Palmer drought severity index as soil moisture indicator

Physical interpretation, statistical behaviour and relation to global climate

István Jankó Szép, J. Mika, Zoltán Dunkel

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Palmer Drought Severity Index (PDSI) series, based on monthly homogenised temperature and precipitation data, are analysed for the 1901-1999 period at three stations in West-Hungary, i.e. in an objectively separating region of the country, concerning spatial variations of the monthly PDSI fluctuations. All displayed results represent computations by the Thorthwaite-type potential evapotranspiration. Some comparison with those index-series, computed by the Blaney-Criddle method is given in the Discussion. Series of PDSI exhibit strong correlation with series of two independent soil moisture estimations. Having the regression coefficient standardised by standard deviation of the soil-moisture, we obtain similar coefficients during the year (allowing for only 10-30% difference). This means, PDSI can be considered as a soil-moisture indicator. It is shown that the monthly standard deviation of PDSI exhibit small variation, ca. 10%, with a minimum in the summer period. Distribution of monthly PDSI can be considered as Gaussian, according to the Kolmogorov-Smirnoff test, whereas according to the χ2-test this is true for more than 2/3 of the cases. Exceptions all fall in the second half of the year. Finally, multi-annual relation of PDSI to the global temperature trends are analysed using the method of "slices" (Mika, 1988), dividing the local and global values into uniform time sequences, the so called time-slices and calculating regression coefficients between the local PDSI and two hemispherical temperature variables. One of the latter is the hemispherical mean, the other is the continent-ocean air temperature contrast. This correlation is always negative and frequently significant, which means that in the 20th century local soil moisture conditions became drier parallel to the hemispherical changes.

Original languageEnglish
Pages (from-to)231-243
Number of pages13
JournalPhysics and Chemistry of the Earth
Volume30
Issue number1-3 SPEC. ISS.
DOIs
Publication statusPublished - 2005

Fingerprint

drought
soil moisture
Drought
Soil moisture
climate
global climate
regression coefficients
standard deviation
method of slices
Temperature
Evapotranspiration
evapotranspiration
indicator
index
Hungary
temperature
potential evapotranspiration
continents
summer
oceans

Keywords

  • Climate change
  • Method of slices
  • Palmer-index
  • Soil moisture

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics

Cite this

Palmer drought severity index as soil moisture indicator : Physical interpretation, statistical behaviour and relation to global climate. / Szép, István Jankó; Mika, J.; Dunkel, Zoltán.

In: Physics and Chemistry of the Earth, Vol. 30, No. 1-3 SPEC. ISS., 2005, p. 231-243.

Research output: Contribution to journalArticle

@article{db36e622dba5416290e1ff09d36c65c7,
title = "Palmer drought severity index as soil moisture indicator: Physical interpretation, statistical behaviour and relation to global climate",
abstract = "Palmer Drought Severity Index (PDSI) series, based on monthly homogenised temperature and precipitation data, are analysed for the 1901-1999 period at three stations in West-Hungary, i.e. in an objectively separating region of the country, concerning spatial variations of the monthly PDSI fluctuations. All displayed results represent computations by the Thorthwaite-type potential evapotranspiration. Some comparison with those index-series, computed by the Blaney-Criddle method is given in the Discussion. Series of PDSI exhibit strong correlation with series of two independent soil moisture estimations. Having the regression coefficient standardised by standard deviation of the soil-moisture, we obtain similar coefficients during the year (allowing for only 10-30{\%} difference). This means, PDSI can be considered as a soil-moisture indicator. It is shown that the monthly standard deviation of PDSI exhibit small variation, ca. 10{\%}, with a minimum in the summer period. Distribution of monthly PDSI can be considered as Gaussian, according to the Kolmogorov-Smirnoff test, whereas according to the χ2-test this is true for more than 2/3 of the cases. Exceptions all fall in the second half of the year. Finally, multi-annual relation of PDSI to the global temperature trends are analysed using the method of {"}slices{"} (Mika, 1988), dividing the local and global values into uniform time sequences, the so called time-slices and calculating regression coefficients between the local PDSI and two hemispherical temperature variables. One of the latter is the hemispherical mean, the other is the continent-ocean air temperature contrast. This correlation is always negative and frequently significant, which means that in the 20th century local soil moisture conditions became drier parallel to the hemispherical changes.",
keywords = "Climate change, Method of slices, Palmer-index, Soil moisture",
author = "Sz{\'e}p, {Istv{\'a}n Jank{\'o}} and J. Mika and Zolt{\'a}n Dunkel",
year = "2005",
doi = "10.1016/j.pce.2004.08.039",
language = "English",
volume = "30",
pages = "231--243",
journal = "Physics and Chemistry of the Earth",
issn = "1474-7065",
publisher = "Elsevier Limited",
number = "1-3 SPEC. ISS.",

