The Impact of Anthropogenic Activities on the Catchment’s Water Quality Parameters

Abstract

Anthropogenic pollution of watersheds significantly threatens aquatic ecosystems, biodiversity, and human health. The present review examines the primary sources of contamination in river catchments, including industrial effluents, agricultural runoff, and urban wastewater discharge. The presence of pollutants degrades water quality, disrupting aquatic habitats and leading to adverse outcomes, including biodiversity loss, eutrophication, and declining fish populations. It also focuses on strategic mitigation approaches, including implementing stricter waste management regulations, adopting sustainable agricultural practices, improving wastewater treatment infrastructure, and public education initiatives. The article summarizes several biotechnological techniques developed to decrease the impact of farming activities on water quality. It also emphasises directions that could be followed concerning specific water chemical indicators, such as the residual quantity of heavy metals. Emphasis is placed on the need for integrated policy frameworks and cross-sector collaboration to safeguard freshwater systems and ensure long-term environmental sustainability.

1. Introduction

1.1. General Background

A complex interplay of natural and anthropogenic factors influences water quality in river catchments. These include pedological characteristics, seasonal variability, watershed type, and particularly, human activities such as industrial discharge, agriculture, urbanization, deforestation, land use changes, and effluents from wastewater treatment plants [1,2,3,4,5,6,7,8].

In addition to anthropogenic pressures, biotic factors and natural phenomena also influence water ecosystems. Such components include climate changes, soil erosion, invasive or non-native species [9], and the hydrologic regime. Since water from different river sectors is often used as a source of drinking water, the quality assurance of this water is significant in the comprehensive management of aquatic supplies. Cucchi et al. identified groundwater as a potentially vulnerable component of the hydrological system [10]. Phenomena such as floods or drought negatively affect the river basin parameters. Different studies emphasize the favorable influence of proper management of all resources [1], especially of the surrounding soil vicinity [11]. Independent of the type, between all these elements are usually summative and/or synergetic effects. The weather modifications have a profound influence on the hydric mechanisms. An increased water quantity from rain and/or melting snow will contribute to the release of chemical compounds that enhance the amount that enters the rivers. The same vector can determine the sediment’s quantity expansion into the catchments due to erosion. Such a situation harms the quality of aquatic habitats. Additionally, the introduction of invasive marine plants and animals can disrupt the ecological balance and compromise water quality in watersheds.

Maintaining and enhancing water quality in river basins involves conservation measures, strict pollution regulations, and sustainable agricultural practices [5]. Liu et al. highlighted the benefits of increased monitoring areas in river basins to preserve optimal parameters [12]. Awareness and information about the impact of human activities on water are crucial for protecting this valuable resource. Assessing the effects of these factors provides a solid foundation for understanding the impact of anthropogenic elements on water quality in river basins and for exploring strategies to manage and conserve these vital resources. By understanding and acknowledging the impact of human activities on water quality in catchment areas, we can develop more effective strategies to protect, manage, and conserve these vital resources that sustain life on our planet.

The objective of this paper is to provide a summary of the key findings presented in the literature on the human factors influencing the characteristics of water in hydrographic basins. Investigation of recent studies in this field is crucial to ascertain the influence of anthropogenic factors on the current water quality in watersheds. Figure 1 highlights the fundamental reasons why this topic is important and should receive due attention. To conduct an up-to-date review, the literature in the field was selected using the Google Scholar search engine and the facilities offered by the ScienceDirect web-based bibliographic database. For each area of documentation, specific keywords were considered based on the initial general background in the field. For the preliminary search, the key terms related to general aspects, such as ”anthropogenic activities”, ”water quality parameters”, ”river basin/watershed pollution”, ”surface water contamination”, or ”human impact on aquatic ecosystems”. Proved to be valid search combinations and phrases like: ”impact of anthropogenic activities on water quality”, ”land use changes and river water quality”, or ”nutrient pollution in freshwater systems”. Considering the activities targeted by the present article, the precise constructions used were of the type: ”the impact of agricultural runoff on water quality in river basins”, “effects of mining on surface water contamination”, “urbanization and non-point source pollution in watersheds”, ”industrial wastewater and heavy metal pollution in rivers”, or “land use change and nutrient enrichment in freshwater systems”.

The river catchments are often used as a source of tap water. Therefore, ensuring water quality in these basins is essential for protecting public health. The second aspect is determined by the quality of the aquatic and agricultural ecosystem products used in human nutrition, which could become unadvisable for consumption if the water utilized comes from contaminated sources. Another aspect that may not be immediately apparent is the potential for using river resources for tourism and leisure activities, such as swimming. Considering such potential is limited by the fulfillment of specific regulations regarding the water parameters.

A pertinent analysis of possible river basin pollutants must be based on two premises. One regards the contaminant’s sources, and the other one their type. Figure 2 is a conceptual map that significantly contributes to the paper’s clarity, coherence, and scientific value. It provides a synthetic and logical view of the links between pollution sources and the effects on water quality, highlighting the interdependencies between variables. Based on these, applicable conceptual models for interpreting the data can be suggested, providing an intuitive and quick visual image of the topic. Through it, it is intended to achieve a systemic approach to the factors that can influence water quality in a river basin. It clarifies the relationships between causes (anthropogenic activities) and effects (changes in water quality).

