Meeting of the Waters A Hydroclimatic Analysis of the Illecillewaet River and Asulkan Brook from September 12th to 14th, 2012 Geography 477: Field Studies in Physical Geography, Fall 2012 By Lindsay James, Emily Clark, Chris Italiano, Dallas Halldorson Instructor: Dr. Dan Smith Department of Geography University of Victoria 1 1 Introduction: 1.1 Purpose of study 4 1.2 Geographic Setting: Columbia, Selkirk, GNP 4 1.3 Geographic Setting: Illecillewaet Catchment 5 1.4 Geographic Setting: Illecillewaet and Asulkan Glaciers 6 1.5 Classification of Illecillewaet River and Asulkan Brook 7 2 Background on study components 2.1 Dissolved and suspended sediments 7 2.2 Glacier runoff and discharge 7 2.3 Geochemical analysis: Silica 8 3 Methodology 3.1 TDS and Electrical Conductivity 9 3.2 Suspended load 9 3.3 Discharge 10 3.4 Air temperature and radiation 11 3.5 Silica analysis 12 4 Results 12 5 Discussion 5.1 Interpretation of Results 18 5.2 Errors and Limitations 24 5.3 Further study 26 6 Conclusion 26 7 List of figures 27 8 References 28 2 Abstract: This study was conducted to analyze the effects of climatology on river hydrology. The response of the river system as the radiation and air temperature change over time was examined. Different aspects of the river that were investigated include water temperature, total dissolved solid load, conductivity, discharge and silica content. The data were collected September 12th and 13th, 2012 at the Meeting of the Waters in Glacier National Park. The background of the different factors involved in the various climatological and hydrological areas was explored. The results from this study were discussed in light of previous research and experiments. It was concluded that the air temperature has a direct effect on the discharge of the two rivers, as well as on the different constituents of river composition. 3 1 Introduction 1.1 Purpose of study The purpose of this paper is to do a hydroclimatic analysis of Illecillewaet River and Asulkan Brook. This was to be done by analyzing the hydrological behavior (conductivity, total dissolved solids, and discharge), performing a silica analysis on water samples taken from the two sites, and analyzing climate data (temperature and radiation) on September 12 and 13, 2012. Some observations were made on the 14th, though no data were collected. 1.2 Geographic Setting: Columbia, Selkirk, GNP The Columbia Mountain range is located in southeastern British Columbia. It contains four distinct ranges: Selkirk, Purcell, Monashee and Caribou. The Selkirk, Purcell, and Monashee ranges all lie parallel to one another. The Caribou range is separated from the others by the North Thompson River. The Columbia Mountains are boarded by the Fraser River (north), Columbia River (south), Rocky Mountain Trench (east), and the Interior Plateau (west) (Columbia Mountains, 2012). The area of study lies within the Selkirk mountain range. The majority of the Selkirk mountain range lies in British Columbia but extends into northern Idaho and Montana. The range is 320 km long and sweeps in a northwesterly ‐ southeasterly arc (Selkirk Mountains, 2012). The geology of the Selkirk range is mainly upper crustal, low‐grade metasedimentary rock. It is within the Ominica Belt of BC (Price and Monger, 2003). The topography consists of high, heavily glaciated peaks and low valleys. Peak height is 2,300m to over 3,000m above sea level. This area contains abundant wildlife, including some endangered species (Selkirk Mountains, 2012). Much of the area lies within Mount Revelstoke and Glacier National Parks. Glacier National Park is 1350 km2 of protected area. The Trans Canada Highway and the Canadian Pacific Railway traverse the park, but there is little other human influence. This area has a continental climate, with four distinct seasons. 4 High precipitation occurs throughout the winter months, with snow packs up to 15m per annum (McCleave, 2008). Glacier National Park (GNP) protects a number of endangered species and ecosystems. Some major mammalian species include wolverine, mountain caribou, and grizzly bear. The valley bottom supports old growth forests of western hemlock and western red cedar. The mid‐upper slopes give way to sub‐alpine fir, mountain hemlock, and Engelmann spruce. Further upslope there are parkland meadows, which transition to alpine tundra in the upper elevations. Though GNP has several distinct ecosystems, the majority of the park’s land cover is alpine tundra, rock, and glaciers (McCleave, 2008). Natural hazards in GNP include forest fires, avalanches, and debris flows (McCleave, 2008). These have been an on going serious issue in maintaining the railroad and highway through the park. A major railway station and destination for outdoor enthusiasts used to exist near the present site of the Illecillewaet Campground, called Glacier House. A kilometer away from the ruins of the former Glacier House is the focus of this study, called the “Meeting of the Waters”, confluence of Illecillewaet River and Asulkan Brooke. 