|Year||Title (Author, Description)||File Download|
Road Sediment Production and Delivery: Processes and Management
Lee MacDonald and Drew B.R. Coe
Unpaved roads are often considered to be the predominant sediment source in forested catchments. In steep, wet climates roads can cause a 10- to 300-fold increase in the landslide erosion rate, and this increase is due to the effects of roads on hillslope flow paths and the structural integrity of hillslopes. The proportion of sediment that is delivered to the stream will generally be very high for road-induced failures in hollows and inner gorge landforms, and much lower for planar hillslope failures. The pulsed input of sediment from roadinduced landsliding can greatly alter stream channel habitat and morphology. Unpaved roads can increase sediment production rates by more than an order of magnitude as a result of road surface erosion. The high surface erosion rate stems from the generation of surface runoff from the highly compacted road travelway, the lack of surface cover, and the availability of fine sediment due to traffic and road maintenance procedures such as grading. Sediment delivery to streams occurs primarily at road-stream crossings and secondarily by road-induced gullies. The proportion of the road network that is connected to the stream network is primarily a function of mean annual precipitation (R2=0.9), and is increased by about 40% in the absence of any engineered drainage structures. The chronic input of the fine sediment from roads can have adverse effects on freshwater aquatic ecosystems as well as coral reefs. Our present understanding of road surface erosion processes is good, but our models to predict road surface erosion and landsliding are much better for relative than absolute predictions. Climate change can greatly increase road-induced landslides and road surface erosion by increasing the magnitude of large storm events and increasing the amount of rain relative to snow. Extensive field surveys also show that relatively few road segments typically generate most of the road-related increases in sediment yields. Road surface erosion, the risk of road-induced landslides, and road sediment delivery can be greatly decreased by improved road designs and maintenance practices. Hence the greatest needs are to develop and provide land managers with the tools for identifying high-risk segments, and then to make the necessary investments in road reconstruction and restoration.
|Contact ALCES for Lee MacDonald and Drew B.R. Coe, 2007|
Spatial Analysis of Rural Residential Expansion in South-Western Alberta
Miistakis Institute for the Rockies
|Contact ALCES for Miistakis Institute for the Rockies, 2003|
Scenario analysis in environmental impact assessment: Improving explorations of the future
Peter Duinker and Lorne Greig
Scenarios and scenario analysis have become popular approaches in organizational planning and participatory exercises in pursuit of sustainable development. However, they are little used, at least in any formal way, in environmental impact assessment (EIA). This is puzzling because EIA is a process specifically dedicated to exploring options for more-sustainable (i.e., less environmentally damaging) futures. In this paper, we review the state of the art associated with scenarios and scenario analysis, and describe two areas where scenario analysis could be particularly helpful in EIA: (a) in defining future developments for cumulative effects assessment; and (b) in considering the influence of contextual change, e.g. climate change, on impact forecasts for specific projects. We conclude by encouraging EIA practitioners to learn about the promise of scenario-based analysis and implement scenario-based methods so that EIA can become more effective in fostering sustainable development. Environmental Impact Assessment Review 27 (2007)
|Contact ALCES for Peter Duinker and Lorne Greig, 2007|
Triage for conserving populations of threatened species: The case of woodland caribou in Alberta
Richard R. Schneider, Grant Hauer, W.L. (Vic) Adamowicz, Stan Boutin
Prioritization of conservation efforts for threatened and endangered species has tended to focus on factors measuring the risk of extirpation rather than the probability of success and cost. Approaches such as triage are advisable when three main conditions are present: insufficient capacity exists to adequately treat all patients, patients are in a critical state and cannot wait until additional capacity becomes available, and patients differ in their likely outcome and/or the amount of treatment they require. The objective of our study was to document the status of woodland caribou (Rangifer tarandus) herds in Alberta, Canada, with respect to these three conditions and to determine whether a triage approach might be warranted. To do this we modeled three types of recovery effort – protection, habitat restoration, and wolf control – and estimated the opportunity cost of recovery for each herd. We also assessed herds with respect to a suite of factors linked to long-term viability. We found that all but three herds will decline to critical levels (<10 animals) within approximately 30 years if current population trends continue. The opportunity cost of protecting all ranges by excluding new development, in terms of the net present value of petroleum and forestry resources, was estimated to be in excess of 100 billion dollars (assuming no substitution of activity outside of the ranges). A habitat restoration program applied to all ranges would cost several hundred million dollars, and a provincial-scale wolf control program would cost tens of millions of dollars. Recovery costs among herds varied by an order of magnitude. Herds also varied substantially in terms of their potential viability. These findings suggest that woodland caribou in Alberta meet the conditions whereby triage should be considered as an appropriate conservation strategy.
