A Systematic Review of Water Resources Assessment at a Large River Basin Scale: Case of the Major River Basins in Madagascar

Assessing water resources at a large river basin scale is important for having an idea of the water situation and efficient water resources management. What is the most appropriate approach to assess the water resources at a large river basin scale? This paper aims to develop a systematic review on water resources assessment at a large river basin scale, intending to present a new assessment method for the major river basins in Madagascar. This review investigates 40 articles from Google Scholar, Web of Science, and PubMed databases, from 2000 to 2022. This review has demonstrated the necessity of water resources assessment at a large river basin scale in Madagascar. An improvement in the use of multiple GCMs and SWAT models for water resources assessment within the basin was found necessary for appropriate water allocating regimes among upper and lower reaches. Water allocation and water scarcity at the basin level could be addressed by using the inter- and intra-basin approaches. The review concludes that a combination of the SWAT, multiple GCMs, and inter- and intra-basin approaches could be efficiently applied for assessing the water resources at a large basin scale. This review may be of benefit to scientists and water specialists.