1.3 Geographic Setting: Illecillewaet Catchment The Illecillewaet River starts at the Illecillewaet Glacier in Glacier National Park, and drains into the Columbia River near Revelstoke. The river’s main sources are the Illecillewaet and Asulkan Glaciers, which share the same névé. The drainage area of the basin is 1150 km2 (Loukas, Vasilliades, & Dalezios, 2002). Most of the water input at the headwaters is from glacier runoff and snowmelt. The surface around the headwater has seen many glacial advances and retreats. Currently 6.6% of the watershed for the Illecillewaet River is glaciated. The land cover downstream is heavily forested, resulting in the watershed having 74% forested land (Loukas et al., 2002). How water enters the system alters greatly downstream due to the change in land cover. Downstream there is more infiltration and therefore more 5 ground water entering the system compared to the large amount of surface runoff up stream. The Illecillewaet watershed is classified as a mountainous catchment. The high altitudes (ranging from 1000m‐2250m), and high amounts of precipitation (up to 1715mm/yr) on the western slopes determine hydrological behavior (Loukas et al., 2002). The amount of impermeable ground of this catchment is 25% (Loukas et al., 2002). This is noteworthy, due to the large area of previously glaciated land, mostly impermeable bedrock. Therefore the majority of water entering the system at and near the headwater is surface runoff. 1.4 Geographic Setting: Illecillewaet and Asulkan Glaciers The source water for the area of study comes from two alpine temperate glaciers, Illecillewaet and Asulkan. Both are classified as temperate or warm based because the ice throughout the glacier is at its pressure melting point. This results in, typically, abundant meltwater within or beneath the glacier. The meltwater emerging from the base has high erosive power and removes much debris from the site of deposition and carries it downstream (Ritter 2011). The Selkirk glaciers were described as retreating by Vaux, in his study published in 1899. He was Figure 1: Google Earth Image of the Meeting of the Waters Site the first to measure the and the Illecillewaet and Asulkan Rivers. GPS Measurements: retreat by simply choosing a Radiometer: 51°15.581’N 117°29.391’W Illecillewaet Transect: 51°15.571’N 117°29.363’W rock at the base of the Asulkan Transect: 51°15.536’N 117°29.400’W Illecillewaet Glacier, then 6 measuring the glacier’s retreat over time (Vaux & Vaux, 1899). 1.5 Classification of Illecillewaet River and Asulkan Brook Both rivers are classified as intermediate rivers with bedload consisting of boulders. The slope range is between 2‐4% (Stream Channel Reference Sites n.d.). There was evidence of previous flood events on the banks of both rivers. They lie in mountainous terrain and are heavily influenced by glaciers. 2 Background on study components 2.1 Dissolved and suspended load in rivers Dissolved and suspended sediments can reveal a lot about a river’s origins. Stream solute levels change in space as well as over time. This is due to the fact that the processes which affect stream flow and its dissolved content are dynamic in nature. Ultimately, the dissolved and suspended sediment loads are conditioned by hydrometeorological events in the drainage basin (Trudgill, 1986). The sediment loads are also determined by the drainage basin characteristics, such as length, slope, shape, vegetation cover and land use. In previous studies, it has been found that solute levels increase progressively downstream when solute‐rich groundwater influences the river discharge (Trudgill, 1986). So areas that have more permeable rock tend to have larger amounts of sediment due to the impact of groundwater. As well, areas of abundant vegetation have a greater amount of biological and organic solutes. It has been shown that the relationship between discharge and suspended sediment is positive, meaning that as discharge increases, often the suspended load increases as well (Trudgill, 1986). 2.2 Glacier runoff and discharge Snowpack and glacial melt result in surface runoff. The amount of runoff is determined by the rate of melting, which in turn is controlled by short and long wave radiation and air temperature (Ward & Robinson, 1990). Therefore the 7 hydrology of glacierized basins is mainly thermally controlled. Within the basin, variations in energy supply and precipitation result either in the storage of ice or production of meltwater, depending on the time of year (Ward & Robinson, 1990). Therefore glacierized basins are characterized by how much their storage of snow and ice changes annually, resulting in total runoff which may be larger or smaller than annual precipitation (Ward & Robinson, 1990). Glacier runoff consists of two main drivers: periodic and aperiodic meltwater (Ward & Robinson, 1990). Periodic meltwater is thermally driven and has separate diurnal and seasonal flow variations. An extreme meterological event or rapid release of glacier meltwater define aperiodic melt.