Fresh groundwater resources are a highly valuable commodity, particularly in semi-arid to arid landscapes where annual precipitation is low and surface water is scarce. Water security, often achieved through the development of groundwater resources, is a high priority for rural communities within these water-limited landscapes. However this is often at the expense of the environment when alterations to the groundwater system, often in conjunction with drought conditions, can detrimentally impact floodplain and riparian vegetation structure and function. Remote-sensing methods can be used to detect such changes in vegetation. In this study, a multi-temporal Landsat Normalised Difference Vegetation Index (NDVI) approach was used to detect changes in riparian and floodplain vegetation in the Lower-Darling floodplain, NSW, Australia. When integrated with surface and subsurface data, these changes provided insight into how surface water availability and subsurface geological and hydrogeological characteristics influenced vegetation distribution and behaviour at multiple scales. It was found that while the availability of water resources was the primary driver of changes in vegetation canopy dynamics, this availability was strongly influenced by both tectonic and hydrogeological processes. These findings were of particular importance when considering the suitability of groundwater development options and they have implications for future groundwater assessment studies.

How much easier it would be to map and quantify the key elements of the hydrological cycle if the Earth's surface was transparent! Unfortunately, this is not the case and it is this very inability to penetrate to sufficient depths to map and quantify groundwater components of the hydrological cycle that currently necessitates the integration of satellite- airborne- and ground observations. In Australia, important advances have been made in the last 3 years in quantifying key elements of the hydrological cycle. This has been achieved in part through the increased use of Landsat, MODIS, SPOT, hyperspectral, NOAA and LiDAR datasets to improve the mapping and quantification of surface water, evapotranspiration, soil moisture and recharge and discharge. However, significant limitations remain in using satellite-based platforms alone for quantifying catchment water balances, surface-groundwater interactions, groundwater resource estimation and managing groundwater dependent ecosystems. Increasingly, the need to map the key elements of the hydrological cycle to calibrate water balance models and for environmental management, is leading to the development of more holistic systems approaches, involving the integration of satellite-, airborne and ground-based techniques and measurements. One example is in the River Murray Corridor (RMC) in SE Australia, where previous attempts to assess the water needs for iconic floodplain wetland ecosystems, based largely on satellite-based measurements, did not adequately take into account sub-surface soil conditions and groundwater quality and processes. In floodplain environments such as the River Murray Floodplain, the factors that govern tree health are invariably complex, and include a wide range of biophysical and biogeochemical factors.

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.

National vegetation cover derived from: - Values 1, 7, and 8 from the 2007 forests dataset (BRS) - Values 2 and 3 from the NVIS 3.1 dataset (ERIN) - Values 1-6 and 9-11 from the catchment scale land use dataset (as at April 2009, BRS) - Any remaining no data areas filled from the Integrated Vegetation 2008 dataset (BRS) The datasets were resampled to 100 metre grids and projected to Albers equal area if required. The integrated vegetation grid was derived using a conditional statement weighing each input grid in the order listed above. Bureau of Rural Sciences, Canberra are custodians of the dataset.

Identification of groundwater-dependent (terrestrial) vegetation, and assessment of the relative importance of different water sources to vegetation dynamics commonly involves detailed ecophysiological studies over a number of seasons or years. However, even when groundwater dependence can be quantified, results are often difficult to upscale beyond the plot scale. Consequently, quicker, more regional mapping approaches have been developed. These new approaches utilise advances in computation geoscience, and remote sensing and airborne geophysical technologies. This study, undertaken in the semi-arid Darling River Floodplain in N.S.W., Australia, combines Landsat Normalised Difference Vegetation Index (NDVI) time series data with hydrogeological, hydrogeochemical and hydrogeophysical data to assess the relative importance of hydrological processes and groundwater characteristics. The first stage in the study combined high-resolution vegetation structural mapping derived from LiDAR data (Canopy Digital Elevation Model and Foliage Projected Cover), with 23 years of Landsat time-series data. Statistical summaries of Normalised Difference Vegetation Index values were generated for each spatially continuous vegetation structural class for each Landsat scene (e.g. stand of closed forest). This has enabled long-term temporal changes in vegetation condition to be assessed against different water regimes (drought, local rainfall, river bank full, overbank flow, and lake filling), and groundwater dependent vegetation to be identified. The second stage involved integration with airborne electromagnetics (AEM), hydrogeology and hydrogeochemistry. This has shown that the deeper (>25m), semi-confined aquifer is only rarely important to vegetation dynamics, with the shallow unconfined aquifer and river lateral bank recharge zones being of greater importance.

