Peter Walsh PhD Student School of Physical, Environmental and Mathematical Sciences UNSW @ ADFA Canberra   ACT   2600 AUSTRALIA Phone: +61 2 6496 1500 Fax: +61 2 Email: peterwa@sf.nsw.gov.au Location:

Field of Study - Geography

Supervisor: Assoc. Prof. Jacky Croke

Co-Supervisor: Dr Ingrid Takken

Research Topic - Development of Methodology to Provide Practical Guidelines for Management of Road Drainage and Water Quality

Background

Research over the past two decades on soil and water management in forests subject to logging, has highlighted the importance of unsealed roads and logging tracks as a major source of sediment.   However, whilst the erosion potential of unsealed roads and logging tracks is well established in the literature, their connection to water quality is not as clearly defined. A number of recent studies have examined the mechanisms by which sediment is delivered from roads to streams and have highlighted the importance of the spatial pattern of roading with respect to the stream network as a critical factor in determining the potential impact of roads on water.   As a result of these studies, the way in which sediment delivery to the stream network is conceptualised has changed, with a shift away from the sediment budget approach with its emphasis on sediment delivery ratios, to a hydrological connectivity approach which relates the degree to which a runoff source is linked to the stream network.

The aim of my project is to

1. quantify the volume of runoff and sediment delivery to drainage features through diffuse delivery pathways below road drainage outlets on hillslopes subject to timber harvesting in NSW, and
2. quantify the impact of management practices designed to enhance sediment deposition and flow dispersion on hillslopes below road drainage outlets.

Publications

Walsh, PG and Humphreys, G (in press). The Relationship Between the Orientation and Spacing of Columnar Peds in a Texture-Contrast Soil to Jointing in the Parent Rock. Geoderma Special Edition .

Walsh PG, Barton CVM and Haywood A (in press). Growth and carbon sequestration rates of some eucalypt species in the low to medium (400-700 mm) rainfall areas of NSW, Australia . Australian Forestry .

Walsh PG, Barton, CVM and Montagu KD (2003). Macquarie catchment pilot project, New South Wales , Australia : a cost-effective, market-based approach to reducing salinity through tree planting. Unasylva , 212: 37-39.

Walsh PG and Lacey ST (2003). A Survey and Assessment of Post-Harvest Erosion Within Native Forests Managed By State Forests of New South Wales . State Forests of NSW Research Paper No. 38.

Walsh PG, Montagu K, Royal, B and Dobson S (2005). Targeting Planted Forests for Dryland Salinity Control: Background to the Establishment of the Research Trials Associated with the Gunnedah 400 ha Dryland Salinity Pilot Project. Forest Resources Research, NSW Department of Primary Industries, Technical Paper No. 69.

Walsh PG (2003). The development of columnar peds in a texture contrast soil in the Pilliga State Forests northwestern NSW. Unpublished Masters thesis.

Humphreys G, Norris E, Hesse P, Hart D, Mitchell P, Walsh P, and Field R. (2001). Soil, vegetation and landform in Pilliga East State Forest . In J. Dargavel, D. Hart and B. Libbis (eds ), Perfumed Pineries Environmental History of Australia 's Callitris Forests . Centre for Resource and Environmental Management, ANU Canberra , pp 71-78.