It schematically presents the elements most likely to be encountered in the field [13,14,15,16]. The same category of pollutants could have different sources [17]. Unfortunately, the river basins will create a situation of cumulative quantities if proper actions are not implemented at the pollutant site. Corrective actions must be implemented to support the conservation of the natural aquatic ecosystem [18].

Based on these considerations, the present study aims to highlight recent data from the literature regarding potential sources of catchment contaminants. The novelty of this study lies in its integration of possible strategies for limiting the proliferation of pollutants in aquatic media. Such an approach proves its feasibility and is supported by the necessity to ensure high-quality water resources for all ecosystem elements, not just for human components. Of course, the impact on the last-mentioned constituent can be direct and indirect. The collateral consequences can be derived from using different polluted products, such as fish and similar products, fruits, and vegetables, or dermal contact with contaminated water sources. The work of Morra et al. can be considered as support for underlining the importance of this scientific approach [19].

This review further introduces novel perspectives by integrating a Strengths, Weaknesses, Opportunities, Threats (SWOT) analysis framework to evaluate current strategies and identify opportunities for improvement. Figure 3 presents key strengths and opportunities associated with water quality management in river catchments. This approach emphasizes the importance of coordinated international cooperation, technological innovation, and environmental education in protecting and conserving water resources. It brings significant added value and clarity to the study. It was considered a valuable method of strategic synthesis that enhances the interpretation of results, supports the formulation of recommendations, and adds value to conclusions and policy proposals. It can be seen as a critical instrument [20] for building the IWRM framework [21]. Several studies have used this tool to determine the degree of implementation of water management sustainability goals [22,23,24].

By synthesizing current literature and presenting a strategic framework for managing anthropogenic water pollution, this study aims to support the development of more effective, sustainable policies and practices that address the complex challenges facing modern river basins.

1.2. Analysis of the Integrated Water Resources Management Framework in the Context of the European Unions Water Framework Directive

Integrated Water Resources Management (IWRM) can be understood as a holistic strategy aimed at balancing the use and protection of water, land, and environmental assets. It seeks to align economic growth and social equity while ensuring the long-term health and resilience of natural ecosystems through coordinated, inclusive planning and management (Figure 4).

The EU Water Framework Directive (WFD), adopted in 2000, operationalizes Integrated Water Resources Management (IWRM) by mandating “good ecological status” for all European water bodies. While IWRM integrates hydrological, ecological, social, and economic considerations, its practical implementation faces significant barriers.

Mukhtarov and Gerlak [25] advocate for epistemic flexibility in knowledge systems, but Nagata et al. [26] and Ma and Gourbesville [27] caution that such flexibility must align with institutional capacity and local context. Although the WFD remains a globally recognized model, legal exemptions and weak enforcement undermine its ecological objectives [28,29,30,31], particularly in agriculture-dominated regions [32].

Monitoring challenges persist, especially in Central and Eastern Europe, where biological assessment frameworks require strengthening [33,34].

Coordination across governance levels is inconsistent, with tensions between centralized planning and local implementation evident in case studies from Norway and England [32,35]. These conflicts reflect broader critiques of new governance models [36].

The WFD aligns with SDG 6, especially indicator 6.5.1 on water management, linking water security to environmental and socio-economic outcomes [37]. However, achieving these goals is hindered by funding constraints, institutional fragmentation, and limited technical capacity [38,39,40,41]. Hileman et al. [41] emphasize the role of socio-political factors in IWRM’s limited uptake.

A successful IWRM model requires adaptive strategies, enhanced monitoring, and cross-sectoral coordination. Key actions include community engagement, better communication, and integrated decision-making tools [40,42]. A recent global report [43] highlights slow progress and calls for increased investment, harmonized policy integration, and improved basin-scale governance.

In Romania, fragmented monitoring by eleven institutions is being addressed through National Recovery and Resilience Plan (PNRR) investments in equipment and emergency systems [44]. This illustrates the critical need for field-level support.

Recognizing IWRM’s relevance to energy and food security, Dinsa and Nurhusein argue for investment in both infrastructure and institutional development [45].

In sum, IWRM and the WFD offer strong conceptual frameworks, but structural reforms, improved funding, and localized, integrated implementation are essential for fulfilling their potential.

2. River Basin’s Main Pollutant Sources

2.1. Agricultural Activities and Their Impact on Watershed Quality

Water availability at the soil level is crucial for crop development, as it facilitates the transport of nutrients throughout plant tissues [46]. Based on these general considerations, it is also essential to emphasize its role as a vector for possible harmful chemicals used in this sector, namely pesticides.

The intensive crop production developed in the last few years could substantially contribute to hydrographic basin pollution. The amount of nitrogen, along with other minerals and/or complex compounds, reached in the tributaries of the rivers should be mainly considered. Xaver et al. suggested the need for extensive research on phosphorus amounts resulting from the use of biological fertilizers. The mineral can be found in significant quantities in the advanced layers of soils, depending on their pedological characteristics [47]. The soil and landscape types and properties can significantly impact the water quality of the river basin [48]. The conclusions formulated by Uniyal et al. after their study also support the observation. They evidenced antipodal results after analyzing the possible impact of clime modification on two watersheds [49]. In such a situation, the possibility of being washed by the underground waters and transported to the nearest catchment could represent a contamination trance. Maintaining the optimal fertilization level for phosphorus should be done from two perspectives. One regards the crop specificities, and the other the soil characteristics. Neglecting the second aspect could have a negative impact on various proximal ecosystems. Where soil characteristics allow an increased mineral transfer, it could be easily tracked down in the adjacent tributary [50].

