Water Static Level Modelling (2040) for Santo Domingo Aquifer

Description

The Santo Domingo aquifer, located in Baja California Sur, was modeled using MODFLOW to determine water depletion scenarios under RCP 8.5 climate change scenario and intensive groundwater extraction conditions. This dataset represents the expected groundwater levels for 2040. It includes X and Y coordinates in WGS84 UTM, as well as groundwater levels referenced to mean sea level in meters.

Steps to reproduce

For the Santo Domingo Valley model, a grid of 56 rows and 76 columns was generated, with a cell size of 2 × 2 km and local refinement to 250 m toward the mouth of the Santo Domingo arroyo. This refinement was applied in the area where there is evidence of advancing saline intrusion. The model domain covers the porous-medium zone north of the Santo Domingo Valley, within the Santo Domingo basin, and extends over an area of approximately 2,450 km². Vertically, the model consists of three layers. The alluvial sediments that form the plain were considered the main aquifer unit (Wurl et al., 2008; Wurl & Imaz-Lamadrid, 2017; CONAGUA, 2020a). To the east, groundwater flow from the Sierra de la Giganta was simulated using fixed-head cells, which were adjusted according to the observed behavior of groundwater levels. To the south, the model boundary was defined using no-flow cells. For the shallow aquifer, hydraulic conductivity values were taken from Wurl et al. (2018). This parameter was estimated through the textural analysis of 554 sediment samples, applying the methodology proposed by Shiozawa and Campbell (1991). CONAGUA provided a database of groundwater extraction wells and their corresponding extraction volumes. This database was converted into vector data and imported into the model. Of the total number of wells included in the database, 167 wells, with a combined extraction volume of 53 Mm³, were incorporated into the model because they were located within the study area. The model developed was run for the 2010–2016 period, with the objective of reproducing the observed static groundwater levels for 2016, as provided by CONAGUA. When the calibration objectives defined by Wels et al. (2012) and Hill (1988) were not met, the model input parameters were recalibrated until the established criteria were achieved. 100 control points were used. The calibration reached a mean variation of 1.18 m, a maximum variation of 8.47 m, and an R² value of 0.9896.

Institutions

• Universidad Autónoma de Baja California Sur

  Baja California Sur, La Paz

Categories

Funders

• CONACYT

  Grant ID: 472873

Licence