<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "https://jats.nlm.nih.gov/nlm-dtd/publishing/3.0/journalpublishing3.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article" specific-use="SMUR" dtd-version="3.0" xml:lang="en">
<front>
<journal-meta>
<journal-id journal-id-type="publisher">EGUsphere</journal-id>
<journal-title-group>
<journal-title>EGUsphere</journal-title>
<abbrev-journal-title abbrev-type="publisher">EGUsphere</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">EGUsphere</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub"></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/egusphere-2025-621</article-id>
<title-group>
<article-title>Gridded Intensity-Duration-Frequency (IDF) curves: understanding precipitation extremes in a drying climate</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Soto-Escobar</surname>
<given-names>Cristóbal</given-names>
<ext-link>https://orcid.org/0009-0005-3867-6991</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zambrano-Bigiarini</surname>
<given-names>Mauricio</given-names>
<ext-link>https://orcid.org/0000-0002-9536-643X</ext-link>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Tolorza</surname>
<given-names>Violeta</given-names>
<ext-link>https://orcid.org/0000-0002-0281-4476</ext-link>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Garreaud</surname>
<given-names>René</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>ICASS, Santiago, Chile</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Department of Civil Engineering, Universidad de la Frontera, Temuco, Chile</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Center for Climate and Resilience Research, Universidad de Chile, Santiago, Chile</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Universidad de la Frontera, Temuco, Chile</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Department of Geophysics, Universidad de Chile, Santiago, Chile</addr-line>
</aff>
<pub-date pub-type="epub">
<day>13</day>
<month>03</month>
<year>2025</year>
</pub-date>
<volume>2025</volume>
<fpage>1</fpage>
<lpage>44</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2025 Cristóbal Soto-Escobar et al.</copyright-statement>
<copyright-year>2025</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://egusphere.copernicus.org/preprints/2025/egusphere-2025-621/">This article is available from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-621/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-621/egusphere-2025-621.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-621/egusphere-2025-621.pdf</self-uri>
<abstract>
<p>Traditionally, Intensity-Duration-Frequency (IDF) curves are based on rain gauge data under the assumption of stationarity. However, only limited long time series of sub-daily precipitation data are available worldwide, making it difficult to accurately estimate precipitation intensity for different durations and return periods, while climate change is challenging stationarity. This study aims to better understand how the stationary assumption and data length of hourly precipitation data influence the annual maximum intensities of precipitation events in continental Chile, a region with varying climate and topography that has been affected by an unprecedented drought since 2010. Five hourly gridded precipitation datasets (IMEGv06B, IMERGv07B, ERA5, ERA5-Land, CMORPH-CDR) and 161 quality-checked rain gauges are used to compute annual maximum intensities (&lt;em&gt;I&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt;, mm h&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) using the stationary and non-stationary Gumbel distribution for six return periods (2&amp;ndash;100 years) and 11 durations (1&amp;ndash;72 h). Bias-correction factors are applied to match the gridded &lt;em&gt;I&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt; values with the in situ ones, and the modified Mann-Kendall test is used to assess the trends in &lt;em&gt;I&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt;. Annual maximum intensities are calculated for the 20-year period (2001&amp;ndash;2021) for all products, while an additional 40-year period (1981&amp;ndash;2021) is used for ERA5 and ERA5-Land to assess the impact of data length. Our results revealed significant decreasing trends across Chile for CMORPH-CDR, decreas-ing trends in Central-Southern Chile (32&amp;ndash;43&amp;deg; S) for ERA5 and ERA5-Land, and isolated, divergent trends for IMERGv06B and IMERGv07B. In addition, our results show that &lt;em&gt;I&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt;&lt;sub&gt; &lt;/sub&gt;reaches its maximum values in central and southern Chile, for all durations, in contrast to the mean annual precipitation, which increases steadily towards the south. For durations of 24 hours or more, the highest intensities are primarily found in the Andes, particularly between the Maule and Araucan&amp;iacute;a region (35&amp;ndash;40&amp;deg; S). While the &lt;em&gt;I&lt;sub&gt;max&amp;nbsp;&lt;/sub&gt; &lt;/em&gt;values were similar for IMERGv07B, ERA5 and ERA5-Land, they were much higher for IMERGv06B and CMORPH-CDR. The difference between stationary and non-stationary &lt;em&gt;I&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt; values ranges from 0 to 5 mm h&lt;sup&gt;&amp;minus;1&lt;/sup&gt; and become smaller for durations greater than 8 h. Despite the differences observed in the Gumbel parameters for ERA5 and ERA5-Land when using 20- and 40-year records, the resulting &lt;em&gt;I&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt; values showed differences with median values below 1 mm&lt;sup&gt; &amp;minus;1&lt;/sup&gt;. The &lt;em&gt;I&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt;&amp;nbsp; values are available on a public and user-friendly web platform (&lt;a href=&quot;https://curvasIDF.cl/&quot;&gt;https://curvasIDF.cl/&lt;/a&gt;).</p>
</abstract>
<counts><page-count count="44"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>Agencia Nacional de Investigación y Desarrollo</funding-source>
<award-id>ANID-Fondecyt Regular 1212071</award-id>
<award-id>ANID-PCI NSFC 190018</award-id>
<award-id>ANID-Fondecyt Iniciación 11190864</award-id>
<award-id>ANID-FONDAP 1522A0001</award-id>
</award-group>
<award-group id="gs2">
<funding-source>Universidad de La Frontera</funding-source>
<award-id>UFRO Postocdoral grant VRIP20P001</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
<body/>
<back>
</back>
</article>