Abstract
Sediment management in hydroelectric power plants has been mainly oriented by economic and technical aspects, unlike current management approaches, which also recognize the importance of integrating social and environmental aspects into decision-making. Consistent with this vision, the concept of corporate sustainability is proposed in the international literature as a management perspective in which the economic, environmental, and social dimensions are considered to guide management in organizations. This article aims to analyze recent studies on sediment management in hydroelectric power plants to evaluate how the corporate sustainability perspective is being integrated into the decision-making processes of sediment management. For this purpose, a systematic literature review was conducted, and its findings lead to the following conclusions: despite the growing interest in corporate sustainability and climate change in the literature, the percentage of publications that include the three dimensions of sustainability as criteria for choosing sediment management alternatives is low. In addition, it has been observed that the economic dimension is still the most relevant criterion for choosing sediment management techniques. Likewise, it has been observed that Multicriteria Decision-Making methods are widely used for selecting sediment management strategies in reservoirs. In the cases in which the three dimensions of corporate sustainability have been integrated into the decisional process, the most used methods are Multi-Attribute Decision-Making.
Plain language summary
This study aims to analyze recent studies on sediment management in hydropower plants to assess how the corporate sustainability perspective is integrated into sediment management decision-making processes. For this purpose, a systematic literature review was carried out, which revealed that despite the growing interest in corporate sustainability and climate change in the literature, the percentage of publications that include the three dimensions of sustainability as criteria for choosing sediment management alternatives is low. In addition, it has been observed that the economic dimension is still the most relevant criterion for choosing sediment management techniques. Likewise, it has been observed that Multicriteria Decision-Making methods are widely used for selecting sediment management strategies in reservoirs. In the cases in which the three dimensions of corporate sustainability have been integrated into the decisional process, the most used methods are Multi-Attribute Decision-Making.
Keywords
Introduction
Hydropower generation through reservoirs is continuously subjected to situations that make its production process vulnerable due to natural, cultural, and technological factors (the progress and advancement of science and technology) (Golubev et al., 2021). A fundamental aspect of the lifetime of a hydropower plant is the water storage capacity in the reservoir because power generation directly depends on it (Do et al., 2022; Kumar et al., 2011; Mekonnen et al., 2022). Sedimentation in hydropower plants, as a natural phenomenon, reduces the long-term water storage capacity of reservoirs (George et al., 2017; Haregeweyn et al., 2012; Kondolf et al., 2014).
Soil erosion as a process of natural or anthropogenic-induced deterioration is one of the main factors that cause sedimentation processes in reservoirs (Farhan & Nawaiseh, 2015; Tuppad et al., 2010; Vignola et al., 2017). This deterioration process is caused by various natural factors (soil characteristics, vegetation cover, climatology, etc.), as well as cultural factors (agriculture, livestock, mining, infrastructure, among others) (Annandale et al., 2016; Do et al., 2022; Kondolf et al., 2014). The entrainment of soil materials by rainwater to rivers deteriorates water quality. Consequently, the supply of reservoirs by river waters induces sedimentation processes of solid materials in the reservoirs (Ding et al., 2024).
The design of sediment management methods in reservoirs has typically focused on controlling these solid materials rather than addressing the anthropogenic and natural factors that generate sediment (Annandale et al., 2016). Therefore, addressing the phenomenon of sedimentation in these infrastructures requires the involvement of several areas of knowledge and, thus, represents a challenge for hydropower generation companies. Even more so, if the design of sedimentation control methods tends to focus exclusively on technical (engineering) and economic (costs) knowledge and, to a lesser extent, on environmental and social knowledge (Alvarez et al., 2009; Haregeweyn et al., 2012). This situation is a determining factor in the decision-making processes related to the management of hydroelectric power plants because it makes it difficult to choose effective measures to control the factors that generate sedimentation in reservoirs. Therefore, in the long term, a reduction in the power generation capacity of this type of hydropower plants is foreseen (Do et al., 2022; Ren et al., 2021).
The design of sediment control systems has focused basically from two perspectives: a) the construction of structures for sediment retention and b) biological (taking advantage of the natural conditions of the territory) (Kong et al., 2023). On the one hand, the construction of sediment control dams has been very effective in the short term, as evidenced in the Yellow River Basin, in which, during the years 2010 to 2017, the sediment level was reduced to 92% with respect to the levels in the 1970s (Kong et al., 2023). However, the lifespan of these infrastructures is limited, as they have been designed to control sediment rather than to address the factors that generate it (Li et al., 2019; Liu et al., 2018). Therefore, in the medium term, they could generate a negative impact on the economy of the companies and, in turn, on the dynamics of the rivers due to the alteration of the channels (Kong et al., 2023).
