A shared river drainage basin primarily necessitates which among the riparian states?

💡 Explanation:

A river drainage basin shared by multiple countries (riparian states) necessitates cooperative agreements for the equitable and sustainable management of water resources. This includes considerations for water allocation, quality, flood control, and infrastructure (like dams and irrigation), which are critical to preventing conflict and ensuring resource security. This requirement is a fundamental aspect of 'hydropolitics' and international geography.