1. Introduction
Groundwater is an essential resource, especially in arid and semiarid areas with shortage of surface. In these areas groundwater is the main supply for different economical purposes such as: industry, agriculture, and domestic consumption [
1,
2]. Agriculture consumes about 70% of the global of water supplies, while the remaining 30% is attributed to industrial and domestic consumption [
3,
4]. The present-day global water demand for is 4,600 km
3 per year and it is estimated that will increase by 20% to 30% by 2050 and up to 5,500 to 6,000 km
3 per year [
5]. The increase in water needs is attributed to the accelerated population growth and expansion of irrigated agriculture [
6,
7,
8]. It is estimated that water deficit will reach 35% and 45% of the population needs by 2030 and 2050 respectively [
9,
10,
11].
Global climate change and variations in the hydrological cycle are exacerbating this problem, creating complex scenarios that worsen the challenges related to estimate groundwater quantity, quality, and availability [
6,
7]. In recent years, aquifer systems have faced a critical level of stress due to both climatic and anthropogenic factors [
12]. The Intergovernmental Panel on Climate Change (IPCC) predicts that the global average surface temperature will rise from 2 to 4 °C by the end of this century [
13,
14]. This increase of temperature in the global climate poses a threat to groundwater recharge in aquifers and the availability of surface water. Cuthbert et al. [
7] report that 44% of aquifers worldwide will be affected by climate change.
More than 35% of global water resources are contained within Latin America territories [
15]. However, some regions still face significant challenges related to groundwater availability and management. Mexico and other Latin American countries as Canada, United States, Brazil, Argentina, Chile, Bolivia and Peru are increasingly dependent on groundwater resources, especially in arid or semi-arid regions [
16,
17]. Canada and the United States have significant groundwater resources, utilizing approximately 23% of available water. In South America, between 40% and 60% of available water is utilized, while in Central America and Mexico, this figure reaches 65% [
17,
18]. For example, in Mexico, 111 of the 653 aquifers have been declared as overexploited [
19]. Due to a continuous population growth and demand for water, combined with change in land use, Latin America is facing challenging issues related to the overexploitation of groundwater resources.
Hydrogeological systems are vulnerable to overexploitation and contamination, particularly in arid and semi-arid areas, due to inadequate water management accomplishing a serious threat to their sustainability. Depletion of piezometric levels, seawater intrusion, soil salinization, land subsidence and ecosystem degradation are as a result of overexploitation in hydrogeological systems [
20,
21]. This issues related to overexploitation of groundwater have been exacerbated by an imbalance between supply and demand, which is worsened by the impacts of climate change and population growth [
3,
20,
22]. In Latin America the 25% of the population inhabits in water-stressed regions, mostly in cities in countries along the west coast of the continent [
17]. In these areas, groundwater can be the unique source of water. Therefore, it is crucial to accurately measure the current water volume and future water availability.
Due to the severity of the current hydrological stress situation in arid and semiarid areas it is important to carry out a systematic planning of groundwater management to assure a sustainable supply. Providing reliable estimates of available groundwater is essential for an efficient use of the groundwater resources and to mitigate future conflicts [
8]. Thus, numerical simulation tools (NST) are powerful tools that provide information for remediation and sustainable groundwater management [
23,
24,
25]. NST simplify complex hydrogeological systems making it easier to investigate specific phenomena or forecast future groundwater and aquifer behavior. However, the challenge is to simplify reality without compromising the accuracy or the ability of the model to achieve it's objectives [
24,
26]. In last years, groundwater models have become essential tools for assessing, developing, and water resources management. These models are useful because they can simulate both groundwater quantity and quality using holistic and multidisciplinary approaches. They can also project various conditions and analyze future management and prediction scenarios [
1,
2,
11,
27,
28]. With massive increase in computational power and vast availability model software, numerical models have proven to be useful and essential tools for management of water resources and addressing challenges such as climate change, overexploitation, land use changes, and urbanization and additionally being helpful to the understanding of the complex hydrological and geochemical processes of aquifers. Therefore, it is important to make a review of the actual and available scientific literature to understand the current state of art and to propose future research opportunities in this field of study.