The terrace construction, as an alternative for trapping sediments, has been recognized for its effectiveness since it reduces the entrainment of solid materials by up to 95% (L. Chen et al., 2007). This technique mitigates the environmental impacts generated by sediment entrainment in water sources. On the other hand, biological measures, such as reforestation and grass planting, are techniques that reduce sediment production (He et al., 2022). These techniques have a more extended effect over time, a lower economic cost, and, in turn, their impact on the environment is positive for both soil and fauna (Quiñonero-Rubio et al., 2016).
The design of sediment control systems including environmental and social criteria, although it is scarce in the literature, has derived very effective results for the control of this problem in reservoirs, as recognized by several authors (Feng et al., 2016; Lyu et al., 2019; Z. Wang et al., 2022; Yang et al., 2018; G. Zhao et al., 2018; L. Zhao et al., 2023). In the particular case of the Yellow River Basin, there is evidence of decreased sediment production due to the drastic increase in soil and water conservation measures (Kong et al., 2023).
The importance of sedimentation management in hydropower plants, due to its implications for long-term operation (George et al., 2017; Opperman et al., 2023), along with the environmental effects it generates, highlights the relevance of implementing a decision-making process that simultaneously incorporates technical, economic, environmental, and social aspects for addressing sedimentation in reservoirs (Alvarez et al., 2009; Kiker et al., 2005).
Decision-making processes have been guided by various methods developed since the 1960s. The Multicriteria Decision-Making Methods (MCDM) have gained great relevance in the international literature (Sahoo & Goswami, 2023). These methods have been designed with a quantitative approach; however, they allow for incorporating qualitative and quantitative information through numerical and categorical variables. Consequently, they are commonly used to support decision-making processes involving variables associated with various fields of knowledge, disciplines, or sciences (economics, sociology, engineering, biology, anthropology, hydrology, etc.) (J. J. Wang et al., 2009). MCDM have become an important support tool in decision-making related to hydropower generation since 2009. These methods have been used in various topics, including dam break risk (Samaras et al., 2014), dam operation (Teegavarapu et al., 2013), reservoir location (Jamali et al., 2014), water quality (Taheriyoun et al., 2010; Ye et al., 2012), flooding (Seibert et al., 2014; Xing et al., 2012), sediment management (Elfimov & Khakzad, 2014; Haregeweyn et al., 2012), among others. Even so, it could be stated that there is currently limited literature on evaluating sediment management alternatives using MCDM with sustainability criteria.
Corporate sustainability is a perspective that allows guiding business management by considering three dimensions: environmental, economic, and social (R. Chang et al., 2017; Purvis et al., 2019). Consequently, this approach proposes to integrate these dimensions into the decisional processes of organizations. In this sense, the integration of corporate sustainability dimensions in the design of sediment control systems could contribute to preventing, mitigating, and correcting negative impacts on the environment (Daus et al., 2021; Quaranta et al., 2023). In turn, linking the economic dimension could prevent the company from incurring cost overruns arising from the implementation and maintenance of sediment management techniques (Kong et al., 2023). Integrating the environmental dimension could mitigate effects such as the deterioration of water quality, the impact on fauna, and the loss of the scenic quality of the environment, among others (Daus et al., 2021). Likewise, involving the social dimension could reduce the negative impacts on the use of water for various purposes of a population, such as domestic consumption, recreation, and agricultural use, in addition to improving the relationship with the impacted communities (Daus et al., 2021). On the other hand, if these dimensions were not considered in the design of sediment management methods but were included as criteria for selecting such methods, the amount and intensity of negative impacts on the environment and society could be reduced. Consequently, it is of significant importance to link the three dimensions of corporate sustainability in the design of sediment management systems and incorporate them into the decision-making processes related to the choice of these alternatives, as highlighted by Quaranta et al. (2023).
This article is oriented from a corporate sustainability perspective. Therefore, its objective is to determine how the dimensions of corporate sustainability are involved in the decision-making processes of sediment management in hydroelectric power plants. To achieve this objective, the following research questions are posed:
What sediment management methods are used in hydroelectric power plants?
What multicriteria decision-making methods are used to select sediment management alternatives?
What dimensions of corporate sustainability are used as evaluation criteria in selecting sediment management alternatives?
To conduct the research, a Systematic Literature Review (SLR) was employed as the data collection methodology, following the model proposed by Amui et al. (2017) and Bandara et al. (2011). Based on the review results, the literature related to the research questions was analyzed, identifying knowledge gaps and offering relevant suggestions for future research (Jamaluddin et al., 2023; Janjua et al., 2021).
The article is structured as follows: First, it introduces the conceptual framework. Then, it describes the methodology used in the systematic literature review. Subsequently, the results section is present, which includes (a) the frequency of occurrence of codes, (b) the frequency of co-occurrence of codes, and (c) the content analysis. Finally, the discussion and conclusions are presented.
