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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>SKET-Monitor: A Knowledge-Driven AI System for Sustainable Environmental and Territorial Monitoring</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Veronica Camerada</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Dario Guidotti</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Salvatore Lampreu</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Laura Pandolfo</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Luca Pulina</string-name>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>DUMAS, University of Sassari</institution>
          ,
          <addr-line>Via Roma 151, 07100, Sassari</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2026</year>
      </pub-date>
      <abstract>
        <p>This paper introduces SKET-Monitor, a knowledge-driven decision support initiative aimed at intelligent environmental and territorial monitoring, particularly in fragile coastal areas facing high tourism pressure. Designed to support local administrations in implementing sustainable, data-informed governance strategies, the system combines real-time sensor data, a digital replica of the monitored area, and a hybrid AI approach integrating symbolic reasoning and machine learning. A pilot deployment is currently underway on the Maria Pia beach in Alghero (Italy), where the system enables predictive analysis, policy scenario simulation, and interactive stakeholder engagement through a unified dashboard. By bridging sensor-based monitoring with AI-supported decision-making, SKET-Monitor lays the foundation for scalable, context-sensitive territorial governance tools aligned with the principles of environmental and social sustainability.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;AI for Environmental Monitoring</kwd>
        <kwd>ASP Decision Support</kwd>
        <kwd>Data-Driven Territorial Governance</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>In recent years, the European Union has promoted a fundamental shift in the design and implementation
of public policies—moving from a top-down, generic, and centralised paradigm to a decentralised,
evidence-based, and context-sensitive approach. This transition reflects two strategic needs: to enhance
policy efectiveness by tailoring interventions to local environmental and social specificities, and to
empower local actors with actionable tools for sustainable governance.</p>
      <p>Coastal areas represent a particularly complex domain for this challenge. Characterised by ecological
fragility, seasonal overcrowding, and infrastructural limitations, they require policy models that are
adaptable, transparent, and rooted in real-time environmental and behavioural data. Yet existing
decision support systems are often limited to black-box machine learning models or siloed monitoring
platforms, which provide limited interpretability and weak integration of domain-specific constraints.</p>
      <p>The SKET-Monitor system (Smart Knowledge-based Environmental and Territorial Monitor)
addresses this gap through an integrated framework for local policy modelling and simulation. Its
architecture combines four key elements: (i) a real-time sensor network monitoring environmental
and behavioural data; (ii) a Digital Twin representing spatial, infrastructural, and regulatory dynamics;
(iii) a hybrid reasoning engine blending statistical learning with symbolic AI; and (iv) a visual and
interactive interface supporting scenario exploration and decision-making. The system is developed
within the context of the SKET-Monitor project, funded by the FAIR – Future AI Research programme,
Spoke 9, under NRRP Mission 4, Component 2, Investment 1.3, and supported by the European Union –
NextGenerationEU.</p>
      <p>
        A distinctive contribution of SKET-Monitor is its use of Answer Set Programming (ASP) [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] to
formalise and simulate public policy choices. ASP is a declarative programming paradigm widely
used in non-monotonic reasoning and knowledge representation. Recent research has demonstrated
its potential in knowledge-intensive applications such as scheduling, configuration, and explainable
recommendation (see, e.g., [
        <xref ref-type="bibr" rid="ref2 ref3 ref4 ref5 ref6">2, 3, 4, 5, 6</xref>
        ]), confirming its suitability for complex decision-making domains.
In particular, ASP’s support for disjunctive rule heads and weak constraints enables the formalisation
of competing policy alternatives and preference-based optimisation. Moreover, ASP benefits from a
mature ecosystem of highly eficient solvers—such as clingo [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] and dlv [
        <xref ref-type="bibr" rid="ref10 ref8 ref9">8, 9, 10</xref>
        ]—which allow the
rapid resolution of large and complex reasoning problems, making the approach practical for decision
support scenarios.
