Floodplain systems

Baldwin DS, Mitchell AM (2000) The effects of drying and re-flooding on the sediment and soil nutrient dynamics of lowland river-floodplain systems a synthesis. Regul Rivers Res Manage 16 457 67... 

Thomaz S, Bini L, Bozelli R (2007) Floods increase similarity among aquatic habitats in river-floodplain systems. Hydrobiologia 579 1-13... 

Junk, W. J., P. B. Bayley, and R. E. Sparks. 1989. The flood-pulse concept in the river-floodplain systems. Canadian Special Publication in Fisheries and Aquatic Sciences. 106 110-127. 

Transport and distribution of sediments derived from Andean erosion across the cratonic landscape of Brazil have caused development of an upstream to downstream trend in geomorphic and hydrologic character of the channel-floodplain system (Mertes et al. 1996). In upstream reaches, scroll bar topography on the floodplain tends to... 

The travel time for suspended load is controlled by the flow velocity and the distance to the basin outlet. Flow velocities do not change much downstream in a typical river system (Leopold, 1953) and typically range from 0.1 to several m/s. Hence, suspended load should be able to travel at least 10 to 100 km per day and the travel time for suspended sediment to traverse even the longest rivers in the world should be less than a season. Although some of the suspended load will be deposited in floodplains, the component of the suspended load that does not get sequestered in terrestrial depositional environments is delivered almost as fast as the water that it flows in. Bedload travels much more slowly. In mountain drainage basins, the velocity of individual bedload clasts is on the... 

Barrios E, Herrera R, Valles JL (1994) Tropical floodplain agroforestry systems in mid-Orinoco River basin, Venezuela. Agroforest Syst 28 143-157... 

Hossain, M.A., Choudhury, M.H.K., Hossain, M.F., and Alam, Q.K. 2002. Effects of ecological agriculture on soil properties and arthropod diversity in rice-based cropping systems in floodplain areas in Bangladesh. Biological Agriculture and Horticulture 20 215-227. 

Wastes generated by mining and milling released these metal sulfides as particulate substances (i). Mixed with uncontaminated sediment in the river system, these particulate wastes moved hundreds of kilometers downstream from their original source (4-7). Channel, floodplains, and reservoir sediments throughout the river now contain much of this contamination. 

In chapter 14, John Melack and Bruce Forsberg provide a quantitative assessment of the role of floodplain lakes in regional cycles of C, N, and P. Floodplain lakes were found to be important centers of organic carbon production and delivery to the river system. The combined primary production of macrophytes, forests, periphyton, and plankton associated with floodplain lakes is estimated at 117 Tg C yri, of which only 24% is remineralized in the lakes. As a result, an estimated 90 Tg C yr are delivered to the river system by continual and seasonal exchanges. This input alone amounts to... 

Sustainable management systems for Amazon floodplains should consider the importance of higher vegetation in the nutrient budget of the region. Because of the favorable nutrient conditions in the varzea forests, they are frequently replaced by farms and pasture lands for cattle and buffalo ranching. The increasing exploitation of... 

Furch, K. 1997. Chemistry of Vaizea and Igapo soils and nutrient inventory of their floodplain forests. In The Amazonian Floodplains Ecology of a Pulsing System, ed. W. J. Junk (Ecological Studies. Springer-Verlag, Berlin), pp. 47-68. 

In Amazon floodplain lakes, daily water column respiration usualiy exceeds planktonic gross photosynthesis, and dissolved oxygen is usually undersaturated (Melack and Fisher 1983). Wissmar et al. (1981) and Richey et al. (1988) found Amazon flood-plain lakes to be consistently undersaturated in O2 and supersaturated in CO2. The deficit of oxygen in these systems is a consequence of high respiration to production ratios. 

Overall, these results suggest a general pattern of carbon flow in lakes on the central Amazon floodplain. Nutritious plant materials, primarily derived from C-3 plants (phytoplankton, periphyton, C-3 macrophyte leaves, tree fruits, and seeds) are selectively consumed by aquatic herbivores and detritivores and dominate the organic carbon flow to higher trophic levels. Some C-3 plant materials and the bulk of C-4 plants decompose and release their organic carbon, predominantly in the dissolved form, to the water column. The labile component of this DOC, dominated by C-4 plant carbon, is rapidly consumed by heterotrophic bacterial communities and released as either CO2 or CH4 to the atmosphere. The more refractory DOC component has a much slower turnover rate and tends to persist in the system where it is eventually exported to the main river channel. 

Experimental manipulations of whole lakes or of enclosures within lakes has proven a valuable approach to decipher processes controlling ecological and biogeochemical activity in lakes. The large number of small to moderate-sized lakes on the Amazon floodplain offers an excellent opportunity to employ replicated, whole-system manipulations. Of particular importance would be experimental alterations of flooding periodicity and depth, and of nutrients inputs. 

The Bengal Basin in Bangladesh contains a sequence of Cretaceous to Recent sediments which is up to 15 km thick and which occupies some 100,000 km of lowland floodplain and delta. The combined deltas of the Ganges, Brahmaputra and Meghna (GBM) river systems lie within Bangladesh. The GBM system carries the greatest total sediment load of any... 

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