Conceptual Framework
Sediment Management
Hydropower plants with reservoirs typically disrupt the natural flow of sediment through river systems. As water enters the reservoirs, its speed decreases, reducing its capacity to transport sediment (George et al., 2017; Ren et al., 2021). Consequently, sediment deposits accumulate in the bottom reservoirs, occupying space initially designated for flood management, power production, and water supply services (Annandale et al., 2016; Kondolf et al., 2014).
Various technologies are available to address sedimentation, which can help mitigate and control these processes. These techniques and treatments can be used in both new and existing projects. According to several studies conducted by Annandale et al. (2016), Kondolf et al. (2014), and Morris (2020), these methods can be broadly classified into four categories:
Methods to reduce upstream sediment input: These are based on strategies to reduce sediment production entering the reservoir from the upstream watershed by controlling soil and channel erosion at the source or trapping eroded sediment upstream of the reservoir.
Methods of passing sediment through or around the reservoir to minimize sediment trapping: Refers to a family of techniques that take advantage of temporal variation in flow by managing flows during periods of increased sediment production to minimize sediment capture in the reservoir.
Methods to redistribute or remove sediment deposits: Hydraulic and mechanical techniques are commonly used for sediment removal from reservoirs and restore some or all of the initial storage capacity.
Methods to adapt to sedimentation: These actions aim to mitigate the impacts of sedimentation but do not involve direct sediment management. They can be used in conjunction with or as an alternative to active sediment management. These include improving operational efficiency, modifying structures to avoid sedimentation, and raising the dam to increase volume.
Sustainable sediment management aims to balance sediment inflow and outflow to reservoirs. This is achieved by restoring sediment supply to the downstream channel to maximize reservoir water storage while ensuring long-term hydropower production (Morris, 2020). The first three categories concentrate on improving sediment balance in reservoirs, while the fourth category involves implementing adaptive strategies that respond to capacity loss without addressing sediment balance (Morris, 2014).
Corporate Sustainability
According to scientific literature, corporate sustainability has no standardized definition (Ahmed et al., 2021; R. Chang et al., 2017). However, there appears to be a common origin in the concept of Sustainable Development as proposed in the Brundtland Report (Lozano, 2008), defined as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (World Commission on Environment and Development, 1987). Since then, the understanding of corporate sustainability has evolved, and various approaches have been proposed to explore the complex interrelationships between sustainability and the organizational world (R. Chang et al., 2017).
The Triple Bottom Line (TBL) approach proposed by Elkington (1998) is widely recognized as a sustainable approach that considers three dimensions: economic, environmental, and social (R. Chang et al., 2017; Purvis et al., 2019; Schneider & Meins, 2012). However, this approach has been criticized for providing a fragmented and static view of sustainability (Lozano & Huisingh, 2011; Polanco et al., 2016). To address this, a more integrated approach has emerged, emphasizing the integration of the economic, environmental, and social dimensions and the relationships between them. This approach seeks to achieve economic prosperity, environmental quality, and social equity simultaneously (Lozano, 2008).
The sustainability strategy of a company links it directly to its surroundings, as its economic, social, and environmental aspects are related to those of the territory where it operates. For hydroelectric power generation companies, adaptation to the territory is determined by access to water and relations with their stakeholders (Polanco, 2014). Therefore, managing this interdependence requires these organizations to integrate sustainability dimensions into their decision-making process. The corporate sustainability concept proposed by Lozano (2011) addresses incorporating these dimensions into business management. It is defined as “Corporate activities that seek to contribute to the balance of todays economic, environmental, and social dimensions, as well as their interrelationships in the short and long term while addressing the systems of the company and its stakeholders.” This concept is adopted in this LSR concerning the decision-making process.
As per the notion of sustainability embraced in this study and the investigations carried out by García et al. (2016), Polanco (2018), and J. J. Wang et al. (2009) the three dimensions of corporate sustainability and their interrelationships will be used for this SLR. The following indicators are considered for each of them:
Social: Social acceptability, Job creation, Social benefits Environmental: Impact on biodiversity, Condition of natural resources (water and soil) Economic: Energy generation, Investment cost, Operation and maintenance cost, Net Present Value (NPV), Monetary compensation associated with the impact of the implementation of management alternatives Social-environmental: Training, consciousness, and environmental culture in the territory. Economic-environmental: Economy of natural resources (supply and demand), Environmental pollution, Basic sanitation Economic-social: Activities for subsistence, Food security, Production organization, Commercialization of farm products
Multicriteria Decision-Making
Decision-making is the core of planning and is defined as the process of choosing one or more suitable alternatives among several possibilities to achieve a desired state, considering the context and resource constraints (Canós Darós et al., 2012; Koontz et al., 2012). According to the number of participants involved in the decisional process, it is possible to identify two types of decisions: individual decisions and group decisions (Mukherjee et al., 2016). In individual decision-making, a single agent assumes the responsibility of choosing, based on one or more criteria, the most appropriate alternative solution to a problem (Taherdoost & Madanchian, 2023). On the other hand, Group Decision-Making (GDM) requires the participation of two or more agents. This group is usually composed of experts in different knowledge areas, whereby it is common for decision-makers to express their opinions using heterogeneous preference structures (B. Zhang et al., 2019). In this case, each expert recognizes the existence of a shared problem and seeks to arrive at a collective decision. The goal of the group decision process is to select, from various criteria, the best alternative to solve a problem (Chao et al., 2021; Xu et al., 2019; H. Zhang et al., 2019; Z. Zhang et al., 2020).
