Geosite of Fiume Piccolo, Puglia: Innovative Technologies for Natural Heritage Monitoring

Abstract

This study aims to enhance natural heritage through detailed monitoring aimed at evaluating ongoing environmental dynamics and anthropic impacts on fragile coastal ecosystems, with particular attention to dune ecosystems and back-dune ponds in Southern Italy. The integration of remote sensing technologies, such as thermal cameras and geospatial data, has made it possible to identify underground water sources that are useful for characterizing and monitoring the water regime of the targeted area. Through modelling software, different methods of assessing the environmental state, aimed at identifying the best sustainable practices that can be implemented in these fragile ecosystems, are also proposed. The presented multidisciplinary approach demonstrates how science and technology can support the sustainable management of protected areas, with positive implications for environmental protection and local development, and the adoption of best practices, inspired by international models, that can promote the conservation of biodiversity and the valorization of historical heritage.

1. Introduction

Natural heritage includes all resources and areas which, due to their ecological, scientific, aesthetic or cultural value, deserve protection and conservation. It represents the biological and geological richness of the Earth, including ecosystems, animal and plant species, geological formations, water basins, natural landscapes and ecological processes fundamental to the well-being of the planet [1,2].

Globally, one of the best-known examples of natural heritage is the Great Barrier Reef in Australia, the largest coral reef system in the world [3]. Another example is the Serengeti National Park in Tanzania, famous for the annual migration of millions of herbivores, such as wildebeest and zebras, which represents one of the most spectacular and vital natural phenomena for the ecosystem [4,5].

In Italy, one of the most relevant examples is the Gran Paradiso National Park, the oldest national park in the country, located in the Western Alps [6]. It is known for its extraordinary biodiversity, hosting species such as the ibex and the chamois, and represents a symbol of nature conservation in Italy. Another example is the Zingaro Nature Reserve in Sicily, a protected coastal area that preserves unique Mediterranean landscapes and is rich in endemic flora and crucial habitats for many bird species [7].

National parks and nature reserves serve as valuable case studies for understanding the interaction between natural ecosystems and anthropogenic pressures, highlighting the importance of sustainable management strategies [8].

While protected natural areas are territories designated for the conservation of biodiversity, ecosystems and natural habitats, geosites are places of geological interest characterized by the presence of particular rock formations, fossils, geomorphological structures, minerals or evidence of past geological processes [9,10]. Their importance is linked, above all, to the scientific, educational and cultural value of geodiversity and the conservation of geological elements of particular scientific or landscape relevance and cultural value, in which very particular and often very fragile ecosystems can form [11,12]. Geosite protection aims to preserve these unique geological phenomena.

A famous example in Italy is Vesuvius, one of the best-known volcanoes in the world. Located near Naples, Vesuvius is a geosite of enormous importance for volcanology, famous for the eruption of 79 AD, which destroyed the towns of Pompei and Ercolano [13,14,15]. Another important Italian geosite is the Grotta del Bue Marino in Sardinia, which features spectacular limestone formations, stalactites, stalagmites and rock carvings dating back to the Neolithic period, testifying to the interaction between man and nature in remote times. These places not only tell the geological history of the Earth but also contribute to tourism and the valorization of the territory [16].

Other important areas are coastal back-dune ecosystems. They contribute significantly to preserving biodiversity and maintaining ecological balance. Their unique geomorphological and hydrological dynamics support diverse plant and animal species, including endemic vegetation and important habitats for migratory birds. These areas act as natural buffers against coastal erosion and contribute to water regulation by sustaining wetlands and groundwater recharge. Additionally, their historical and cultural significance underscores the long-standing interaction between humans and these fragile environments. Historically, the dune lakes were used for aquaculture, as shown by century-old masonry works, offering insights into past land and water management [17]. In terms of cultural, educational and tourist interest, these areas represent a precious natural heritage to be valorized. Their landscape and hiking value are high, offering visitors a unique context to explore the richness of coastal biodiversity and understand the ecological dynamics that characterize Mediterranean wetlands.

Preservation of such fragile and complex ecosystems requires sophisticated monitoring approaches and techniques. Recent technological advancements have opened new possibilities for environmental and natural heritage observation, monitoring and management.

