Rainfall variability, drought characterization, and efficacy of rainfall data reconstruction: case of eastern Kenya

This study examined the extent of seasonal rainfall variability, drought occurrence, and the efficacy of interpolation techniques in eastern Kenya. Analyses of rainfall variability utilized rainfall anomaly index, coefficients of variance, and probability analyses. Spline, Kriging, and inverse dista...

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Autores principales: Kisaka, M. Oscar, Mucheru-Muna, M., Ngetich, Felix K., Mugwe, JN, Mugendi, D, Mairura, Franklin S.
Formato: Journal Article
Lenguaje:Inglés
Publicado: Hindawi Limited 2015
Acceso en línea:https://hdl.handle.net/10568/66587
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author Kisaka, M. Oscar
Mucheru-Muna, M.
Ngetich, Felix K.
Mugwe, JN
Mugendi, D
Mairura, Franklin S.
author_browse Kisaka, M. Oscar
Mairura, Franklin S.
Mucheru-Muna, M.
Mugendi, D
Mugwe, JN
Ngetich, Felix K.
author_facet Kisaka, M. Oscar
Mucheru-Muna, M.
Ngetich, Felix K.
Mugwe, JN
Mugendi, D
Mairura, Franklin S.
author_sort Kisaka, M. Oscar
collection Repository of Agricultural Research Outputs (CGSpace)
description This study examined the extent of seasonal rainfall variability, drought occurrence, and the efficacy of interpolation techniques in eastern Kenya. Analyses of rainfall variability utilized rainfall anomaly index, coefficients of variance, and probability analyses. Spline, Kriging, and inverse distance weighting interpolation techniques were assessed using daily rainfall data and digital elevation model using ArcGIS. Validation of these interpolation methods was evaluated by comparing the modelled/generated rainfall values and the observed daily rainfall data using root mean square errors and mean absolute errors statistics. Results showed 90% chance of below cropping threshold rainfall (500 mm) exceeding 258.1 mm during short rains in Embu for one year return period. Rainfall variability was found to be high in seasonal amounts (CV = 0.56, 0.47, and 0.59) and in number of rainy days (CV = 0.88, 0.49, and 0.53) in Machang’a, Kiritiri, and Kindaruma, respectively. Monthly rainfall variability was found to be equally high during April and November (CV = 0.48, 0.49, and 0.76) with high probabilities (0.67) of droughts exceeding 15 days in Machang’a and Kindaruma. Dry-spell probabilities within growing months were high, (91%, 93%, 81%, and 60%) in Kiambere, Kindaruma, Machang’a, and Embu, respectively. Kriging interpolation method emerged as the most appropriate geostatistical interpolation technique suitable for spatial rainfall maps generation for the study region.
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spelling CGSpace665872025-03-13T09:44:18Z Rainfall variability, drought characterization, and efficacy of rainfall data reconstruction: case of eastern Kenya Kisaka, M. Oscar Mucheru-Muna, M. Ngetich, Felix K. Mugwe, JN Mugendi, D Mairura, Franklin S. This study examined the extent of seasonal rainfall variability, drought occurrence, and the efficacy of interpolation techniques in eastern Kenya. Analyses of rainfall variability utilized rainfall anomaly index, coefficients of variance, and probability analyses. Spline, Kriging, and inverse distance weighting interpolation techniques were assessed using daily rainfall data and digital elevation model using ArcGIS. Validation of these interpolation methods was evaluated by comparing the modelled/generated rainfall values and the observed daily rainfall data using root mean square errors and mean absolute errors statistics. Results showed 90% chance of below cropping threshold rainfall (500 mm) exceeding 258.1 mm during short rains in Embu for one year return period. Rainfall variability was found to be high in seasonal amounts (CV = 0.56, 0.47, and 0.59) and in number of rainy days (CV = 0.88, 0.49, and 0.53) in Machang’a, Kiritiri, and Kindaruma, respectively. Monthly rainfall variability was found to be equally high during April and November (CV = 0.48, 0.49, and 0.76) with high probabilities (0.67) of droughts exceeding 15 days in Machang’a and Kindaruma. Dry-spell probabilities within growing months were high, (91%, 93%, 81%, and 60%) in Kiambere, Kindaruma, Machang’a, and Embu, respectively. Kriging interpolation method emerged as the most appropriate geostatistical interpolation technique suitable for spatial rainfall maps generation for the study region. 2015 2015-06-02T16:52:21Z 2015-06-02T16:52:21Z Journal Article https://hdl.handle.net/10568/66587 en Open Access Hindawi Limited Kisaka, M. Oscar; Mucheru-Muna, M.; Ngetich, F. K.; Mugwe, J. N.; Mugendi, D.; Mairura, F.. 2015. Rainfall variability, drought characterization, and efficacy of rainfall data reconstruction: case of eastern Kenya . Advances in Meteorology 16 p.
spellingShingle Kisaka, M. Oscar
Mucheru-Muna, M.
Ngetich, Felix K.
Mugwe, JN
Mugendi, D
Mairura, Franklin S.
Rainfall variability, drought characterization, and efficacy of rainfall data reconstruction: case of eastern Kenya
title Rainfall variability, drought characterization, and efficacy of rainfall data reconstruction: case of eastern Kenya
title_full Rainfall variability, drought characterization, and efficacy of rainfall data reconstruction: case of eastern Kenya
title_fullStr Rainfall variability, drought characterization, and efficacy of rainfall data reconstruction: case of eastern Kenya
title_full_unstemmed Rainfall variability, drought characterization, and efficacy of rainfall data reconstruction: case of eastern Kenya
title_short Rainfall variability, drought characterization, and efficacy of rainfall data reconstruction: case of eastern Kenya
title_sort rainfall variability drought characterization and efficacy of rainfall data reconstruction case of eastern kenya
url https://hdl.handle.net/10568/66587
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