The Brigalow Catchment Study: II. Clearing brigalow (Acacia harpophylla) for cropping or pasture increases runoff
- 1 January 2007
- journal article
- research article
- Published by CSIRO Publishing in Soil Research
- Vol. 45 (7), 496-511
- https://doi.org/10.1071/sr07064
Abstract
The Brigalow Catchment Study (BCS) was established to determine the impact on hydrology when brigalow land is cleared for cropping and grazing. The paired catchment study was commenced in 1965 using catchments of approximately 15 ha, with natural vegetation dominated by brigalow scrub (Acacia harpophylla). Three contiguous catchments were selected near Theodore in central Queensland to represent the extensive brigalow bioregion of central and southern Queensland and northern New South Wales (~40 Mha). The hydrology of the 3 catchments was characterised during a 17-year calibration period (1965–81). The catchments were considered hydrologically similar, with sufficient data available for an empirical comparison between catchments. In 1982, two of the catchments were cleared, with one developed for cropping and the other sown to improved pasture. The third catchment was used as an uncleared control. Hydrologic characteristics were then compared for the following 21 years. In their virgin state, the catchments behaved similarly, with average annual runoff being 5% of annual rainfall. Once cleared, total runoff from the cropping catchment increased to 11% of annual rainfall and total runoff from the pasture catchment increased to 9% of annual rainfall; however, timing of the individual runoff events varied between land uses. In order to confirm that changes in hydrology were a function of land use and not just seasonal variability or sampling error, several analytic techniques were used: a simple comparison of runoff totals, comparison of events, comparison of probability of exceedance for daily runoff, and comparison of predicted and observed runoff using a water balance modelling approach.Keywords
This publication has 31 references indexed in Scilit:
- The Brigalow Catchment Study: I. Overview of a 40-year study of the effects of land clearing in the brigalow bioregion of AustraliaSoil Research, 2007
- A review of paired catchment studies for determining changes in water yield resulting from alterations in vegetationJournal of Hydrology, 2005
- LONG–TERM GRAZING DENSITY IMPACTS ON SOIL COMPACTIONTransactions of the ASAE, 2002
- Change in soil infiltration associated with leys in south-eastern QueenslandSoil Research, 1998
- Change in infiltration characteristics associated with cultivation history of soils in south-eastern QueenslandSoil Research, 1997
- Physical rehabilitation of degraded krasnozems using ley pasturesSoil Research, 1997
- The effect of crop type, crop rotation, and tillage practice on runoff and soil loss on a Vertisol in central QueenslandSoil Research, 1997
- Surface runoff, soil and nutrient losses from farming systems in the Australian semi-arid tropicsAustralian Journal of Experimental Agriculture, 1996
- Effect of Trends and Long-term Fluctuations of Rainfall on Watershed RunoffTransactions of the ASAE, 1994
- Surface soil chemical and physical patterns in a brigalow–Dawson gum forest, central QueenslandAustralian Journal of Ecology, 1986