Methodological and empirical considerations when assessing freshwater ecosystem service provision in a developing city context: Making the best of what we have

Abstract

This study contributes to both the methodological and empirical literature by developing an integrative approach to assessing temporal and spatial change in riparian ecosystem service delivery by drawing on available and diverse data sets. These data sets act as multiple lines of evidence in supporting comparisons between data sets to test the validity of developed methods and the application of such methods. In order to synthesise these data as well as to determine the fluctuations in riparian ecosystem service provision a scoring system was developed. Methodologically, the scoring system proved informative across the majority of ecosystem services categories, showing close to 80% similarity in outcomes when comparing the scoring method to trends in long-term water quality measurements. Other benefits of the scoring system included its design simplicity, cost-effectiveness, and applicability and replicability across various urban settings. Empirically, the data sets used support the findings of the ecosystem services scoring exercise and suggests that fluctuations in ecosystem service delivery through time and across the river reaches are linked to land-use change and other human activities. Findings suggest that as water leaves an urban protected area and travels across transformed and impacted landscapes, the results are poor water quality and diminished ability of rivers to yield ecosystem services the further the river flows into the urban setting. Urbanisation and changes in land-uses in developing city contexts is therefore shown to affect potential ecosystem services benefits, necessitating increasing management interventions.