Besides the well-known pesticides and fertilizers, constitutive minerals that can be encountered in the river catchments, Zarrinabadi et al. pointed out the possibility of increasing the quantity of carbon in the regions situated in the surrounding areas [51]. The situation may be determined by the vegetable residues transported by the surface water. Such an element could be relevant since the ground biocarbon may be involved in different processes that increase greengage levels. Its presence and other specific parameter variations in time, such as pH or nitrogen levels, depend on each area and the pedologic and topographic particularities encountered [52,53,54]. It is also necessary to mention the possible contamination of watersheds with traces of heavy metals or selenium. These elements can result from washing the surface waters of contaminated agricultural areas [55] through abiotic mechanisms. Aquatic soil lavation appears to be more intensive in regions with a higher ground slope.

Consequently, the contaminants that arrived in the catchments could be higher. A possible explanation of the mechanism is based on findings by Liu et al., highlighting the higher probability of straightforward areas maintaining augmented water quantities [56]. Improved resource management considers both agriculture and water availability and needs, as well as environmental impact. A direction that could be explored was suggested by Rahmani et al., who saw the potential of land offset as a key to such a situation [57].

An aspect that could be considered for farming and silvicultural area management is implementing sustainable actions targeting soil erosion, particularly by limiting sediment migration in river basins and promoting vegetable rotation. Attention must be directed to areas that change destination through deforestation and/or reconversion [58]. Suitable mechanisms implemented in these domains will improve water catchment characteristic parameters [59]. Effective administrative actions for preserving aquatic and terrestrial ecosystems cannot be adequately implemented without considering the human factor and its associated attitudes. Zhang et al.’s research suggested a direct, possible, and reliable connection between the water regimes that arrived in the studied catchment, independent of the derived source. An opposite situation was observed for the land layout, forest restoration, vegetal species presets in the surroundings, or the local mapping specificities [60]. Yuan et al. emphasized the need for decision-makers to establish this link [61]. Masha et al. emphasized the potential synergistic effect of implementing tangible actions to mitigate soil-limiting degradation and improve agricultural practices [62]. Planting specific species [63] to stabilize the soil around water basins [64] and chelating pollutants is a feasible approach. In this way, the water quality could be improved by reducing contaminants and decreasing eutrophication. The specific manifestation of clime modification, such as the thermal and hydric regime, directly impacts crop and forestry development. The secondary manifestation appears to be at ground level, undergoing degradation [65]. The local and national strategies designed to limit human action on different ecosystems could be based on considering such findings and incorporating a comprehensive view.

The presence of small-dimension synthetic compounds between the native geomorphic components represents a recently observed situation that raises environmental challenges. Such a situation has an additional implication. Micro and nano plastics can reach the nearest aquifers and subsequently flow into different river basins. The migration capacity of these compounds depends on their chemical composition and the ability to bind to soil components. Other factors are related to the ground pedologic attributes [66]. In the same direction, the possibility of using biodegradable cover sheets for various vegetable varieties is also being explored to ensure durable cultivation procedures. The classic synthetic one could contribute to the carbon quantity released into the environment [67]. Various strategies are currently being designed to mitigate the impact of this sector on ecosystem components. Some of the recent ones are summarized in

Table 1. Biotechnological techniques developed to reduce the impact of farming activities on water quality.

Method	Target Pollutant/Process	Reference
Moving Bed Biofilm Reactor (MBBR)	clodinafop-propargyl (CF) reduce and biological material degrade	[68]
Corn-straw (Zea mays L.) biochar electrode	Nitrate removal	[53]
P. brevicompactum, Eisenia andrei	Degradation of commercial agricultural mulch biofilm; transformation of functional groups (dependent on biofilm vitality and replication	[69]
Periphyton biofilms	Removal of non-point source (NPS) contaminants	[70]

.

Table 2. Quantitative information about agriculture quantifiable pollutant concentrations.

Nutrient	Value	Reference
N-NO2	0.01–0.09 mg/L	[71]
N-NO3	0.12–1.99 mg/L
N-NH4+	0.01–0.44 mg/L
TN	0.84–5.32 mg/L
P-PO43−	0.02–0.20 mg/L
TP	0.14–2.97 mg/L
Ammoniacal N	1–7.4 mg/L	[72]
Nitrate	0.12–3.00 mg/L
Nitrite	0.05–0.86 mg/L
Phosphate	0.05–0.09 mg/L
Pretilachlor	0.01–0.19 mg/L
Oxyfluorfen	0.01–0.64 mg/L
Thiamethoxam	0.01–0.39 mg/L
Chlorantraniliprole	0.001–35.10 mg/L
Fenobucarb	0.01–17.20 mg/L
Fipronil	0.02–0.03 mg/L
Diazinon	0.01–0.22 mg/L
Etofenprox	0.01–0.03 mg/L
Tebuconazole	0.015–0.06 mg/L
Captan	0.016–711.22 mg/L
PO43−	3.0 mg/L	[73]
SO42−	110 mg/L
NO2− + NO3−	1.76 mg/L
NO3−–N	0.72–6.3 mg/L	[74]

presents quantitative data on the concentrations of the primary pollutants from agricultural activities identified in different river basins. These data aim to highlight the impact of farming practices on the quality of water resources and support decision-making in sustainable environmental management. The concentration of contaminants also depends on weather stability, as highlighted by Muoi et al. [71]. Usually, it is not possible to identify a singular source for hazards in a river catchment. Each possible root may have a specific contribution.