In a group decision-making context, Multicriteria Decision-Making methods (MCDM) are used to find optimal solutions based on expert preferences. These methods have been designed to address complex problems that have high uncertainty, conflicting objectives, as well as multiple interests and perspectives (Peniwati, 2017; Sahoo & Goswami, 2023). MCDM methods are divided into Multi-Objective Decision-Making (MODM) and Multi-Attribute Decision-Making (MADM). The difference between them lies in the type of decision problem they address (Hwang & Yoon, 1981; Taherdoost & Madanchian, 2023).
MODM methods are used to solve continuous problems and are based on optimization theory, which implies that the set of solution alternatives to a problem is infinite. In these methods, the criteria are explicit objectives, the attributes are implicit, and experts contribute to modeling the objective functions and constraints to guarantee the feasibility of the solutions (Low et al., 2024). On the other hand, MADM methods are used in discrete problems where the set of solution alternatives is finite. In this case, the objectives are implicit, and the attributes (that correspond to the criteria) are explicit. In MADM methods, experts evaluate the solution alternatives based on decision criteria (economic, technical, quality, etc.) to select the best alternative in a decision-making problem (Basílio et al., 2022).
The MADM methods allow the incorporation of both quantitative and qualitative information in decisional processes through the use of indicators (Mardani et al., 2015), which are expressions representing a specific variable or category. To integrate qualitative-type indicators related, for example, to aspects of the social and/or human sciences, these methods transform qualitative information into quantitative information through the process of quantification (Yan et al., 2017). This process involves assigning numerical values to qualitative information using rating scales or score assignments to facilitate aggregation and comparison (del Pozo et al., 2020). Therefore, MADM methods are very useful for incorporating the economic, environmental, and social dimensions proposed by corporate sustainability in organizational decision-making processes (Zolghadr-Asli et al., 2021).
Methodology
A systematic literature review (SLR) was conducted using the methodology described by Amui et al. (2017) and Bandara et al. (2011). The review followed a four-stage structure: the first stage considers collecting available articles on the topic; the second stage consists of developing and using a structured coding system based on the conceptual framework; the third stage involves identifying the main findings of the articles based on the coding system; the fourth stage consists of analyzing knowledge gaps, as well as identifying opportunities and challenges for future studies. This type of literature review has become popular among scholars from various research fields, such as Amui et al. (2017), Jamaluddin et al. (2023), Janjua et al. (2021), and Lammers & Hoppe (2018).
The data collection was carried out from 1960 to 2023 because the methodologies for decision-making were created and developed in the 1960s (Mardani et al., 2015). For this study, the Web of Science (WOS) and Scopus databases were used, both of which are globally recognized for their prestige in the field (Q. Wang & Waltman, 2016). The document search was limited to publications in English that were available in the databases since this language is widely recognized as the most commonly used in scientific publications globally. Likewise, given the significance of reservoir sedimentation issues in hydroelectric power plants worldwide, the search for information was not limited by continent, region, or country. Four groups of research terms were identified based on the research questions: decision making, sediment management, corporate sustainability, and the hydropower sector. For each group, keywords were selected, considering different synonyms used to describe the same concept (see Figure 1)
Keywords for data collection.
Using the Boolean operator “AND,” forty-eight equations were created by combining all possible keyword groups (Table 1). These equations were then searched for “article title, abstract, and keywords” in the abovementioned databases.
Documents Found by Search Equation.
Subsequently, 275 papers were examined by reviewing their titles and abstracts to identify those that appeared to be relevant to the study problem (Figure 2). This process led to an initial selection of 55 documents. A full-text search was conducted, but only 44 of the 55 pre-selected papers were available for an exhaustive reading. In the final phase, 25 documents were excluded as they provided relevant information to the research questions. Finally, 19 papers, which included articles and book chapters, were selected for detailed analysis. These documents were chosen to help answer the research questions. Table 2 presents the articles selected for the systematic literature review.
