Long-term reliability of the Athabasca River (Alberta, Canada) as the water source for oil sands mining

Abstract

Exploitation of the Alberta oil sands, the world's third-largest crude oil reserve, requires fresh water from the Athabasca River, an allocation of 4.4% of the mean annual flow. This allocation takes into account seasonal fluctuations but not long-term climatic variability and change. This paper examines the decadal-scale variability in river discharge in the Athabasca River Basin (ARB) with (i) a generalized least-squares (GLS) regression analysis of the trend and variability in gauged flow and (ii) a 900-y tree-ring reconstruction of the water-year flow of the Athabasca River at Athabasca, Alberta. The GLS analysis removes confounding transient trends related to the Pacific Decadal Oscillation (PDO) and Pacific North American mode (PNA). It shows long-term declining flows throughout the ARB. The tree-ring record reveals a larger range of flows and severity of hydrologic deficits than those captured by the instrumental records that are the basis for surface water allocation. It includes periods of sustained low flow of multiple decades in duration, suggesting the influence of the PDO and PNA teleconnections. These results together demonstrate that low-frequency variability must be considered in ARB water allocation, which has not been the case. We show that the current and projected surface water allocations from the Athabasca River for the exploitation of the Alberta oil sands are based on an untenable assumption of the representativeness of the short instrumental record.paleohydrology | statistical hydrology | oil sands | Alberta | climate variability

Dendrohydrology and water resources management in South-Central Chile: Lessons from the Río Imperial streamflow reconstruction

“…Some of this change may be linked with recent anthropogenic climate forcing, and the detectable influence on regional precipitation trends (Boisier et al, 2016). In a similar manner as documented in several recent 20 studies targeting other regions of the world (e.g Woodhouse and Lukas (2006) and Sauchyn et al (2015b), among others), our reconstruction of natural hydroclimatic variability of the Río Imperial can provide a valuable framework to ponder the impact of anthropogenic climate change on future hydroclimatic changes in SCC, thus leading to a prudent water resource management strategy. Furthermore, water managers could use the reconstructed flows of the Río Imperial to plan mitigation strategies for drought events with return periods of five, 10 and 20 years.…”

“…Considering the implications of our results, we assert that the extended record we have provided must be utilized for water resources managers to more accurately determine the range of "worst-scenario" droughts, thus helping the planning and implementation of more efficient mitigation policies. Sauchyn et al (2015b) presented an example in which a series of hydroclimatic scenarios derived from tree-ring chronologies were formally included in a government-supported hypothetical decision-making exercise where relevant stakeholders were tasked with developing adaptation measures for drought episodes.…”

Pacific North American circulation pattern links external forcing and North American hydroclimatic change over the past millennium

“…Results indicate that, on interannual and interdecadal timescales, the PNA interacts with Pacific SST, solar, volcanic, and GHG forcings to modulate North American hydroclimate variability. The recent positive PNA pattern is unprecedented over the past millennium, likely aggravating snowpack decline (14,15), drought (6), and wildfire (48,61) across parts of the northwestern United States and moderating drought conditions in the southwestern United States (21). The PNA reconstruction not only provides a framework for understanding North American hydroclimate variability but also provides a benchmark for evaluating model simulations of the PNA (24), raising questions about the ability of current models to accurately predict future hydroclimate change in the region.…”

“…paleoclimate | atmospheric circulation | Holocene | climate change | North America R ecent drought intensification (1,2) and mountain snowpack declines (3,4) have raised concerns about future water shortages and wildfires throughout western North America, from the southwestern United States to Alaska (5,6). Although many lines of evidence have pointed to the impact of anthropogenic warming (3,7,8), naturally occurring atmospheric variability also contributes to the observed changes (9)(10)(11).…”

Cooperative and adaptive transboundary water governance in Canada’s Mackenzie River Basin: status and prospects

“…Some models indicate that annual discharge may increase in the Peace River region, with higher discharge in the fall and winter months but reduced discharge in the late summer and early fall (Schnorbus et al 2011). Modeling future Athabasca River flows indicates a trend of decreasing flows, which is expected to continue because of declining glacier ice and snowpack at higher elevations (Sauchyn et al 2015). There is some uncertainty about the impacts of the climate change in the basin.…”