Hydrology

Hydrology research has water as the primary focus  – water transport, quantity and quality, fate and how it interacts with forests, watersheds and climate. Hydrology research covers a wide array of topic areas that impact British Columbia's forested ecosystems and their dependent plants and animals.  

Snow Cover Timing from Satellite Imagery Opportunities for Near-real-time Mapping and Seasonal Forecasting - TR129

This document summarizes recent research on snow cover timing and duration in British Columbia as estimated from satellite imagery. The data were generated by Bevington et al. (2019) and have been studied previously by hydrological zone (Figure A1). This technical note summarizes snow cover timing by Natural Resource District (NRD) (Figure 1) and investigates the influence of atmosphere–ocean teleconnections (e.g., the El Niño Southern Oscillation) on snow cover timing. The intended audience of this report includes natural resource practitioners and water managers. Bevington et al. (2019) provide details beyond the scope of this report, namely the technical details regarding how the data were generated and a robust error assessment and validation of the methodology.

Research and Information Needs Assessment to Support Sustainable Watershed Management in the South Coast and West Coast Natural Resource Regions, British Columbia - TR110

Watershed management issues are among the many challenges facing natural resource managers in British Columbia. The B.C. Ministry of Forests, Lands and Natural Resource Operations (FLNRO) conducted a research and information needs assessment survey to help identify specific knowledge gaps and develop strategic priorities for research to support sustainable water resource management in the South Coast and West Coast Natural Resource Regions of British Columbia. In total, 216 individuals who were familiar with surface water and/or groundwater issues in these two regions completed all or portions of the survey and identified priority topics for research, monitoring, data collection, and policy development. The survey was conducted from October 20 to November 30, 2015. This report is the third in a series of regional assessments that are being conducted across British Columbia. 

Equivalent Clearcut Area as an Indicator of Hydrologic Change in Snow-dominated Watersheds of Southern British Columbia - EN118

Forest disturbance, whether natural or as a result of timber harvesting, directly affects stand-scale hydrologic processes through changes in interception, evaporation, and transpiration. When disturbance occurs over a large enough area, hydrogeomorphic processes at the watershed scale can also be affected. In British Columbia, statistically significant shifts in the timing and magnitude of snowmelt dominated streamflows and in the frequency of peak flow events of all magnitudes have been measured in watersheds where more than 25% of the area has been clearcut (Moore and Scott 2005; Zhang and Wei 2012; Winkler et al. 2015). Streamflow regimes may also be affected following less extensive changes in forest cover where disturbance location and watershed attributes synchronize melt runoff timing and delivery to stream channels (Schnorbus and Alila 2004, 2013; Green and Alila 2012). These increases may have subsequent downstream effects on channel morphology, aquatic habitat, alluvial fans, floodplains, infrastructure, and community water supplies.

Research and Information Needs Assessment to Support Sustainable Watershed Management in the Thompson–Okanagan Natural Resource Region, British Columbia - TR95

Watershed management issues are among the many challenges facing natural resource managers in British Columbia. The B.C. Ministry of Forests, Lands and Natural Resource Operations (FLNRO) conducted a research and information needs assessment survey to help identify specific knowledge gaps and develop strategic priorities for research to support sustainable water resource management in the Thompson–Okanagan Natural Resource Region of British Columbia. In total, 137 individuals who were familiar with surface water and/or groundwater issues in this region completed all or portions of the survey and identified priority topics for research, monitoring, data collection and policy development. The survey was conducted from October 15 to December 31, 2015. This report is the second in a series of regional assessments that are being conducted across British Columbia. The first regional assessment was completed in northeastern British Columbia (Lapp et al. 2015).

Research and Information Needs Assessment to Support Sustainable Watershed Management in Northeast British Columbia - TR90

Resource development in northeast British Columbia is resulting in increased pressure on water resources. The concurrent development of multiple resources in a remote and diverse landscape has led to many questions about the state of water resources and how to manage them in a sustainable manner. To help identify specific knowledge gaps and develop strategic priorities for research, an information needs assessment was conducted by surveying key people involved in water research and management in northeast British Columbia. In total, 65 respondents completed the survey and identified priority topics for research, monitoring, tools, and policy. Priority research needs consistently identified by respondents included the following: • water balance research that quantifies fluxes (e.g., evapotranspiration, recharge) and storage (e.g., groundwater, lakes, wetlands) for the range of landscapes and land cover types (e.g., wetlands, upland forests, ponds) present in northeast British Columbia. Due to differences in physiography and climate between the northeast and other regions of British Columbia, knowledge gained from long-term watershed research in other areas may not be directly transferrable; • development and testing of methods/models for defining environmental flow needs; • aquifer identification and characterization to quantify the availability and extent of groundwater resources; • climate change effects on all aspects of water resources, aquatic ecology, and natural hazards; and • development of methods for quantifying cumulative effects of resource development and land use change on water quantity and quality.

