The volumetric flow rate is the volume of fluid which passes through a given surface per unit time (e.g. m3/s, cubic meters or litres per second). Mass flow rate is the mass of substance which passes through a given surface per unit time.
Perspectives are different frameworks from which to explore the knowledge around sustainable sanitation and water management. Perspectives are like filters: they compile and structure the information that relate to a given focus theme, region or context. This allows you to quickly navigate to the content of your particular interest while promoting the holistic understanding of sustainable sanitation and water management.