The Surface Hydrology Points (Regional) dataset provides a set of related features classes to be used as the basis of the production of consistent hydrological information. This dataset contains a geometric representation of major hydrographic point elements - both natural and artificial. This dataset is the best available data supplied by Jurisdictions and aggregated by Geoscience Australia it is intended for defining hydrological features.

Subtitle: Behind the Scenes of Geofabric Version 3 Pilot & the Future of Geospatial Surface Water Information The Bureau of Meteorology's Australian Hydrological Geospatial Fabric (Geofabric) was established in 2008 as the spatial information database to support water accounting and resource assessment mandated under the Water Act 2007. Foundation layers for Geofabric versions 1 and 2 were developed from 1:250K streamline data and the 9 second resolution national DEM. The uses of the Geofabric data have expanded to new disciplines and have resulted in increased demand for finer national resolution. Version 3 of the Geofabric is now under development in a collaborative project between Geoscience Australia, CSIRO, Australian National University (ANU) and the Bureau of Meteorology. The foundation inputs for Geofabric version 3 are based on the integrated national surface hydrology dataset which uses the best available scale data from the jurisdictions and the 1 second resolution SRTM DEM. This significant enhancement presents both challenges and opportunities. This presentation at the Surveying & Spatial Sciences Institute (SSSI) ACT Region conference on 16 August 2013 aims to show the work being undertaken in the pilot areas of the Namoi and Murrumbidgee River Regions.

Geoscience Australia has conducted four surveys in the Swan River Estuary to investigate benthic nutrient fluxes and their impact on water quality. Surveys were undertaken in March 2000, March 2001, September 2001 and October 2006, and both the upper and lower sections of the estuary were sampled. This report details the findings of the most recent benthic nutrient survey (October 2006) and compares benthic fluxes at selected sites during all four surveys. During the October 2006 survey, very high nutrient fluxes were recorded in the upper estuary muddy sites. Combined with very low denitrification efficiencies, large sediment nutrient pool sizes and hypoxic bottom waters, these muds are a significant source of bioavailable nutrients to the water column. Between 2000 and 2006 there has been a significant increase in the amount of organic matter decomposition and nutrient release from the muddy sediments in the upper estuary. A similar pattern is observed in the central basin, however, the change is not as severe. The shallow sandy margins of the lower estuary are sites of photosynthetic production, however, these differ between benthic and pelagic production depending on the light attenuation. When light is available at the sediment surface benthic production is evident, when light penetration is insufficient to reach the sediment surface pelagic production is more evident.

Geoscience Australia (GA) was invited by Murray-Darling Basin Authority (MDBA) in 2010 to participate in an evaluation of the Intermap IFSAR (Interferometric Synthetic Aperture RADAR) data that was acquired as part of the Murray-Darling Basin Information Infrastructure Project Stage 1 (MDBIIP1) in 2009. This evaluation will feed into the business case for Stage 2 of the project. As part of the evaluation GA undertook the following: 1. A comparison of the IFSAR Digital Surface Model (DSM) and Digital Terrain Model (DTM) with a recent LiDAR acquisition, covering approximately 9000Km2 of the Lower Darling Region. It focused on assessment of the data over various land cover and terrain types and identified opportunities and issues with integrating IFSAR with LiDAR. 2. A comparison of the IFSAR Vegetation Canopy Surface (DSM minus DTM) with the Lower Darling LiDAR Canopy Elevation Model (CEM). 3. A comparison between currently mapped man-made and natural water bodies over the Murray-Darling Basin with the IFSAR derived products (water mask). 4. Application of the National Catchment Boundaries (NCBs) methodology to the IFSAR data and comparison with the delineated watersheds from PBS&J (Intermap's sub-contractor). This report outlines the findings of this evaluation based on the 4 items above MDBA requested.

A detailed analysis of aquifer systems in the Broken Hill Managed Aquifer Recharge priority areas has clarified our understanding of key components of the aquifer systems. Of the priority areas examined in detail, the aquifers located in the Darling Floodplain are considered to have the greatest potential for developing Managed Aquifer Recharge (MAR) options and for hosting significant volumes of previously undefined fresh and brackish groundwaters with low levels of allocation, thereby assisting the larger strategic effort aimed at identifying significant water-saving measures for the Darling River system.

