Soil Erosion and Sedimentation Estimates for the Northwest Miramichi Watershed, New Brunswick

Transcription

1 Soil Erosion and Sedimentation Estimates for the Northwest Miramichi Watershed, New Brunswick Shane Furze, BSc, MEM, PhD (Candidate) University of New Brunswick November 6 th, 2013 ESRI UC Halifax, N.S.

2 OVERVIEW Background Location and Uses Issue Methodology Locating and sizing road-stream crossings Calculating soil loss at crossings Locating potential sediment deposition sites along channels Implementation of ArcGIS extensions and Model Builder Potential Applications 2

3 BACKGROUND East/Central New Brunswick 220,000ha drainage area 83% crown land World renown for Salmo salar (Atlantic Salmon) $100 million (1995) Dominant forestry operations Miramichi City Kilometers 3

4 ISSUE Forestry = runoff potential = peak flows Inadequate drainage Road washouts Channel blockage Roads Soil loss and sediment transport Effects on salmon: Turbidity and gill abrasion, alteration to channel morphology death ics/geologichazardsmapping/pages/landslid es_thurstonslide2.aspx _01_archive.html 4

5 METHODOLOGY 5

6 METHODOLOGY ROAD-STREAM CROSSINGS Intersect road and streams to determine crossings 4 ha flow accumulation threshold Labels = Catchment area (ha) # of crossings = 5, Kilometers Legend!( Crossings NWM_Roads NWM_Streams Slope % High : Low : Kilometers 6

7 METHODOLOGY CULVERT DIAMETER CALCULATIONS 1) Determine Peak Flow: Burkli-Ziegler Formula (Rothwell, 1978): where: Q = C x I x A(S/A) 0.25 Q = peak flow (ft 3 /second) A = Drainage area (acres) C = Runoff coefficient (0.3) (Pelletier, 1999) I = Rainfall intensity per hour for severe rainfall event (in/hr) (Hogger, 19875) S = average slope/ 1000 feet (80). Manning Formula (Rothwell, 1978): 2) Calculate Culvert Diameter (cm): D = ((2.159 x Qn / S 0.5 ) ) x where: D = culvert diameter (feet) Q = peak flow (ft 3 / second) S = slope of culvert (0.015) n = culvert roughness coefficient (0.023) (Chow, 1959) 7

8 METHODOLOGY CALCULATING SOIL LOSS Revised Universal Soil Loss Equation (RUSLE) (Renard et al., 1997): A i = R i x K i x L i x S i x C i x P i Where A i = estimated average annual soil loss per unit area (tonnes/ha/year) R i = rainfall erosivity- factor (MJ mm/ha/h/year) K i = soil erodibility- factor (tonne h/mj/mm) (Colpitts et al., 1995), (Fahmy et al., 2010), (Wall et al.,2002) L i S i = Slope length and steepness factor (Van Remortel, 2003) C i = Surface cover and management factor (0 1) P i = Support practice factor (0 1) Erodibility Slope length and Steepness 8

9 METHODOLOGY CALCULATING SEDIMENT YIELD Converting soil loss (tonnes/ ha/ year) into yield (mg/l): Where: Yield (mg/l) = A x 10 5 / D A = soil loss from RUSLE (tonnes/ ha/ year) D = annual discharge (mm/year) Kilometers Legend NWM_Roads NWM_Streams Sediment Yield mg/l!( !( !( !( !( !( !(

10 METHODOLOGY DETERMINING CHANNEL VELOCITIES 1) Calculate bankfull discharge (Q bfk ) and mean annual discharge (Q maf ) (Caissie, 2005): Where: A = catchment area (km 2 ) Q bfk = 0.343A 0.93 Q maf = A ) Calculate bankfull width (W bfk ) and mean annual width (W maf ): W bfk = 4.47( Q bfk ) W maf = 9.7( Q maf ) 10

11 METHODOLOGY DETERMINING CHANNEL VELOCITIES CONT D 3) Apply relationships from circle geometry: r = half width of bankfull width = 0.5 x W bfk c = mean annual width = W maf t = change in depth = r 2 c 2 /4 Θ= (Atan(T/(W maf /2))) r Θ t c K = half cross-sectional area) (r 2 x (Θ (sin (Θ)))/2 K h WP = Wetted Perimeter = 2 x (Θ x r) WP HR = Hydraulic Radius = K/ WP (Raymond, 2012) 11

