous discharge of polluting elements, the Gallinas River has a good assimilation capacity thanks to reaeration processes that permit efficient recovery of the dissolved oxygen in the water column. Gallinas River is located in the region known as the Huasteca Potosina, this investigation is relevant for the region due to the River is of vital importance being the main tributary that allows socioeconomic development activities in this zone. To carry out the simulations, was used the Explorer Modeling System 8.4 (EFCD) model and was performed two samplings campaign along 15 km in the water body to calibrate the numerical model to represent the dry and wet seasons during May and September respectively named as calibration scenarios.

Hydrodynamical Assessment of the Recent Droughts at Gallinas River in San Luis Potosí México and Its Impact on the Waterfall Tamul

“…The process to determine the causes of flow loss could be used to determine the effects of extreme weather events on the rivers of our plan, such as droughts, and extreme rains, in any region of the world; in this sense, hydrodynamic models are a valuable tool for determining many hydrodynamic processes, such as the assimilation capacity of a river [23], heavy metals transport [37] or to determine the transport and distribution of any contaminant [42].…”

“…To carry out accurate modeling, it is necessary to collect the hydrological and hydraulic conditions of the Gallinas River and identify variations in river flow. The EFDC model was used to carry out the numerical simulations because it is a well-proven code to predict hydrodynamics, solving the momentum and free surface equations considering the continuity and mass balance equations [23].…”

Impact of Reservoir Operation Policies on Spatiotemporal Dynamics of Sediment Methane Production and Release in a Large Reservoir

“…Following previous studies (Gustafsson et al., 2015; Saltelli et al., 2000), we adjust one parameter at one time to create scenarios and calculate a relative sensitivity coefficient introduced by Cunderlik and Simonovic (2004) to compare the sensitivities of different parameters. The EFDC model allows for setting a dynamic time step to handle the model stability and increase computational efficiency (Villota‐López et al., 2021). The starting time step is usually short, and it increases during the run while assuring the model stability.…”

Flood risk assessment of the Garita River in the urban zone of San Luis Potosí City, by hydrodynamic modeling

“…The main objective of this research is to assess the Garita Stream within the city of San Luis Potosí and determine the conditions under which the stream overflows. The EFDC (Environmental Fluid Dynamics Code) model is a powerful tool for simulating fluid flow in natural water bodies 10 – 13 . Still, it can also be adapted for urban flooding simulations 14 – 18 .…”