Indicator System Ecosystem Vitality

The Ecosystem Vitality component of the FHI is composed by four major indicators: Water Quantity, Water Quality, Basin Condition, and Biodiversity. Each of these indicators is composed by one up to three sub-indicators as indicated below. Table below provides a summary of the indicators and sub-indicators comprising the Ecosystem Vitality component.

Water Quantity measures the stock and flow of water through the drainage basin and changes in water-storage capacity. This indicator is composed by two sun-indicators: Deviation from Natural Flow Regime measuring the degree to which current flow conditions have shifted from historic natural flows; and Groundwater Storage Depletion measuring changes in the availability of water stored in underground aquifers.

Water Quality measures the state of water quality in the basin relevant for maintaining biodiverse aquatic ecosystems, rather than for human consumption. This indicator is composed by one sub-indicator: Water Quality Index measuring by how much water quality parameters (e.g., concentrations of total nitrogen, total phosphorus, and suspended sediment) deviate from required concentrations to maintain natural ecosystem functioning.

Drainage Basin Condition measures the extent of physical modifications to the drainage basin and flow network. Such changes result in habitat degradation that impacts biodiversity. This indicator is composed by three sub-indicators: Bank Modification measuring the degree of change in floodplain (lateral) connectivity; Flow Connectivity measuring the degree of fragmentation of the drainage network; and Land Cover Naturalness measuring the degree of human-induced transformation of the landscape.

Biodiversity measures potential shifts in ecosystem functioning by measuring changes in the constituent biota that are integral components of freshwater ecosystems. The status and trends of biodiversity in a basin signify ecosystem health, with declining populations of native species and increasing populations of invasive and nuisance species indicating a deteriorating ecosystem (Dudgeon et al. 2006). This indicator is composed by two sub-indicators: Species of Concern measuring the degree of threat to aquatic and riparian species, as well as, to species of interest (such as keystone or umbrella species); and Invasive and Nuisance Species measuring the degree of predominance of alien species in the basin.

Ecosystem Vitality indicators and sub-indicators