The use of satellite images and drones has revolutionized the monitoring of wetlands behind the dunes and in protected areas, allowing detailed, real-time data to be obtained. Through remote sensing, it is possible to monitor the extension of wetlands; in this specific case, multispectral satellite images are used to precisely map changes in the extension of wetlands behind the dunes over time, identifying reductions due to evaporation or drought [18]. Drones equipped with high-resolution sensors allow us to detect illegal activities, such as waste abandonment and arson, illegal constructions or roads and paths within protected areas, and monitor unauthorized urban expansion and many other activities with a high anthropogenic impact [19,20]. Furthermore, the use of drones and satellite images allows the detection of changes in water quality through the measurement of parameters such as turbidity and the presence of chemical substances, which are useful for identifying pollution of agricultural or industrial origin [21]. From an ecosystemic point of view, it is possible to monitor the expansion of urban areas surrounding protected areas, highlighting the degree of fragmentation of natural habitats and potential threats to biodiversity; it is possible to monitor changes in the coastline and dune erosion, phenomena often accelerated by human activities or climate change [22,23].

Some drones equipped with infrared sensors detect the health of vegetation in wetlands by calculating vegetation indices and identifying the spread of invasive species or the degradation of natural habitats caused by pollution or hydrological changes [24,25,26,27]. This technique should certainly be accompanied by the detection of vegetation through more traditional techniques, based on the phytosociological approach, used to describe and classify plant communities based on the abundance and coverage of species in an area. This method allows us to identify plant associations and monitor ecological changes over time [28].

The conservation status of migratory and sedentary bird species, such as herons and ducks, can be assessed using GPS and miniaturized geolocators. These technologies track movements, enable population censuses, and identify critical resting and nesting areas requiring protection. In case of difficulty for humans to carry out ringing operations, it is possible to use thermal sensors to monitor populations of resident anatids, detecting the presence of birds in areas that are difficult to access or covered by dense vegetation. This mode allows for more accurate estimates of populations without disturbing natural habitats.

Current knowledge documents the ecological significance of natural heritage and geosites, emphasizing their role in biodiversity conservation and environmental education. However, a critical gap remains in integrating advanced detection technologies with environmental monitoring to enhance conservation strategies, particularly in fragile coastal wetland ecosystems.

In this context, this study proposes an integrated approach combining advanced detection technologies and data integration methods, with a particular focus on water resource modelling software. This approach offers a new perspective on wetland conservation by demonstrating how the output of these analyses can serve as input for other environmental models. It also highlights future directions to improve site knowledge for conservation purposes. By providing precise, real-time data, this study supports sustainable management practices and informed policy decisions. This is especially relevant in the context of coastal wetland monitoring and management, whereby technologies of Earth observation, including proximal and remote sensing techniques, are essential in tracking natural change and anthropogenic impacts on back-dune wetlands.

2. Materials and Methods

2.1. Study Area

The small geosite “Stagno di Fiume Piccolo” near “Lido Morelli” is located about 10 km south of the town of Torre Canne, immediately north of Torre San Leonardo, in the Puglia region [29] (Figure 1). It consists of a characteristic pond behind the dunes, delimited towards the coast by a dune belt extending from Torre Canne to the “Il Pilone” Village [30].

The study area represents a valuable site for monitoring natural heritage due to its unique geomorphological and ecological features; it is an exceptional example of a back-dune coastal ecosystem with considerable scientific, geomorphological, hydrogeological, botanical, faunal and historical interest. These environments are characterized by the presence of a dune belt formed during the Holocene, which allowed water stagnation and the rise in the water table, favouring the creation of coastal ponds and wetlands that have supported a rich ecosystem for millennia. From a geomorphological and hydrogeological point of view, the interaction between the dunes and the water behind the dunes constitutes a phenomenon of great interest. The dunes contributed to the formation of the ponds, retaining the water and creating favourable conditions for the development of a peculiar ecosystem. However, the construction of modern infrastructures, such as the adjacent highway, has partially compromised this balance, leading to land reclamation, landfill and loss of biodiversity.

Despite these pressures, these remain a determining factor for biodiversity. The dune system hosts typical Mediterranean vegetation, including juniper trees of considerable ecological importance. In the Mediterranean scrub of the dunes of the geosite, typical species such as juniper, mastic and myrtle stand out, while the centuries-old junipers add further naturalistic value to the landscape [31]. Beyond the dunes, the landscape transitions into dense Mediterranean maquis, dominated by species such as Pistacia lentiscus and Myrtus communis, which contribute to the area’s resilience against coastal erosion and habitat degradation. At a botanical level, the areas are rich in halophilous herbaceous species such as salicornia, rushes and statice, with the presence of Limonium apulum, an endemic species of the Apulian coasts, which confers an important conservation value [32,33].

