ASSESSMENT OF INTRA-BASIN WATER RESOURCES: CASE OF THE MAJOR RIVER BASINS IN MADAGASCAR

Abstract

 Understanding the situation of the potential water resources (PWR) available and their spatial distribution is essential for an efficient water management on a basin scale. Water scarcity is a complex issue that many countries in the world, including Madagascar, face. In this article, we assess the potential water resource availability and the competition of use within a basin. Here we show the importance of the water resources assessment within a large river basin scale. Three imbalance indicators were introduced to evaluate the spatial availability, distribution, and variability of the PWR available for daily life use and agriculture. The Indicator N°1 presents the total amount of PWR per capita and agriculture area in the whole basin. The Indicator N°2 indicates the distribution of water compared to the outlet if there is more or less water in the upstream area. Indicator N°3 demonstrates the water variability upstream to downstream. Results reveal the uneven spatial distribution of the water available upstream-downstream which is the core issue of the river basin management. Our results demonstrate how the three imbalance indicators provide a relevant information about the situation of water resources, helping to solve the conflicts of use and to overcome the pressures on water scarcity.