Agricultural activities are one of the primary diffuse sources of water pollution in river basins, significantly contributing to the degradation of water resource quality. The analyzed data indicate the constant presence of several compounds, such as nitrates, phosphates, and pesticides, correlated with intensive agricultural practices and the uncontrolled use of agrochemicals. The cumulative impact of these is reflected in both the surface waters’ eutrophication and groundwater contamination, thereby affecting the ecological functions of aquatic ecosystems.

The results emphasize the need to develop and implement coherent public policies that promote good agricultural practices, the rational use of chemical inputs, and the protection of water resources at the river basin level. In this regard, the development of integrated systems for monitoring diffuse pollution and the strengthening of the legislative framework for sustainable soil and water management are essential.

For future research, in-depth investigations on the relationship between land use patterns and pollutant loads specific to each type of aquatic ecosystem are recommended, as well as evaluating the efficiency of nutrient loss reduction technologies. Additionally, integrating hydrological models with scenarios of changing agricultural practices could provide valuable predictive tools in the process of territorial planning and climate change adaptation.

2.2. Households and Farms

As illustrated in Figure 2, various pollutants found in river catchments often originate from multiple overlapping sources. A typical example is phosphorus contamination, which can stem from industrial and domestic sources, such as household cleaning agents and agricultural fertilizers [75]. Sulfates and other emerging contaminants are frequently detected, particularly in household wastewater [76]. This highlights the urgent need for effective sewage treatment technologies capable of removing such pollutants to ensure the safe reuse of water, including for human consumption. These should be able to release secure water, allowing it to be further used, even for human consumption. Emerging contaminants—pharmaceuticals, personal care products [77], and polar pesticides—have become increasingly prevalent in effluents. This is especially concerning in regions where advanced treatment infrastructure is lacking, and downstream populations rely on river water for drinking. Such scenarios can contribute to the development of antibiotic resistance in human populations [78]. Pesticides, although primarily associated with agriculture, are also detected in domestic sewage due to the use of biocides in residential areas, particularly during warmer seasons [79].

In recent years, tree farming has expanded, which offers several environmental benefits. Fast-growing species can serve as renewable energy sources and carbon sinks, reducing atmospheric CO₂. Additionally, these plantations serve as natural rainwater filters, thereby improving the water quality that ultimately reaches river catchments [80]. Tree roots also stabilize soil, reducing surface runoff and sedimentation in adjacent water bodies.

Household activities can also serve as a toxicological vector for water contamination with heavy metals or other chemical pollutants, such as organic pesticides [81]. These may be found in the sediments [68,82] transported to river basins, ingested by aquatic creatures [83], and ultimately, in human nourishment. The situation highlights the importance of attention that must be given to sewage water treatment, regardless of its source.

Both farming and domestic waste mismanagement contribute significantly to nitrogen pollution in aquatic systems, primarily through groundwater transport [84]. Veterinarian waste, in the form of organic slurry, is a major contributor to nitrate levels in water bodies [65]. Mitigation strategies include composting and anaerobic fermentation, which reduce environmental impact and yield byproducts such as biofertilizers and bioenergy.

2.3. Minerals Exploatation

Exploitation of mineral resources poses a significant risk to water quality in river catchments worldwide. Activities such as mining for coal, metals, salts, and industrial minerals, as well as quarrying for rock, sand, and gravel, often result in the release of various pollutants into surface and groundwater systems. These operations, especially when unregulated, can disrupt aquatic ecosystems, degrade water quality, and pose serious risks to human health and biodiversity [85].

Mining operations contribute a diverse range of contaminants, depending on the resource extracted and the method employed. Open-pit and underground mining of metals such as gold, silver, and copper often leads to the mobilization of heavy metals, including lead (Pb), arsenic (As), iron (Fe), and mercury (Hg), which can leach into nearby water bodies. These metals are persistent and bioaccumulative, posing a significant threat to both aquatic life and human health [86].

Coal mining is associated with the release of ash, slurry, and acid mine drainage. These waste products can carry high loads of suspended solids and hazardous substances that alter pH levels and reduce water quality. In addition, nutrient pollution has been observed from potassium and phosphate mining, contributing to eutrophication and excessive algal blooms that deplete oxygen and harm aquatic species.

Salt mining, particularly the extraction of halite, can increase salinity in freshwater systems, thereby altering the osmoregulatory balance of aquatic organisms. Quarrying for stone and extracting sand and gravel from riverbeds may increase sedimentation and turbidity, affecting light penetration and benthic habitats [87,88].

Illegal or artisanal mining practices are increasingly recognized as a significant source of water contamination. These unregulated operations, often located near watercourses to meet processing demands, discharge untreated waste directly into rivers. Identifying pollution sources becomes particularly challenging in catchments where multiple anthropogenic activities coexist. Dube et al. [89] highlighted that nitrogen-based compounds, such as nitrate, nitrite, and ammonia, may originate from mining and agricultural practices, thereby complicating the attribution of sources.

Moreover, illegal mining often operates outside of environmental oversight, allowing for the unchecked discharge of heavy metals and toxic chemicals into the environment. The diffuse nature of such operations undermines monitoring efforts and regulatory enforcement [90,91].

Seasonal variations in hydrology often compound the impacts of mineral exploitation on water quality. For instance, during periods of heavy rainfall, surface runoff from mine tailings and waste piles can lead to significant increases in turbidity and contaminant loads in downstream waters. Dry seasons may concentrate pollutants in stagnant water, exacerbating toxicity levels.