From a faunal point of view, the area in question serves as a habitat for numerous species of sedentary and migratory birds. Among these, there are the little egret, the grey heron, the purple heron, the black-winged stilt and the spoonbill, as well as various species of ducks, making the area a fundamental site for the protection of avifauna and birdwatching [34].

Historically, the lagoon was used for aquaculture, evidenced by remnants of masonry structures and water control mechanisms that can still be observed today. These features reflect a historical interaction between humans and the wetland environment, highlighting the importance of balancing conservation efforts with sustainable use practices.

In the context of natural heritage monitoring, this area offers valuable insights into the impacts of human activity on coastal ecosystems and karst aquifer [35]. Monitoring the site’s biodiversity, vegetation dynamics and water quality can inform strategies to mitigate the effects of tourism and infrastructure development. Furthermore, regular assessments of habitat conditions are essential for identifying priority areas for restoration, promoting the resilience of these delicate ecosystems and preserving their ecological functions for future generations.

2.2. Source Mapping and Characterization

Thermal sensors are essential tools for detecting and monitoring temperature changes in the environment. They work by converting heat into electrical signals, allowing for the precise measurement of surface temperatures and their variations. These devices, widely used in many sectors, also find application in the study of natural sources, allowing the identification and mapping of phenomena that are difficult to observe with traditional methods.

From a technological point of view, thermal sensors can be made using different materials and physical principles. Thermistors vary their electrical resistance based on temperature, while thermocouples exploit the potential difference generated by two different metals exposed to different temperatures. However, for advanced applications, such as thermal mapping of sources, passive detection devices based on microbolometers and photodiodes are used. These sensors detect infrared radiation emitted by objects, enabling the creation of detailed thermal images without direct contact.

The use of advanced thermal imaging cameras allows us to identify underground sources based on the thermal differences between the emerging water and the surrounding ground. Thermal images provide useful information to determine the exact location of springs, the thermal characteristics of the site and even the flow rate of water. The information collected allows us to monitor the evolution of the sources over time, identify any alterations linked to climate change or human activities and support the sustainable management of water resources. This technique is particularly useful in areas that are difficult to access (as in our case) or where direct observation is complicated, allowing the collection of important data for the study of groundwater, water resources management and environmental monitoring.

In this case study, a portable thermal imaging camera, the FLIR ONE^®, was used, which allows for fast and precise detection in the field. Although originally developed for industrial applications—such as inspecting electrical systems or diagnosing air conditioning systems—these thermal imaging cameras have also proven invaluable for environmental monitoring.

2.3. Data Processing

The procedure developed for processing thermal images acquired with the FLIR ONE^® thermal camera aims to overcome limitations imposed by the proprietary software provided by the manufacturer. Specifically, the standard software does not grant full control over the raw data, restricting its use to predefined visual outputs and basic analyses. This limitation can be particularly problematic for scientific applications that require precise quantitative data, such as environmental monitoring, hydrological modelling and thermal anomaly detection.

By implementing a customized data extraction workflow, it is possible to access raw temperature values from thermal images. These raw datasets are essential for feeding advanced hydrological models like MODFLOW [36] and Soil and Water Assessment Tool (SWAT) [37], which require accurate temperature input to simulate subsurface water flow, identify thermal springs and estimate groundwater contributions to surface water bodies.

The process of extracting and manipulating raw thermal data involves the use of R [38], an open-source programming language widely adopted in the scientific community for its capabilities in data analysis, statistical modelling and visualization. R provides the necessary tools to handle large datasets, automate data cleaning and apply advanced statistical techniques to thermal data, including time-series analysis, clustering and spatial interpolation. Moreover, the extensive package ecosystem of R allows for the integration of thermal data with geographic information systems (GIS), further enhancing the potential for spatial analysis and environmental assessments.

This advanced data-handling approach significantly enhances the utility of thermal imaging devices in research settings. While commercial software may be sufficient for basic diagnostic tasks, scientific applications often demand more flexible and precise data manipulation. The ability to process raw temperature data enables researchers to perform custom analyses that go beyond the scope of the manufacturer’s software, thus expanding the range of potential applications in environmental monitoring:

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Detection of groundwater recharge areas through temperature anomalies;

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Quantification of thermal flows from underground water sources;

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Assessment of the thermal impact of natural springs on ecosystems.

