<?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-2026-1296</article-id>
<title-group>
<article-title>Towards the development of a national drought monitoring framework for India: Reconstruction of historical droughts using CLM5</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Naik</surname>
<given-names>Devavat Chiru</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>Dhanya</surname>
<given-names>Chandrika Thulaseedharan</given-names>
<ext-link>https://orcid.org/0000-0003-0206-5193</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>Hendricks Franssen</surname>
<given-names>Harrie-Jan</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Department of Civil and Environmental Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Agrosphere (IBG-3), Forschungszentrum Juelich GmbH, Juelich, Germany</addr-line>
</aff>
<pub-date pub-type="epub">
<day>17</day>
<month>04</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>50</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Devavat Chiru Naik et al.</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://egusphere.copernicus.org/preprints/2026/egusphere-2026-1296/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1296/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1296/egusphere-2026-1296.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1296/egusphere-2026-1296.pdf</self-uri>
<abstract>
<p>In this study, we evaluate the Community Land Model version 5.0 (CLM5.0) as a first step toward building a National Drought Monitoring Framework &amp;ndash; DRISHTI (&lt;strong&gt;D&lt;/strong&gt;rought &lt;strong&gt;R&lt;/strong&gt;isk &amp;amp; &lt;strong&gt;I&lt;/strong&gt;mpact &lt;strong&gt;S&lt;/strong&gt;urveillance using &lt;strong&gt;H&lt;/strong&gt;ydrometeorological, &lt;strong&gt;T&lt;/strong&gt;errestrial &amp;amp; &lt;strong&gt;I&lt;/strong&gt;nference Models) in India. CLM5.0 was applied over India at 0.1 &amp;deg; resolution (1980&amp;ndash;2020), using India Meteorological Department (IMD) precipitation and two atmospheric forcing datasets: the Indian Monsoon Data Assimilation and Analysis (IMDAA) regional reanalysis and the fifth generation ECMWF Re-Analysis (ERA5). Model performance was assessed for soil moisture (SM), evapotranspiration (ET), and runoff under rainfed and irrigated conditions against in-situ measurements and satellite/reference datasets: Soil Moisture Active Passive (SMAP), Global Land Evaporation Amsterdam Model (GLEAM), and Global Runoff Reconstruction (GRUN).&lt;/p&gt;
&lt;p&gt;CLM5.0 reproduced spatial and temporal hydrological variability well. Model diagnostics revealed three climate-zone biases: (1) an apparent &apos;Dry Bias&apos; in humid zones (Am) characterized by low SM, runoff, and ET. This bias reflects underestimation of precipitation in IMD rather than model process deficiencies; (2) a &apos;Wet Bias&apos; in semi-arid and arid zones (BSh, BWh), where the Dry Surface Layer scheme suppresses evaporation, generating excess storage and runoff; and (3) a &apos;Runoff Paradox&apos; in temperate zones (Cwa, Cwb), where high surface SM coincides with low runoff. Systematic runoff underestimation in complex terrains reflects limitations in sub-grid hillslope lateral flow representation, which led to high moisture retention. Relative to ERA5-driven simulations, IMDAA reduces RMSD in SM and runoff by 10% and 2.5 %, respectively, while ERA5 improves ET estimates by 17 %. At the national scale, rainfed simulations generally outperform irrigated runs; however, irrigation leads to localized improvements - most notably over the Indo-Gangetic Plain - with a stronger influence on root-zone SM than on surface SM. Specifically, irrigation reduces errors over ~26 % of irrigated grid cells for root-zone SM compared to ~23 % for surface SM, while corresponding improvements are observed over ~33 % and ~45 % of irrigated grid cells for runoff and ET, respectively. Despite these limitations, CLM5.0 successfully reproduces historical droughts, demonstrating its utility for drought monitoring in data-scarce regions while highlighting the need for improved irrigation parameterization, targeted model calibration, and careful selection of meteorological forcing datasets.</p>
</abstract>
<counts><page-count count="50"/></counts>
</article-meta>
</front>
<body/>
<back>
</back>
</article>