Heavy metals and suspended solids impair drinking water sources and threaten aquatic biodiversity. Elevated levels of Fe, As, and Pb have been documented in rivers downstream of mining areas, frequently exceeding the thresholds set by environmental protection agencies [86]. Chronic exposure to these substances can lead to biomagnification within food webs and pose significant health risks to communities that depend on these water sources.

Restoration of mining-impacted catchments remains a complex and resource-intensive process. Various techniques, from passive remediation to active chemical treatments, have been proposed and tested. For example, Chen et al. [92] proposed the use of acidic carbonates for removing arsenic and antimony ions from settling basins, demonstrating high efficacy in both laboratory and field settings.

In some cases, abandoned gravel pits and excavation sites have been repurposed to support the recovery of ecosystems. Ghirandi et al. [93] noted that these formations can function as water retention zones, which help reduce nutrient loads—especially nitrates—through sedimentation and natural filtration processes. These water bodies may also provide secondary ecological benefits by supporting wetland development and biodiversity conservation.

Despite these efforts, large-scale restoration is often hindered by the extensive degradation caused by mining activities, the complexity of pollutant mixtures, and the need for long-term monitoring.

Table 3. Processes designed to mitigate the impact of mining on river water quality.

Operation	Result	Reference
Use of drinking water treatment residues to grow Phalaris arundinacea on Pb- and Zn-contaminated soil	Promising results in laboratory-scale experiments; limited effectiveness under field conditions	[94]
Application of calcite-based residual material	Complete removal of Al and Fe; approximately 90% Cu removal; no significant effect on Co and Ni	[95]
Fe–Cu–chitosan nanocomposite	Highest antimony (Sb) binding observed at a 2:1 Fe:Cu ratio	[96]
Bioremediation with metal-tolerant bacterial strains	Effective against Cd, Pb, Cu, Cr, Ni, and Zn contamination	[97]

provides an overview of selected remediation strategies implemented in different mining contexts, including their mechanisms, effectiveness, and limitations.

Heavy metals, such as lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As), are environmental contaminants with a significant toxic impact on ecosystems and human health. These elements can persist in soil, water, and air, being bioaccumulated by living organisms and transmitted along food chains. Due to their toxic potential, even at low concentrations, international bodies such as the World Health Organization (WHO) and the US Environmental Protection Agency (EPA) have established strict threshold values for their presence in different environments (drinking water, soil, air). The research made by Zhou et al. highlighted differences concerning the decade analysis. In the 70th and 80th years, the presence of contaminants was lower compared to the next 30 years. The simultaneous occurrence of multiple risks can also significantly impact the situation [98].

The European Parliament and the Council elaborated Directive 2008/105/EC. It was applied on 16 December 2008 and comprises environmental quality standards in the field of water. It aims to achieve good chemical status in surface waters. According to documents released by the Romanian National Institution in the field of environmental protection (NAEP), water bodies located near the former mines have an increased level of heavy metals.

Although essential for industrial development, mining activities leave behind profoundly altered landscapes and degraded ecosystems. These affected areas, often characterized by acidic soils, heavy metal contamination, and the destruction of local biodiversity, require complex interventions to be restored to a functional ecological state. In recent decades, the ecological rehabilitation of these lands has become a priority in environmental policies, with sustainable, innovative, and efficient solutions being developed.

One of the most promising ecological technologies successfully applied in mining rehabilitation is the creation of constructed wetlands, a bioengineering technique based on natural processes of phytoremediation, sedimentation, and biotransformation of pollutants. These artificial ecosystems, modeled after natural wetlands, can retain and neutralize contaminants such as heavy metals by utilizing hyperaccumulating plants, microorganisms, and reactive substrates.

Designing wetlands using bioengineering tools presents several advantages, including low long-term maintenance costs, aesthetic and ecological integration into the landscape, the potential to transform polluted lands into protected natural areas, and the involvement of local communities in environmental restoration processes [99]. The integration of green technologies in rehabilitating mining areas represents an ecological necessity and an opportunity for regenerating natural capital [100]. Due to their efficiency and adaptability, constructed wetlands can become a key component in the global strategy for ecological restoration and transition to a circular economy. Several studies, including the pilot scale [101], have highlighted the potential of such approaches.

2.4. Industrial Activities

Accelerated industrialization in recent decades has resulted in a substantial increase in waste production and pollutant emissions. While some regions have implemented strict regulations to limit environmental impacts, others face challenges in enforcing ecological policies. The European Union is frequently cited as a model for environmental regulation, unlike South Asia, where socio-economic and institutional pressures often hinder effective implementation.

In the context of global initiatives such as the European Green Deal and the drive toward climate neutrality, benchmarking regional differences in environmental compliance is crucial. These disparities reflect not only administrative and technological gaps but also political will and resource availability differences.

I Industrial operations are a significant source of pollution in river catchments. They affect water quality by discharging wastewater, fine particles, and other contaminants. These pollutants may enter aquatic systems via rainwater runoff or direct infiltration [102,103].

For example, Fadel et al. [104] identified significant concentrations of Ca²⁺ and SO₄²⁻ in catchment waters linked to emissions from cement factories.

Sustainable management of water resources necessitates that all stakeholders—especially industrial operators—are adequately informed about and compliant with environmental regulations. However, as Ferreira et al. demonstrated in the Moju River catchment, awareness and compliance remain limited [105].