In Supplementary Materials, we provide the pseudocode for processing FLIR thermal camera data in R, which consists of three main steps. First, the FLIR image is converted to CSV format using the Thermimage package. Next, the CSV file is transformed into an ASCII GRID format, enabling its import into GIS software such as QGIS version 3.40. Finally, the CSV data are used to generate an interactive image map, allowing users to click on specific points to retrieve temperature values.

2.4. Emissivity Values

Emissivity values represent the ability of a material to emit energy in the form of thermal radiation relative to an ideal black body, which has an emissivity of 1. Materials with high emissivity (close to 1) emit radiation efficiently, while those with low emissivity (close to 0) reflect more. These values are essential for precise temperature measurements with instruments such as thermal imaging cameras. This value must be correctly set in the data processing.

Table 1. Typical thermal emissivity values for various materials.

Material	Emissivity Value (ε)
Asphalt	0.90–0.98
Concrete	0.85–0.95
Sand	0.76–0.90
Soil (earth)	0.90–0.96
Water	0.95–0.99
Ice	0.96–0.98
Glass (smooth)	0.87–0.92
Plastic	0.85–0.95
Human Skin	0.97–0.99
Coal (powder)	0.96–0.98
Black Rubber	0.94–0.98
Wood (natural)	0.85–0.90
Paper	0.90–0.95

Note: The emissivity values are unitless and typically range from 0 to 1. Surfaces that are rough or painted tend to have higher emissivity values, while smooth or shiny surfaces usually exhibit lower emissivity.

reports typical thermal emissivity values for various materials. These values can vary depending on the surface condition, temperature and measurement method.

2.5. Data Elaboration Workflow

To streamline the data processing phase, we developed a dedicated data elaboration workflow. A detailed pseudocode script is available in the Supplementary Materials for further reference. This workflow highlights the full potential of data processing, including the possibility of integrating the results into GIS environments and environmental modelling software, enhancing their applicability for analysis and decision-making (Figure 2).

The entire workflow for processing thermal data acquired with a thermal camera is divided into four main phases. The first phase, data processing, involves the conversion of FLIR radiometric images into a matrix of temperature values using the Thermimage library, with subsequent export in CSV format for more flexible data management. In the second phase, spatial integration, the CSV file is transformed into ASCII GRID format, making it compatible with GIS software. This step reorganizes the data into a raster structure, optimizing it for spatial analysis. The third phase, analysis and visualization, uses several libraries to generate an interactive thermal image, facilitating the identification of thermal anomalies, underground sources and other environmental features of interest. The results obtained are subsequently analyzed in the fourth phase, results, for an in-depth evaluation aimed at extracting relevant information.

3. Results

A comparative analysis between optical photographs and thermal images highlighted the added value of thermal imaging in detecting temperature variations in the environment.

The thermal survey led to the identification of a previously unrecorded underground water source. The temperature anomaly detected through thermal imaging indicated the presence of this hidden source, which had not been documented in prior surveys. These results highlight the practical advantages of integrating thermal imaging in environmental monitoring, particularly for the identification and mapping of water sources in natural and remote areas.

In addition, thanks to the application of the thermal data processing procedure, it was possible to obtain an image with temperature values approximated to a tenth of a degree (sufficient for our application) (Figure 3).

By following the thermal variations in the surface of the lake, it was possible to trace the position of the source, which was difficult to access, hidden among the vegetation and not previously mapped. Figure 4 shows the points with the known sources, while in Figure 5, the point in the small source is identified with a thermal camera.

The identified source falls into the category of emergency sources that are generated when underground water emerges in free-flow conditions through spring mouths that reach sea level along the stratification and fracturing joints of the outcropping limestones (or calcarenites) (Figure 6). In some cases, the accentuated fracturing of the limestones near the coast allows the piezometric surface of the aquifer to lower to sea level even before reaching the coastline so that the spring flow occurs inland.

