{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T14:20:11Z","timestamp":1772202011310,"version":"3.50.1"},"reference-count":75,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2018,1,12]],"date-time":"2018-01-12T00:00:00Z","timestamp":1515715200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","award":["WaterJPI\/0004\/2014"],"award-info":[{"award-number":["WaterJPI\/0004\/2014"]}]},{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","award":["UID\/MAT\/00297\/2013"],"award-info":[{"award-number":["UID\/MAT\/00297\/2013"]}]},{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","award":["SFRH\/BPD\/99757\/2014"],"award-info":[{"award-number":["SFRH\/BPD\/99757\/2014"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Water"],"abstract":"<jats:p>Drought class transitions over a sector of Eastern Europe were modeled using log-linear models. These drought class transitions were computed from time series of two widely used multiscale drought indices, the Standardized Preipitation Evapotranspiration Index (SPEI) and the Standardized Precipitation Index (SPI), with temporal scales of 6 and 12 months for 15 points selected from a grid over the Prut basin in Romania over a period of 112 years (1902\u20132014). The modeling also took into account the impact of North Atlantic Oscillation (NAO), exploring the potential influence of this large-scale atmospheric driver on the climate of the Prut region. To assess the probability of transition among different drought classes we computed their odds and the corresponding confidence intervals. To evaluate the predictive capabilities of the modeling, skill scores were computed and used for comparison against benchmark models, namely using persistence forecasts or modeling without the influence of the NAO index. The main results indicate that the log-linear modeling performs consistently better than the persistence forecast, and the highest improvements obtained in the skill scores with the introduction of the NAO predictor in the modeling are obtained when modeling the extended winter months of the SPEI6 and SPI12. The improvements are however not impressive, ranging between 4.7 and 6.8 for the SPEI6 and between 4.1 and 10.1 for the SPI12, in terms of the Heidke skill score.<\/jats:p>","DOI":"10.3390\/w10010065","type":"journal-article","created":{"date-parts":[[2018,1,15]],"date-time":"2018-01-15T04:01:55Z","timestamp":1515988915000},"page":"65","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Monthly Prediction of Drought Classes Using Log-Linear Models under the Influence of NAO for Early-Warning of Drought and Water Management"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0116-1917","authenticated-orcid":false,"given":"Elsa","family":"Moreira","sequence":"first","affiliation":[{"name":"Center of Mathematics and Applications (CMA), Faculty of Sciences and Technology, New University of Lisbon, 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0042-2441","authenticated-orcid":false,"given":"Ana","family":"Russo","sequence":"additional","affiliation":[{"name":"Instituto Dom Luiz (IDL), Faculty of Sciences, University of Lisbon, 1749-016 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4183-9852","authenticated-orcid":false,"given":"Ricardo","family":"Trigo","sequence":"additional","affiliation":[{"name":"Instituto Dom Luiz (IDL), Faculty of Sciences, University of Lisbon, 1749-016 Lisboa, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2018,1,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1571","DOI":"10.1002\/joc.846","article-title":"Drought climatology for Europe","volume":"22","author":"Saunders","year":"2002","journal-title":"Int. J. Climatol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1519","DOI":"10.5194\/hess-13-1519-2009","article-title":"Observed drought and wetness trends in Europe: An update","volume":"13","author":"Bordi","year":"2009","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_3","unstructured":"Pereira, L.S., Cordery, I., and Iacovides, I. (2009). Coping with Water Scarcity, Addressing the Challenges, Springer."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1016\/j.jhydrol.2010.07.012","article-title":"A review of drought concepts","volume":"391","author":"Mishra","year":"2010","journal-title":"J. Hydrol."},{"key":"ref_5","unstructured":"Vogt, J.V., Barbosa, P., Hofer, B., Magni, D., De Jager, A., Singleton, A., Horion, S., Sepulcre, G., Micale, F., and Sokolova, E. (2011). Developing a European drought observatory for monitoring, assessing and forecasting droughts across the European continent. AGU Fall Meeting Abstracts 1, American Geophysical Union. NH24A-07."