One emerging trend in industrial activity is the shift toward renewable energy sources, particularly hydropower. While often considered a cleaner energy alternative, hydropower can disrupt aquatic ecosystems through flooding and habitat destruction. To minimize these impacts, pollution risk assessments should precede infrastructure development. Tools such as geospatial analysis and morphometric assessment of hydrographic basins can guide responsible site selection [106].

Another growing concern is hydraulic fracturing (fracking) for hydrocarbon extraction. This technique poses risks to surface and groundwater through the potential migration of contaminants. Analytical methods such as isotope dating and tracer analysis have been proposed to trace pollutant pathways in aquatic environments [107].

Biological monitoring has become an increasingly important tool for assessing the health of aquatic ecosystems affected by industrial activity [108]. Certain organisms are bioindicators, offering insights into ecosystem integrity and pollution levels. For instance, Krodkiewska et al. [109] used benthic macroinvertebrates to evaluate the impact of industrial and domestic effluents, finding that untreated or poorly treated wastewater—especially with high salinity—significantly degraded river water quality.

The EU has set high standards for industrial emissions through legislation such as the Industrial Emissions Directive (IED, 2010/75/EU). According to the European Environment Agency (EEA), compliance rates are high across most Member States due to robust monitoring and reporting systems, regular inspections, and Best Available Techniques (BATs) application.

A particularly pressing issue is the presence of antibiotics and antibiotic-resistant microorganisms in river systems. Teixeira et al. [110] identified such contamination as a consequence of inadequate purification processes in urban wastewater treatment and animal husbandry operations. These substances persist in aquatic environments, raising public health concerns and pointing to the need for advanced treatment technologies.

A multi-pronged approach is needed to address regional disparities in environmental compliance. This could include technology transfer, strengthening the legal framework, international cooperation, green financing mechanisms tailored to developing regions, and global minimum standards for hazardous waste [103].

2.5. Urban Activities

Urban development has a significant impact on the quality of water in river basins, making it a central concern for civic planning and environmental conservation. The rapid growth of the global population and the accelerated expansion of urban areas have placed considerable strain on freshwater resources. Effective management of these pressures is essential to preserve both ecosystem integrity and water quality.

Khare et al. examined changes in water parameters in the Hillsborough River watershed in Florida, which transitioned from primarily agricultural to urban land use. Their study observed notable increases in total phosphorus, nitrogen, and organic forms of nitrogen, particularly ammonia nitrogen—measured as total Kjeldahl nitrogen (TKN), a key indicator in urban wastewater treatment assessments [111]. Similarly, modeling conducted by Goodarzi et al. on the Dez River basin projected that without sustainable interventions to mitigate urban impacts, levels of chemical oxygen demand (COD) and ammonia would significantly rise within a decade [112].

Urban areas introduce a wide variety of pollutants into river systems. Stormwater runoff, sewage overflows, and discharges from streets and industrial zones contribute chemicals, heavy metals, and excess nutrients that degrade water quality. A growing concern in recent research is microplastic pollution [113], which originates from anthropogenic sources and accumulates in aquatic environments. He et al. conducted a comprehensive analysis linking microplastics with elevated levels of heavy metals in river sediments, suggesting that chemical additives in plastic materials may facilitate the binding and transport of metal ions [114].

Urban infrastructure development—such as roads, bridges, and buildings—can further disrupt natural ecosystems by increasing soil erosion and stormwater runoff. These activities often introduce sediments and pollutants into watersheds. Beqaj demonstrated that adhering to best practices in construction near the Skotini stream resulted in infrastructure development that complied with environmental standards [115]. An often-overlooked impact arises from vehicles crossing water bodies or engaging in recreational water sports, which can lead to oil and fuel spills that harm aquatic life [116].

Table 4. Quantitative information about runoff coefficients and pollutant concentrations.

Operation	Result	Reference
surface runoff from an exemplary rest area	TSS concentration exceeded the maximum acceptable level during all rainfall events based on a hydrodynamic method	[117]
seasonal behavior of water runoff	climate change in summer, with absolute changes of 5021.9 and 2473.19 m3/s human activities in winter, with absolute changes of 263.04 and 296.84 m3/s	[118]
height of the path curb (1–2 cm; 2–3 cm) the surrounding height of the field ridge	17.5%, respectively 91.1% decrease in the runoff generation increased efficiency for total phosphorus load than the loads of compared to total nitrogen, chemical oxygen demand, and ammonia nitrogen	[119]

presents comparable data across land use categories, including urban areas.

Different models are currently used to forecast the path of the contaminant. Although their precision could be considered significant [120,121], t it is necessary to correlate the information given with in-situ evaluation [117] and base it on current data.

Urban expansion into previously undeveloped areas also contributes to riverbank erosion and increased sedimentation in stream systems. Strategies to mitigate these effects may include partial bank reinforcement or the installation of impermeable barriers in urban river channels to stabilize flow and prevent erosion [122,123]. However, it remains challenging to quantify the interdependencies between urban land-use changes and the dynamics of aquatic ecosystems. Chadwick et al. emphasized that industrialization in upstream catchments can influence river ecosystems at multiple levels, altering the decomposition of organic matter and, in turn, the functioning of aquatic systems [124].

