Afua G. Owusu

International Water Management Institute | IWMI

VegDischarge v1, which covers over 64,000 river segments in Africa, is a natural river discharge dataset produced by coupled modeling; the agro-hydrologic VegET model and the mizuRoute routing model for the period 2001-2021. Using remote sensing data and hydrological modeling system, the 1-km runoff field simulated by VegET, was routed with mizuRou...

Agriculture consumes the largest share of freshwater globally; therefore, distinguishing between rainfed and irrigated croplands is essential for agricultural water management and food security. In this study, a framework incorporating the Budyko model was used to differentiate between rainfed and irrigated cropland areas in Africa for eight remote...

Occurrence of frequent dryspell is affecting agriculture; productivity in the semi-arid areas of West Africa such as northern Ghana. The objective of this study was to analyze the effects of dryspells on rainfed maize (early and late maturing), millet, and sorghum yields in a savanna agro-ecosystem in northern Ghana, and suggest management options...

Study Region: Continental Africa Study Focus: This study evaluates the accuracy of eight gauge-corrected rainfall products across Africa through direct comparisons with in situ observations for the period 2001-2020. The effect of validation datasets on the performance of the rainfall products was also quantified in ten African countries. Four categ...

Environmental flows (e-flows) aim to mitigate the threat of altered hydrological regimes in river systems and connected waterbodies and are an important component of integrated strategies to address multiple threats to freshwater biodiversity. Expanding and accelerating implementation of e-flows can support river conservation and help to restore th...

The construction of the Akosombo and Kpong dams in the Lower Volta River basin in Ghana changed the downstream riverine ecosystem and affected the lives of downstream communities, particularly those who lost their traditional livelihoods. In contrast to the costs borne by those in the vicinity of the river, Ghana has enjoyed vast economic benefits...

The construction of the Akosombo and Kpong dams in the Lower Volta River Basin in Ghana changed the downstream riverine ecosystem and affected the lives of downstream communities, particularly those who lost their traditional livelihoods. In contrast to the costs borne by those in the vicinity of the river, Ghana as a whole, has enjoyed vast econom...

The provision of flows for the environment, e-flows, is a means to restore the benefits of naturally flowing rivers. Despite the development of numerous methodologies to determine e-flows and optimize dam releases, actual implementation is relatively limited. Examples of successful e-flows implementation through dam reoperation exist in scientific...

The Volta clam, Galatea paradoxa, is a freshwater macrobenthic bivalve which is endemic to the Lower Volta River in Ghana. The range of occurrence of the clam has been influenced by the flow regime in the Lower Volta which is in turn controlled by operation of two dams located upstream. Previous research has documented the changes to the Lower Volt...

Dam construction and operation are known to alter the hydrology of rivers and degrade riverine ecosystems. In recent decades, the call to reverse these negative impacts by re‐operating dams has become stronger. Dams can support riverine ecosystems by releasing environmental flows (e‐flows). Unfortunately, despite the development of numerous methodo...

Sustainable intensification for smallholder farming systems in sub-humid and semiarid zones of West Africa critically hinges not only on agronomy and crop varieties but also the management of on-farm water in rainfed and dry seasons to enhance crop and livestock productivities. Long term dry spell analysis was carried out using INSTAT+ v3.37 and CR...

This paper provides the climatic and biophysical context of three watersheds in northern Ghana - Anyari and Zanlerigu in the Upper East region and Bihinaayili in the Northern region. The objective of the study is to describe the agro-climatic and hydrological features of the watersheds from a landscape perspective, which can be used as baseline inf...

ABSTRACT Sustainable intensification for smallholder farming systems in sub-humid and semiarid zones of West Africa critically hinges not only on agronomy and crop varieties but also the management of on-farm water in rainfed and dry seasons to enhance crop and livestock productivities. Long term dry spell analysis was carried out using INSTAT+ v3....