      </p>
      <p>SKET-Monitor is not merely a monitoring platform: it enables the construction, validation, and
comparison of public policy alternatives under dynamic environmental conditions and institutional
constraints. Through its symbolic reasoning core, it supports both tailor-made policies—anchored in
local geographies—and evidence-based policies—grounded in structured data and domain knowledge.
The system aims to provide local administrations with an accessible and explainable tool for exploring
the consequences of their choices.</p>
      <p>A first pilot of the system is underway in the coastal zone of Maria Pia beach in Alghero (Italy), an area
under intense tourism pressure and ecological vulnerability. The deployment includes environmental
sensors, mobility tracking, and a knowledge base of municipal constraints and regulatory thresholds.
This real-world case serves as a demonstrator for future extensions to other fragile or high-impact
regions.</p>
      <p>The remainder of the paper is structured as follows: Section 2 presents the system architecture and
its core modules. Section 3 describes the Maria Pia pilot and selected policy simulations, while Section 4
concludes the paper and discusses future work.</p>
    </sec>
    <sec id="sec-2">
      <title>2. System Architecture</title>
      <p>The architecture of SKET-Monitor is organised as a modular pipeline that transforms heterogeneous
sensor data into structured, explainable, and localised policy recommendations. It supports
decisionmakers in environmentally and socially sensitive areas by combining real-time environmental sensing,
semantic spatial modelling, and symbolic AI. Figure 1 illustrates the processing chain.
Environment and Sensors. The monitored territory includes natural and infrastructural elements
such as sand dunes, pine forests, footpaths, and tourist access points. In the pilot site of Maria Pia beach
in Alghero, Sardinia, a combination of IoT sensors and presence-detection devices provides continuous
monitoring. Specifically, devices such as SenseCAP S2103, S1000, and S800 capture temperature,
humidity, pressure, wind, solar radiation, and air quality (CO2, PM), while the Xplore DataNode
estimates visitor flows through Wi-Fi probe signals.</p>
      <p>Unified Sensor Interface. A middleware layer handles heterogeneous data acquisition and
standardisation. It normalises incoming records into a unified JSON format, enriched with temporal and spatial
metadata. This abstraction enables seamless integration of additional sensors and promotes syntactic
and semantic interoperability across system modules.</p>
      <p>UDP Emulator. The UDP Emulator, implemented via a MongoDB instance, acts as a semantic-aware
storage and API layer. It stores validated, time-stamped, and geo-referenced records, and makes them
accessible via RESTful APIs. Inspired by Urban Data Platform paradigms, this component bridges raw
sensor data and higher-level reasoning.</p>
      <p>Digital Twin. The Digital Twin is a dynamically updated, semantically structured representation of
the monitored environment. It includes models of functional zones (e.g., beach sectors, parking areas),
infrastructural nodes (paths, service points), environmental states (pollution, crowding), and simulable</p>
      <sec id="sec-2-1">
        <title>Environment Monitoring (IoT Sensors + People Counters)</title>
      </sec>
      <sec id="sec-2-2">
        <title>Unified Sensor Interface (Data Normalisation &amp; Metadata)</title>
      </sec>
      <sec id="sec-2-3">
        <title>UDP Emulator (Storage, Validation, APIs)</title>
      </sec>
      <sec id="sec-2-4">
        <title>Digital Twin (Geospatial + Semantic Model)</title>
      </sec>
      <sec id="sec-2-5">
        <title>Symbolic Reasoning (ASP Rules)</title>
      </sec>
      <sec id="sec-2-6">
        <title>Inductive Models (AI/ML Forecasting)</title>
      </sec>
      <sec id="sec-2-7">
        <title>Simulation &amp; Policy Evaluation</title>
      </sec>
      <sec id="sec-2-8">
        <title>Stakeholder Dashboard (Indicators &amp; Recommendations)</title>
        <p>events (e.g., overcrowding, heatwaves). The twin supports both forward simulations and retrospective
queries.</p>
