The GLOWA Volta project: Integrated assessment of feedback mechanisms between climate, landuse, and hydrology

Giesen, Nick van de; Kunstmann, Harald; Jung, Gerlinde; Liebe, Jens; Andreini, M.; Vlek, Paul L. G.

doi:10.1007/0-306-47983-4_9

Cited by 23 publications

(15 citation statements)

References 5 publications

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“…Even in this relatively well-studied region, the numbers do not always converge. According to van de Giesen et al (2002) there are about 160 small reservoirs in the region, while Birner (2008) found a different total of 126 small reservoirs in the Upper East Region based on a field survey and the use of remote sensing tools, which is also different to the estimate of the GIDA-MoFA (2008) study. The majority of reservoirs in the Upper East Region was built in -or prior to -1980, while the exact construction date of some 18 small reservoirs could not be determined.…”

Section: Small Reservoir-based Communal Irrigation Systemsmentioning

confidence: 94%

Typology of irrigation systems in Ghana.

Namara¹,

Horowitz²,

Kolavalli³

et al. 2011

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I n t e r n a t i o n a l Water Management I n s t i t u t e years IWMI Celebrating Working PapersThe publications in this series record the work and thinking of IWMI researchers, and knowledge that the Institute's scientific management feels is worthy of documenting. This series will ensure that scientific data and other information gathered or prepared as a part of the research work of the Institute are recorded and referenced. Working Papers could include project reports, case studies, conference or workshop proceedings, discussion papers or reports on progress of research, country-specific research reports, monographs, etc. Working Papers may be copublished, by IWMI and partner organizations.Although most of the reports are published by IWMI staff and their collaborators, we welcome contributions from others. Each report is reviewed internally by IWMI staff. The reports are published and distributed both in hard copy and electronically (www.iwmi.org) and where possible all data and analyses will be available as separate downloadable files. Reports may be copied freely and cited with due acknowledgment. About IWMIIWMI's mission is to improve the management of land and water resources for food, livelihoods and the environment. In serving this mission, IWMI concentrates on the integration of policies, technologies and management systems to achieve workable solutions to real problems-practical, relevant results in the field of irrigation and water and land resources.

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Section: Small Reservoir-based Communal Irrigation Systemsmentioning

confidence: 94%

Typology of irrigation systems in Ghana.

Namara¹,

Horowitz²,

Kolavalli³

et al. 2011

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“…GLOWA Volta is a multidisciplinary effort to study the physical and socioeconomic determinants of the hydrological cycle (Van de Giesen et al 2001). The climate system in the Volta basin is mainly controlled by the meridional movement of the intertropical convergence zone, the African easterly jet, and pressure disturbances that traverse from east to west across Africa (Burpee 1972).…”

Section: A Site Description and Experimental Setupmentioning

confidence: 99%

Satellite-Based Actual Evapotranspiration over Drying Semiarid Terrain in West Africa

Schüttemeyer

Schillings

Moene

et al. 2007

Journal of Applied Meteorology and Climatology

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A simple satellite-based algorithm for estimating actual evaporation based on Makkink's equation is applied to a seasonal cycle in 2002 at three test sites in Ghana, West Africa: at a location in the humid tropical southern region and two in the drier northern region. The required input for the algorithm is incoming solar radiation, air temperature at standard level, and the green-vegetation fraction. These data are obtained from Meteorological Satellite (Meteosat) and Moderate-Resolution Imaging Spectroradiometer (MODIS) images. The observation period includes the rapid wet-to-dry transition after the wet season. Incoming solar radiation and air temperature are validated against local measurements at the three sites. It is found that the incoming solar radiation obtained from Meteosat corresponds well with the measurements. For air temperature from Meteosat data, the diurnal cycle is realistically reproduced but is in need of a bias correction. The algorithm output is compared with the evapotranspiration data obtained from hourly large-aperture scintillometer observations and simultaneous "in situ" measurements of net radiation and soil heat flux. It is found that the actual evapotranspiration can be monitored using the modified Makkink method, with daily mean errors of between 5% and 35% of measured evapotranspiration and a seasonal error smaller than 5%. Furthermore, it appears that the algorithm realistically describes the daily cycle of evapotranspiration.

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“…Each of these sites was considered representative of larger areas and their choice took into account the different geographical and climatological parameters influencing the hydrological cycle. All measurements were gathered in the context of long-term observations concerning the water and energy balance in the Volta basin within the Global Change in the Hydrological Cycle (GLOWA)-Volta project (Van de Giesen et al 2002).…”

Section: A Study Areamentioning

confidence: 99%

Evaluation of Two Land Surface Schemes Used in Terrains of Increasing Aridity in West Africa

Schüttemeyer

Moene

Holtslag

et al. 2008

Journal of Hydrometeorology

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In this study different parameterizations for land surface models currently employed in meteorological models at ECMWF [Tiled ECMWF Surface Scheme for Exchange Processes over Land (TESSEL)] and NCEP (Noah) are evaluated for a semiarid region in Ghana, West Africa. Both schemes utilize the JarvisStewart approach to calculate canopy conductance as the critical variable for partitioning the available energy into sensible and latent heat flux. Additionally, an approach within Noah is tested to calculate canopy conductance based on plant physiology (A-gs method), where the photosynthetic assimilation is coupled to the leaf stomatal conductance.All parameterizations were run offline for a seasonal cycle in 2002/03 using observations as forcings at two test sites. The two locations are in the humid tropical southern region and in the drier northern region. For the purpose of forcing and evaluation, a new set of data has been utilized to include surface fluxes obtained by scintillometry. The measurements include the rapid wet-to-dry transition after the wet season at both sites.As a general trend, it has been found that during the wet period of a season net radiation is described well by all parameterizations. During the drying process the errors in modeled net radiation increased at both sites. The models perform poorly in simulating soil heat fluxes with larger errors for TESSEL for both sites. The evolution in time for sensible heat flux and latent heat flux was tackled in different ways by the utilized parameterizations and sites with enhanced model performance for the more southern site. Soil moisture in the upper soil layers is modeled with small errors for the different parameterizations.Key adjustments for reducing net radiation during the dry period of a season are discussed. In particular, the ratio of roughness length of momentum and heat was found to be an important parameter, but will require seasonal adjustments.

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The GLOWA Volta project: Integrated assessment of feedback mechanisms between climate, landuse, and hydrology

Cited by 23 publications

References 5 publications

Typology of irrigation systems in Ghana.

Typology of irrigation systems in Ghana.

Satellite-Based Actual Evapotranspiration over Drying Semiarid Terrain in West Africa

Evaluation of Two Land Surface Schemes Used in Terrains of Increasing Aridity in West Africa

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