The combination of anthropogenic activity and climate variability has resulted in changes to hydrologic regimes across the globe. Changes in water availability impact on vegetation structure and function, particularly in semi-arid landscapes. Riparian and floodplain vegetation communities are sensitive to changes to surface-water and groundwater availability in these water-limited landscapes. Remote-sensing multi-temporal methods can be used to detect changes in vegetation at a regional to local scale. In this study, a `best-available pixel' approach was used to represent dry-season, woody-vegetation-canopy characteristics inferred from Normalised Difference Vegetation Index (NDVI). This paper describes a method in which Landsat 5 TM and Landsat 7 ETM+ data from 1987 to 2011 were processed using object-based image-analysis techniques to generate annual minimum NDVI values for vegetation communities in the Lower-Darling floodplain The changes detected in riparian and floodplain canopies over time can then be integrated with other spatial data to identify water-source dependence and infer a relationship between changes to the hydrologic characteristics of specific water sources and vegetation dynamics.

Identification of groundwater-dependent terrestrial vegetation, and assessment of the relative importance of different water sources to vegetation dynamics, typically requires detailed ecophysiological studies over a number of seasons or years. However, even when groundwater dependence can be quantified, results are often difficult to upscale beyond the plot scale. Quicker, more regional approaches to mapping groundwater-dependent vegetation have consequently evolved with technological advancements in remote sensing techniques. These approaches however often fail to incorporate sub-surface hydrogeological processes in their interpretation of groundwater dependence. This study, undertaken in the semi-arid Darling River Floodplain in NSW, Australia, innovatively combines Landsat Normalised Difference Vegetation Index (NDVI) time series data with hydrogeological, hydrogeochemical and hydrogeophysical data to assess the relative importance of hydrological processes and groundwater characteristics. Central to the approach is the use of airborne electromagnetics which provides a 3-dimensional context to otherwise point-based borehole data. This approach has resulted in an improved understanding of vegetation dynamics including the spatial distribution of vegetation utilising groundwater, timing and duration of groundwater use, and response to different hydrologic regimes (e.g. rainfall, lateral bank recharge, and overbank flooding). In particular, the study has established that the deeper (>25m), semi-confined aquifer is only rarely important to vegetation dynamics, with the shallow unconfined aquifer and river flush zones being of greater importance. These findings are being used to assess the suitability of proposed groundwater-development schemes in the study area, and have implications for riparian vegetation management more broadly.

The Sustainable Management of Coastal Groundwater Resources Project was co-funded by the Raising National Water Standards Program, which supports the implementation of the National Water Initiative Program. The project was led by GHD Hassall, in consultation with Kempsey Shire Council, Geoscience Australia, NSW Department of Environment, Climate Change and Water, and Ecoseal Developments Pty. Ltd. The project aimed to improve the management of groundwater in coastal dune aquifers, undertaking a case study of the Hat Head National Park region on the Mid North Coast of New South Wales. Due to increasing pressures on groundwater resources from expanding urbanisation and tourism in this region, the sustainable management of the existing groundwater resources is of vital importance. There are many potential risks associated with extraction of groundwater resources including acidification of soils, seawater intrusion and increased salinity levels, and detrimental impacts on groundwater dependent ecosystems (GDEs). This final report documents all of the work undertaken by Geoscience Australia relating to Groundwater Dependent Ecosystems, or more specifically groundwater dependent terrestrial vegetation. Groundwater dependent ecosystems (GDEs) are naturally occurring ecosystems that require access to groundwater to meet all or some of their water requirements so as to maintain their communities of plants and animals, ecological processes and ecosystems services. Often the natural water regime of GDEs will comprise one or more of groundwater, surface water and soil moisture.

The purpose of the Global Map is to accurately describe the present status of the global environment in international cooperation of respective National Mapping Organisations (NMOs) of the world. The Landcover, Vegetation Percentage Tree Cover and Elevation imagery have been developed by using satellite imagery with cooperation between participating NMOs and supporting stakeholders.

Subtidal to intertidal deposits from Kaipara Harbour in Northland preserve a 23,000+ year incomplete sedimentary record of the transition from terrestrial to estuarine conditions in the Wairoa River arm of the harbour. Cores are used to reconstruct the depositional setting for this transition, which we interpret as a succession from dune and freshwater wetland to shallow estuarine environments. The fossil pollen record provides a proxy of Last Glacial Maximum and Late Glacial vegetation for the area. Stability of the palaeo-dune landscape during the postglacial marine transgression is interpreted on the basis of strong dominance of tall forest taxa (Dacrydium) in the pollen record and soil development in dune sands. Reworking of buried dune and wetland sediments has only reached to a depth of 1.5 m below the modern tidal flat. As such, the site provides a rare example of good preservation of Pleistocene deposits at the coast, where extensive reworking and loss of record are more typical.