Revised Snow Recovery Estimates for Pinedominated Forests in Interior British Columbia - EN116

In most interior British Columbia watersheds, the single largest annual hydrologic event is the spring streamflow peak, generated primarily by snowmelt. The magnitude, volume, and timing of spring peak flows are a function of melt rate, snowmelt volume, soil and vegetation characteristics, watershed topography, and weather (Winkler et al. 2010a). Consequently, changes in snow regime—as influenced by forest cover—can significantly affect spring peak flows (Stednick 1996; Moore and Wondzell 2005; Green and Alila 2012; Schnorbus and Alila 2013). Both snow accumulation and ablation (combined losses from melt and evaporation) vary with weather, location, and forest cover (Figure 1). In a summary of North American and European studies, forest cover explained 57% and 72% of the variance in snow accumulation and ablation, respectively, among 65 sites (Varhola et al. 2010). 

Desktop Watershed Characterization Methods for British Columbia - TR79

In recent years, the accessibility of online mapping tools and GIS information has dramatically increased. As a result, it is now possible to remotely gather information about a watershed’s potential disturbance, hydrologic, and climatic characteristics. Watershed characterizations are often used when developing plans for monitoring, research projects, water quality objectives, industrial use, and other end uses, such as fisheries restoration or small-scale power projects. A watershed characterization is distinctly different from a watershed assessment that develops specific disturbance indicators and then ranks them accordingly. Desktop characterization of a watershed in advance of fieldwork allows for improved planning of field activities and/or monitoring projects, thereby increasing efficiency and reducing costs.

Small Stream Riparian Retention: the Prince George Small Streams Project - EN100

The Prince George Small Streams Project was initiated in the Prince George Forest District in 2001 to assess the effectiveness of the Prince George District Manager’s policy (pgdm 1999) to maintain the riparian functions and fish habitat values of small streams that are less than 1.5 m bankfull width. This extension note provides a project overview and highlights specific findings to inform forest professionals about small stream riparian management in the Central Interior of British Columbia. A more complete description of the project and all of its findings can be found on the British Columbia Ministry of Forests and Range Fish-Forest Interaction website and in a forthcoming 6-year synthesis report that will be available on the Ministry’s publications website. Although this project was developed under the Forest Practices Code (fpc) regulatory regime, it is equally relevant today because the lack of mandatory riparian reserves for small (class s4) fish-bearing streams in the fpc remains unchanged in the current Forest Planning and Practices Regulation (fppr s. 47(4)). Furthermore, current emphasis on professional reliance underscores the importance of making research findings available to forest professionals so they can formulate appropriate forest practices for managing riparian areas adjacent to small streams.

In 1999, the Prince George District Manager expressed concerns about the effectiveness of fpc riparian management regulations that allow for zero tree retention along s4 streams. In accordance with section 41(1)(b) of the fpc, the District Manager must be satisfied that an operational plan for harvesting will “adequately manage and conserve” forest resources in the area addressed by the plan. Following a review of the scientific literature and reporting by resource professionals, the District Manager approved a policy designed to address the biological and physical habitat requirements of small fish-bearing streams (s4). The policy’s purpose was to guide resource professionals in preparing operational plans and to guide the statutory decision-maker when approving those operational plans.

Compendium of Forest Hydrology and Geomorphology in British Columbia - LMH66

Over the last two decades, hydrologists and geomorphologists have often discussed the need to document the history, scientific discoveries, and field expertise gained in watershed management in British Columbia. Several years ago, a group of watershed scientists from academia, government, and the private sector gathered at the University of British Columbia to discuss the idea of a provincially relevant summary of hydrology, geomorphology, and watershed management. Their main objectives were to bridge the sometimes disparate views in watershed science with an integrated understanding of forest hydrology and geomorphology and to create a “go-to” reference for this information. Through this meeting, the Compendium of Forest Hydrology and Geomorphology was born.