Unlike the new source identified, the Fiume Morello and Fiume Piccolo springs are overflow sources due to damming, created by a fossil dune cord deposited on the Cretaceous limestones during the last post-glacial transgression and partially covered by the current dunes. This sandy dune belt prevents the normal flow of groundwater towards the sea, causing it to emerge along a strip parallel to the current coast. This alignment follows an old coastline dating back to the Tyrrhenian era, located at an altitude of 3–4 m above current sea level.

The flow rate of the Fiume Morello has shown significant variability over time. In 1930, it was recorded at around 200 L/s, increasing significantly between 1950 and 1955, with values ranging from 180 to 600 L/s. In 1985, the flow remained between 250 and 500 L/s, while in 2000, it decreased, fluctuating between 70 and 420 L/s. By 2010, the flow rate continued to vary between 130 and 350 L/s, confirming a downward trend compared to historical data. The residual solids at 180 °C in the Fiume Morello have progressively increased over time. In 1980, values ranged from 420 to 500 g/L, stabilizing at around 420 g/L in 1990. In 1995, there was a slight increase to 450 g/L, followed by a further rise between 2000 and 2010, reaching a peak beyond 720 g/L.

The flow rate of the Fiume Piccolo has fluctuated over time. In 1925, it was recorded at around 200 L/s, while in 1930, it ranged between 160 and 500 L/s. In 1950, it settled around 300 L/s, increasing slightly to 380–420 L/s in 1955. By 1985, a decline was observed, with values ranging from 250 to 400 L/s, and in 2000, the flow rate further decreased, varying between 200 and 380 L/s. The residual solids at 180 °C in the Fiume Piccolo showed less marked variations compared to other watercourses. In 1980, the recorded value was around 450 g/L, dropping to 400 g/L in 1990. In 2000, levels returned to those of 1980, around 450 g/L, followed by a sharp increase in 2005, when residual solids reached 600 g/L.

The Fiume Grande has shown significant fluctuations in flow rate over time. In 1925, it was recorded at around 500 L/s, then ranged between 400 and 1000 L/s in 1930. Between 1935 and 1940, the flow rate decreased, fluctuating between 300 and 900 L/s. In 1950, it stabilized between 400 and 650 L/s, while in 2000, it further declined (280–550 L/s). By 2010, the flow rate exhibited a wide variability, ranging from 100 to 1000 L/s. The residual solids at 180 °C in the Fiume Grande have consistently increased over time. In 1980, values ranged between 580 and 700 g/L, rising to 630 g/L in 1990. By 2000, residual solids had increased further, fluctuating between 800 and 950 g/L, reaching the highest recorded levels in 2010, with values ranging from 900 to 1200 g/L. Figure 7 summarizes the data retrieved from previous monitoring programmes of these sources.

4. Discussion

The analysis of the data relating to the three sources highlights trends (some significant R² > 0.9) in the variation in flow rate and solid residue over the years. For the Morelli River, the flow shows a decreasing trend with an R² = 0.8665, indicating a strong relationship over time related to reduced water flow. At the same time, the solid residue follows an increasing trend (R² = 0.8986), suggesting a possible process of concentration of dissolved solids due to saline intrusion, excessive exploitation and, less likely, an increase in the supply of sediments.

For the Fiume Piccolo, the decrease in flow rate is less marked than for the Fiume Morelli, with an R² = 0.5463, suggesting greater variability in the data and the possible influence of non-systematic external factors. Instead, the solid residue shows an R² = 0.9453, indicating a very evident increase that is well correlated with time. This could reflect an intensification of salt ingression processes, given that the river is close to the sea, or excessive changes in land use, which has led to an increase in the solid load.

The Fiume Grande, however, presents a different behaviour: The flow rate does not show a clear trend (R² = 0.1747), which indicates the absence of a clear relationship with time. On the other hand, the solid residue shows an increasing trend with an R² = 0.9292, similar to the other two rivers, suggesting that the phenomenon of saline ingression and accumulation of dissolved solids is common to all the sources analyzed [39,40].

Overall, these results suggest that they all show a significant increase in solid residue over time. This could be linked to common environmental factors, such as saline intrusion (also due to excessive exploitation, which creates a lowering of the groundwater level), the reduction in precipitation and the intensification of agricultural use of the surrounding soils. Furthermore, the decrease in flow rate observed in the Fiume Morelli and Piccolo Rivers could amplify the phenomenon, reducing the dilution capacity and increasing the concentration of solids.