This study provides a comprehensive systematic review of research on numerical groundwater flow modeling, with a focus on it's application in water resources planning and management in Latin America from 2000 to February 2024. In this work we consider several key research questions, such as: what are the most commonly used software in numerical groundwater flow modeling? Is numerical modeling an effective tool for water supply and demand planning and management? Can it predict the future impacts of climatic and anthropogenic factors? Does it contribute to promoting groundwater resource sustainability? This systematic review is organized as follows:
Section 2 details the methods used for the systematic review, research design, and literature selection process.
Section 3 presents the results obtained and discussion.
Section 4 addresses the identified challenges and suggests possible directions for future research. Finally, Section 5 presents the main conclusions derived from this review.
2. Materials and Methods
2.1. Methodology
A systematic literature review (SLR) was conducted to analyze numerical modeling of groundwater flow for groundwater resources planning and management. The SLR was performed using the methodology proposed by De León Pérez et al. [
29], which combines the guidelines outlined by Nguyen & Singh [
30] and Kitchenham [
31] with the steps suggested by Muka et al. [
32]. This method synthesizes all available literature on a given topic or field of research, providing a structured and objective approach that improves the quality and reliability of the information obtained. It also helps to identify important insights, research gaps, and future research topics [
33,
34,
35]. The methodology developed in this systematic review is displayed in the flowchart shown in
Figure 1.
Figure 1 displays the flowchart of the methodology developed in this systematic review [
29].
2.2. Selection of Literature
Elsevier's Scopus and Clarivate's Web of Science bibliographic databases were used to conduct the search protocol [
36]. The search string for each database was customized using the keywords listed in
Table 1. Four sequential filters were applied as inclusion and exclusion criteria: year of publication (2000-2024), document type (article), language (English and Spanish), and region (Latin American countries), taking advantage of the automatic tools available in the databases.
A total of 2580 journal articles in English and Spanish from 2000 to 2024 were reviewed (1414 from Scopus and 1166 from Web Science). The articles were downloaded and stored in the reference management software Mendeley. Duplicates were removed using the 'Check for Duplicates' tool. After excluding duplicates, 1418 articles were assesed based on their title and abstract using the following inclusion criteria:
(1) Study Topic: the research article should focus on a case study, such as a basin, aquifer, or river-aquifer interaction.
(2) Application of groundwater flow modeling software: the article should use software to assess and manage groundwater resources (e.g., MODFLOW, FEFLOW).
(3) Model calibration and validation: numerical model fitting should be performed with performance metrics (e.g., R2, RMSE, MAE, NSE).
(4) Scenario evaluation and forecasting: simulation of future scenarios for a period of time (e.g., climate change, pumping rate, recharge-discharge, population growth, water demand, pollution).
After filtering, 1036 manuscripts were discarded and from the remaining 382 only 354 were available in full text. The full text manuscripts retrieved were read completely and the methodology, results, and conclusions were assessed. We only selected the texts that provided relevant information to answer the research questions that were selected. Finally, after the filtering selection applied 188 articles were discarded and the database was enclosed with 166 research articles for this systematic review (Appendix A and B, online supplementary material).
4. Conclusions
This work summarized the current state of numerical groundwater flow models used to evaluate water resources management in Latin America from 2000 to 2024. Research studies from Scopus and Web of Science databases were collected and reviewed. We found that Visual MODFLOW, MODELMUSE, GMS, GV, and FEFLOW are the most commonly used software for visual numerical groundwater simulation. In practice, they have proven to be effective modeling tools that provide valuable information for developing adaptation and mitigation strategies to face of future challenges such as climate change, increased water demand due to population growth and agricultural and industrial development. Additionally, scenario simulation and assessment of aquifer system responses should be included in future activities. It's important to simulate the combined effects of climate change and other pressures. The root mean square error (RMSE) was the most commonly used performance metric for model calibration and validation. These models were developed mostly in arid and semi-arid regions, where groundwater management challenges are most significant. Numerical models have significantly contributed to the understanding of aquifer systems and have successfully supported water management processes. However, numerical modeling faces numerous challenges and limitations. The availability of data to construct or validate conceptual models is often inadequate. In addition to the scarcity of studies and data in some areas, climate change also presents challenges to groundwater sustainability. Arid and semi-arid regions will be particularly affected by this phenomenon, making them a priority for future research. Continued research, improvement and development of numerical groundwater models is essential to ensure the sustainability of groundwater resources.