Does a rainfall-based drought index simulate hydrological droughts?
2013; Wiley; Linguagem: Inglês
10.1002/joc.3879
ISSN1097-0088
Autores Tópico(s)Flood Risk Assessment and Management
ResumoInternational Journal of ClimatologyVolume 34, Issue 9 p. 2853-2871 RESEARCH ARTICLE Does a rainfall-based drought index simulate hydrological droughts? Muhammad Rahiz, Corresponding Author Muhammad Rahiz orcid.org/0000-0002-2021-3578 School of Geography and the Environment, University of Oxford, Oxford, UK African Climate and Development Initiative, University of Cape Town, Cape Town, South AfricaCorrespondence to: M. Rahiz, African Climate and Development Initiative, University of Cape Town, Private Bag X3, Rondebosch 7701, Cape Town, South Africa. E-mail: [email protected]Search for more papers by this authorMark New, Mark New School of Geography and the Environment, University of Oxford, Oxford, UK African Climate and Development Initiative, University of Cape Town, Cape Town, South Africa Department of Environmental and Geographical Science, University of Cape Town, Cape Town, South AfricaSearch for more papers by this author Muhammad Rahiz, Corresponding Author Muhammad Rahiz orcid.org/0000-0002-2021-3578 School of Geography and the Environment, University of Oxford, Oxford, UK African Climate and Development Initiative, University of Cape Town, Cape Town, South AfricaCorrespondence to: M. Rahiz, African Climate and Development Initiative, University of Cape Town, Private Bag X3, Rondebosch 7701, Cape Town, South Africa. E-mail: [email protected]Search for more papers by this authorMark New, Mark New School of Geography and the Environment, University of Oxford, Oxford, UK African Climate and Development Initiative, University of Cape Town, Cape Town, South Africa Department of Environmental and Geographical Science, University of Cape Town, Cape Town, South AfricaSearch for more papers by this author First published: 26 December 2013 https://doi.org/10.1002/joc.3879Citations: 5Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL ABSTRACT The drought severity index (DSI) is applied at 3-, 6-, 12- and 24-month time scales to both monthly gridded rainfall and monthly river flow datasets to evaluate if a rainfall-based drought index is able to simulate hydrological droughts. Time series of the rainfall-based and the flow-based DSIs are analysed at different drought severities and seasons at seven benchmark catchments in England. The analysis also includes the ability of the indices to reproduce the statistics of three drought characteristics, namely drought intensity, frequency of drought months and frequency of drought events at a given duration. Results of this study show that: (1) the rainfall-based DSI is able to capture periods of low flows as can be seen in its ability to represent major hydrological drought events as simulated by the flow-based DSI, (2) the rainfall-based DSIs generally represent moderate hydrological droughts better than extremes as shown by the smaller difference between the rainfall-based and the flow-based DSIs in terms of the statistics of the three drought characteristics and (3) there is a positive relationship between the time scale of DSI and the intensity (and duration) of the drought event it produces. As a secondary objective, the study has shown that the monthly gridded rainfall is a good proxy for monthly catchment rainfall and can therefore be considered a reliable dataset against which climate change experiments can be evaluated. The study concludes that the DSI is a credible index in estimating hydrological droughts. The strong positive correlation between the rainfall-based and the flow-based DSI time series suggests that changes and trends in rainfall-based DSIs can provide useful inferences for understanding changes in future hydrological droughts, as well as meteorological droughts. It is hoped that results from this study provide useful information when utilizing the DSI for assessment of drought impacts and future planning and management of water resources. Citing Literature Supporting Information Filename Description joc3879-sup-0001-TableS1.docWord document, 616 KB Table S1. Common drought months between the rainfall-based and the lagged-flwo based DSIs for the Lud catchment for the (a) dry and (b) wet seasons. joc3879-sup-0002-TableS2.docWord document, 616 KB Table S2. Common drought months between the rainfall-based and the lagged-flwo based DSIs for the Bedburn Beck catchment for the (a) dry and (b) wet seasons. joc3879-sup-0003-TableS3.docWord document, 616 KB Table S3. Common drought months between the rainfall-based and the lagged-flwo based DSIs for the Beult catchment for the (a) dry and (b) wet seasons. joc3879-sup-0004-TableS4.docWord document, 616 KB Table S4. Common drought months between the rainfall-based and the lagged-flwo based DSIs for the Dove catchment for the (a) dry and (b) wet seasons. joc3879-sup-0005-FigureS5.docWord document, 616 KB Table S5. Common drought months between the rainfall-based and the lagged-flwo based DSIs for the East Dart catchment for the (a) dry and (b) wet seasons. joc3879-sup-0006-TableS6.docWord document, 616 KB Table S6. Common drought months between the rainfall-based and the lagged-flow based DSIs for the Ellen catchment for the (a) dry and (b) wet seasons. joc3879-sup-0007-FigureS1.docWord document, 616 KB Figure S1. Histogram of the frequency of drought months (FDM) at a given DSI time scale and percentile threshold exceedance for the Bedburn Beck catchment. p > 95, p > 90, p > 70 and p > 55 indicate the 95th, 90th, 70th and 55th percentile threshold exceedance, respectively. 'Rain' and 'Flow' refer to rainfall-based and flow-based DSIs, respectively. joc3879-sup-0008-FigureS2.docWord document, 616 KB Figure S2. Histogram of the frequency of drought months (FDM) at a given DSI time scale and percentile threshold exceedance for the Beult catchment. p > 95, p > 90, p > 70 and p > 55 indicate the 95th, 90th, 70th and 55th percentile threshold exceedance, respectively. 'Rain' and 'Flow' refer to rainfall-based and flow-based DSIs, respectively. joc3879-sup-0009-FigureS3.docWord document, 616 KB Figure S3. Histogram of the frequency of drought months (FDM) at a given DSI time scale and percentile threshold exceedance for the Dove catchment. p > 95, p > 90, p > 70 and p > 55 indicate the 95th, 90th, 70th and 55th percentile threshold exceedance, respectively. 'Rain' and 'Flow' refer to rainfall-based and flow-based DSIs, respectively. joc3879-sup-0010-FigureS4.docWord document, 616 KB Figure S4. Histogram of the frequency of drought months (FDM) at a given DSI time scale and percentile threshold exceedance for the Lud catchment. p > 95, p > 90, p > 70 and p > 55 indicate the 95th, 90th, 70th and 55th percentile threshold exceedance, respectively. 'Rain' and 'Flow' refer to rainfall-based and flow-based DSIs, respectively. joc3879-sup-0011-TableS5.docWord document, 616 KB Figure S5. Histogram of the frequency of drought months (FDM) at a given DSI time scale and percentile threshold exceedance for the Ellen catchment. p > 95, p > 90, p > 70 and p > 55 indicate the 95th, 90th, 70th and 55th percentile threshold exceedance, respectively. 'Rain' and 'Flow' refer to rainfall-based and flow-based DSIs, respectively. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Volume34, Issue9July 2014Pages 2853-2871 RelatedInformation
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