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Forest Watershed Management Course Objective: Understand the impact of forest management activities on water yield and quality. Become familiar with best management practices (BMP’s), the specific BMP programs of several states, and the role of foresters in BMP implementation and watershed management.
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Grading Grades are based on: Four quizzes - 30% Final examination - 30% Project - 30% Class participation - 10%
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Research Paper Due Date: December 8, 2000 Length: 1,200 words Topic:You may write about anything related to the course or watershed management in general. I suggest selecting a topic of particular interst to you. Prof. Hoover is available to discuss possible topics. Format: This is to be a research paper. This means all factual statements must be based on published research. Any conclusions should be based on the evidence available in the literature, not mere opinion. Number of citations: Provide a minimum of six citations for sources of information included in your paper.
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What Is A Watershed? Also referred to as a “catchment” Topographically delineated area drained by a stream system –No specific scale implied Total land area above a designated point on a stream or river that drains past that point For planning and management purposes it’s a –Physical-biologic unit –Socioeconomic-political unit
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Why Study Forest Watershed Management? Historically focus was forest hydrology –Hydrological effects of vegetation and land management practices on water quantity and quality, erosion, and sedimentation at specific sites Hydrology – science of water concerned with the origin, circulation, distribution, and properties of the waters of the earth.
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Sources of Soil Erosion – “It’s All Relative Folks” Construction sites Cropland Forest roads Forest land
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12T/A/Yr
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Soil Erosion on Forest Land Piedmont Region of Southeastern U.S. = 0.4 tons/acre/year = 0.04 tons/acre/year (conversion factor: kg/ha x 0.892183 = lb/acre) Source: John D. Hewlett. 1982. Principles of Forest Hydrology, Univ. Ga. Press, p. 150
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Forest Activities & Soil Erosion (in order of contribution to erosion) Roads and skid trails Channel encroachment Site preparation Harvesting activities Fire prevention and suppression Recreation activities Flatwoods drainage Wildlife management activities Source: John D. Hewlett. 1982. Principles of Forest Hydrology, Univ. Ga. Press, p. 149
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Hydrologic Affects of Silvicultural Practices Clearcut –Expose mineral soil –Increase soil temperatures –Reduce evapotransporation –Increase exposure to wind and associated evaporation –Increase erosion and stream sedimentation
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Hydrologic Affects of Road Systems Creates impermeable surface –Increases surface flow –Channelizes surface water flow –May channelize shallow subsurface flow
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Forest Watershed Management Clean Water Act –Sec. 1329 focuses attention of forest land through nonpoint source pollution requirements Citizen interest –Poor practices would cause shutdowns of forest operations Best management practices (BMP) adopted in most states
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An Issue in All States Areas of abundant rainfall –Impacts of storm events Droughty areas –Capture and allocation of available water
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Best Management Practices Focus of forestry and forest products community BMP’s are either regulations or guidelines for silvicultural activities –Planting –Harvesting –Roads Usually emphasize water quality
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Focus of Course: Knowledge to Implement Forest BMP Practices Understand action of water in forest environments Knowledge of applicable BMP’s Skill to apply BMP’s to a specific project on a specific site
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Knowledge of Precipitation Amounts and Patterns Plan drainage structures –Size temporary culverts to handle storm events during period of operations –Size permanent drainage structure to handle 100 year storms
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Knowledge of Precipitation Amounts and Patterns Time operations –Expose soil during dry periods if possible –Establish vegetative cover as soon as possible –Use native vegetation whenever possible
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Become familiar with precipitation patterns Sources of data –NOAA –NWS –State climatologist Usually at Land Grant University Vast amount of data available on line
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National Climatic Data Center
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National Weather Service
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Indiana Climate Page http://shadow.agry.purdue.edu/index.html
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Variation in Precipitation Random Seasonal Proximity to water body (lake affect) Prevailing winds with moisture Topographic
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Seasonal Variation
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Proximity to Water Body
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Prevailing Winds
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Topographic Affect Rising air cools Dew point reached Water vapor condenses to form clouds Precipitation may occur
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Cloud patterns induced by passage of air current over mountains Precipitation concentrated on windward side of mountain, and mountain top Tends to be rain shadow on leeward side
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Fidalgo Island in rain shadow of the Olympic Mountains. Rainforests with up to 200 inches of precipitation on the west side. Rain shadow area northeast of the Peninsula with only one- half (20 inches) of the normal rainfall for the rest of the region.
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Clearwater 118.5” Coupeville 21.14” Puget Sound Area, Washington
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Storm Events, 1 st Qtr.
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Storm Events, 2 nd Qtr.
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Storm Events, 3 rd Qtr.
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Storm Events, 4 th Qtr.
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Monroe County Airport, April 15-16, 1998 15th0953.03 1053.26 1158.00 1253.01 1353.0 1453.04 1553.0 1953.14 2053.12 2153.10 2253.36 2353.17 16th0053.32 0153.22 0253.25 0353.08
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Some Basic Hydrologic Concepts Weir are used to measure volume of water flowing past a point.
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What Happens to Precipitation? Hydrologic cycle P = RO + ET + S, Where, P ≡ precipitation RO ≡ runoff ET ≡ evapotranspiration S ≡ storage
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Evapotranspiration Loss of water from a given area during a specified time by evaporation from the soil surface and by transpiration from the plants. Supports plant life Reduces water yield
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Runoff Provides Major Benefits RO = P – ET Moose Creek, Clearfield County, PA WLH
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Where does runoff go to? RO = CI + SRO + SSF + BF, –where, CI ≡ channel interception SRO ≡ surface run off SSF ≡ subsurface flow BF ≡ base flow
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Where does runoff go to? –CI ≡ channel interception Precipitation falling directly into channel Susquehanna River, Clearfield, PA, WLH
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Where does runoff go to? –SRO ≡ surface runoff or overland flow Precipitation not infiltrating soil Sheet erosion of cropland resulting from surface runoff Source: http://www.agric.gov.ab.ca/agdex/500/72000003.html
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Where does runoff go to? –SSF ≡ subsurface flow, or interflow Infiltrating precipitation intercepted by hardpan or bedrock before entering groundwater pool
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Where does runoff go to? –BF ≡ base flow or ground water flow Precipitation entering water table
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Research results come from experimental watersheds such as: Hot Link to Website
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What We’ll Look At Erosion –Impacts of Roads Harvests Water flows –Storm events –Storage Water yield –Amount –Timing Montgemory Reservoir, Clearfield, PA, WLH
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