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1016\/j.gloplacha.2015.01.012","article-title":"European drought climatologies and trends based on a multi-indicator approach","volume":"127","author":"Spinoni","year":"2015","journal-title":"Glob. Planet. Chang."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"509","DOI":"10.1016\/j.ejrh.2015.01.001","article-title":"The biggest drought events in Europe from 1950 to 2012","volume":"3","author":"Spinoni","year":"2015","journal-title":"J. Hydrol. Reg. Stud."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1002\/wcc.81","article-title":"Drought under global warming: A review","volume":"2","author":"Dai","year":"2011","journal-title":"WIREs Clim. Chang. Adv. Rev."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2792","DOI":"10.1002\/joc.3875","article-title":"World drought frequency, duration, and severity for 1951\u20132010","volume":"34","author":"Spinoni","year":"2014","journal-title":"Int. J. Climatol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"044001","DOI":"10.1088\/1748-9326\/9\/4\/044001","article-title":"Evidence of increasing drought severity caused by temperature rise in southern Europe","volume":"9","author":"Revuelto","year":"2014","journal-title":"Environ. Res. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1038\/nclimate2067","article-title":"Global warming and changes in drought","volume":"4","author":"Trenberth","year":"2014","journal-title":"Nat. Clim. Chang."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1894","DOI":"10.1002\/joc.1836","article-title":"Wet and dry summers in Europe since 1750: Evidence of increasing drought","volume":"29","author":"Briffa","year":"2009","journal-title":"Int. J. Climatol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1007\/s00704-008-0061-1","article-title":"Combining the standardized precipitation index and climatic water deficit in characterizing droughts: A case study in Romania","volume":"97","author":"Paltineanu","year":"2009","journal-title":"Theor. Appl. Climatol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"33","DOI":"10.5194\/nhess-11-33-2011","article-title":"Trends and extremes of drought indices throughout the 20th century in the Mediterranean","volume":"11","author":"Sousa","year":"2011","journal-title":"Nat. Hazards Earth Syst. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2146","DOI":"10.1175\/JCLI-D-11-00296.1","article-title":"On the Increased Frequency of Mediterranean Drought","volume":"25","author":"Hoerling","year":"2012","journal-title":"J. Clim."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/j.gloplacha.2016.11.013","article-title":"Pan-European seasonal trends and recent changes of drought frequency and severity","volume":"148","author":"Spinoni","year":"2017","journal-title":"Glob. Planet. Chang."},{"key":"ref_17","unstructured":"Intergovernmental Panel on Climate Change (IPCC) (2018, January 10). Climate Change 2014, Synthesis Report, WMO and UNEP, Geneva. Available online: https:\/\/www.ipcc.ch\/pdf\/assessment-report\/ar5\/syr\/SYR_AR5_FINAL_full_wcover.pdf."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1007\/s00704-014-1290-0","article-title":"Recent climatic changes in Romania from observational data (1961\u20132013)","volume":"122","author":"Dumitrescu","year":"2015","journal-title":"Theor. Appl. Climatol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"21","DOI":"10.5194\/asr-10-21-2013","article-title":"An overview of drought events in the Carpathian Region in 1961\u20132010","volume":"10","author":"Spinoni","year":"2013","journal-title":"Adv. Sci. Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.quaint.2014.06.021","article-title":"Temporal-spatial characteristics of severe drought events and their impact on agriculture on a global scale","volume":"349","author":"Wang","year":"2014","journal-title":"Quat. Int."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"123","DOI":"10.3354\/cr00953","article-title":"Changes in precipitation with climate change","volume":"47","author":"Trenberth","year":"2011","journal-title":"Clim. Res."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"725","DOI":"10.1038\/nclimate2657","article-title":"Attribution of climate extreme events","volume":"5","author":"Trenberth","year":"2015","journal-title":"Nat. Clim. Chang."