Managing Forested Watersheds for Hydrogeomorphic Risks on Fans - LMH61

Fans are linked to their watersheds by hydrogeomorphic processes—floods, debris floods, and debris flows. These processes move water, sediment, and debris from the hillslopes of a watershed through channels to the fan. Fans in British Columbia are often the site of residential developments, and transportation and utility corridors, as well as high-value habitat for fish and high-productivity growing sites for forests. Collectively, these features are termed “elements-at-risk” because they may be vulnerable to watershed-generated hydrogeomorphic processes that issue onto the fan. These processes may be natural or result from land use activities, and can cause the partial or total loss of some or all of the elements on the fan.

Mountain Pine Beetle and Salvage Harvesting: Small Stream and Riparian Zone Response in the Sub-Boreal Spruce Zone - EN90

The mountain pine beetle (mpb) infestation and its related salvage harvesting activities adjacent to streams have the potential to influence small stream (< 2 m bankfull width) and riparian zone function by altering and removing riparian vegetation and causing other disturbances. These alterations are a significant management issue because small streams are the most predominant channel type on the landscape, comprising upwards of 80% of a watershed’s total channel length (Shreve 1969). Accordingly, understanding the influence of these changes on small streams and their riparian zones is important to forest management.

The Bowron River Watershed: A Synoptic Assessment of Stream and Riparian Condition 20–30 Years after Salvage Logging - EN86

Challenges associated with the current mountain pine beetle (Dendroctonus ponderosae) infestation have prompted investigation into the recovery of the Bowron River watershed, a basin that was extensively logged between the mid-1970s and the mid-1980s in response to a spruce-beetle outbreak. Although harvesting occurred before riparian reserve zones were implemented by the Forest Practices Code, comparisons can still be made because the Forest and Range Practices Act allows for riparian harvesting under specific circumstances. Specifically, harvesting in riparian reserves is permitted under the Forest Planning and Practices Regulation s.51(f) for the purposes of sanitation or s.51(g) damage by insects as long as it will not have a material adverse impact on the riparian zone.

Dendroecology A Guide for Using Trees to Date Geomorphic and Hydrologic Events - LMH58

The study of tree response to environmental conditions is called dendroecology. This discipline can offer key advice to forest practitioners regarding when landslides or flooding have occurred in the past. When trees are tilted, buried, or scarred by events, or established on sediment following an event, a record is left in the tree rings. This guidebook provides forest practitioners with information and straightforward techniques for interpreting those records. The additional time and expense incurred is of minor importance compared to the information generated and the degree of confidence that can be placed in the identification of geomorphic and hydrologic hazards influencing a site.

Forest Management on Fans Hydrogeomorphic Hazards and General Prescriptions - LMH57

Forested alluvial and colluvial fans can be runout zones for debris flows and debris floods, and are subject to floods. Forest management activities on areas of fans with this hydrogeomorphic activity can exacerbate the effects of these events and lead to substantial damage to infrastructure such as roads and bridges, productive forest sites, and fish habitat. This handbook presents a six-step hazard recognition scheme that enables forest practitioners to prepare appropriate strategies and prescriptions. The six steps are: fan identification in an operating area, pretyping watersheds, aerial photograph interpretation, fieldwork, prescription development, and monitoring. The scheme is applicable to forested fans throughout British Columbia.

Modelling Forest Harvesting Effects on Maximum Daily Peak Flow at Upper Penticton Creek - EN67

Forest harvesting can have a significant effect on hydrologic processes such as interception, snowmelt, and evaporation, as well as on the magnitude and frequency of geomorphically and ecologically important stream-flow events. These changes may affect water supplies, channel form, and the functioning of stream/riparian ecosystems. This note describes preliminary research modelling the effects of forest cover removal on peak flows in a small headwater stream in the south-central Okanagan.

Snow Avalanche Management in Forested Terrain - LMH55

Snow avalanches are a common phenomenon in most mountain ranges of British Columbia and forest damage is a natural occurrence. Forest harvesting on steep slopes in areas of high snow supply can create new avalanche start zones. Snow avalanches starting in recently harvested areas can damage new plantations, destroy downslope forest resources, and lead to soil loss and site degradation. Snow avalanches can be triggered by forest workers or winter recreationists in steep cutblocks; that is, in areas that were not prone to avalanching prior to harvest.

This handbook addresses snow and avalanche phenomena in a forestry setting and presents a risk assessment procedure suitable for incorporation in the terrain stability field assessment process. The handbook outlines harvest design and silvicultural strategies to reduce the risk of avalanche damage resulting from forest harvesting. Strategies for managing avalanche risks in winter are presented. An extensive bibliography is included, along with links to relevant publications, data sources, and resources available on the internet.

