Line 1 L1 L2 Line 2 L = (L1 + L2) / 2 The differences in volume quantities between HYPACK and other programs is sometimes caused by differences in the computed distance between lines.ġ0 Different Distances for Left, Middle and Right SegmentsĬS&V computes a separate distance for: LL = Left side slope LC = Center channel or… LCL = Left of Center Channel LCR = Right of Center Channel LR = Right side slope CS&V also determines the area of material in each segment: VL = LL * (A1L + A2L) / 2 Vc = Lc * (A1C + A2C) / 2 VR = LR * (A1R + A2R) / 2 It repeats this calculation for: Material Above Design Template Material in Overdepth Area Material in Supergrade Area Line 1 LL LLC LC LR LRC Line 2 Methods that divide the center channel into left and right sections can result in volume differences from methods that treat it as a single area.

AEA1 can give a different result than Philadelphia PreDredge, even though they are both Average End Area methods!ĬS&V does not create data or extrapolate trends. In the figure above: V = L * (A1 + A2) / 2. The resulting volume would be less than the actual amount. V23 = 100*(A2+A3)/2 V34 = 100*(A3+A4)/2 Since A3 is less than it should be, the volume quantity will also be less. It might be more accurate to leave Line 3 out of the computation. V24 = 200*(A2+A4)/2 Better overall result if the sectional profiles are similar.įor Interior Data Gaps: CS&V interpolates the soundings across the internal gap to compute volume quantities. CS&V colors the area, to indicate it has been included in volume computations. CS&V does not draw a solid line (black in example) across the profile, indicating the gap in the data is larger than the user- defined gap distance. No solid profile line means you have a data gap!ġ4 Testing for Gaps Click ‘Graph Options – Data’.ġ 1 Click ‘Graph Options – Data’. 2 2 4 4ġ5 Differing Coverage Before Dredge versus After Dredge Data Only Where Both Surveys Have Data: Computes areas only where ‘before’ and ‘after’ section overlap. HYPACK BEACH VOLUME CROSS SECTIONS FULLįull Length of Before Survey (not recommended): Computes areas based on limits of before survey. Differences between the volume results in HYPACK and other packages can result based on how the other package handles the problem of unequal coverage.ĬS&V does not care if your lines intersect. CS&V does not care if there are turns in the channel between lines. HYPACK BEACH VOLUME CROSS SECTIONS FULLĬreating lines perpendicular to the channel centerline can exaggerate these errors.

Cross sections in hypack