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Spinoni, J., Vogt, J.V., Naumann, G., Barbosa, P., and Dosio, A. (2017). Will drought events become more frequent and severe in Europe?. Int. J. Climatol.","DOI":"10.1002\/joc.5291"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"153","DOI":"10.3354\/cr012153","article-title":"Climate change impact on agricultural crops and adaptation options in Romania","volume":"12","author":"Cuculeanu","year":"1999","journal-title":"Clim. Res."},{"key":"ref_25","first-page":"50","article-title":"The potential of climate change on the main components of water balance relating to maize crop","volume":"6","author":"Marica","year":"2004","journal-title":"Romanian J. Meteorol."},{"key":"ref_26","unstructured":"(2018, January 10). Romanian National Climate Change Strategy (2013\u20132020), Adaptation Component, Report. Available online: http:\/\/climate-adapt.eea.europa.eu\/countries-regions\/countries\/romania."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"485","DOI":"10.1111\/1477-9552.12053","article-title":"Crop Insurance as a Strategy for Adapting to Climate Change","volume":"65","author":"Falco","year":"2014","journal-title":"J. Agric. Econ."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1038\/nature16467","article-title":"Influence of extreme weather disasters on global crop production","volume":"529","author":"Lesk","year":"2016","journal-title":"Nature"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"9","DOI":"10.5937\/GeoPan1501009O","article-title":"Impact of drought on the productivity of agricultural crops within the Oltenia Plain, Romania","volume":"19","author":"Ontel","year":"2015","journal-title":"Geogr. Pannonica"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1665","DOI":"10.1016\/j.pnsc.2009.08.001","article-title":"Climate change impacts on crop yield, crop water productivity and food security\u2014A review","volume":"19","author":"Kang","year":"2009","journal-title":"Prog. Nat. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Nguyen, T., Mula, L., Cortignani, R., Seddaiu, G., Dono, G., Virdis, S.G.P., Pasqui, M., and Roggero, P.P. (2016). Perceptions of Present and Future Climate Change Impacts on Water Availability for Agricultural Systems in the Western Mediterranean Region. Water, 8.","DOI":"10.3390\/w8110523"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1175\/BAMS-D-11-00176.1","article-title":"Toward global drought early warning capability: Expanding international cooperation for the development of a framework for monitoring and forecasting","volume":"94","author":"Pozzi","year":"2013","journal-title":"Am. Meteorol. Soc."},{"key":"ref_33","unstructured":"(2018, January 10). National Drought Mitigation Center (NDMC): What is Drought?. Available online: http:\/\/drought.unl.edu\/DroughtBasics\/WhatisDrought.aspx."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.wace.2014.03.005","article-title":"Information systems in a changing climate: Early warnings and drought risk management","volume":"3","author":"Pulwarty","year":"2014","journal-title":"Weather Clim. Extremes"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"084006","DOI":"10.1088\/1748-9326\/aa7859","article-title":"Summer drought predictability over Europe: Empirical versus dynamical forecasts","volume":"12","author":"Turco","year":"2017","journal-title":"Environ. Res. Lett."},{"key":"ref_36","unstructured":"Palmer, W.C. (1965). Meteorological Drought."},{"key":"ref_37","unstructured":"Rossi, G., Vega, T., and Bonaccorso, B. (2007). Testing a modification of the Palmer drought severity index for Mediterranean environments. Methods and Tools for Drought Analysis and Management, Springer."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1493","DOI":"10.5194\/nhess-12-1493-2012","article-title":"Spatial and temporal variability of precipitation and drought in Portugal","volume":"12","author":"Martins","year":"2012","journal-title":"Nat. Hazards Earth Syst. Sci."},{"key":"ref_39","unstructured":"McKee, T.B., Doesken, N.J., and Kleist, J. (1995, January 15\u201320). Drought monitoring with multiple time scales. Proceedings of the 9th Conference on Applied Climatology, Dallas, TX, USA."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1696","DOI":"10.1175\/2009JCLI2909.1","article-title":"A multi-scalar drought index sensitive to global warming: The Standardized Precipitation Evapotranspiration Index\u2014SPEI","volume":"23","year":"2010","journal-title":"J. Clim."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2056","DOI":"10.1175\/1520-0493(1990)118<2056:MWROTN>2.0.CO;2","article-title":"Multiple weather regimes over the North Atlantic: Analysis of precursors and successors","volume":"118","author":"Vautard","year":"1990","journal-title":"Mon. Weather Rev."