This work exposes how water flow links nature and society through water's many parallel functions as the "blood stream" of both the natural environment and the embedded human environment - and the resulting conflicts that arise.

This work exposes how water flow links nature and society through water's many parallel functions as the "blood stream" of both the natural environment and the embedded human environment - and the resulting conflicts that arise. The authors argue that a sustainable future depends fundamentally on our ability to manage these trade-offs. They advocate an ecological approach to land/water/environmental problems and argue for viewing precipitation as the gross water resource. Distinguishing between terrestrial aquatic ecosystems, they show how an ecological approach can be expressed in water-related trade-offs, incorporating criteria for long-term resilience. Based on per capita needs for an acceptable nutritional diet, the authors analyse the amounts of water needed for global food production by 2050 and identify potential sources. Drawing on small-scale experiences in Africa and Asia, they also cover the vulnerability of the semi-arid tropics, disentangling it into green and blue water scarcity components.

Part 1 Water functions in the life-support system: the blood stream of the biosphere
water availability
human water requirements
incorporating water for ecosystem "services"
regional differences. Part 2 Closing up on the vulnerable Savanna zone: vulnerability to the Savanna zone
water perspective of feeding humanity
closing the yield gap on the Savanna. Part 3 Finding the balance between water for humans and for nature: towards hydro-solidarity through integrated land/water ecosystem management.