Seasonal snow is an essential renewable resource that provides water storage for hydroelectric power generation in most of the alpine catchments of New Zealand. Snowmelt contributes more than 10% of the total annual flow for a number of large rivers in the South Island (Kerr, 2013), provides up to 20% of the water needed for irrigation, and provides an important enhancement to base stream flow during the spring growth season. In addition, long term storage of water resources in the glaciers of the Southern Alps supports a significant contribution to baseflow in rivers, particularly during dry years (Sirguey, 2009; Kerr et al., 2013) when irrigation demand is high. Much of the snow and ice that eventually contribute to New Zealand’s water resources are located in challenging terrain and areas that are difficult to access or monitor. In these inaccessible areas, satellite remote sensing is a powerful tool to monitor snow and ice, but this technology has received only limited consideration to date in New Zealand. The establishment of CSST would capitalise on a unique opportunity to make a significant contribution to a range of users in New Zealand.
Seasonal snow is essential for the ski industry which generates $1.4 billion annually. Information on the current state of seasonal snow as it relates to the ski industry is lacking, with Statistics New Zealand tracking ski-field operating days for only three commercial ski areas. The future outlook for the industry under scenarios of climate change is not well constrained (e.g., Hendrikx and Hreinsson, 2012). Seasonal snow also presents hazards in the form of avalanches and large low-elevation snow storms, which present a significant hazard to transport and electricity supply.
The development of satellite products to effectively monitor snow and ice in New Zealand will be a major asset for business-led efforts on a regional, national and international scale. Importantly, the proposed research will provide a working platform that contains high quality snow and ice products from remote sensing products that will be attractive and accessible for business-led efforts. For example, a detailed understanding of the past and present (‘live’) variability in the extent of seasonal snow will encourage and enable business-led efforts to make informed decisions about investment opportunities in alpine regions in New Zealand. Whether it is a business-led effort directly linked to an activity above the winter snow line (e.g., ski field) or those dependent on water from seasonal snow and/or glacier runoff (e.g., hydroelectric power company, irrigation users) it is likely that the proposed high level satellite products will increase R&D intensity, either driven directly by the users themselves or by them sourcing support through contractors. Importantly, high level satellite products that provide detailed information about snow and ice will be extremely beneficial to the Central Otago/Lakes district (e.g. Queenstown and Wanaka), which has become one of the fastest business growth regions in New Zealand.
Immediate goals for CSST include:
- Consult widely with CRIs, hydro-electricity producers, regional councils in which snow and ice is a recognized resource, irrigation companies, and the skiing industry to better understand their needs and how these needs could be met by operational snow products from space-based observations.
- Consult with the New Zealand Snow and Avalanche Committee, Mountain Safety Council, New Zealand Transport Agency, and the Department of Conservation regarding meeting their needs for avalanche forecasting.
- Investigate the utility of space-based measurements to enhance models of seasonal snow, such as SnowSim, which has been identified as a pressing area of need (Clark et al., 2009). Improved performance of snow and hydrological models will result in better assessments of the state of seasonal snow, which will have direct benefits for end users such as water managers and those linked to the ski industry.
- Research and develop new snow products such as snow albedo and grain size mapping to improve knowledge of snow cover conditions.
- Develop, consolidate, and distribute a long-term multi-sensor/multi-resolution data set of New Zealand snow cover that would allow the medium to long term impact of climate change on snow to be assessed.