12 METHODOLOGY DETERMINING CHANNEL VELOCITY CONT D 4) Reclassifying slope (m/m) into roughness coefficients (Raymond, 2012): Slope (m/m) Roughness Coefficient (n) ) Manning Velocity Equation (Rothwell, 1978): Where V = (kn/n) x HR (2/3) x S 0.5 V = channel's cross-sectional average velocity (m/s) kn = conversion factor (Length (1/3) / Time) (1m (1/3) /s) n = Manning's roughness coefficient HR = hydraulic radius (m) S = channel slope (m/m) Kilometers 12

13 IMPLEMENTATION OF ArcGIS EXTENSIONS AND MODEL BUILDER 13

14 IMPLEMENTATION OF ArcGIS EXTENSIONS AND MODEL BUILDER Culvert Diameter Model 14

15 Flow Direction Streams and Crossings Runoff Coefficient (C) Peak Flow (Q) Rainfall Intensity (I) Average Slope (S) Roughness Coefficient (n) Culvert Diameters (D) 15

16 IMPLEMENTATION OF ArcGIS EXTENSIONS AND MODEL BUILDER Channel Velocity Model 16

17 Mean Annual Discharge Catchment Area Change in Depth Mean Annual Width Bankfull Discharge Wetted Perimeter Bankfull Width Central Angle Cross Sectional Area Hydraulic Radius Channel Velocity Roughness Coefficients 17

18 IMPLEMENTATION OF ArcGIS EXTENSIONS AND MODEL BUILDER Soil Loss Model 18

19 Soil Erodibility Sediment Yield Soil Loss Channel Velocity Culvert Diameter Sediment Yield and Velocity at Stream Crossings 19

20 POTENTIAL APPLICATIONS Locating areas with inadequate road-stream crossings Identifying areas with high erosion rates Useful tool in development of best management practices Locating potential sediment deposition sites and areas requiring sediment buffers Locating salmon spawning habitats Mapping salmon pools to locate areas of importance Determine sites where forestry operations should be avoided and areas where forest roads should be decommissioned 20

21 CURRENT WORK Focusing on determining the sediment yield and culvert requirements where wetland features are along roads. Calculated catchment areas above specific wetlands for hydrological importance: Wetlands Catchment (Ha) ,000 1,000-5,000 5,000-10,000 10,000-50,000 50, , , ,000 Frequency Distribution for the outlet catchment areas of wetlands, 30 m buffered Count From To Ha , ,260 2, ,510 5, ,010 10, ,000 19, ,950 39, ,810 79, , , , , Kilometers 21

22 REFERENCES Caissie, D River discharge and channel width relationships for New Brunswick rivers. Can. Tech. Rep. Fish. Aquat. Sci. 2637: 26pgs. Chow, V.T Open channel hydraulics. New York: McGraw-Hill. 680pgs. Colpitts, M.C.; Fahmy, S.H.; MacDougall, J.E.; Ng, T.; McInnis, B.G.; and V.F. Zelanzy Forest soils of New Brunswick. Department of Natural Resources Canada, Canadian Forest Service, Agriculture and Agri-Food Canada, Research Branch. 59 pgs. Fahmy, S.H.; Hann, S.W.R.; and Y. Jiao Soils of New Brunswick: The second approximation. Agriculture and Agri-Food Canada, Western Canada Soil and Water Conservation Center. 87pgs. Hogger, W.D Rainfall Frequency Atlas for Canada. Minister of Supply and Services Canada. Pelletier, P.M The water survey of Canada: Hydrometric technician career development program lesson package 16. Environment Canada, Water Resources Branch. Winnipeg, Manitoba Renard, K.G.; Foster; G.R.; Weesies, G.A.; McCool, D.K.; and D.C. Yoder Predicting soil erosion by water: a guide to conservation planning with the revised universal soil loss equation (RUSLE). U.S. Department of Agriculture Handbook No p 404 Raymond, J Circle segment equations formulas calculator - math geometry. Retrieved from: Raymond, J Hydraulic radius design equations formulas calculator - open channel flow- fluid mechanics- hydraulics. Retrieved from: Rothwell, R.L Watershed management guidelines for logging and road construction in Alberta: Information report NOR -X-208. Environment Canada, Forestry Service, Edmonton, Alberta, Canada. 52pgs. Wall, G.J.; Coote, D.R.; Pringle, E.A.; and I.J, Shelon (editors) RUSLEFAC- revised universal soil loss equation for application in Canada: A handbook for estimating soil loss from water erosion in Canada. Agriculture and Agri-Food Canada, Research Branch. Ottawa, Ontario, Canada. 117pgs. 22

23 QUESTIONS? 23