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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ISPRS-Archives</journal-id>
<journal-title-group>
<journal-title>The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences</journal-title>
<abbrev-journal-title abbrev-type="publisher">ISPRS-Archives</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">2194-9034</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/isprs-archives-XLIX-B4-2026-337-2026</article-id>
<title-group>
<article-title>Digital Detectives of Environment Tackling Cigarette Butt Pollution</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Topcu</surname>
<given-names>İbrahim</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Anbaroğlu</surname>
<given-names>Berk</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Department of Geomatics Engineering, Hacettepe University, Ankara, Türkiye</addr-line>
</aff>
<pub-date pub-type="epub">
<day>04</day>
<month>08</month>
<year>2026</year>
</pub-date>
<volume>XLIX-B4-2026</volume>
<fpage>337</fpage>
<lpage>343</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 İbrahim Topcu</copyright-statement>
<copyright-year>2026</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://isprs-archives.copernicus.org/articles/XLIX-B4-2026/337/2026/isprs-archives-XLIX-B4-2026-337-2026.html">This article is available from https://isprs-archives.copernicus.org/articles/XLIX-B4-2026/337/2026/isprs-archives-XLIX-B4-2026-337-2026.html</self-uri>
<self-uri xlink:href="https://isprs-archives.copernicus.org/articles/XLIX-B4-2026/337/2026/isprs-archives-XLIX-B4-2026-337-2026.pdf">The full text article is available as a PDF file from https://isprs-archives.copernicus.org/articles/XLIX-B4-2026/337/2026/isprs-archives-XLIX-B4-2026-337-2026.pdf</self-uri>
<abstract>
<p>The aim of this paper is to design and develop an openly accessible, web-based Crowdsourced Geographic Information (CGI) framework, referred to as the Digital Detectives of Environment (DiDE), to facilitate the collection of geo-located events. The framework incorporates three user roles: (i) citizens, (ii) experts, and (iii) supervisors. Citizens can browse relevant events without requiring authentication, while experts are responsible for collecting geographic data, including the optional attachment of photographs or videos. Supervisors, on the other hand, define and manage event types. Each event type is classified as either useful or harmful, which determines its visibility to citizens. The pilot implementation was conducted at the Beytepe Campus of Hacettepe University, focusing on four event types aligned with Green Deal actions: rubbish bins and recycling bins (useful), and cigarette butts and full rubbish/recycling bins (harmful). During a one-week data collection period, a total of 490 events were recorded by 37 students. The results reveal clear clustering patterns in both space and time. Temporally, a large proportion of the data was collected on the final day, indicating a tendency toward procrastination among participants. Spatially, events are concentrated in the southern part of the campus, where most facilities are located. This pattern is further supported by analyses using the F and G functions. In particular, cigarette butt events exhibit strong spatial clustering, with a mean nearest-neighbour distance of approximately 25 metres. This finding provides empirical support for the &lt;em&gt;broken windows&lt;/em&gt; theory.&lt;br /&gt;Project&amp;rsquo;s GitHub repo: &lt;code&gt;https://github.com/ibrahimtopcu11/DiDe/tree/isprs26&lt;/code&gt;&lt;br /&gt;Dataset: &lt;code&gt;https://zenodo.org/records/19442148&lt;/code&gt;</p>
</abstract>
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