Journal Articles

2000

Detailed geomorphic observations in El Cautivo badland area, in the semiarid SE of Spain, show a recent renewal of linear channel erosion following a period of aggradation. Prior to this renewal, the landscape was characterized by smooth colluvial pediments on the north-east facing aspects and relatively steep crusted microhillslopes on south-west facing aspects. First-order valleys within the badland landscape were smooth-floored and filled with silty deposits connected with pediment colluvial deposits.

Resource Type: Journal Articles

Ground-water flow simulations are used to evaluate the importance of three parameters on vertical flow in peatlands: regional slope. permeability of the mineral soil underlying the peat, and peatland topography. Our results indicate that the extent of vertical ground-water flow in peatlands is primarily controlled by mineral soil permeability. Local ground-water flow cells that form under small water-table mounds at bog domes can drive peat pore water into permeable mineral soil.

Resource Type: Journal Articles

The relationship between wetland soils and hydrology can be better understood by linking soil geomorphological features to the measurement of groundwater depths in the soil. Soil stratigraphic analysis and long-term measurements of soil water levels in piezometers were used at the Jackson-Frazier wetland in western Oregon to investigate the interaction between local geomorphological history and the hydrology of the wetland.

Resource Type: Journal Articles

1999

The hydrology of the near-stream riparian zone in upland humid catchments is poorly understood. We examined the spatial and temporal aspects of riparian flowpaths during snowmelt in a headwater catchment within the Sleepers River catchment in northern Vermont. A transect of 15 piezometers was sampled for Ca, Si, DOC, other major cations, and delta(18)O. Daily piezometric head values reflected variations in the stream hydrograph induced by melt and rainfall. The riparian zone exhibited strong upward discharge gradients.

Resource Type: Journal Articles

1998

Conservative solute injections were conducted in three first-order montane streams of different geological composition to assess the influence of parent lithology and alluvial characteristics on the hydrological retention of nutrients.

Resource Type: Journal Articles

A hydrological investigation was conducted in a small headwater peatland located in the Experimental Lakes Area, north-western Ontario, Canada, to determine the subsurface and surface flow paths within the peatland, and between the peatland and an adjacent forested upland during baseflow and storm flow conditions. Distinct zones of groundwater recharge and discharge were observed within the peatland. These zones are similar to those found in much larger flow systems even though the peatland was only influenced by local groundwater flow.

Resource Type: Journal Articles

1997

Floodplains mitigate against extreme annual hydrologic phenomena by storing substantial volumes of water which would otherwise increase flood volumes. Later floodplains gradually release this water which serves to maintain baseflows. This phenomenon, called bank storage, has important physical and ecological ramifications which in addition to reducing flood peaks, include sustaining riparian vegetation and improving water quality. We developed a model of bank storage based upon the earlier work of Neuman and Witherspoon (Wat. Resour.

Resource Type: Journal Articles

1996

European settlement of SE Australia has been associated with the extension and deepening of drainage lines by gully erosion. There has been considerable research into the hydrological impacts of clearing vegetation from catchments, but none into the hydrological implications of gully networks.

Resource Type: Journal Articles

1994

Channel incision is a widespread phenomenon that results in stream and riparian habitat degradation. Fishes and physical habitat variables were sampled at base flow from three incised stream channels and one reference stream in northwest Mississippi, USA, to quantify incision effects on fish habitat and provide a basis for habitat rehabilitation planning and design. Incised channels were sampled in spring and autumn; the reference channel was sampled only in the autumn.

Resource Type: Journal Articles

Late Quaternary stratigraphy of a 50 km2 catchment on the south-eastern highlands of Australia reveals processes and history of denudation, and helps resolve a long-standing debate about factors controlling episodic valley aggradation and degradation during Holocene times. Valley sedimentation occurred when swampy vegetation fully colonized valley floors and obliterated all channels, promoting aggradation for periods of several thousand years, with most incoming sediment being trapped in swampy meadows.

Resource Type: Journal Articles