No abstract

The importance of transience in the management of hydrogeologic systems is often uncertain. We propose a clear framework for determining the likely importance of transient behavior in groundwater systems in a management context. The framework incorporates information about aquifer hydraulics, hydrological drivers, and time scale of management. It is widely recognized that aquifers respond on different timescales to hydrological change and that hydrological drivers themselves, such as climate, are not stationary in time. We propose that in order to assess whether transient behavior is likely to be of practical importance, three factors need to be examined simultaneously: (1) aquifer response time, which can be expressed in terms of the response to a step hydrological change (τstep ) or periodic change (τcycle ); (2) temporal variation of the dominant hydrological drivers, such as dominant climatic systems in a region; (3) the management timescale and spatial scale of interest. Graphical tools have been developed to examine these factors in conjunction, and assess how important transient behavior is likely to be in response to particular hydrological drivers, and thus which drivers are most likely to induce transience in a specified management timeframe. The method is demonstrated using two case studies; a local system that responds rapidly and is managed on yearly to decadal timeframes and a regional system that exhibits highly delayed responses and was until recently being assessed as a high level nuclear waste repository site. Any practical groundwater resource problem can easily be examined using the proposed framework.

GWML2 is an international standard for the online exchange of groundwater data that addresses the problem of data heterogeneity. This problem makes groundwater data hard to find and use because the data are diversely structured and fragmented into numerous data silos. Overcoming data heterogeneity requires a common data format; however, until the development of GWML2, an appropriate international standard has been lacking. GWML2 represents key hydrogeological entities such as aquifers and water wells, as well as related measurements and groundwater flows. It is developed and tested by an international consortium of groundwater data providers from North America, Europe, and Australasia, and facilitates many forms of data exchange, information representation, and the development of online web portals and tools.

In keeping with the standard scientific methods, investigations of salinity processes focus on the collection and interpretation of contemporary scientific data. However, using multiple lines of evidence from nonhydrogeologic sources such as geomorphic, archaeological and historical records can substantially add value to the scientific investigations. By using such evidence, the validity of the assumptions about salinity processes in Australian landscapes is challenged, especially the assumption that the clearing of native vegetation has resulted in rising saline groundwater in all landscapes. In the Corangamite region of southwest Victoria, salinity has been an episodic feature of the landscapes throughout the Quaternary and was present at the time of the Aboriginal inhabitants and the first pastoral settlement by Europeans. Although surface-water salinity has increased in some waterways and the area of salinised land has expanded in some landscapes, there is no recorded evidence found which supports significant rises in groundwater following widespread land-use change. In many areas, salinity is an inherent component of the region's landscapes, and sustains world-class environmental assets that require appropriate salinity levels for their ecological health. Managing salinity requires understanding the specific salinity processes in each landscape.

Soil data form the basis of soil information systems across the globe. Soil information needs, and the questions posed by users, are likely to evolve in response to advances in technology in this era of Big Data. This poses a challenge to the pedological community which is already experiencing a decline in soil knowledge and expertise. With a decrease in soil data collection by governments, it is timely to reconsider howand what soil information should be provided to future users. A public-private partnership is advocated to deliver timely and accessible soil information to users. Two public-private provisioning programs are presented, and advantages and considerations for sharing soil data and information amongst industry, government, research organizations, service providers and land managers for these are discussed.Interoperable, open-source and agreed soil community standards are used to present soil data and information through spatial web portals with tools for interpretation of soil data for public and private beneficiaries. K E Y W O R D S accessible, data interoperability, interactive, interpretable, public-private partnership, soil data standards, soil information systems | 95 ROBINSON et al.