idaho’s experience with random design using nhd
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Idaho’s Experience with Random Design using NHD. Mary Anne Nelson, Michael McIntyre, Michael Edmondson, Glen Pettit Idaho Department of Environmental Quality. Intermittent streams and other considerations. Sampling Design. Sample Population All perennial, wadeable streams 1:100,000 scale - PowerPoint PPT PresentationTRANSCRIPT
Idaho’s Experience with Random Design using NHD
Intermittent streams and other considerations
Mary Anne Nelson, Michael McIntyre, Michael Edmondson, Glen Pettit
Idaho Department of Environmental Quality
Sampling Design• Sample Population
– All perennial, wadeable streams– 1:100,000 scale
• Sampling Frame– NHD supplied to ORD (Corvallis, OR)– Strahler order (1-5)– DEQ Region
• Survey Design– Generalized random tessellation stratified
survey design for a linear network
• Multi-Density Categories– DEQ Regions (6)– Strahler Order
• 1&2 (50%)• 3 (30%)• 4&5 (20%)
• Panels: 5 panels of 50 sites statewide, 1 panel monitored each year
• 500% Oversample
Sampling Design
Site Selection • Wadeable vs. Non-Wadeable
– 4th order or less– Less than 15 m average wetted width– Less than 0.4 m average depth at base flow
• Inaccessible– Minimum 2 hour hike to access– Safety issues
• Dry• Wetland/No Flow• Denied Access• Impoundments
– Beaver dams• Map Error
Where rubber meets the road
Accessibility
Flow
Random Monitored
Target Monitored
Target Rejected
Repeat
Reference
Random Rejected
Monitoring Effort in 200456 Random Sites (8.5%)220 Rejected Random Sites (33.38%)238 Target Sites (36.12%)104 Rejected Target Sites (15.78%)6 Random Repeat (0.91%)35 Reference Trend (5.31%)
Total Sites 65942.79% Effort in
Random Sites57.21 % Effort in
Targeted Sites
50 Primary Sites250 Secondary Sites56 Monitored Random Sites
2004 Site Selection Results
Of the 50 Primary Sites11 Monitored32 Rejected7 unknown
2004 Rejected Random Sites
116 Not Visited 104 Visited
54 INACCESSIBLE 69 DRY29 ACCESS DENIED 10 NON WADEABLE15 NON WADEABLE 7 NO FLOW
8 DRY 4 ACCESS DENIED4 NO FLOW 4 WETLAND3 T & E SPECIES 3 ALTERED1 ALTERED 3 INACCESSIBLE1 MAP ERROR 3 MAP ERROR
1TEMP
INACCESSIBLE 1 NORMAL
220 Rejected Sites in 2004
Random Monitored
Random Rejected
Target Monitored
Target Rejected
Repeat
Reference
Monitoring Effort in 200549 Random Sites (12.16%)187 Rejected Random Sites (46.40%)109 Target Sites (27.05%)22 Rejected Target Sites (5.46%)6 Random Repeat (1.49%)30 Reference Trend (7.44%)
Total Sites 40360.05 % Effort in
Random Sites39.95 % Effort in
Targeted Sites
89 Not Visited 98 Visited30 INACCESSIBLE 58 DRY26 DRY 9 DENIED ACCESS11 ACCESS DENIED 9 HIGH FLOW10 LIMITED ACCESS 8 NO FLOW/WETLAND9 NON-WADEABLE 7 INACCESSIBLE2 NO FLOW 3 UNKNOWN1 NO DATA 2 BEAVER COMPLEX
1 LIMITED ACCESS1 NO RIFFLES
2005 Rejected Random Sites
187 Rejected Sites in 2005
Dry Sites in Idaho
Monitored Sites in Idaho
Precipitation
2004 Monitored
Sites
2005 Monitored
Sites7-10” 3 010-20” 10 9
20-30” 19 17
30-40” 14 19
40-50” 7 3
50-60” 2 1
77 Sites Rejected in 2004 as Dry84 Sites Rejected in 2005 as Dry
Public Lands
Sites on Private Land
Monitored
Access Denie
d2004 18 332005 15 20
Sites on Public Land2004 382005 34
Land Type AcresFederal 33,764,66
4Private 16,387,87
3State 2,615,417
Breakdown of Land Ownership
Private Public
Land % 30.99% 68.79%
2004 Sites Monitored 32.14% 67.86%
2005 Sites Monitored 30.61% 69.39%
Landuse Patterns
2004 2005Dryland Ag 4 0
Forest 35 31Irrigated-Gravity 3 2
Irrigated-sprinkler
3 1
Rangeland 13 13
Urban 0 2
GIS Site Analysis• GIS coverages
– Precipitation– Land Use
• Satellite imagery – NAIP imagery– Vegetative Cover
• Catchment area– ArcGIS Spatial Analyst– USGS StreamStats
Conclusions• To achieve the required 50 sites/year,
roughly 200 sites were rejected– 31 % of sites are dry– 23 % of sites are inaccessible
• Need to improve NHD coverage to address intermittent and ephemeral waters
• Working on low-flow model with USGS• Assessment of these sites to be carried out
in May 06 for inclusion in the 06 integrated report