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Johnson Lake


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Improvement District No. 9 AB
Canada

Johnson Lake


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Location

Mountain View County AB
Canada

Documenting Dene traditional environmental knowledge


Author(s): Johnson, M.

Year: 1992

Abstract:
In a participatory action research project, local Dene and non-Native researchers in Fort Good Hope and Colville Lake, Northwest Territories (Canada), are documenting Dene traditional environmental knowledge and resource management systems. Problems in integrating Dene knowledge and Western science stem from incompatible world views.

Oil sands sludge dewatering by freeze-thaw and evapotranspiration


Year: 1993

Abstract:
The dewatering of oil sands sludge is a major technological, economical, and environmental challenge to the oil sands industry of northeastern Alberta. Sludge is a mixture of small mineral particles (less than 44 µm in diameter), residual bitumen from the extraction process, and water. Sludge consolidates at the bottom of tailings ponds to approximately 30% solids in 2 years and will remain at this level of solids and water indefinitely. At 30% solids, sludge acts as a liquid; unstable and extremely low in strength. Approximately 25 million cubic metres of sludge at 30% solids are produced each year by the two operating extract ion plants owned by Syncrude Canada Ltd. and Suncor Inc. More than 500 million cubic metres of sludge have been produced over the first 20 years these plants have operated. The experiments detailed in this report show that it was possible to increase the solids content of sludge to 50% solids by adding three parts sand (tailings sand) to one part sludge. At 505 solids, the sand-sludge mixture was semi-plastic, but extremely weak. One thousand parts per million of lime were needed to keep the sand from segregating from the sludge. Drainage of sand-sludge mixtures, even under the pressure of self-consolidation, was slow and uneconomical. The sand-sludge mixture had to be dewatered to 85% solids content before its shear strength was sufficiently high to support machine traffic or the overboarding of more sand-sludge mixture. At 85% solids, the sand-sludge mixture had a shear strength in excess of 100 kPa. Freezing and thawing sludge (without sand) caused the solids content to increase from 30% to 50%. Another 10% increase in solids content was achieved by several more cycles of freezing and thawing. At 50% solids, sludge was semi-plastic. Ditches or grooves ploughed into the sludge remained, but the shear strength was very low (less than 2 kPa). Sludge without sand needed at least 80% solids to have sufficient shear strength (more than 100 kPa) to support machinery traffic or sludge overboarding. If snow was removed from the surface periodically, the sludge froze to 165 cm depth in one winter in Mildred Lake, the Syncrude Canada Ltd. plant and mine site, approximately 40 km north of fort McMurray, Alberta. If the snow cover was left in place, freezing was restricted to 30cm. Laboratory and pilot-plant experiments showed that the amount of sludge that could be frozen in one winter could be increased by freezing the sludge in thin layers. Using this technique, a layer only a few centimetres deep was deposited and left to freeze for a day or two; as soon as it was frozen, a second layer was deposited. Layered freezing was also slightly more effective at dewatering sludge than freezing a pool of sludge from the top down. The water released from the sludge during the thaw period rose almost immediately to the sludge surface. Surface water had to be drained away to allow further dewatering, either by evaporation or vegetation-controlled evapotranspiration. Standing water on the sludge surface prevented the establishment and growth of adapted vegetation by floating seeds, making the rooting medium unstable, or inhibiting oxygen flux to the root zone. If the water was removed, two species of plants—reed canary grass and western dock—were well adapted to the sludge environment and capable of removing enough water from the sludge to dry it to 80% solids. Reed canary grass was the best adapted plant to both sludge and sand-sludge mixtures. Furthermore, reed canary grass grew from small sections of its own rhizome, known as sprigs. Starting plants on sludge with sprigs of reed canary grass may allow for large scale (hundreds of hectares) dewatering by vegetation. Sprigs were easy to spread, not subject to movement by wind or small amounts of water, and fast to establish new plants. Sludge at 50% solids that was planted to reed canary grass was dewatered to 80% solids in one growing season. At 80% solids the sludge had a shear strength of 120 kPa and could support machine traffic of any kind or the overboarding of several metres of liquid sludge. However, the rapid removal of surface water and the quick establishment of a dense plant community were essential. Otherwise, dewatering during the summer months was minimal, less than a 5% increase in solids from May to October. Sand-sludge mixtures were also dewatered by freezing and thawing. A 1 year dewatering cycle that included freezing and thawing and summer evaporation, but no plant controlled evapotranspiration, increased the solids content of a 2-m deep sand-sludge mixture from 50% to 80% solids. Reed canary grass and western dock also grew well on sand-sludge mixtures and aided in dewatering, if the surface water was removed.

