Managing water services in tropical regions: From land cover proxies to hydrologic fluxes

Abstract

Watershed investment programs frequently use land cover as a proxy for water-based ecosystem services, an approach based on assumed relationships between land cover and hydrologic outcomes. Water flows are rarely quantified, and unanticipated results are common, suggesting land cover alone is not a reliable proxy for water services. We argue that managing key hydrologic fluxes at the site of intervention is more effective than promoting particular land-cover types. Moving beyond land cover proxies to a focus on hydrologic fluxes requires that programs (1) identify the specific water service of interest and associated hydrologic flux; (2) account for structural and ecological characteristics of the relevant land cover; and, (3) determine key mediators of the target hydrologic flux. Using examples from the tropics, we illustrate how this conceptual framework can clarify interventions with a higher probability of delivering desired water services than with land cover as a proxy.

Ecohydrological processes and ecosystem services in the Anthropocene: a review

“…The effects of vegetation on water supply are more pronounced in water-limited regions than water unlimited (energy-limited) regions ). For example, deforestation in areas with precipitation formation dominated by cloud could reduce interception of precipitation and thus reduce streamflow (Ponette-Gonzalez et al 2015). In a special case, extensive deforestation in snow-dominated Northern Angara region in Russia caused a deceased in river flow by about 10-20 mm over the first two decades following clearcutting the deciduous forests (Onuchin et al 2017).…”

Hydrologic ecosystem services: linking ecohydrologic processes to human well‐being in water research and watershed management

“…Thus, we focused our project on comparing groundwater recharge under different types of land cover . Because recharge can occur under forest, grassland, or even in drywells in an urbanized area, it was crucial to explicitly and specifically identify plausible future land‐cover types in order to produce informative findings …”

“…Also of note, we found that in some cases, a land transition that increased water availability simultaneously increased the provision of other ecosystem services but that ecosystem services did not consistently rise and fall together. This highlights the importance of evaluating synergies and trade‐offs among ecosystem services relative to specific land‐use transitions …”

“…However, they largely lack quantification of hydrologic service provision; 80% rely on assumptions about service provision in their analysis (Figure ). The lack of hydrologic measurement and modeling in water‐related ecosystem services studies indicates a pressing need to better integrate hydrologic methods into social evaluations of ecosystem services assessment …”

Groundwater and ecosystem services: a framework for managing smallholder groundwater-dependent agrarian socio-ecologies - applying an ecosystem services and resilience approach

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