The New Zealand Geospatial Office (NZGO) was recently happy to have David Maidment, principal developer for the ArcHydro data model, visit and present on developments and initiatives in water resource GIS.  A Kiwi who has lived in the US for 30 years, David met LINZ CE Colin MacDonald at last month's Esri User Conference in San Diego. He offered to tour LINZ and discuss his work, as part of a planned trip to visit family in the area.

David is the Director of the Center for Research in Water Resources at the University of Texas, Austin. Before he relocated to the US, he received his Bachelor's degree from the University of Canterbury and worked as a research scientist at the Ministry of Works and Development. Amongst his many roles and responsibilities, David also leads the Consortium of Universities for the Advancement of Hydrologic Science, Inc (CUAHSI). This is an initiative to improve access to hydrologic data across universities, initially in the US but ultimately on a global scale. David counts himself amongst a rare group in the geospatial industry, having received Esri's Lifetime Achievement Award in 2003 for his contributions to the application of GIS to water resources.

David started his visit to LINZ with a tour of the LINZ Topographic and Hydrographic units, where he was happy to load New Zealand data onto his new iPad. This was followed by an informal meeting with NZGO staff and Julian Sykes from NIWA.  David was particularly keen to hear about developments at NIWA in the construction of a hydrologic network to support aquatic species predictive modelling. He compared notes with Julian about former colleagues from his days collecting data for the New Zealand Hydrologic Survey. NZGO staff filled him in on the Geospatial Strategy and projects under the NZGO work programme.

In the afternoon, David presented on his work and ideas to an audience including NIWA, Ministry for the Environment, NZGO, University of Otago, MoRST, Hutt City Council and Horizons Regional Council. He explained how his love of rivers during his youth in New Zealand set the direction for his professional career. Having been involved in many foundational efforts to establish water resource GIS, David is now focused on synthesising all of the key components to create a future where accurate, high-resolution hydrologic map and analysis information is readily available on the web. This will involve fully developing and combining mapping, analysis data and tools, and internet resources to generate an intuitive web interface. In David's vision, a user will simply be able to click on web service map features and call up whatever information they need. This might include catchment areas, water quality, channel characteristics, gauging station time series data, and so on.

Two recent key developments are moving this vision closer to reality. With the release of ArcGIS 10, Esri has now incorporated time into geographic features. This will allow the mapping of water time series data, traditionally displayed as a series of graphs, directly into and as part of map features including stream segments. In effect this merges those two worlds, helping support David's idea of a unified mapping and analysis interface.

In addition, David and his team are working with Esri to develop the next version of ArcHydro called ArcHydro River. This data model will incorporate details about river morphology, including a river channel's shape and how it changes over time. This will be a model for rivers, as David explains, that approximates how rivers really are, incorporating all of their complexity and moving beyond traditional "blue lines" representations. Bringing this all full circle, David is keen to incorporate New Zealand input to inform the development of ArcHydro River, acknowledging the importance of rivers to the Kiwi way of life.

David's visit for me encapsulated the value of such events. A leader in their field not only sharing their vision and ideas but openly accepting feedback and perspectives from those of us in the New Zealand geospatial industry, in an informal and enjoyable environment.  It is my hope to coordinate more such events in the future, so watch this space!

Kevin Sweeney

Geospatial Custodian
New Zealand Geospatial Office