No abstract available

We examine surface sediment and water column total nutrient and chlorophyll a concentrations for 12 estuaries with average water depths <4 m, and calculated sediment loads ranging from 0.2 to 10.8 kg m-2 year-1. Sediment total nitrogen, phosphorus and organic carbon concentrations vary inversely with sediment loads due to: (i) the influx of more mineral-rich sediment into the estuaries; and (ii) increasing sediment sulfidation. Sediment total organic carbon (TOC) : total sulfur (TS) and TS : Fe(II) ratios correlated to sediment loads because enhanced sedimentation increases burial, hence the importance of sulfate reduction in organic matter degradation. Curvilinear relationships were found between a weathering index and organic matter 13C in sediment, and sediment load. The rising phase of the curve (increasing weathering, lighter isotopic values) at low to intermediate loads relates to soil erosion, whereas regolith or bedrock erosion probably explains the declining phase of the curve (decreasing weathering, heavier isotopic values) at higher sediment loads. The pattern of change for water column total nutrients (nitrogen and phosphorus) with sediment loads is similar to that of the weathering index. Most water quality problems occur in association with soil erosion, and at sediment loads that are intermediate for the estuaries studied. Limited evidence is presented that flushing can moderate the impact of sediment loads upon the estuaries.

No abstract available

Islands in the Pacific region rely heavily on their fresh groundwater, and for a number of islands it is the only reliable source of freshwater throughout the year. Stresses on groundwater resources in many Pacific Island countries are set to escalate in the future with projected population and economic growth. In addition, there are likely to be future climate impacts on groundwater availability and quality. Although a number of studies have been undertaken at a local scale, very limited information is available to consider the impacts of future climates on groundwater systems at a regional scale. This project provides a first-pass regional-scale assessment of the relative potential vulnerability of groundwater to: (i) low rainfall periods and (ii) mean sea-level rise for 15 Pacific Island countries and territories. The dataset associated with this report can be obtained from www.ga.gov.au using title "Pacific Island Groundwater Vulnerability to Future Climates Dataset" or catalogue number 81575.

This document represents part of Geoscience Australia's contribution to the National Estuaries Assessment and Management (NE) project, Theme 5 (Assessment and Monitoring), Task 5A 'Conceptual Models of Australian Estuaries and Coastal Waterways'. The report contains comprehensive conceptual models of the biophysical processes that operate in a wide range of estuaries and coastal waterways found around Australia. Geomorphic conceptual models have been developed for each of the seven types of Australian estuaries and coastal waterways. Each conceptual model comprises a three-dimensional block diagram depicting detailed summaries of the structure, evolutionary characteristics, and geomorphology of each coastal waterway type, which are ?overlain? by flow diagrams that depict some of the important biotic and abiotic processes, namely: hydrology, sediment dynamics, and nutrient dynamics. Geomorphology was used as the common 'base layer' in the conceptual models, because sediment is the fundamental, underlying substrate upon which all other estuarine processes depend and operate. In the conceptual models, wave-dominated systems are depicted as having a relatively narrow entrance that restricts marine flushing, and low water-column turbidity except during extreme events. Tide-dominated systems feature relatively wide entrances, which likely promote efficient marine flushing, very large relative areas of intertidal habitats, and naturally high turbidity due to strong turbulence induced by tidal currents. Strong evidence exists suggesting that estuaries (both wave- and tide-dominated) are the most efficient 'traps' for terrigenous and marine sediments, and these are depicted as providing the most significant potential for trapping and processing of terrigenous nutrient loads. Intertidal areas, such as mangroves and saltmarshes, and also the central basins of wave-dominated estuaries and coastal lagoons, are likely to accumulate the majority of trapped sediments and nutrients. Conceptual model diagrams, with overlays representing environmental processes, can be used as part of a decision support system for environmental managers, and as a tool for comparative assessment in which a more integrative and shared vision of the relationship between components in an ecosystem can be applied.