Document selection procedure.
Systematic Literature Review Articles.
To conduct a detailed analysis of the 19 selected papers, the qualitative analysis tool ATLAS.ti was employed, which, in the context of a literature review, enhances the ability to extract adequate meaning from the underlying data, contributes to systematic data management and facilitates thematic analysis to identify recurring themes and synthesize results (Bandara et al., 2011). This approach has been successfully employed in previous research (Cortés et al., 2020; Hautala et al., 2018; Lammers & Hoppe, 2018).
The analysis began with deductive coding, focused on the categories of sediment management alternatives, decision-making, and corporate sustainability. In parallel, inductive coding was performed based on emerging categories identified in the analyzed articles (Bonilla & Rodríguez, 1995; Caldera et al., 2017). Specific codes and sub-codes were defined for each category (see Table 3). In the Sediment Management Alternatives category, four codes and twenty-two sub-codes were proposed, according to the classification established by Annandale et al. (2016), Hauer et al. (2018), and Sumi and Kantoush (2011). In the Corporate Sustainability category, six codes and eighteen sub-codes were established, covering economic, environmental, and social dimensions and their interactions, according to García et al. (2016), J. J. Wang et al. (2009), and Polanco (2018). Finally, in the Multicriteria Decision-Making category, one code and fifteen sub-codes were established following the research of J. J. Wang et al. (2009). Using the ATLAS.ti tool, the frequency of occurrence for each code and sub-code was analyzed, along with the frequency of co-occurrence between two or more of these elements.
Codes and Sub-codes for Content Analysis.
Results
The systematic literature review results are presented below, considering the objective of this study and the methodology adopted. This section comprises three sections: frequency of occurrence, frequency of co-occurrence, and content analysis.
Frequency of Occurrence
Sediment management alternatives category: About the frequency of occurrence of the codes of this category: RED-SED, REM-SED, AD-STG, and ROU-SED, the following results were obtained: 68%, 24%, 24%, 5%, and 3%, respectively (Figure 3).
Quotation percentage—Sediment management alternatives codes.
In the RED-SED sediment management methods, land use and management practices have the highest frequency of occurrence (41%), followed by the construction of dispersed structures (check dams, agricultural ponds, stone blocks, vegetative filter strips) with 15% and reforestation with 11%. Regarding the most investigated methods in the REM-SED techniques, it is observed that the empty flushing alternative presents a frequency of occurrence of 7%, followed by dry excavation at 6% and dredging (discharge below or outside the channel) at 5%.
The sediment management alternatives less referred to in the studies include the construction of large dams, off-stream reservoirs, vent turbid density currents, and water loss control and conservation. See Figure 4.
Quotation percentage—Sediment management alternatives sub-codes.
Corporate sustainability category: In this category, the code corresponding to the economic dimension is the most cited, with a prevalence of 30% concerning the other codes. The economic-environmental and economic-social codes have an importance of 15% each. The environmental code has a relevance of 11%, followed by the social and socio-environmental codes, both with 10%. In the coding process, the technical code emerged with a frequency of 9%. See Figure 5.
Quotation percentage—Corporate sustainability codes.
Regarding the sub-codes associated with the corporate sustainability category, the investment cost sub-code had the highest frequency of occurrence (12%). As a result of the coding process, the sub-codes water quality, with a frequency of 9%, and sediment control, with a frequency of 7%, emerged. The sub-codes with the lowest frequency are basic sanitation, commercialization of farm products, the economy of natural resources, and maximum flushing outflow. See Figure 6.
Quotation percentage—Corporate sustainability sub-codes.
Multicriteria Decision-Making category (MCDM): In this category, the frequency of occurrence of the MADM code was 39%. In the coding process of this category, the Multi-Objective Decision-Making (MODM) code emerged, whose frequency of occurrence was 61%. See Figure 7.
Quotation percentage—MCDM codes.
Regarding the MADM and MODM sub-codes, the following frequencies were obtained: in the MADM code, the most relevant techniques are Structured Value Referendum (SVR) with 10%, Analytic Network Process (ANP) with 8%, Weighted Additive with 7%, and Analytical Hierarchy Process (AHP) with 5%. In the MODM code, the frequency of sub-codes was as follows: Fuzzy Programming Approach is the most mentioned method, with a relevance of 29%, followed by Multi-Objective Game Theory with 18%, and finally, the Non-Dominated Sorting Genetic Algorithms-II (NSGAII) with 14%. See Figure 8.
Quotation percentage—MCDM subcodes.
