Evidence map›Paper›PMID 42821247›Full record

ArticleEnvironmental science and pollution research international2026

A novel multivariate vine-copula-based drought index with application to high-elevation catchments.

Zanib Badar, Ishfaq Ahmad, Touqeer Ahmad, Ibrahim Mufrah Almanjahie

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Article in Environmental science and pollution research international, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

4 authors.

Zanib BadarDepartment of Mathematics and Statistics, International Islamic University, Islamabad, Islamabad, 44000, Pakistan.
Ishfaq AhmadDepartment of Mathematics and Statistics, International Islamic University, Islamabad, Islamabad, 44000, Pakistan.
Touqeer AhmadDepartment of Mathematics, University of Oslo, Oslo, 0851, Norway. touqeera@math.uio.no.ORCID http://orcid.org/0000-0002-2046-6268
Ibrahim Mufrah AlmanjahieDepartment of Mathematics, College of Science, King Khalid University, Abha, 62223, Saudi Arabia.

Funding

Deanship of Scientific Research, King Khalid University RGP2/456/46
6 · The paper itself

Abstract

Drought is a complex, slowly evolving hazard governed by multiple interacting hydro-climatic factors, making it difficult to monitor, characterize, and predict. Conventional single-variable indices fail to capture the nonlinear, asymmetric dependence between precipitation and temperature-a limitation that is particularly critical in data-scarce, high-mountain catchments, where incomplete drought characterization undermines the reliability of early-warning systems. To address this, we propose a novel vine-copula-based Multivariate Drought Index (VMDI) that integrates the Standardized Precipitation Index (SPI), the Standardized Precipitation Evapotranspiration Index (SPEI), and the Standardized Precipitation Temperature Index (SPTI) within a flexible, station-adaptive dependence-modeling framework. VMDI's key novelty lies in its station-adaptive canonical vine (C-vine) copula structure in which each index is first transformed into uniform pseudo-observations via rank-based empirical CDFs. Dependence is then decomposed into unconditional (Tree 1) and conditional (Tree 2) pair-copulas with SPTI as the root variable, capturing both direct interactions and joint behavior conditioned on SPTI. Copula families are selected locally via information criteria, and Kendall's

Indexed as

DroughtsEnvironmental MonitoringAltitudeRainTemperatureAsymmetric dependenceC-vine copulaExtreme drought detectionMultivariate Drought IndexReal-time drought monitoring

Identifiers

PMID42821247
PMCPMC13645877

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.