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1559","DOI":"10.1002\/1097-0088(20001115)20:13<1559::AID-JOC555>3.0.CO;2-5","article-title":"Circulation weather types and their influence on the precipitation regime in Portugal","volume":"20","author":"Trigo","year":"2000","journal-title":"Int. J. Climatol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1196\/annals.1446.014","article-title":"North Atlantic wind and cyclone trends and their impact in the European precipitation and Atlantic significant wave height","volume":"1146","author":"Trigo","year":"2008","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"676","DOI":"10.1126\/science.269.5224.676","article-title":"Decadal trends in the North Atlantic Oscillation: Regional temperatures and precipitation","volume":"269","author":"Hurrell","year":"1995","journal-title":"Science"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"9","DOI":"10.3354\/cr020009","article-title":"The North Atlantic Oscillation influence on Europe: Climate impacts and associated physical mechanisms","volume":"20","author":"Trigo","year":"2002","journal-title":"Clim. Res."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"14095","DOI":"10.1038\/s41598-017-14488-5","article-title":"Evidence of long-term NAO influence on East-Central Europe winter precipitation from a guano-derived \u03b415N record","volume":"7","author":"Cleary","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"538","DOI":"10.1034\/j.1600-0870.1996.t01-3-00004.x","article-title":"Changes in the winter precipitation in Romania and its relation to the large-scale circulation","volume":"48","author":"Busuioc","year":"1996","journal-title":"Tellus"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"597","DOI":"10.1007\/s00704-012-0755-2","article-title":"Spatiotemporal distribution of aridity indices based on temperature and precipitation in the extra-Carpathian regions of Romania","volume":"112","author":"Croitoru","year":"2013","journal-title":"Theor. Appl. Climatol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1134\/S0097807816010061","article-title":"Hazards resulting from hydrological extremes in the upstream catchment of the Prut River","volume":"43","author":"Corduneanu","year":"2016","journal-title":"Water Resour."},{"key":"ref_50","unstructured":"Bojariu, R. (2017, July 31). Prut River Basin. Available online: http:\/\/imdroflood.csic.es\/wp-content\/uploads\/2016\/09\/Bojariu.pdf."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1007\/s00704-004-0082-3","article-title":"Winter precipitation variability and large-scale circulation patterns in Romania","volume":"81","author":"Tomozeiu","year":"2005","journal-title":"Theor. Appl. Climatol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"641","DOI":"10.3402\/tellusa.v57i4.14709","article-title":"The North Atlantic Oscillation signal in a regional climate simulation for the European region","volume":"57","author":"Bojariu","year":"2005","journal-title":"Tellus A"},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Bojariu, B., and Paliu, D. (2001). North Atlantic Oscillation Projection on Romanian Climate Fluctuations in the Cold Season. Detecting and Modelling Regional Climate Change, Springer.","DOI":"10.1007\/978-3-662-04313-4_29"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"626","DOI":"10.1061\/(ASCE)1084-0699(2007)12:6(626)","article-title":"Drought forecasting using a hybrid stochastic and neural network model","volume":"12","author":"Mishra","year":"2007","journal-title":"J. Hydrol. Eng."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1061\/(ASCE)1084-0699(2003)8:6(319)","article-title":"Nonlinear model for drought forecasting based on a conjunction of wavelet transforms and neural networks","volume":"8","author":"Kim","year":"2003","journal-title":"J. Hydrol. Eng."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1175\/JHM-D-10-05007.1","article-title":"Long lead time drought forecasting using a wavelet and fuzzy logic combination model: A case study in Texas","volume":"13","author":"Ozger","year":"2012","journal-title":"J. Hydrometeorol."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1143","DOI":"10.1007\/s00477-008-0288-5","article-title":"Adaptive neuro-fuzzy inference system for drought forecasting","volume":"23","author":"Bacanli","year":"2009","journal-title":"Stoch. Environ. Res. Risk Assess."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.jhydrol.2011.03.049","article-title":"Drought modeling\u2014A review","volume":"403","author":"Mishra","year":"2011","journal-title":"J. Hydrol."