Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/927582
- Development of trigger levels to assess catchment disturbance on stream suspended sediment loads in the Magela Creek catchment, Northern Territory, Australia
Moliere, Dene R.;
Evans, Kenneth G.
- The University of Newcastle. Faculty of Science & Information Technology, School of Environmental and Life Sciences
- Trigger levels for fine suspended sediment (FSS) load in streams are required to identify rainfall-runoff events that have significantly elevated FSS loads, compared with expected background loads, as a result of catchment disturbance. Stream FSS load data collected in the mine-impacted Magela Creek catchment in the wet-dry tropics were used to derive water quality management trigger levels for two approaches – a Before-After-Control-Impact Paired difference design (BACIP) and a regression relationship between observed FSS load and corresponding event discharge characteristics. The results indicate that both the BACIP and regression relationship approaches behave similarly, with similar FSS load events elevated above trigger levels. Notwithstanding this, it is recommended that in order to reliably assess the location and magnitude of a catchment disturbance on FSS load, a combination of BACIP and regression relationship approaches must be adopted. In this study, an event with a FSS load above trigger levels associated with both BACIP and the regression relationship fitted for the downstream site is considered to be significantly elevated as a result of a disturbance within the mine-impacted region. While this technique cannot conclusively determine whether the cause of the disturbance is mine-related or natural (such as fire or bank erosion), it is an efficient statistical method of identifying events that warrant further investigation and management action, if required.
- Geographical Research Vol. 48, Issue 4, p. 370-385
- Publisher Link
- Wiley-Blackwell Publishing Asia
suspended sediment transport;
wet dry tropics
- Resource Type
- journal article