Another urban impact on river basins is the rising water temperature due to heated runoff and reduced vegetation. Tudesque et al. recorded a trend of rising water temperatures from the 1980s to 1990s, followed by a decrease in nutrient levels, likely due to improved wastewater treatment across the region [125]. Nonetheless, elevated temperatures can stress aquatic ecosystems and degrade water quality. Urban modifications, such as dams, canals, and dikes, can disrupt habitats and biodiversity. Additionally, increased use of pesticides, fertilizers, and urban chemicals can lead to runoff that contaminates surface waters and potential drinking water sources.

As urbanization progresses, a clear ecological trend is the decline in native species and the proliferation of pollution-tolerant organisms [126]. Urban watersheds typically exhibit higher concentrations of nutrients and pollutants, largely driven by stormwater and domestic wastewater discharges. To counteract these impacts, the design and implementation of integrated, sustainable water collection and treatment systems are essential [127].

3. Results and Discussion

Classifying or assessing potential sources of watershed pollution according to intensity (how severely they affect water quality) and frequency (how often they are present or active) is essential for establishing monitoring and intervention priorities. Diffuse sources (such as agriculture and urban activities) are challenging to control but have a high frequency and significant cumulative impact. Point sources (such as industrial facilities, large farms, and spills) are easier to locate and regulate but can have severe local impacts. Historical sources (abandoned mines) can produce persistent pollution, even after economic activity has ended.

Table 5. Assessment of pollution sources in river basins.

Pollution		Frequency	Intensity	Potential Hazard/Effect
Source	Type
Agriculture	Diffuse	High	High	fertilizers (nitrates, phosphates); pesticides/eutrophication, toxicity
Farms	Diffuse & localized	Medium to high	Medium High	ammoniacal nitrogen, organic matter, microbiological
Households without sewage	Point (uncontrolled)	High in rural areas	Medium	microbiological contamination, nitrates, phosphates
Industrial activities	Point	Medium	High	heavy metals, toxic compounds, high COD
Mining	Point and historical	Low to medium	High locally	heavy metals, low pH/persistent effects
Urbanization and stormwater	Diffuse (urban runoff)	High	Medium	hydrocarbons, metals, sediments, detergents

presents a systematized view of the different polluters’ impacts on the catchment’s parameters and the potential risk elements. Several authors underlined the utility of using model patterns to estimate water quality [128,129].

Unsustainable resource use and diverse land-use pressures—from agriculture and urban development to mining and industry—drive water quality degradation in watersheds. Traditional watershed management approaches often fail to prioritize pollution sources based on their relative impact and mitigation complexity. A strategic, evidence-based framework is urgently needed. Multi-Criteria Decision Analysis (MCDA) provides a powerful method for evaluating pollution sources across environmental, technical, and institutional dimensions (

Table 6. Multi-Criteria Decision Analysis Scoring Matrix.

Sector	Pollution Intensity	Frequency of Emission	Spatial Impact	Regulatory Control	Ease of Mitigation	Total	Rank
Agricultural Activities	5	4	5	2	2	18	1
Urban Activities	4	4	4	3	3	18	1
Industrial Activities	5	3	4	3	2	17	3
Households & Farms	3	4	3	2	4	16	4
Mineral Exploitation	4	2	3	2	2	13	5

Note: Scores were assigned on a 1 (very low) to 5 (very high) scale, and total scores were used for final ranking.

).

Agricultural and urban activities consistently rank highest due to diffuse runoff, nutrient loading, and widespread surface water contamination. While mining and household-level pollution are more localized, their impacts remain significant.

Overall, persistent and multifaceted pollution across sectors reflects deep-rooted failures in environmental governance. Regulatory frameworks are fragmented, inconsistently enforced, and poorly suited to emerging challenges. Zhang et al. highlight these pollutants’ diverse and substantial impacts and stress the need for targeted, sector-specific interventions [130]. In addition, unsustainable water extraction and overflow from human activities warrant immediate policy and management attention.

The extraction and overflow of water from various anthropogenic activities, including agriculture, urban development, and industrial processes, warrant immediate scrutiny.

Despite the known economic reliance on river basins, local administrative entities frequently overlook the long-term consequences of unsustainable water use [131,132]. Zhou et al. highlighted a potential causal relationship between hydrological regimes and transboundary tributary dynamics, emphasizing how regional interactions complicate basin-level management [90]. Similarly, Rankin et al. warned that land reconversion could further deteriorate nearby river systems if conducted without strict sustainability guidelines [133].

Although various studies—including those cited earlier—propose solutions such as sediment control, wastewater treatment, and bioremediation techniques, their practical implementation often falls short of expectations. Technologies tested at lab or pilot scale frequently fail to translate into effective real-world applications, as seen in the mining sector’s limited success in mitigating heavy metal contamination. These discrepancies suggest that many “solutions” remain theoretical or symbolic without institutional backing and proper resource allocation.

A deeper issue is the reactive rather than preventive nature of current management practices. Urban expansion continues to displace natural buffer zones, increase impervious surfaces, and exacerbate flood and pollution risks. Agricultural activities persist with insufficient oversight, and sewage systems in many regions remain underdeveloped or outdated. Despite calls for cleaner technologies and machine learning–based predictive tools [134], most regions—especially those with limited technical or financial capacity—struggle to implement even the most basic environmental safeguards.

Furthermore, mineral exploitation presents a particularly severe challenge. Beyond the direct release of toxic elements, illegal or poorly monitored mining operations, often located near water bodies, further complicate the tracing and enforcement of pollution. While some remediation methods (e.g., nanocomposites or bioremediation) offer potential, they require significant investment and contextual adaptation, which are not always feasible.