Frequency of Co-occurrence
The co-occurrence analysis was performed to determine the frequency with which the codes are mentioned simultaneously among the different categories (sediment management alternatives, corporate sustainability, and MCDM). The co-occurrence analysis between the categories sediment management alternatives and corporate sustainability yielded the following results: the codes of the corporate sustainability dimensions are more frequently associated with the RED-SED sediment management alternatives. Notably, the economic dimension is the most commonly reiterated. This frequency of co-occurrence of corporate sustainability codes has the same tendency as the REM-SED sediment management alternatives. In contrast, the association of corporate sustainability dimensions with sediment management alternatives is minimal with the ROU-SED and AD-STG codes. See Table 4.
Frequency of Co-occurrence of Codes.
The analysis of co-occurrence between the alternative sediment management and MCDM categories yielded the following results: RED-SED and REM-SED codes are most frequently associated with Multi-Objective Decision-Making Methods (MODM) and Multi-Attribute Decision-Making methods (MADM). The highest frequency of co-occurrence is associated with MODMs. In contrast, no association exists between ROU-SED and AD-STG codes with MCDMs. See Table 4.
Content Analysis
This section provides an in-depth analysis of the 19 selected articles, beginning with the country of origin of the research, year of publication, and contributing authors. Subsequently, it analyzes the previously established categories: sediment management alternatives, dimensions of corporate sustainability, and Multicriteria Decision-Methods (MCDM).
According to the analysis findings, a large percentage of the studies have been developed in Asia (55%) and America (21.1%) and, to a lesser extent, in Africa (15.8%) and Europe (5.3%). Likewise, it is possible to observe that the country with the most case studies is China, with 21%, followed by Iran, with 16%, and Taiwan and South Korea, with 11% each. The remaining countries have 5.3% each. Regarding the research publication period, it is distributed as follows: 52% corresponds to articles published between 2014 and 2024, while the remaining 48% covers the period between 1995 and 2013. The frequency of publications per author is uniform, given that only one article per author was identified. See Table 5.
Summary of the Analyzed Articles.
The frequency of use of the sediment management alternatives shows vast differences among them: RED-SED (68%), REM-SED (37%), AD-STG (10%), and ROU-SE (5%). These results show a clear preference for the use of RED-SED and REM-SED. Within the practices associated with RED-SED, the most employed strategies are land use and management practices and dispersed structures. As for REM-SED, the most commonly used techniques are flushing, excavation, and modifying operating rules.
Regarding incorporating corporate sustainability dimensions into decision-making processes related to sediment management, a significant increase has been shown from the first decade of the 21st century to the present (2024). In particular, over the last decade, using all three dimensions as criteria for selecting sediment management alternatives has become increasingly common. However, the economic dimension continues to prevail over the other dimensions of sustainability.
According to the SLR, in the last 30 years, MADM and MODM methods have been mainly used as decision-support tools in choosing sediment management alternatives. The frequency of use of these methods is as follows: MADM methods have been applied in 42% of the analyzed cases, while MODM methods have been applied in 37%. In addition, other methods have been applied less frequently, with Cost-Benefit Analysis being used in 10.5% of the cases, while the remaining 10.5% corresponds to other methods. These data show the growing importance of the MADM and MODM methods. It is essential to highlight that, in the research analyzed, when the three dimensions of corporate sustainability are integrated in sediment management, the most used methods are the MADM methods. Within this classification, the following techniques are used: ANP, AHP, WAM, SVR, and Weighted Additive.
In recent decades, MCDM methods (MADM and MODM methods) have been used as support tools for selecting alternatives for sediment management, including the dimensions of corporate sustainability as criteria of choice. This integration has been done with different frequency levels: in 36.8% of the cases, all three dimensions are included, 21.05% include two dimensions, 36.8% include one dimension, and in 5%, no dimension was included.
When using the MCDM methods, the dimensions of corporate sustainability have been linked as evaluation criteria with the following frequency: the economic dimension was used in 84.2% of the cases analyzed, the environmental dimension in 57.9%, and the social dimension in 47.4%. By integrating these dimensions into the decision-making process, RED-SED was favored over the other alternatives.
Discussion
According to the results of the systematic literature review, sediment management alternatives classified as Reduce Sediment Yield from Upstream (RED-SED) and Remove or Redistribute Sediment Deposits (REM-SED) are the most widely used compared to other sediment management methods. These prevention and mitigation measures seem to be adopted primarily to avoid the reduction of reservoir storage capacity rather than to prevent the generation of adverse environmental impacts (Annandale et al., 2016). This could be explained because sediment management alternatives do not aim to prevent, mitigate, or correct the negative environmental effects caused by sediments on the water resource, such as increased turbidity and changes in water color, odor, and taste since the primary objective of these control systems is to prevent sediment accumulation in the reservoir (Annandale et al., 2016; Kondolf et al., 2014; Morris, 2020). These environmental effects alter water quality; however, they do not affect power production. Therefore, they are not usually of interest for the design of sedimentation management methods; perhaps because of this, they are not relevant for power generation companies. This situation evidences the interest in controlling sediment accumulation in reservoirs primarily to ensure power production rather than to care for water quality (Annandale et al., 2016).
