This study uses the latest monitoring technologies (e.g., Campbell Sci. Ltd OBS-3+ turbidity probes) and Time Series Analysis (e.g., CAPTAIN Toolbox) to address seven key objectives and deliverables, building upon experience with these approaches applied within humid tropical Borneo Island.
The seven objectives are:
Chappell, N.A., Tych, W., Shearman, P., Lokes, B., and Chitoa, J. 2011. River sediment monitoring for baseline and change characterisation: a new management tool for the Ramu River Communities in Papua New Guinea. In: Sediment Problems and Sediment Management in Asian River Basins, Walling D (ed) IAHS Publication 349, Wallingford, IAHS Press. 92-102. view abstract (pdf), paper (colour pdf version).
U.S. DOE. 2012. Research Priorities for Tropical Ecosystems Under Climate Change Workshop Report, DOE/SC-0153. U.S. Department of Energy Office of Science (Chapter 11 "Hydrology within Tropical Natural Forests: Implications for Large-Scale Ecosystem Modeling" p77-84 by Chappell, N.A.) view chapter or whole report (pdf).
Chappell, N.A., and Tych, W. 2012. Identifying step changes in single streamflow and evaporation records due to forest cover change. Hydrological Processes, 26, 100-116 doi:10.1002/hyp.8115. view paper (pdf).
BRG (pFACT 46089)
Dr Nick A Chappell; Dr Wlodek Tych; Dr Phil Shearman; Ms Barbara Lokes
We observe that the natural variability in the suspended sediment load is much larger within the sedigraphs of the wet season, small changes resulting from anthropogenic disturbances will be more difficult to identify within this wet season. Thus the Ramu River Communities are more likely to observe shifts from the baseline sediment behaviour in the dry season. While the suspended sediment loads within the Upper Ramu are naturally high, mining-related fine sediments may contain much higher heavy metal concentrations in comparison to fine sediment mobilised from natural slopes. Thus small changes in suspended sediment load within the dry season may indicate an anthropogenic shift in the heavy metal load. If sediment monitoring indicates the possibility of enhanced inputs of heavy metals bound to elevated fine sediment inputs, this would provide the impetus for the Ramu River Communities to seek help to initiate the more costly intensive chemical sampling of the Ramu main stem.
Given the different shapes of the sedigraphs and hydrographs and their flashy nature over sub-daily timescales (i.e., rapid rise and fall), it is important that sub-daily monitoring of turbidity (and stage) is maintained to not only help identify behavioural shifts in suspended sediment load within the dry season, but also to allow the calculation of reliable values of seasonal and annual sediment load. The increased reliability and reducing costs of current turbidity and stage monitoring systems means that such systems ought to be deployed more widely in the humid tropics, particularly in environments with high sediment loads, such as New Guinea Island.
1. Simulation of sediment dynamics within the Ramu basin using TRMM data and CAPTAIN modelling.
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Please email Dr Nick A Chappell for further information on the RamuSED project