Spatial variation measurements of the hydrology and glaciology of the Dry Valleys

The long term hydrology/glaciology study carried out in the McMurdo Dry Valleys was conducted to gain information on the hydrological behaviour of the Dry Valleys rivers and lakes, particularly for the insight they provide into climatic change. Identifications of real trends in climate cannot be based on observations at only one site as it may be unrepresentative, and therefore it was proposed in the 1985/86 field season that a programme of hydrological monitoring be undertaken at a network of site throughout the Dry Valleys to examine the degree of hydrological unity of the region and define the representativeness of the Wright Valley System. The rivers of the Victoria, Taylor, Marshall, Garwood and Miers Valleys, and the Walcott Bay area were investigated to determine the feasibility of carrying out hydrological investigations, to assess the value of such investigations, to select appropriate sites and carry out the necessary site surveys to prepare for equipment installation in the 88/89 season. At each site, the following actions were taken: a) survey of longitudinal stream profile and channel slopes, b) stream cross section survey and definition of flood levels, c) stream bed sediment size distribution survey, d) testing of VHF radio communication for radio telemetry data and e) erection of marker cairns and full photographic record of each site for reference. Lake levels were surveyed at Keyhole Lake and Hidden Lake. The glacier terminus location and height of the Miers and Adams Glaciers were measured. After investigation, the sites chosen to add spatial variability to the existing hydrological and glaciological study were the glacier-river-lake system of the Miers Valley, and the streams in the Victoria Valley and Garwood Valley. Stream flow monitoring stations were erected near the outlet of the Upper Victoria Lake in Victoria Valley and downstream from the Garwood Glacier Lake in the Garwood Valley both of which would compliment glacial-lake studies in these Valleys.