The hydrology of the humid tropics


Hydrological processes in the humid tropics differ from other regions in having greater energy inputs and faster rates of change, including human-induced change. Human influences on population growth, land use and climate change will profoundly influence tropical hydrology, yet understanding of key hydrological interactions is limited. We propose that efforts to collect tropical data should explicitly emphasize characterizing moisture and energy fluxes from below the ground surface into the atmosphere. Research needs to chiefly involve field-based characterizations and modelling of moisture cycling and catchment processes, as well as long-term data acquisition and organization.

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Figure 1: Schematic view of the tropical hydrological cycle with water fluxes represented by dashed lines.
Figure 2: Average discharge per unit drainage area as a function of latitude at the river mouth, showing differences between tropical and temperate latitudes.
Figure 3: Example of how evapotranspiration rates in disturbed rainforests in the dry season are related to land-use history.
Figure 4: Schematic of local and regional hydrological response to deforestation.
Figure 5: Number of precipitation stations in the Global Historical Climatology Network data set for each year.


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Funding for the March 2011 tropical hydrology workshop that formed the starting point for this paper was provided by the US Army Research Office. We thank H. Rogers for hosting the workshop, and J. DeLay, C. Downer, H. Elsenbeer, E. McDonald and S. Turnbull for discussions during the workshop.

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All authors contributed to writing the synthesis offered in this Review. Individual subtopics covered by each author are: E.W., lead author and fluvial geomorphology and Fig. 2; A.B. and N.B., atmospheric processes; N.B., Fig. 5; N.A.C., J.M. and F.O., hillslope hydrology; M.C., stream hydrology and Fig. 4; T.G. and J.J., land–atmosphere interactions; S.G. and R.H., biogeochemistry; S.G., Fig. 1; J.M.H.H., soil hydrology and remote sensing and Fig. 3.

Correspondence to Ellen Wohl.

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Wohl, E., Barros, A., Brunsell, N. et al. The hydrology of the humid tropics. Nature Clim Change 2, 655–662 (2012).

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