Gravitational water is held in large soil pores and rapidly drains out under the action of gravity within a day or so after rain. Plants can only make use of gravitational water for a few days after rain.
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.