The absence of a clear trend in the flow of the Fiume Grande suggests a greater complexity in the source feeding dynamics, which could be influenced by local factors or by non-linear variations in the hydrological regime.

However, the available dataset presents notable limitations that prevent a robust statistical validation of these trends. The data points are not continuous, with large temporal gaps between measurements (flow rate measurements start from 1920 but those of solid residue from 1980), and the observed variability within single time points suggests high dispersion. This discontinuity hinders the application of statistical models capable of providing certainty in identifying long-term trends. Nevertheless, despite the lack of a complete and systematically collected dataset, the observed patterns strongly suggest hydrological and qualitative variations over time.

In addition to these considerations, looking at the data series in Figure 7, it emerges that the effluent flow rates from the Fiume Morello and Fiume Piccolo sources are comparable, being, on average, equal to 300 ÷ 400 L/s, even if the available measurements have provided very scattered results. For the Morello River source, for which more recent data are known, obtained within the framework of recent monitoring programmes [41], a reduction in the spring flow rate has been highlighted in recent years, even if the aforementioned notable dispersion of the data does not allow us to give statistical certainty.

The Fiume Grande spring, although close to the Fiume Morello and Fiume Piccolo springs, has a very different water flow from the latter. Along the coast, in front of the springs, calcareous rocks from the Cretaceous period emerge, covered by ancient soils and recent sandy deposits; therefore, the whole area of the spring allows a strong concentration of water flow thanks to the numerous fractures present in the Cretaceous limestones. These fractures cause the water table to drop to sea level before it even reaches the coast [42]. After emerging, the spring waters flow towards the sea through an artificial canal currently lined with concrete. The flow rate of the spring is significantly higher than that of the nearby sources from Fiume Piccolo and Fiume Morello, averaging around 600 L/s and reaching maximum peaks of just under 1200 L/s.

The chemical characteristics of the spring waters are, also for this spring, strongly influenced by marine intrusion. For at least the last 30 years, there seems to have been a progressive deterioration in the quality of the spring group [39].

From this perspective, using thermal imaging to monitor underground sources could prove to be a very useful technology and offers many advantages but also has some limitations. In terms of advantages, the use of thermal imaging cameras allows for the rapid and non-invasive characterization and monitoring of surface temperatures of coastal surface water bodies. As seen, these thermal imaging cameras can indicate the presence of underground water sources based on the temperature difference between the outgoing water and the surrounding soil, even in the case of small underground sources, especially those that are difficult to detect with aircraft-mounted thermal sensors. These portable thermal imaging cameras enable close-up, detailed monitoring, allowing the detection of temperature changes on a very small scale, and can be used in hard-to-reach areas or in weather conditions that reduce visibility for drones. Being portable instruments, they are also cheaper and more easily transportable, which makes them ideal for repeated and short-term surveys, such as in mountainous contexts or complex environments. These tools offer a practical solution to integrate monitoring with more extensive techniques, providing a greater level of detail for mapping small springs and micro-hydrological systems.

Instead, the use of airborne thermal sensors on drones or aircraft allows us to monitor long stretches of coastline quickly and economically, facilitating the identification of large underwater sources and illegal discharges. Aerial thermography detects temperature differences between seawater and water from drains or springs, allowing us to identify thermal anomalies that are invisible to the naked eye. This method is particularly effective for detecting illegal discharges and leaks from coastal infrastructures, supporting environmental management and the protection of marine ecosystems, especially in areas subject to strong anthropogenic pressure [43,44].

Studies using airborne thermographic cameras in the coastal regions of the Pacific Northwest of the United States have shown that this technology is effective in identifying underwater freshwater flows that are often difficult to detect with other, more invasive or expensive techniques [45,46]. In these contexts, groundwater from springs maintains stable temperatures, making it detectable with thermal instruments. The cumulative thermal anomalies can be used to estimate the groundwater fraction relative to the total infiltration surface [47].

Airborne thermal imaging cameras are increasingly being used for various coastal water monitoring applications. One of these is the calculation of flow speed and capacity [48,49,50,51,52].

This represents one of the most promising uses; in fact, thanks to the ability of thermal cameras to detect even minimal thermal differences, it is possible to estimate the water flow. Knowing the thermal variations and applying thermodynamic laws, it is possible to calculate the heat flow and, consequently, estimate the flow rate of the sources. These data, once acquired, can be integrated into advanced hydrologic models such as the USGS’s modular hydrologic model MODFLOW [36] or the Soil and Water Assessment Tool (SWAT) [37], tools that allow the simulation of underground and surface water flows in different environmental conditions.

