ID | 1578 |
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Citation | Schnorbus, M. 2012. Hydrologic Impacts Research Plan for 2012-2016. Pacific Climate Impacts Consortium. |
Organization | PCIC |
URL | http://www.pacificclimate.org/sites/default/files/publications/Schnorbus.HI_Plan_April2012.pdf |
Abstract/Description or Keywords | The hydro-climatology of British Columbia (BC) is complex, in part due to its close proximity to the Pacific Ocean, mountainous terrain and large latitudinal expanse. Historical changes to climate and hydrology have been documented in British Columbia and western North America by Rodenhuis et al. (2009). Historical changes are in part attributable to climate variability on annual to decadal timescales, such as teleconnection patterns coming from El Niño/Southern Oscillation (ENSO) or the Pacific Decadal Oscillation (PDO). In addition, recent hydro-climatic trends in western North America have also been affected by anthropogenic climate change, predominantly in the form of increased regional warming (Barnett et al. 2008; Bonfils et al. 2008; Pierce et al. 2008). The regional response to climate variability and trends can potentially affect all aspects of the hydrologic cycle, including the hydrologic extremes of flood and drought (Hamlet and Lettenmaier 2007; Sheffield and Wood 2008). Ultimately it is recognized that the hydro-climatic system can no longer be considered stationary, and from a management perspective the past may become progressively less informative of future conditions (Milly et al. 2008). Consequently, the aim of the Hydrologic Impacts (HI) theme at the Pacific Climate Impacts Consortium (PCIC), and the purpose of the proposed applied research, is to quantify the effects of climate change and variability on water resources within the Pacific and Yukon region (PYR) of western Canada. The main purposes of HI theme products are to: • Inform and support the sustainable use of the region’s water resources in order to help reduce society’s vulnerability to climate change and climate variability; and • Raise awareness of potential hydrologic implications of climate change and climate variability. All this is to be accomplished at spatial scales relevant to regional and local management and over multiple planning and adaptation time frames. Spatial scales range from several hundreds of thousands of square kilometres (e.g. the Fraser River basin) to several hectares (e.g. drainage culvert design) and timeframes vary from monthly to century. Of particular interest for management and planning is a greater emphasis on knowledge regarding changes in hydrologic variability and changes in extremes, such as flood and drought, and phenomena that affect that variability, such as changes in the frequency and intensity of storms affecting the PYR. Climate, and subsequently hydrology, varies over a wide range of space and time scales as a result of processes both internal and external to the Earth’s climate system (Keenlyside and Ba 2010). External forcing includes climate variations caused by factors external to the climate system, such as changes in radiative forcing as a result of human-derived greenhouse gas (GHG) emissions. Internal processes are reflected by internal climate variability, which arises from natural interactions within the earth-oceanatmosphere climate system, such as manifested in the ENSO or Pacific Decadal Oscillation phenomena. Different time frames can be organized and distinguished by characterizing them by the degree to which the driving climate is dominated by internal climate variability versus external forcing. Therefore, in order to assess the possible hydrologic effects of both climate change and climate variability over a broad range of time scales, the work of the HI theme will be organized along the following three time frames (Figure 1): • Short-term - monthly to annual; • Near-term - annual to multi-decadal; and • Long-term - multi-decadal to century. Over the short term, hydro-climatic processes are governed predominantly by internal climate variability, whereas over the long-term these processes are strongly affected by external forcing (Figure 1). In the near-term, hydro-climatic processes are affected by both internal variability (particularly for time frames of a decade or less; Keenlyside and Ba 2010) and, over multiple decades, by external forcing. The activities with which the HI theme intends to address and estimate hydrologic impacts within the short-, near- and long-term timeframes are classified into forecasting, prediction and projection, respectively. A forecast is the estimation of values or magnitude of hydro-climatic conditions (or their probabilities) at a specific future time, or during a specific time interval (e.g. reservoir inflow over the coming six months; Lettenmaier and Wood (1993)). A prediction is the estimation of future hydroclimatic conditions, but is herein distinguished from forecasting in that it is not referenced to a specific date or time, but instead seeks to predict the statistical characteristics of hydro-climatic conditions over some defined time period (e.g. the frequency of flood events over the next five years). A projection is the estimated response of the hydro-climate system to changes in radiative forcing. As projections must be explicitly tied to assumptions of how future greenhouse gas emissions may evolve in response to human activities (in the form of emissions scenarios), they are neither forecasts nor predictions (Bray and von Storch 2009). Projections aim to provide a set or range of plausible, but not necessarily likely, outcomes. Over the short-term, forecasts are an “initial value” problem in that forecast results and skill are sensitive to specified initial states (climatologic and hydrologic) and radiative forcing can be set to reflect present conditions. Long-term projections are “boundary value” problems in that the evolution of hydroclimatology is strongly affected by assumptions regarding the evolution of greenhouse gas concentrations and consequent radiative forcing. Near-term decadal to multi-decadal predictions can be considered a hybrid problem, in that predictions are expected to be sensitive to some aspects of both the initial states and assumptions regarding future greenhouse gas concentrations and other external factors affecting the climate system. climate change, streamflow, water supply, peak flow, low flow |
Information Type | report |
Regional Watershed | All |
Sub-watershed if known | |
Aquifer # | |
Comments | |
Project status | complete |
Contact Name | Markus Schnorbus |
Contact Email | [email protected] |