Mechanisms responsible for streamflow generation on a small, salt-affected and deeply weathered hillslope

Authors

Richard J. George, Department of Agriculture, Western AustraliaFollow
Arthur J. Conacher, University of Western Australia

Document Type

Article

Publication Date

6-1993

Journal Title

Earth Surface Processes and Landforms

ISSN

ISSN: 0197-9337, eISSN: 1096-9837

Keywords

Streamflow, Throughflow, Runoff, Groundwater, Salinity, Recharge

Disciplines

Geology | Hydrology | Natural Resources and Conservation | Soil Science | Water Resource Management

Abstract

This paper considers the contributions of overland flow, throughflow and deep seepage to the generation of streamflow in a salt-affected, deeply weathered landscape.

Runoff mechanisms on a small hillslope in south-western Australia were dependent on the extent and development of variable source areas. In winter, streamflow generation was controlled by returnflow, saturation overland flow and throughflow. In summer, post-ponding, infiltration-excess and saturation overland flow dominated. The extent of the variable source area and the magnitude of streamflow were due to antecedent soil moisture, rainfall and slope morphology. Concave hillslope sections accumulated soil moisture due to both saturated and unsaturated lateral flow processes.

Throughflow provided the mechanism and vehicle for solute movement from the groundwater discharge area to the stream. However, discharge from the deep aquifer was the primary mechanism responsible for soil salinity and maintaining the core of the variable source area. Estimates of throughflow which only take account of soil-water movement and disregard returnflow, will underestimate the magnitude of throughflow.

Recommended Citation

George, R.J. and Conacher, A.J. (1993), Mechanisms responsible for streamflow generation on a small, salt-affected and deeply weathered hillslope. Earth Surf. Process. Landforms, 18: 291-309. https://doi.org/10.1002/esp.3290180402