Among the methods classified as RED-SED, land use and management practices tend to be the most widely used. This implies a linkage of the social dimension in sediment management since it is related to the use of the territory for agricultural and livestock production. It is evident that, although sedimentation is a natural process, practices to prevent or reduce sediment generation tend to focus predominantly on anthropogenic aspects, such as correcting human intervention practices, rather than considering elements of natural order, such as the conservation of forest and grassland cover (Diyabalanage et al., 2017; Lee et al., 2013; Vignola et al., 2017). This trend could be evidenced by the studies of Cotter et al. (2014), Ferreira et al. (2016), Lee et al. (2013), Moradi and Limaei (2018), Qiu et al. (2018), and Vignola et al. (2017), which highlight that land use planning and improved agricultural practices not only reduce soil erosion but also involve relatively low costs, increase soil productivity, and, consequently, improve the socioeconomic conditions of local communities by generating employment and increasing farmers incomes (Amasi et al., 2021).
Regarding the methods used to select sediment management alternatives, the use of Multi-Criteria Decision-Making methods (MCDM), particularly Multi-Attribute Decision-Making Methods (MADM), predominates. This preference could be associated with a trend toward the search for solutions to the increasingly complex problem of sediment management, characterized by the need to link multiple variables and relationships under dynamic conditions. This complexity reflects a reality that demands the integration of diverse areas of knowledge in decision-making processes.
The MADM methods are widely recognized in the international literature for their relevance in business, as well as in water resources planning and management (Zolghadr-Asli et al., 2021). In the context of hydropower generation, these methods stand out for their usefulness and versatility (J. J. Wang et al., 2009). A particularly relevant aspect of these methods is that they allow the integration of qualitative and quantitative information concurrently, thus enabling the simultaneous consideration of corporate sustainability dimensions as evaluation criteria in decision-making processes (Zolghadr-Asli et al., 2021). Additionally, MADM methods facilitate the collaboration of experts from various knowledge areas in decision-making processes (Singh et al., 2022). Therefore, they have acquired great relevance given the increasing importance of stakeholder participation in the organizational world in recent decades, as well as the pressure that these groups exert on companies to align their decisions with a corporate sustainability approach (Sartori et al., 2017).
According to the results obtained in the corporate sustainability category, it is essential to highlight that using the economic dimension as an evaluation criterion when choosing sediment management alternatives is considerably higher than the other dimensions. The investment, operation, and production costs criteria are the most relevant in this category. Likewise, it was evidenced that the environmental dimension is more important than the social dimension. Under this consideration, it can be affirmed that economic and financial interests predominantly influence the adoption and implementation of sediment management measures. This trend, which has remained constant over the past 15 years, was documented in the study by Wang et al. (2009), which highlights that in the decision-making processes in hydropower plants, the dimensions of sustainability are considered in the following order of priority: economic, environmental, and social.
Inequitable integration of the three dimensions of corporate sustainability in decision-making processes related to sediment management could generate several negative impacts. In the economic dimension, this includes increased operating costs derived from investments for constructing and maintaining new infrastructure and correcting adverse effects on water sources. These situations, in turn, could reduce profits from business operations (Kong et al., 2023). In the environmental dimension, impacts could include deterioration of water quality, loss of fauna species, deterioration of scenic quality of the landscape, and soil erosion, among others. Regarding the social dimension, the decline of the well-being of the communities, the interruption of their productive activities, and the deterioration of relations between the company and the affected communities stand out. It is important to highlight that the adverse effects associated with the environmental and social dimensions derived from hydropower production are usually interpreted as externalities (Costa & Ferreira, 2023). This perception could diminish the relevance of these dimensions in business decision-making processes. As a result, companies could lose their corporate image, negatively impacting their reputation and compromising their long-term sustainability.
Integrating corporate sustainability dimensions as selection criteria for sediment management alternatives allows for the prevention, mitigation, and correcting of negative effects, both for the company and the environment and society. These negative effects may be inversely proportional to the number of sustainability dimensions incorporated in the selection process; that is, a few dimensions could generate more significant negative impacts on the company and its environment, while an integral inclusion of all dimensions could significantly reduce such effects.
According to the results, although the search information in the Systematic Literature Review (SLR) was not limited by continent, region, or country, for the reasons given in the methodology, a large percentage of the studies analyzed were developed in Asia and the Americas. According to these results, it could be difficult to generalize and use them in other regions with different environmental, social, and geographical conditions. Even so, this study shows a growing tendency in the last 20 years to use MCDM methods to choose sediment management alternatives.