Plants and habitats — a consideration of Dene ethnoecology in northwestern Canada


Author(s): Johnson, L. M.

Year: 2008

Abstract:
This paper discusses local understanding of plants and habitats, based on the linguistic evidence [terms for plants and (or) habitats] gathered from ethnobotanical and ethnoecological field work conducted with several Dene Nations of the Canadian northwestern boreal forest and adjacent regions. Nations involved in the study include (Mackenzie Delta Region), Sahtú’otine’ (Great Bear Lake), Kaska Dena (southern Yukon), and Witsuwit’en (northwest British Columbia). Key plant-related habitats include meadow, “swamp”, forest, “willows”, and “brush”. The ethnobotanical classification of willows is explored in conjunction with the explanation of the Dene habitat concept. In local classifications, ‘willow’ is not co-extensive with the genus Salix, but includes a variety of medium to tall woody shrubs that lack either conspicuous flowers, ‘berries’, or thorns; these may include shrubby species of Salix, Alnus, Cornus, and Betula. Shoreline and alpine environments are also discussed as plant habitats. Dene use of alpine environments and resources is ancient, according to the results of recent alpine ice patch research in the Yukon region. The Human dimensions of habitat knowledge are presented. Indigenous concepts of plant taxa and of landscape associations or habitats may differ substantially from those of scientific botany and ecology, and are based in a holistic and interactive ethnoecology. [ABSTRACT FROM AUTHOR]

Relict grassland in northern Saskatchewan: A phytogeographic study in the Clearwater River Valley


Author(s): Johnson, R. H.

Year: 1989

Abstract:
The main purpose of this research was to characterize the vegetation of the open slopes along the lower Saskatchewan reach of the Clearwater River. Examination of the species that constitute a representative site and the environmental conditions within which they exist was essential to the prediction of vegetation status and continued site occupation. An hypothesis was put forward on the origin of these communities and various methods to measure environmental parameters were used to determine the present site conditions. Many plants of the community were found to be displaced in Saskatchewan flora range and outside their normal climatic region. Most notable species are Anemone cylindrica A. Gray, Artemisia frigida Willd., Aster conspicuus Lindl., A. laevis L., Penstemon gracilis Nutt. and Stipa curtiseta (Hitchc.) Barkworth. Near the steppe study site, Abiesbalsamea (L.) Mill. exists as an isolated population in well protected spring-sapping zones. Calamagrostis purpurascens R. Br., a northern resident found previously as far south as the Cluff Lake area, represents a southern range extension. The data collected suggest recent advancement of footslope overstory but that maximum upslope movement may have been reached. The grassland species present are explained as being a relict community of previously widespread steppe origin.

Survey of rare vascular plants in Fidler-Greywillow Wildland Provincial Park


Year: 2005

Abstract:
Fidler-Greywillow Wildland Provincial Park is one of 81 recently designated protected areas, established in March 1998. It is a remote site located in the northeast corner of Alberta, north of Lake Athabasca, about 315 km north of Fort McMurray. This park includes portions of the north shore of Lake Athabasca and a series of islands, two of which are amongst the largest islands in the lake. FGWPP falls within the Kazan Upland and Athabasca Plain subregions of the Canadian Shield Natural Region of Alberta.The two main objectives of this reconnaissance survey were to a) document location, habitat and population size information for tracked vascular plant taxa occurring within the study site, and b) to update the list of vascular plant species for FGWPP.

Traditional Dene environmental knowledge: a pilot project conducted in Ft. Good Hope and Colville Lake, N.W.T. 1989 - 1993


Author(s): Johnson, M., & Ruttan R. A.

Year: 1993

Abstract:
Report on a three-year project to gather and document knowledge of the natural environment inherent in the cultures of the Dene peoples of the Mackenzie Valley, Northwest Territories, specifically at Fort Good Hope (Ra deli Ko) in the North Slavey region, and at Colville Lake (K'ah ba mi Tue).