Critically, the fragmented response to river basin pollution often overlooks the importance of public engagement and local context. Top-down policies are unlikely to succeed without a grounded understanding of regional ecological, economic, and social conditions. Zhou’s emphasis on cross-boundary water governance [90], for instance, highlights the political complexity involved in managing shared watersheds. Meanwhile, the assumption that technology alone can resolve these systemic issues oversimplifies the socio-environmental challenges.

Research gaps in watershed management and water quality must be addressed holistically, considering multidisciplinary factors. Key issues include poor integration of satellite, in-situ, and socio-economic data, limited system interoperability, and lack of data standardization.

While models commonly assess water quality, many lack high-resolution climate inputs or are not calibrated for extreme events—additionally, few account for the growing impacts of rapid urbanization and intensive agriculture.

Effective water quality management also requires greater local stakeholder engagement. Research into community perceptions and behaviors around water protection should be expanded.

Advanced technologies can enhance real-time water quality monitoring but are underutilized due to high costs and maintenance demands (

Table 7. Technology-Driven Strategies for Water Quality Management.

Technology	Application	Benefit
IoT-Based Water Sensors	Real-time water quality monitoring	Enables rapid response to pollution events
AI and ML Algorithms	Predictive modeling of runoff and flow	Enhances proactive intervention strategies
Constructed Wetlands	Passive nutrient and sediment treatment	Low-cost, ecosystem-based solution
Precision Agriculture	Optimized fertilizer/pesticide application	Reduces non-point source pollution
Phytoremediation Techniques	Contaminant removal via native flora	Biologically sustainable remediation

).

Precision tools can model the cumulative impact of human activities on watersheds [135]. Widely used instruments include smart sensors for pH, turbidity, conductivity, and nutrients. Forhad et al. developed an IoT-based system for treatment plants, measuring key parameters such as pH, dissolved oxygen, total dissolved solids, and temperature [136].

Wireless networks [137], satellite imagery, and drones can detect diffuse pollution, land-use changes, and sediment fluxes—provided infrastructure supports their deployment. However, these tools may struggle to identify specific pollutants [138]. Combining methods, such as convolutional neural networks (CNNs) and gated recurrent units (GRUs) [139], has shown promise in improving monitoring accuracy.

AI is increasingly used to predict nutrient contamination, identify pollution sources, and optimize water infrastructure. Singh et al. created a wireless network to predict E. coli levels in water bodies [140].

Digital twins offer real-time 3D simulations of river basins, capturing both natural and human dynamics. Blockchain can enhance data security and traceability across stakeholders.

A more holistic and resilient strategy must combine stringent regulatory enforcement with proactive stakeholder involvement. Education and awareness-raising campaigns could transform local behaviors and reduce non-point source pollution, especially in agricultural and rural sectors. As noted by various studies, including recent work on communication strategies in farming communities [141,142], tailored messaging and digital tools can significantly enhance the adoption of sustainable practices.

Therefore, although numerous technological and policy solutions exist, they remain underutilized, misapplied, or inadequately adapted. Effective river basin protection requires not only cross-sectoral collaboration and investment but also a shift in institutional culture toward accountability, foresight, and inclusivity.

4. Conclusions and Future Perspectives

This review highlights the pervasive and complex impact of human activities on river basin water quality, revealing the diversity of pollutants and the limitations of current mitigation efforts. While significant attention has been given to identifying sources—from urban runoff and agricultural discharge to industrial waste and mining operations—the response has often been fragmented, reactive, and lacking long-term sustainability.

Freshwater resources are finite and under increasing stress due to population growth, urban sprawl, and intensified land use. The recurring patterns of pollution across different catchments—whether from nutrient overload, heavy metals, emerging contaminants, or microplastics—emphasize the urgent need for an integrated, system-based approach to managing river basins. Importantly, technological solutions alone are insufficient if comprehensive policy frameworks, local adaptation, and adequate institutional capacity do not support them.

Moving forward, robust and enforceable regulations must be complemented by regionally tailored strategies that address both point and non-point pollution sources. Investments in modern sewage and stormwater management infrastructure, as well as the rehabilitation of degraded riparian zones, are essential. At the same time, land-use planning must prioritize ecological stability, particularly in rapidly urbanizing areas where impermeable surfaces often replace natural buffers.

Moreover, education and stakeholder engagement are not optional add-ons but core components of effective water governance. Without raising public awareness and building a culture of environmental stewardship—especially among farmers, industries, and municipal authorities—many proposed interventions risk being ignored or unsustainable.

Policymaking should shift from short-term mitigation to long-term prevention, grounded in scientific evidence and informed by local realities. Digital tools, including geospatial mapping and predictive modeling, can support this transition by identifying high-risk areas and forecasting pollutant flows. However, these tools require both technical expertise and political will to be implemented meaningfully.

Ultimately, safeguarding river basins is not only an environmental necessity but a socio-economic imperative. Clean water underpins food production, public health, biodiversity, and climate resilience. As such, future strategies must embrace a multidisciplinary lens—bridging environmental science, urban planning, hydrology, and social behavior. Only through a coherent, inclusive, and forward-looking approach can we begin to reverse the degradation of these vital ecosystems and secure their functionality for future generations.

The efficiency of the measures will be increased if their design considers the potential threats and weaknesses of anthropic actions, as shown in Figure 5.