        <p>AI and Reasoning Modules. From the Digital Twin, structured state descriptions are passed to two
complementary reasoning modules. The symbolic engine, based on ASP, parses the state into logical
facts and applies policy constraints, thresholds, and preferences. The inductive engine includes ML
models trained to forecast environmental trends and crowding dynamics. Their outputs feed into a
simulation module that estimates the impacts of potential interventions.</p>
        <p>Simulation and Dashboard. The simulation module consolidates the outputs of symbolic and
inductive reasoning to evaluate the feasibility and impact of policy alternatives. These results are
made accessible through a dashboard for stakeholders, showing real-time indicators, justifications for
actions, and ranked recommendations. This promotes transparency and supports human-in-the-loop
decision-making.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Use Case: Coastal Monitoring in Alghero</title>
      <p>The pilot site for SKET-Monitor is a critical segment of Maria Pia beach in Alghero, Sardinia—an
ecologically sensitive coastal area subject to intense seasonal tourism. Characterised by delicate ecosystems
such as sand dunes and a pinewood forest, as well as narrow access points and limited infrastructure,
the site sufers from severe overcrowding, increased vehicle emissions, and mobility bottlenecks during
the high season. The selected portion of the territory, highlighted in Figure 2, was chosen for its
representativeness of the challenges facing coastal municipalities in managing environmental sustainability
and tourist pressure. This area serves as the focus of the pilot implementation, allowing the system to
capture and simulate critical dynamics through real-world data. These pressures place significant strain
on both the environment and local services, underscoring the need for proactive, data-driven territorial
management.</p>
      <p>To address these challenges, the pilot deployment involves a network of environmental and
behavioural sensors installed throughout the selected area. These devices are strategically distributed
to capture key indicators such as CO2 levels, particulate matter (PM2.5 and PM10), temperature, solar
radiation, and visitor flows. Their spatial arrangement is shown in Figure 3, which displays the satellite
view of the monitored area. Each labelled point (P#) corresponds to a monitoring station equipped
with a specific combination of sensing technologies—including environmental sensors, crowd detection
devices, and weather stations—designed to capture real-time information under diverse conditions.</p>
      <p>The data collected from these stations continuously feeds into a dynamically updated Digital Twin,
which semantically models the current state of the territory. This structured representation is used by the
symbolic reasoning engine, which leverages ASP to evaluate the system’s state against defined regulatory
thresholds, simulate viable policy responses, and generate explainable, ranked recommendations for
decision-makers.</p>
      <p>To demonstrate the reasoning process, we consider a hypothetical but realistic scenario derived
from synthetic data emulating the summer of 2024. During this simulated period, the system detected
consistently high crowding (an average of 330 people/day over 20 consecutive days), elevated CO2 levels
during peak hours, PM concentrations exceeding safe thresholds, and unfavourable meteorological
conditions such as low wind speed. Based on these inputs, the reasoning module constructs a set of
ASP facts and rules for policy inference, as illustrated in the following excerpt:
% Aggregated environmental facts
avg_presence(maria_pia, summer, 330).
days_over_presence(maria_pia, 20).
avg_co2(maria_pia, summer, 620).
avg_pm25(maria_pia, summer, 38).
avg_pm10(maria_pia, summer, 58).
avg_wind_speed(maria_pia, summer, 1.2).
% Thresholds
threshold_presence(300).
threshold_days(10).
threshold_co2(600).
threshold_pm25(25).
threshold_pm10(50).
threshold_wind_min(2.0).
% Policy options (exclusive)
activate_policy(Z, shuttle_system);
activate_policy(Z, traffic_restriction);
activate_policy(Z, partial_access_closure) :- critical_zone(Z).
% Preferences via weak constraints
:~ activate_policy(Z, shuttle_system).