Carnation Creek and Queen Charlotte Islands Fish/Forestry Workshop: Applying 20 Years of Coastal Research to Management Solutions - LMH41

Both the Carnation Creek and Fish/Forestry Interaction Program (FFIP) have advanced our understanding of fish, forestry, and the effects of forestry and fisheries. It is important that both projects started at opposite ends of the spectrum. Carnation Creek was driven by research people who wanted to provide the basic, locally generated knowledge for fish/forestry management. To a degree, the program was calm, and it wasn’t until a decade after the program started that managers said, “Let’s use this information now.” The Fish/Forestry Interaction Program was the silver lining to the dark cloud of Riley Creek. Managers wanted to know yesterday. There was hot, dirty water all over the place. Things were never calm in FFIP, and scientists were pressed to come up with interpretations immediately. There was no time for researchers to quietly mull over their data.

Rainstorm and Flood Damage: Northwest British Columbia 1891–1991- LMH31

Historical reports of important rainstorm and flood events in northwest British Columbia and the Queen Charlotte Islands are compiled for the years 1891-1991. A brief descriptive history is presented for each event, including date, storm duration, precipitation data, storm damage details, and other relevant storm facts, along with a list of the source materials. Storm and flood dates were determined from Environment Canada climatological and streamflow data and local reports (e.g., in newspapers). Storm and flood details were gathered from newspapers, technical reports, scientific publications, ship logs, and diaries. The information is assembled in a chronological catalogue of events. The report will provide land managers, planners, foresters, engineers, and historians with an appreciation for the severity and extent of past historical events and the damage they caused. An understanding of the magnitude and frequency of the events described may help in project planning, emergency plan-ning and risk assessment.

Streamside Management: A Decision-Making Procedure for South Coastal British Columbia - LMH1

This booklet is a site-specific guide to the management of streamsides on Vancouver Island and South Coastal British Columbia for which logging is proposed. It should be considered an aid for field level personnel to determine what logging practices should be used and how much vegetation, if any, should be left along streamsides to provide for the requirements of non-timber users. The procedure deals with the maintenance of fisheries, wildlife, recreational, aesthetic, and water quality values while harvesting timber. It does not deal with stream rehabilitation or stream improvement projects, nor does it consider the trade-offs between resource values. However, it does provide information which may help to make those trade-offs.

Research and Information Needs Assessment to Support Sustainable Watershed Management in the Skeena, Omineca, Cariboo, and Kootenay/Boundary Natural Resource Regions, British Columbia - TR116

Watershed management issues are among the many challenges facing natural resource managers in British Columbia. The B.C. Ministry of Forests, Lands, Natural Resource Operations and Rural Development (FLNRO) conducted a research and information needs assessment survey to help identify specific knowledge gaps and develop strategic priorities for research to support sustainable water resource management in the Skeena, Omineca, Cariboo, and Kootenay/Boundary Natural Resource Regions of British Columbia. In total, 224 individuals who were familiar with surface water and/or groundwater issues in these regions completed all or portions of the survey and identified priority topics for research, monitoring, data collection, and policy development. The survey was conducted from May 19 to September 30, 2016. This report is the fourth in a series of regional assessments that have been conducted across British Columbia. The first regional assessment was completed in northeastern British Columbia in 2014, the second regional assessment was completed in the Thompson/Okanagan region in 2015, and the third regional assessment was completed in the South Coast and West Coast regions in 2016.

Forest Management on Alluvial and Colluvial Fans: Extension Plan and Evaluation Survey of Workshops, Publications, and Presentations - TR31

Extension of results is a key aspect of effective research. Part 1 of this report presents the extension plan developed for the Forest Management on Alluvial and Colluvial Fans research project. Components of the extension plan include descriptions of the target audiences, extension goals, learning objectives, and extension barriers. The extension plan establishes evaluation targets to help assess the success and (or) failure of extension activities conducted over the past 5 years (2001-2005). Part 2 presents a Web-based survey of individuals who attended extension events related to the project. The survey results detail the effectiveness of three types of extension methods used in the forested fan research project: publications, presentations, and workshops. The findings of the survey show that extension efforts affected the attitudes, skills, and, in some cases, forest management approaches of a large percentage of forestry practitioners and researchers who received information on forested fans or attended a workshop. The findings serve as a valuable information source for strengthening future extension delivery.