Integrated Ecohydrologic Research and Hydro‐Informatics

The purpose of this paper is to offer our view of where ecohydrologic research will be going in the next 20 years and suggest how enabling technologies from hydro-informatics will support this research. Two decades ago Klemes (1986) suggested that the hydrologist’s “efforts expended on the fitting of flood and drought frequency curves would be better spent in acquiring deeper knowledge of climatology, meteorology, geology, and ecology.” Klemes was of course calling for interdisciplinary hydrology. Recently, a number of community reports have proposed a more interdisciplinary approach to hydrology, including the development of community infrastructure such as large scale hydrologic observatories with integrated, multi-scale monitoring and advanced informatics tools to enable this research (Band et al. 2002, Gupta et al. 1999, Hornberger et al. 2000, Maidment 2008). Specific calls were included to integrate the more physically or statistically oriented approaches in hydrology with ecosystem sciences including biogeochemical cycling and population ecology. The emergence of ecohydrologic research is one example of how hydrologic science has begun to move in this direction. Ecohydrologic research seeks to understand how hydrological processes affect biological communities, and in turn how such communities affect water cycling (Newman et al. 2006, Rodriguez-Iturbe 2000). With this marriage of ecology and hydrology new avenues of research are opening up, and with these come new scientific and technical challenges. Some of the scientific challenges relate to the long-term memory in biological and geomorphic systems, complex feedbacks on water cycling, and the continuum of such interactions across space. Technical challenges include building more sophisticated simulation models to deal with such spatial dynamics, acquiring and managing the data needed to support these models, improving geo-visualization of spatial predictions and errors, and quantifying uncertainty associated with model structure and parameterization. Another interdisciplinary subfield of hydrology, hydroinformatics, emphasizes the development of information technology to help meet these challenges. Newman et al. (2006) identified a number of research challenges for ecohydrologic research in semi-arid regions, including dealing with spatial and temporal heterogeneity, scaling up to regional and global extent, improving understanding of subsurface processes, and addressing long-term processes. They argue for a greater emphasis on place-based research where long-term data sets are being compiled. Efforts aimed at addressing these problems are underway, albeit with a focus on vegetation in semi-arid environments, equilibrium models with stochastic inputs, and knowledge obtained in traditional plots or stands. We suggest that for ecohydrologic research to be globally relevant it must embrace the full spectrum of environments, including non-water limited regions and wetland-rich regions. Over the next two decades, ecohydrologic research will explore more deeply the nature of transient system evolution and elucidate characteristic timescales of processes, such as those associated with ecosystem aggradation and degradation. It will move toward developing predictive capability that builds from an understanding of processes along spatial gradients, including adaptations of nutrient cycling and plant hydraulics at wetland-upland transitions. Moreover, as cyber-infrastructure improves these activities will transcend individual study sites by utilizing combinations of data sets 16