In the case of MODFLOW, for example, spring temperature data are used to simulate groundwater behaviour and predict the interaction between natural springs and nearby water bodies. A practical application of this type was conducted in Yellowstone National Park, where thermal imaging cameras allowed an analysis of the impact of hot springs on surface waters, contributing to the management of local water resources [53,54,55,56]. A similar approach was applied in other areas of potential geothermal interest, such as La Hermida in Spain, using UAVs, low-cost sensors and GIS integration to create detailed mapping of the effluents [57].

Similarly, the SWAT model can benefit from the integration of thermal data to analyze the contribution of groundwater sources to the overall water balance of a catchment. In a study conducted in the Ebro Basin, Spain, thermal measurements of springs allowed us to quantify the underground water flow, supporting sustainable water management decisions [58].

Another fundamental aspect concerns the possibility of identifying aquifer recharge areas, essential to guarantee sustainable management of water resources. By monitoring the thermal characteristics of springs and surface water, researchers can identify areas where rain or surface water enters the ground to replenish groundwater [59,60]. This type of analysis, carried out with the aid of thermal imaging cameras, provides essential information for planning aquifer protection and conservation interventions, which are particularly relevant in contexts characterized by drought or water stress.

The use of thermal imaging cameras, therefore, is not limited to a superficial analysis but allows the collection of crucial data for the understanding of underground water dynamics, offering a powerful tool for monitoring natural heritage and sustainable management of water resources.

Here is a comparison table between MODFLOW and SWAT (

Table 2. Main characteristics, applications and differences between the MODFLOW and SWAT hydrological models.

Characteristic	MODFLOW	SWAT
Type of Model	Groundwater flow model	Hydrological and water quality simulation model
Purpose	Model groundwater flow and distribution	Evaluate water balance and water quality in watersheds
Processes Modelled	Groundwater flow, recharge, pumping, drainage	Surface flow, runoff, erosion, nutrient transport
Applications	Water resource management, contamination studies	Water resource management planning, impacts of agricultural practices
Spatial Scope	Specific geographic areas (e.g., aquifers)	Large-scale watersheds
Input Data	Hydrogeological properties, recharge data, extraction data	Meteorological data, land use, agricultural practices, soil characteristics
User Interface	Requires technical skills for setup	More accessible interface with visualization tools
Examples of Application	Analyzing the impact of pumping on an aquifer, contamination study	Assessing the impacts of agricultural management on rivers, studying water resources in river basins
Limitations	Does not directly manage surface runoff	Does not focus exclusively on groundwater flow

) as potential tools for future investigations. This table provides an overview of the differences and similarities between MODFLOW and SWAT, highlighting how both models are useful for different purposes in water resource management and environmental planning.

Thermal sensors can also be used to study ecosystem interactions, i.e., how groundwater sources influence local ecosystems, particularly in wetlands. By monitoring temperature changes both in and around springs, it is possible to collect data on species interactions, habitat use and overall ecosystem health [61,62], even in ecosystems that are highly dependent on water resources in arid environments [63].

There are also critical aspects to consider. Thermal imaging cameras do not provide direct information on the flow rate of springs but only on temperature variations, which must then be correlated with hydrological models to estimate the flow; therefore, in this type of activity, it is always necessary to consider the errors and limitations of flow measurement.

Thermal cameras can have variable accuracy, typically ±0.5 °C. This uncertainty in temperature measurement can lead to errors in the flow rate calculation that may or may not be considered negligible depending on the purposes of the study. Environmental factors such as air temperature and the presence of vegetation or other objects that affect the thermal reading can affect the results.

The accuracy of the calculated flow rate also depends on the hydrological model used and the assumptions made, such as the constancy of the water temperature over time. We must always consider a certain natural variability as underground springs can vary in flow rate depending on climatic and hydrological conditions. Therefore, a single measurement may not accurately represent the average flow rate.

In cold and mountainous areas, environmental conditions may make the effective use of thermal imaging cameras for source monitoring impossible, especially during the winter season, as the accuracy of thermal imaging cameras depends on the calibration of soil and water emissivity, which may introduce margins of error in areas covered with snow and ice.

