Analysis of hydrological variability over the Volta river basin using in-situ data and satellite observations
By combining satellite altimetry with Gravity Recovery and Climate Experiment derived terrestrial water storage-TWS (2002–2014), this study used a two-step procedure based on spherical harmonic synthesis and statistical decomposition to support the understanding of the Volta basin's natural hyd...
Main Authors: | , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Elsevier
2017-08-01
|
Series: | Journal of Hydrology: Regional Studies |
Subjects: | |
Online Access: | http://www.sciencedirect.com/science/article/pii/S2214581816303305 |
id |
doaj-96f32f3d01c24b2f8b3bf222e84fd002 |
---|---|
record_format |
Article |
spelling |
doaj-96f32f3d01c24b2f8b3bf222e84fd0022020-11-24T22:36:33ZengElsevierJournal of Hydrology: Regional Studies2214-58182017-08-0112C8811010.1016/j.ejrh.2017.04.005Analysis of hydrological variability over the Volta river basin using in-situ data and satellite observationsChristopher E. Ndehedehe0Joseph L. Awange1Michael Kuhn2Nathan O. Agutu3Yoichi Fukuda4Department of Spatial Sciences, Curtin University, Perth, AustraliaDepartment of Spatial Sciences, Curtin University, Perth, AustraliaDepartment of Spatial Sciences, Curtin University, Perth, AustraliaDepartment of Spatial Sciences, Curtin University, Perth, AustraliaDepartment of Geophysics, Kyoto University, JapanBy combining satellite altimetry with Gravity Recovery and Climate Experiment derived terrestrial water storage-TWS (2002–2014), this study used a two-step procedure based on spherical harmonic synthesis and statistical decomposition to support the understanding of the Volta basin's natural hydrology and its freshwater systems. Results indicate that Lake Volta contributed 41.6% to the observed increase in TWS over the basin during the 2002–2014 period. The statistical decomposition of TWS over the basin (after removing the Lake's water storage) resulted in a statistically significant (α = 0.05) loss of 59.5 ± 8.5 mm/yr of TWS in the lower Volta region of the basin between 2007 and 2011. This trend is attributed to a base flow recession resulting from the negative trends in precipitation around the lower Volta (2002–2014) and limited river flows of the Volta river system. While it also coincides with observed decline in net precipitation (−15 mm/yr), the long dry periods in the basin (2001–2007) also contributed to this storage depletion. The Lake Volta shows sensitivity to incoming flows of the Volta river system with a lag spanning between less than one and up to two years. In addition to this, a 4–5 year cycle in the clustering of dry and wet periods resulting from the impact of climate variability on the basin was noticed.http://www.sciencedirect.com/science/article/pii/S2214581816303305Volta basinRainfallSatellite altimetryFreshwaterLake VoltaClimate variability |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Christopher E. Ndehedehe Joseph L. Awange Michael Kuhn Nathan O. Agutu Yoichi Fukuda |
spellingShingle |
Christopher E. Ndehedehe Joseph L. Awange Michael Kuhn Nathan O. Agutu Yoichi Fukuda Analysis of hydrological variability over the Volta river basin using in-situ data and satellite observations Journal of Hydrology: Regional Studies Volta basin Rainfall Satellite altimetry Freshwater Lake Volta Climate variability |
author_facet |
Christopher E. Ndehedehe Joseph L. Awange Michael Kuhn Nathan O. Agutu Yoichi Fukuda |
author_sort |
Christopher E. Ndehedehe |
title |
Analysis of hydrological variability over the Volta river basin using in-situ data and satellite observations |
title_short |
Analysis of hydrological variability over the Volta river basin using in-situ data and satellite observations |
title_full |
Analysis of hydrological variability over the Volta river basin using in-situ data and satellite observations |
title_fullStr |
Analysis of hydrological variability over the Volta river basin using in-situ data and satellite observations |
title_full_unstemmed |
Analysis of hydrological variability over the Volta river basin using in-situ data and satellite observations |
title_sort |
analysis of hydrological variability over the volta river basin using in-situ data and satellite observations |
publisher |
Elsevier |
series |
Journal of Hydrology: Regional Studies |
issn |
2214-5818 |
publishDate |
2017-08-01 |
description |
By combining satellite altimetry with Gravity Recovery and Climate Experiment derived terrestrial water storage-TWS (2002–2014), this study used a two-step procedure based on spherical harmonic synthesis and statistical decomposition to support the understanding of the Volta basin's natural hydrology and its freshwater systems. Results indicate that Lake Volta contributed 41.6% to the observed increase in TWS over the basin during the 2002–2014 period. The statistical decomposition of TWS over the basin (after removing the Lake's water storage) resulted in a statistically significant (α = 0.05) loss of 59.5 ± 8.5 mm/yr of TWS in the lower Volta region of the basin between 2007 and 2011. This trend is attributed to a base flow recession resulting from the negative trends in precipitation around the lower Volta (2002–2014) and limited river flows of the Volta river system. While it also coincides with observed decline in net precipitation (−15 mm/yr), the long dry periods in the basin (2001–2007) also contributed to this storage depletion. The Lake Volta shows sensitivity to incoming flows of the Volta river system with a lag spanning between less than one and up to two years. In addition to this, a 4–5 year cycle in the clustering of dry and wet periods resulting from the impact of climate variability on the basin was noticed. |
topic |
Volta basin Rainfall Satellite altimetry Freshwater Lake Volta Climate variability |
url |
http://www.sciencedirect.com/science/article/pii/S2214581816303305 |
work_keys_str_mv |
AT christopherendehedehe analysisofhydrologicalvariabilityoverthevoltariverbasinusinginsitudataandsatelliteobservations AT josephlawange analysisofhydrologicalvariabilityoverthevoltariverbasinusinginsitudataandsatelliteobservations AT michaelkuhn analysisofhydrologicalvariabilityoverthevoltariverbasinusinginsitudataandsatelliteobservations AT nathanoagutu analysisofhydrologicalvariabilityoverthevoltariverbasinusinginsitudataandsatelliteobservations AT yoichifukuda analysisofhydrologicalvariabilityoverthevoltariverbasinusinginsitudataandsatelliteobservations |
_version_ |
1725719598665302016 |