ABSTRACT

Water plays an essential role in the functioning of ecosystems, underpinning biochemical cycles, supporting living organisms and their growth, and creating aquatic habitats on Earth (Chapin et al. 2002). In addition, humans and society rely on ecosystems to provide hydrological services and the resulting benefits (MA 2003). Two major types of hydrological services (Figure 11.1) can be identified according to the benefits they generate: (1) water supply, which includes water for household, irrigation, and industry; hydropower generation; freshwater products; transportation; and recreational and spiritual benefits and (2) water damage mitigation, which includes the reduction in the number and severity of floods, the decrease in soil erosion and sediment deposition, and the mitigation of landslides (Brauman et al. 2007). Both types of services may be evaluated according to three dimensions: (1)  quantity (i.e., total amount of water), (2) timing (i.e., seasonal distribution of the water), and (3) quality (related to removal and breakdown of pollutants and trapping of sediments) (Brauman et al. 2007; Elmqvist et al. 2009).