|Contact ALCES for Richard R. Schneider, Grant Hauer, W.L. (Vic) Adamowicz, Stan Boutin , 2010|
From Science-Based Thresholds to Regulatory Limits: Implementation Issues for Cumulative Effects Management
Steve Kennett, Canadian Institute of Resources Law
|Contact ALCES for Steve Kennett, Canadian Institute of Resources Law , 2006|
Sediment Production and Delivery from Forest Roads and Off-Highway Vehicle Trails in the Upper South Platte River Watershed, Colorado
Matthew J. Welsh
Sediment is a principal cause of impairment to surface water quality. Erosion is a particularly important environmental issue in the Upper South Platte River (USPR) watershed of Colorado because it is the primary source of drinking water for Denver, has a high-value fishery, and several stream reaches are impaired by high levels of sediment. Unpaved roads are often considered a dominant source of sediment in forested watersheds, and off-highway vehicle (OHV) trails are another potentially important but largely unquantified sediment source. The objectives of this study were to: (1) quantify sediment production and delivery from forest road and OHV trail segments in the USPR watershed; (2) test the accuracy of WEPP:Road, SEDMODL2, and two empirical models for predicting sediment production from roads and OHV trails; and (3) compare sediment production, sediment delivery, and sediment yields from forest roads and OHV trails. Rainfall, site characteristics, and sediment production were measured on 14-22 native surface road segments from 2001 to 2006, and these data were used to test the accuracy of WEPP:Road and SEDMODL2. Empirical models for predicting storm-based and annual sediment production were developed from the first four years of data; the last two years of data were used for model testing. Similar measurements on 5-10 OHV trail segments from 2005 to 2006 were used to test WEPP:Road and SEDMODL2. Sediment delivery was assessed by detailed surveys along 17 km of roads and 10 km of OHV trails. In 2006 mean sediment production from the 10 OHV trail segments was 18.5 kg m-2 yr-1, or six times the mean value from the 21 road segments. The percentage of OHV trails connected to streams was 24%, or 70% higher than for roads, largely because more OHV trails were in the valley bottoms. None of the models accurately predicted sediment production from roads or OHV trails, but the performance of SEDMODL2 was greatly improved by calibrating the geology and traffic factors to the study area. SEDMODL2 also could be improved by adjusting the slope factor, better accounting for rill density on native surface roads, and making the rainfall factor dependent on rainfall erosivity rather than rainfall depth. WEPP:Road could be improved by making sediment production decrease rather than increase with higher soil rock content, and increasing the effect of a categorical change from no traffic to low traffic. Road density in the study area is 0.6 km km-2, or three times the density of OHV trails. Multiplying unit area sediment production normalized by summer erosivity times the density, mean active width, and percent connectivity indicates that roads and OHV trails are respectively delivering approximately 1.1 Mg km-2 and 0.8 Mg km-2 of sediment to the stream network per year. Sediment delivery to streams can be reduced by locating roads and OHV trails out of valley bottoms and off steep hillslopes, decreasing segment lengths, and reducing segment slopes.
|Contact ALCES for Matthew J. Welsh, 2008|
Sediment Production from Forest Roads with Wheel Ruts
Randy b. Foltz and Edward R. Burroughs, Jr.
