Standardized Precipitation and Evapotranspiration Index Approach for Drought Assessment in Slovakia—Statistical Evaluation of Different Calculations
In the conditions of rising air temperature and changing precipitation regimes in Central Europe and Slovakia over the last two decades, it is necessary to analyse drought, develop high-quality tools for drought detection, and understand its reactions to the emerging drought situation. One of the fr...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-09-01
|
| Series: | Atmosphere |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4433/14/9/1464 |
| _version_ | 1797581312081526784 |
|---|---|
| author | Jaroslava Slavková Martin Gera Nina Nikolova Cyril Siman |
| author_facet | Jaroslava Slavková Martin Gera Nina Nikolova Cyril Siman |
| author_sort | Jaroslava Slavková |
| collection | DOAJ |
| description | In the conditions of rising air temperature and changing precipitation regimes in Central Europe and Slovakia over the last two decades, it is necessary to analyse drought, develop high-quality tools for drought detection, and understand its reactions to the emerging drought situation. One of the frequently used meteorological drought indices is the Standardized Precipitation and Evapotranspiration Index (SPEI). Several parameters can be modified in different steps of the calculation process of SPEI. In the article, we analyse the influence of selected adjustable parameters on the index results. Our research has shown that the choice of a statistical distribution (Log-logistic, Pearson III, or Generalized Extreme Value) for fitting water balance can affect the feasibility of calculating distribution parameters (and thus the index) from the provided input data, as well as lead to either underestimation or overestimation of the index. The normality test of SPEI can be used as a tool for the detection and elimination of highly skewed indices and cases when the indices were not well determined by the distribution function. This study demonstrated improved results when using the GEV distribution, despite the common use of the Log-logistic distribution. With the Pearson III distribution, unusually high or low SPEI values (|SPEI| > 6) were detected. |
| first_indexed | 2024-03-10T23:03:38Z |
| format | Article |
| id | doaj.art-7641a2158316416f8759d1370dbc6f86 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T23:03:38Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-7641a2158316416f8759d1370dbc6f862023-11-19T09:31:39ZengMDPI AGAtmosphere2073-44332023-09-01149146410.3390/atmos14091464Standardized Precipitation and Evapotranspiration Index Approach for Drought Assessment in Slovakia—Statistical Evaluation of Different CalculationsJaroslava Slavková0Martin Gera1Nina Nikolova2Cyril Siman3Faculty of Mathematics, Physics, and Informatics, Comenius University, 842 48 Bratislava, SlovakiaFaculty of Mathematics, Physics, and Informatics, Comenius University, 842 48 Bratislava, SlovakiaFaculty of Geology and Geography, Sofia University “St. Kliment Ohridski”, 1504 Sofia, BulgariaSlovak Hydrometeorological Institute, Jeséniova 17, 833 15 Bratislava, SlovakiaIn the conditions of rising air temperature and changing precipitation regimes in Central Europe and Slovakia over the last two decades, it is necessary to analyse drought, develop high-quality tools for drought detection, and understand its reactions to the emerging drought situation. One of the frequently used meteorological drought indices is the Standardized Precipitation and Evapotranspiration Index (SPEI). Several parameters can be modified in different steps of the calculation process of SPEI. In the article, we analyse the influence of selected adjustable parameters on the index results. Our research has shown that the choice of a statistical distribution (Log-logistic, Pearson III, or Generalized Extreme Value) for fitting water balance can affect the feasibility of calculating distribution parameters (and thus the index) from the provided input data, as well as lead to either underestimation or overestimation of the index. The normality test of SPEI can be used as a tool for the detection and elimination of highly skewed indices and cases when the indices were not well determined by the distribution function. This study demonstrated improved results when using the GEV distribution, despite the common use of the Log-logistic distribution. With the Pearson III distribution, unusually high or low SPEI values (|SPEI| > 6) were detected.https://www.mdpi.com/2073-4433/14/9/1464standardized precipitation evapotranspiration indexmeteorological drought indexLog-logistic distributionPearson III distributiongeneralized extreme value distributiondrought intensity |
| spellingShingle | Jaroslava Slavková Martin Gera Nina Nikolova Cyril Siman Standardized Precipitation and Evapotranspiration Index Approach for Drought Assessment in Slovakia—Statistical Evaluation of Different Calculations Atmosphere standardized precipitation evapotranspiration index meteorological drought index Log-logistic distribution Pearson III distribution generalized extreme value distribution drought intensity |
| title | Standardized Precipitation and Evapotranspiration Index Approach for Drought Assessment in Slovakia—Statistical Evaluation of Different Calculations |
| title_full | Standardized Precipitation and Evapotranspiration Index Approach for Drought Assessment in Slovakia—Statistical Evaluation of Different Calculations |
| title_fullStr | Standardized Precipitation and Evapotranspiration Index Approach for Drought Assessment in Slovakia—Statistical Evaluation of Different Calculations |
| title_full_unstemmed | Standardized Precipitation and Evapotranspiration Index Approach for Drought Assessment in Slovakia—Statistical Evaluation of Different Calculations |
| title_short | Standardized Precipitation and Evapotranspiration Index Approach for Drought Assessment in Slovakia—Statistical Evaluation of Different Calculations |
| title_sort | standardized precipitation and evapotranspiration index approach for drought assessment in slovakia statistical evaluation of different calculations |
| topic | standardized precipitation evapotranspiration index meteorological drought index Log-logistic distribution Pearson III distribution generalized extreme value distribution drought intensity |
| url | https://www.mdpi.com/2073-4433/14/9/1464 |
| work_keys_str_mv | AT jaroslavaslavkova standardizedprecipitationandevapotranspirationindexapproachfordroughtassessmentinslovakiastatisticalevaluationofdifferentcalculations AT martingera standardizedprecipitationandevapotranspirationindexapproachfordroughtassessmentinslovakiastatisticalevaluationofdifferentcalculations AT ninanikolova standardizedprecipitationandevapotranspirationindexapproachfordroughtassessmentinslovakiastatisticalevaluationofdifferentcalculations AT cyrilsiman standardizedprecipitationandevapotranspirationindexapproachfordroughtassessmentinslovakiastatisticalevaluationofdifferentcalculations |