}

TY - JOUR

T1 - Palmer drought severity index as soil moisture indicator

T2 - Physical interpretation, statistical behaviour and relation to global climate

AU - Szép, István Jankó

AU - Mika, J.

AU - Dunkel, Zoltán

PY - 2005

Y1 - 2005

N2 - Palmer Drought Severity Index (PDSI) series, based on monthly homogenised temperature and precipitation data, are analysed for the 1901-1999 period at three stations in West-Hungary, i.e. in an objectively separating region of the country, concerning spatial variations of the monthly PDSI fluctuations. All displayed results represent computations by the Thorthwaite-type potential evapotranspiration. Some comparison with those index-series, computed by the Blaney-Criddle method is given in the Discussion. Series of PDSI exhibit strong correlation with series of two independent soil moisture estimations. Having the regression coefficient standardised by standard deviation of the soil-moisture, we obtain similar coefficients during the year (allowing for only 10-30% difference). This means, PDSI can be considered as a soil-moisture indicator. It is shown that the monthly standard deviation of PDSI exhibit small variation, ca. 10%, with a minimum in the summer period. Distribution of monthly PDSI can be considered as Gaussian, according to the Kolmogorov-Smirnoff test, whereas according to the χ2-test this is true for more than 2/3 of the cases. Exceptions all fall in the second half of the year. Finally, multi-annual relation of PDSI to the global temperature trends are analysed using the method of "slices" (Mika, 1988), dividing the local and global values into uniform time sequences, the so called time-slices and calculating regression coefficients between the local PDSI and two hemispherical temperature variables. One of the latter is the hemispherical mean, the other is the continent-ocean air temperature contrast. This correlation is always negative and frequently significant, which means that in the 20th century local soil moisture conditions became drier parallel to the hemispherical changes.

AB - Palmer Drought Severity Index (PDSI) series, based on monthly homogenised temperature and precipitation data, are analysed for the 1901-1999 period at three stations in West-Hungary, i.e. in an objectively separating region of the country, concerning spatial variations of the monthly PDSI fluctuations. All displayed results represent computations by the Thorthwaite-type potential evapotranspiration. Some comparison with those index-series, computed by the Blaney-Criddle method is given in the Discussion. Series of PDSI exhibit strong correlation with series of two independent soil moisture estimations. Having the regression coefficient standardised by standard deviation of the soil-moisture, we obtain similar coefficients during the year (allowing for only 10-30% difference). This means, PDSI can be considered as a soil-moisture indicator. It is shown that the monthly standard deviation of PDSI exhibit small variation, ca. 10%, with a minimum in the summer period. Distribution of monthly PDSI can be considered as Gaussian, according to the Kolmogorov-Smirnoff test, whereas according to the χ2-test this is true for more than 2/3 of the cases. Exceptions all fall in the second half of the year. Finally, multi-annual relation of PDSI to the global temperature trends are analysed using the method of "slices" (Mika, 1988), dividing the local and global values into uniform time sequences, the so called time-slices and calculating regression coefficients between the local PDSI and two hemispherical temperature variables. One of the latter is the hemispherical mean, the other is the continent-ocean air temperature contrast. This correlation is always negative and frequently significant, which means that in the 20th century local soil moisture conditions became drier parallel to the hemispherical changes.

KW - Climate change

KW - Method of slices

KW - Palmer-index

KW - Soil moisture

UR - http://www.scopus.com/inward/record.url?scp=13244251051&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=13244251051&partnerID=8YFLogxK

U2 - 10.1016/j.pce.2004.08.039

DO - 10.1016/j.pce.2004.08.039

M3 - Article

VL - 30

SP - 231

EP - 243

JO - Physics and Chemistry of the Earth

JF - Physics and Chemistry of the Earth

SN - 1474-7065

IS - 1-3 SPEC. ISS.

ER -