Index of Watershed Integrity (IWI) of a Central Mexican Plateau Microwatershed: An Instrument of Environmental Governance
Watershed management must be prioritized in Mexico due to environmental degradation. To address the prioritization process a tool for processing biophysical information is needed by decision-makers and planners. To develop such a tool, we evaluated the functional conditions of a microwatershed (a watershed of less than 5000 ha) located in the hydraulic headwater of the Querétaro River watershed. We used the Index of Catchment Integrity (ICI) to evaluate local condition and the Index of Watershed Integrity (IWI) to evaluate the cumulative conditions. The implementation of the IWI in La Laborcilla microwatershed required some adaptations to the locally available data. We integrated information generated through two indices: the Environmental Water Quality Index (EWQ(i)) which evaluates the physicochemical conditions of water from an ecosystem perspective, and the Hydrogeomorphological Index (IHG), which assesses the conditions of naturalness or alteration of riparian ecosystems. The implementation of these complementary indices generated detailed information on the stressors that affect the functioning of the six key watershed functions proposed in the IWI. The evaluated watershed is located in an area with low population density and little urban land cover. Overall, the watershed had medium-low integrity (IWI=0.43). The integrity of the catchments spanned from (ICI=0.27) to (ICI=0.58). This assessment and other elements belonging to this approach are important to integrate the watershed approach in an operational form in ecological management programs and other environmental policy instruments.