Resource Category: Journal Papers and Book Chapters

Ring-width data from 138 sites in the Canadian Prairie Provinces and adjacent regions are used to estimate
summer drought severity during the past several hundred years. The network was divided into five regional
groups based on geography, tree species, and length of record: the eastern Rockies, northern Saskatchewan,
central Manitoba, southern Manitoba, and northwestern Ontario. Regional tree-ring records are primarily
related to summer moisture and drought conditions, and are less responsive to droughts caused by deficits in
winter precipitation. These summer-sensitive data are not linearly related to major modes of climate
variability, including ENSO and the Pacific decadal oscillation (PDO), which primarily affect the climate of
western Canada during winter. Extended drought records inferred from tree rings indicate that drought on
the Canadian Prairies has exhibited considerable spatial heterogeneity over the last several centuries.

The hydrology of subarctic northern watersheds is
changing in response to recent anthropogenic global warming [Hinzman et al., 2005]. Climate model results predict
the intensification of the hydrological cycle and increased
river discharge in subarctic and arctic regions [Milly et al.,
2005]. Increasing annual flows to the Arctic Ocean have
been detected in Eurasian rivers [Peterson et al., 2002;
McClelland et al., 2006]. However, decreasing annual flows
to the Arctic Ocean have been shown for rivers discharging
into Hudson, James and Ungava Bays [De´ry et al., 2005];
and basically unchanged annual flow to the Arctic Ocean
shown for northern Canadian rivers [De´ry and Wood, 2005].

Groundwater could be an increasingly important water supply in the Canadian interior
with global warming and declining summer runoff; however, not enough is known about
the behaviour of groundwater under climatic variability. A network of over 33 wells is
analyzed in order to document variability of groundwater levels and their sensitivity to
climatic events. Groundwater wells are spread through the three Prairie Provinces with
median monthly groundwater level records spanning up to 40 years. The aquifers are
mostly in sand and sandstone which make them highly sensitive to climatic variations.

Myths of abundant and stationary water resources have infl uenced water policy and
management in western Canada. Data presented in this chapter demonstrate that
water use, policy and management were established during a period of fairly stable
and reliable water supplies as compared to preceding and projected hydrological
regimes. These data include tree-ring and historical evidence of prolonged drought,
recent trends (glacier wastage, declining snowmelt runoff and summer fl ows), and
global circulation models (GCM)-based scenarios of precipitation and runoff. We
consider how water policy and management might be adjusted to compensate for a
long-term view of the surface hydrology that includes more prolonged drought and
lower average flows than observed and experienced in the twentieth century.

This study compared the hydroclimatic signals recorded in annually laminated (varved) sediments and
tree rings within a small study area in the Selwyn Mountains of the southwestern Northwest
Territories/southeastern Yukon Territory border region of Canada. The records were located
immediately adjacent to each other and within 6 km of instrumental meteorological and hydrometric
records, which permitted a detailed analysis of climate in the area from AD 1704 to 1996. This study
explored the challenges of annually-resolved multi-proxy hydroclimate analyses and examined how
best to interpret the climate record given the differences in proxy formation and the respective signals.

The morphometry of chutes (couloirs), rock funnels, and open cirques are related to the structure of dissected rock
masses in the Kananaslds region of the Canadian Rocky Mountains. Data for ten morphometric variables were derived from
digital elevation models of 56 open rock basins. The basins were classified structurally according to the relative orientations
of bedding planes and the rock slopes. A hypothesis of no differences in morphometry among structural classes is rejected
from the results of nonparametric analysis of variance and paired comparisons of rank scores. Basins on dip and overdip
slopes have a distinct :size, and those on anaclinal slopes have a distinct width and shape.

Prairie agriculture is exposed to large climate variability, extreme weather events and to
the climate sensitivity of production systems, agri-ecosystems and the soil and water
resources that support agriculture. A high adaptive capacity in the agricultural sector has
been attributed to a history of adaptation to climate risks. This chapter adopts mainly the
impact-based approach described in Chapter 2 of this volume. The material presented
here considers the potential and net impacts from climate change by examining the
exposure of prairie agriculture to risks and the related climate sensitivity of the soil, water
and ecological resources that enable crop and livestock production.

The landscape of southern Saskatchewan is drought prone and dominated by agriculture.
Certain landscapes are more sensitive to degradation. Given the potential impact of climate change on the
landscapes and their productivity, a regional scale investigation was undertaken using three global climate
models (GCMs) and two geographic information system (GIS) overlay methods to examine the sensitivity of
the landscapes surrounding the six rural communities of Balcarres, Carlyle, Craik, Eastend, Naicam and
Willow Bunch for the periods of 1961–91 and for the 2050s. Regardless of the method used, the most sensitive landscapes are land under cultivation.

The least annual precipitation in the western interior of North America occurs in the
northern Great Plains, including an area that encompasses parts of south-eastern Alberta,
south-western Saskatchewan and eastern Montana. During 1999–2001, most climate
stations in this region had record low precipitation. This paper examines this three-year
drought in the context of historical climate records from Medicine Hat, Alberta and
Havre, Montana and summer (June–July) and annual (August–July) precipitation reconstructed from standardized tree-ring widths (residual chronologies) from Pinus contorta
(lodgepole pine) sampled in the Cypress Hills of Alberta and Saskatchewan and the Bears
Paw Mountains of north-central Montana. Drought is operationally defined as precipitation
in the lower 10th and 20th percentiles.

The Prairie Ecozone is the only major region of Canada where drought is a landscape hazard; aridity is linked to soil erosion. Management of prairie ecosystems and
soil landscapes therefore requires an understanding of past and future trends and variability in regional aridity. We used instrumental and paleoclimatic records to define a
regional baseline for prairie aridity, to evaluate the utility of modern climate normals (i.e.1961-1990) as a benchmark for future climatic change, and to provide a historical context for a range of General Circulation Model (GCM) forecasts of regional aridity. A warmdry scenario derived from the Canadian GCM projects a significant increase in the area of subhumid and semiarid climate.