Finally, it is highlighted as a finding that although there is a growing trend to evaluate sediment management alternatives considering the dimensions of corporate sustainability, as evidenced by Haregeweyn et al. (2012), Elfimov & Khakzad (2014), and Vignola et al. (2017), the number of studies remains unrepresentative of what happens in other regions. According to this result, it is possible to state that corporate sustainability has not yet decidedly permeated the planning process of hydropower plants and particularly sediment management, except in the countries indicated in the results. Consequently, if this scenario continues, in the medium and long term, the risk of generating negative environmental impact in areas surrounding hydroelectric power plant will be increasingly greater, to the point that it could become cumulative and irreversible. In addition, the lack of studies linking corporate sustainability to sediment management could lead to similar behavior in reservoir management in other countries, further accelerating environmental deterioration processes. This situation evidences the need for more research that closes the gap found in the scientific literature on implementing Multicriteria Decision-Making methods, integrating the holistic vision of corporate sustainability in sediment management. One way to address the lack of studies that involve corporate sustainability with sediment management in hydropower plants could be by designing sediment management methods that simultaneously link the dimensions of corporate sustainability.
To reverse the current tendency of companies to integrate sustainability dimensions in sediment management inequitably, a possible alternative would be to internalize the externalities caused by this behavior. For this purpose, some practical measures are proposed below, which could act as incentives for companies. Evaluate the positive impact on corporate image derived from adopting sediment management systems that link the three dimensions of corporate sustainability. Estimate the reduction in transaction costs of adopting sediment management methods with less environmental impact. Evaluate the reduction in social conflict that could be achieved by incorporating corporate sustainability into decision-making processes. Estimate the improvement in business profits from reduced investments in environmental protection measures. Calculate the reduction of economic costs related to adopting environmental compensation measures. Economically valuing the positioning of the company in the stock market due to improved environmental performance. In this way, companies could perceive the benefits associated with adopting corporate sustainability as a perspective to guide sediment management in hydroelectric power plants.
Conclusions
In reservoir sediment management, the use of Reduce Sediment Yield from Upstream (RED-SED) methods predominates. This trend seems to be motivated mainly by economic objectives within companies rather than by environmental protection and conservation. If this trend continues, the negative environmental and social effects will likely persist in the medium and long term, which could intensify the cumulative impacts on the environment, even becoming irreversible.
Despite the relevance of environmental issues and climate change over the past four decades, it can be affirmed that the dimensions of corporate sustainability have not widely influenced the design of sediment management methods. Furthermore, in cases where these dimensions are incorporated, they are not usually linked simultaneously. This situation is likely due to the prominence of the economic dimension in the objectives and interests of companies, which presents a challenge for sediment management method designers seeking to develop solutions more aligned with sustainable development goals
Although the last decade has seen a growing interest in integrating corporate sustainability into the choice of sediment management methods in reservoirs, the predominance of the economic dimension over the environmental and social dimensions is still evident. This trend could be reversed through mechanisms that encourage companies to integrate the three dimensions of corporate sustainability in their decision-making processes simultaneously and in a balanced way.
The international literature shows the widespread use of Multicriteria Decision-Making methods (MCDM) in the selection of alternatives for sediment management in reservoirs, with a predominance of Multi-Attribute Decision-Making methods (MADM) over Multi-Objective Decision-Making methods (MODM). However, incorporating sustainability in its economic, environmental, and social dimensions and their interrelationships in decision-making remains underexplored. This seems to be more due to the political will of business managers than to technical limitations, given that MCDM methods allow the integration, qualitatively and/or quantitatively, of the three dimensions of corporate sustainability in the selection of alternatives. Therefore, implementing MCDM methods can potentially guide corporate planning processes towards more sustainable performance.
To mitigate the negative impacts that the operation of hydropower plants may have on the social and environmental dimensions, it is crucial to design sedimentation control systems that more assertively integrate the dimensions proposed by the concept of corporate sustainability. Likewise, MCDM methods should be used more frequently in decision-making processes, as they facilitate the incorporation of the dimensions of corporate sustainability.
Footnotes
Acknowledgements
Thanks to the Ministerio de Ciencia, Tecnología e Innovación de Colombia - Minciencias for their support in funding the research project.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Ministerio de Ciencia, Tecnología e Innovación de Colombia - Minciencias, the University of Medellin, and a large private energy company (FP44842-034-2016).
Ethical Approval
All the work outlined in this paper is our own except where otherwise acknowledged and referenced. The work contained in the manuscript has not been previously published, in whole or in part, and is not under consideration by any other journal. All authors are aware of, and accept responsibility for, the manuscript.
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Data Availability Statement
Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.