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1007\/s00477-005-0238-4","article-title":"Drought forecasting using stochastic models","volume":"19","author":"Mishra","year":"2005","journal-title":"Stoch. Environ. Res. Risk Assess."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"1398","DOI":"10.1016\/j.mcm.2009.10.031","article-title":"Drought forecasting based on the remote sensing data using ARIMA models","volume":"51","author":"Han","year":"2010","journal-title":"Math. Comput. Model."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.ecolmodel.2006.04.017","article-title":"Drought forecasting using feed-forward recursive neural network","volume":"198","author":"Mishra","year":"2006","journal-title":"Ecol. Model."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"953","DOI":"10.1175\/2009JHM1034.1","article-title":"Seasonal predictability of European discharge: NAO and hydrological response time","volume":"10","author":"Bierkens","year":"2009","journal-title":"J. Hydrometeorol."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1813","DOI":"10.1007\/s11269-006-9129-9","article-title":"Prediction of SPI drought class transitions using Markov chains","volume":"21","author":"Paulo","year":"2007","journal-title":"Water Resour. Manag."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1016\/j.jhydrol.2008.03.002","article-title":"SPI-based drought category prediction using log-linear models","volume":"354","author":"Moreira","year":"2008","journal-title":"J. Hydrol."},{"key":"ref_65","doi-asserted-by":"crossref","unstructured":"Moreira, E.E., Pires, C.L., and Pereira, L.S. (2016). SPI Drought Class Predictions Driven by the North Atlantic Oscillation Index Using Log-Linear Modeling. Water, 8.","DOI":"10.3390\/w8020043"},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"801","DOI":"10.1007\/s11269-006-9062-y","article-title":"Drought forecasting using the Standardized Precipitation Index","volume":"21","author":"Cancelliere","year":"2007","journal-title":"Water Resour. Manag."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1016\/j.jhydrol.2015.01.070","article-title":"Probabilistic forecasting of drought class transitions in Sicily (Italy) using Standardized Precipitation Index and North Atlantic Oscillation","volume":"526","author":"Bonaccorso","year":"2015","journal-title":"J. Hydrol."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"2103","DOI":"10.1002\/joc.1498","article-title":"Drought forecasting using artificial neural networks and time series of drought indices","volume":"27","author":"Morid","year":"2007","journal-title":"Int. J. Climatol."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1016\/j.pce.2015.10.019","article-title":"SPI drought class prediction using log-linear models applied to wet and dry seasons","volume":"94","author":"Moreira","year":"2016","journal-title":"Phys. Chem. Earth"},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1080\/02508060608691913","article-title":"Drought concepts and characterization: Comparing drought indices applied at local and regional Scales","volume":"31","author":"Paulo","year":"2006","journal-title":"Water Int."},{"key":"ref_71","unstructured":"Agresti, A. (1990). Categorical Data Analysis, John Willey & Sons."},{"key":"ref_72","doi-asserted-by":"crossref","unstructured":"Jolliffe, I., and Stephenson, D. (2011). Forecast Verification: A Practitioner\u2019s Guide in Atmospheric Science, Willey. [2nd ed.].","DOI":"10.1002\/9781119960003"},{"key":"ref_73","unstructured":"Wilks, D.S. (2011). Statistical Methods in the Atmospheric Sciences, Academic Press. [3rd ed.]."},{"key":"ref_74","unstructured":"Montgomery, D.C. (1997). Design and Analysis of Experiments, John Willey & Sons. [5th ed.]."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"3011","DOI":"10.5194\/hess-16-3011-2012","article-title":"Are drought occurrence and severity aggravating? A study on SPI drought class transitions using log-linear models and ANOVA-like inference","volume":"16","author":"Moreira","year":"2012","journal-title":"Hydrol. Earth Syst. Sci."}],"container-title":["Water"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4441\/10\/1\/65\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:51:02Z","timestamp":1760194262000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4441\/10\/1\/65"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,1,12]]},"references-count":75,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2018,1]]}},"alternative-id":["w10010065"],"URL":"https:\/\/doi.org\/10.3390\/w10010065","relation":{},"ISSN":["2073-4441"],"issn-type":[{"value":"2073-4441","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,1,12]]}}}