Artificial rainfall was applied to two sets of paired plots 30.5 m long by 1.52 m wide, each set on a different soil type. One plot in each set contained a wheel rut while the other did not. Measurements of water and sediment yield on rutted plots showed sediment production declined with cumulative runoff while unrutted plots did not show a significant sediment depletion. This difference was a result of concentrated flow versus sheet flow.
|Contact ALCES for Randy b. Foltz and Edward R. Burroughs, Jr., 1990|
Institutional requirements for watershed cumulative effects assessment and management: Lessons from a Canadian trans-boundary watershed
Poornima Sheelanere, Bram F. Noble, Robert J. Patrick
Watersheds are under increasing stress from the cumulative environmental effects of water and land use disturbances caused by both anthropogenic and natural causes. Yet, while the science of watershed cumulative effects assessment and management (CEAM) is advancing much less is known about the institutional and capacity requirements to implement and sustain watershed CEAM. Based on lessons from a transboundary watershed in western Canada this paper presents eight institutional requirements, or requisites, for the implementation of watershed-based CEAM. We suggest that effective watershed CEAM requires government leadership to move beyond the current inward focus on project approvals toward an outward focus on the cumulative effects of all disturbances in a watershed; complementary monitoring programs at the project and watershed scale, and a means to ensure the sharing of monitoring data across watershed stakeholders; and a nested planning framework to coordinate watershed planning objectives with individual project impact assessment and decision making. Results of this paper show that simply scaling up from individual project-based assessments to the watershed scale exposes many institutional constraints that can impede CEAM action.
|Contact ALCES for Poornima Sheelanere, Bram F. Noble, Robert J. Patrick, 2012|
Shell Jackpine Mine Expansion Project
Oil Sands Environmental Coalition
The Panel’s responsibilities to determine if the Project is in the public interest and determine if it will create significant adverse effects, is onerous. We believe it would assist the Panel in discharging its responsibility to protect the public interest and make its assessment of the residual impacts, if it ensured that mitigation will, in fact, be implemented and knew the status of its previous recommendations, and commitments made by the proponent on which the Panel and ERCB relied upon – particularly as it relates to Shell’s projects and the projects in the Muskeg River basin.
|Contact ALCES for Oil Sands Environmental Coalition, 2012|
Soil Carbon Sequestration and Land-Use Change: Processes and Potential
W. M. Post, and K. C. Kwon
When agricultural land is no longer used for cultivation and allowed to revert to natural vegetation or replanted to perennial vegetation, soil organic carbon can accumulate by processes that essentially reverse some of the effects responsible for soil organic carbon losses from when the land was converted from perennial vegetation.We discuss the essential elements of what is known about soil organic matter dynamics that may result in enhanced soil carbon sequestration with changes in land-use and soil management.We review literature that reports changes in soil organic carbon after changes in land-use that favor carbon accumulation. This data summary provides a guide to approximate rates of SOC sequestration that are possible with management, and indicates the relative importance of some factors that influence the rates of organic carbon sequestration in soil. There is a large amount of variation in rates and the length of time that carbon may accumulate in soil that are related to the productivity of the recovering vegetation, physical and biological conditions in the soil, and the past history of soil organic carbon inputs and physical disturbance. Maximum rates of C accumulation during the early aggrading stage of perennial vegetation growth, while substantial, are usually much less than 100 g C m y . Average rates of accumulation are similar for forest or grassland establishment: 33.8 g C m y and 33.2 g C m y respectively. These observed rates of soil organic C accumulation, when combined with the small amount of land area involved, are insufficient to account for a significant fraction of the missing C in the global carbon cycle as accumulating in the soils of formerly agricultural land.
|Contact ALCES for W. M. Post, and K. C. Kwon, 1999|