Conservation and sustainable management strategies for protected areas must integrate advanced technologies and multidisciplinary approaches to ensure a balance between environmental protection and economic development. A significant example concerns water management in the Camargue Reserve in France, where water techniques have been adopted to restore natural conditions and promote biodiversity. A similar approach could be applied to the Lido Morelli Pond, restoring the water regime of the Murge blades to reduce coastal erosion and the silting up of the pond.

Another crucial aspect concerns the valorization of the historical heritage linked to the ancient aquaculture plants located behind the dunes. ICT technologies and geomatic survey methods can facilitate the recovery and valorization of traditional structures, as demonstrated in the Venice Lagoon, where restored facilities have been integrated with sustainable and educational tourism activities. The historic fishpond of Fiume Morelli, dating back to the 19th century and recovered in 2009 for the practice of organic aquaculture, represents an opportunity to combine environmental protection and local economy [64].

Controlling urbanization and removing invasive infrastructure are also key to requalifying the area. In Po Delta Park, the demolition of non-essential buildings has allowed the recovery of degraded habitats, an action that can be replicated in the study area to try to limit the human impact. Together with the latter, environmental education programs, such as those adopted in the Abruzzo National Park, could actively involve the local community in the protection of the area through educational paths and interactive tools. The restoration of the ecological balance also involves the removal of non-native plant species and the planting of typical Mediterranean scrub plants, such as myrtle and mastic, to promote biodiversity [28]. The creation of ecological corridors, such as in the Maremma Park, would allow a connection between dunes, wetlands and agricultural areas, improving ecological resilience. Even the use of artificial intelligence to process data from drones and thermal sensors, as tested in the Venice Lagoon and the Trapani Salt Pans Park, would allow us to monitor and predict environmental changes, optimizing management strategies.

The integration of geospatial technologies and ICT tools would facilitate the development of sustainable models for coastal landscape management and environmental protection, ensuring a scalable and replicable approach in different protected areas also adding meaning to the visitor experience. For example, interactive applications can be used that, through dynamic maps and guided tours, allow you to explore these sites in an informed way, receiving real-time information on flora and fauna and better evaluate human impacts through the use of augmented reality and 3D reconstructions [65,66]. These technologies allow digital images to be superimposed onto real landscapes, showing visitors what the ecosystem looked like in the past and illustrating how it could evolve with conservation actions.

5. Conclusions

The conservation of natural heritage is essential to ensure biodiversity and the proper functioning of ecosystem services that are fundamental for human and environmental well-being. The “Stagno di Fiume Piccolo”, located in the province of Brindisi, represents a site of high ecological value thanks to the presence of a dune system, a retro-dune wetland and a brackish water basin. However, the area is threatened by anthropogenic pressures, including urbanization, infrastructure and agricultural activities, which have altered its ecological integrity.

This study highlighted how the use of advanced and low-cost technologies can support the conservation of these fragile ecosystems. In particular, the use of thermal sensors has allowed us to identify previously undocumented underground water sources, providing essential data for water resource management and ecosystem monitoring. The use of portable thermal imaging cameras has proven to be an effective tool for detecting hydrological micro-systems, complementing airborne remote sensing techniques. Their versatility extends to monitoring spring flows, providing valuable insights for conservation. Future studies should prioritize more frequent and standardized measurements to enable statistical validation and a deeper understanding of the factors influencing the hydrological regime of the springs.

This study also highlights that conservation and sustainable development strategies must integrate multidisciplinary approaches to promote a balance between environmental protection and economic development. By applying an approach aimed at restoring the natural water regime, it is possible to contribute to the reduction in coastal erosion and the regeneration of the wetland ecosystem, promoting the recovery of biodiversity.

A further element of valorization is represented by the recovery of the ancient back-dune aquaculture plants, a historical heritage that can be preserved through ICT technologies and geomatic survey methods. The example of the Venice Lagoon demonstrates how the restoration of such structures can be integrated with sustainable and educational tourism activities, promoting knowledge of local traditions and the circular economy.

The integration of artificial intelligence in environmental management enhances monitoring and predictive modelling, supporting more effective planning and impact mitigation.

Protecting the Stagno di Fiume Piccolo requires an integrated approach that combines advanced technologies, sustainable management strategies and the valorization of cultural heritage. Only through holistic planning and the involvement of the local community will it be possible to ensure the conservation of this unique ecosystem while promoting the sustainable development of the region.