:~ activate_policy(Z, traffic_restriction).</p>
      <p>This encoding formalises the environmental conditions and thresholds, defines when a zone becomes
critical, and specifies mutually exclusive policy responses. The use of weak constraints enables a
preference ordering: the system favours shuttle deployment, followed by trafic restrictions, and uses
partial closures only as a last resort.</p>
      <p>Based on these rules, the reasoning engine produces a ranked list of policy alternatives, which are
evaluated for feasibility and impact using the Digital Twin and domain-specific constraints. Table 1
summarises the available interventions.</p>
      <p>The ASP solver ultimately selects the most preferred feasible action, generating justifications
alongside each policy recommendation. These explanations, displayed through the system’s stakeholder
dashboard, help promote transparency and accountability in local decision-making. This symbolic
reasoning layer complements the system’s inductive components, demonstrating how explainable
AI can be efectively used to support sustainable, context-aware governance in complex territorial
scenarios.</p>
    </sec>
    <sec id="sec-4">
      <title>4. Conclusion and Future Work</title>
      <p>SKET-Monitor showcases the potential of combining real-time environmental sensing, semantic
modelling, and symbolic reasoning to support evidence-based, explainable, and adaptive policy-making
at the local scale. The system was conceived to address the growing complexity of governance in fragile
and tourism-intensive territories, where sustainability imperatives meet operational constraints and
social expectations. By leveraging ASP as a core component of its policy engine, the system is able
to represent legal norms, evaluate alternative interventions, and express contextual trade-ofs in a
transparent and modular way.</p>
      <p>The pilot case of Maria Pia beach in Alghero demonstrates how this hybrid approach—combining
live sensor data and structured policy logic—can yield practical, interpretable recommendations for
territorial management. The architecture’s modularity and domain-agnostic interfaces also favour
transferability to other ecological or urban contexts.</p>
      <p>Looking ahead, several directions are being pursued to further develop and expand the system’s
scope. In the framework of the Spoke 2 of ecosystem e.INS (https://eins-spoke2.uniss.it), SKET-Monitor
will be integrated with sentiment analysis data, enabling local administrations to couple environmental
indicators with qualitative feedback from visitors. This will enrich the system’s reasoning capabilities
and foster the co-design of services attuned to users’ perceptions and needs.</p>
      <p>In synergy with the C-WISE project (RAISE ecosystem, https://www.raiseliguria.it), new use cases
are being developed to model policies for inclusive urban mobility, with particular attention to the
needs of vulnerable citizens. The ASP-based reasoning module is under active development to support
personalised recommendations and inclusive accessibility policies, building upon shared infrastructures
such as the Urban Data Platform and the Digital Twin.</p>
      <p>Additionally, through the regional initiatives InnTerr and T3, financed by the Sardinian Regional
Government, the described infrastructure is currently being deployed across over 30 coastal and
inland municipalities in Sardinia. These testbeds ofer a unique opportunity to assess the system’s
generalisability, resilience, and policy impact in diverse territorial settings—ranging from touristic
shorelines to depopulated rural areas.</p>
    </sec>
    <sec id="sec-5">
      <title>Acknowledgments</title>
      <p>The contributions of V. Camerada, S. Lampreu, and L. Pulina are funded by the project FAIR – Future
AI Research, Spoke 9, under NRRP Mission 4, Component 2, Investment 1.3, funded by the European
Union – NextGenerationEU.</p>
      <p>The research activities of D. Guidotti and L. Pandolfo are funded by the project e.INS – Ecosystem
of Innovation for Next Generation Sardinia (code ECS00000038), financed by the Italian Ministry for
Research and Education (MUR) within the framework of NRRP – Mission 4, Component 2, “From
research to business,” Investment 1.5, “Creation and strengthening of ecosystems of innovation” and
construction of “Territorial R&amp;D Leaders” (CUP J83C21000320007).</p>
      <p>We also wish to express our sincere gratitude to Prof. Gavino Mariotti, scientific coordinator of
the projects InnTerr and T3, for his fundamental support in facilitating the deployment of the
described system across a wide range of Sardinian municipalities through direct engagement with local
administrations.</p>
    </sec>
    <sec id="sec-6">
      <title>Declaration on Generative AI</title>
      <p>During the preparation of this work, the author(s) used ChatGPT in order to: Grammar and spelling
check. After using this tool, the authors reviewed and edited the content as needed and takes full
responsibility for the publication’s content.</p>
    </sec>
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