Debris-flow and flooding hazards associated with the December 1999 storm in
coastal Venezuela and strategies for mitigation
Open File Report 01-0144
Table 2. Characterization of flood and debris-flow deposition in examined watersheds.
Size of drainages is from MARN (2000). Velocity estimates are calculated from
evidence of superelevation. Flow depth (*) reported where evidence of deposit
had been removed.
|
Drainage Camuri
Chiquito San
Julian Cerro
Grande Camuri
Grande Q.
Alcantarilla Q.
Seca El
Cojo San Jose de Galipan Osorio |
Size (km2) 10.2 21.3 25.4 45.3 1.5 3.0 6.5 15.0 4.7 |
Sequence
and Type of Deposition (top to bottom) Coarse
DF/Fine DF/Flood incision Coarse
DF/Flood/Fine DF/Flood incision Flood/Flood
incision Coarse
DF/Hypcon. Flow/Flood incision Coarse
DF/Sandy Flood/Flood incision Coarse
DF/Flood incision Debris
Flow/Flood incision Debris
Flow/Flood incision Debris
flow/Flood incision |
Deposit
Thickness (m) 3.0-4.0 4.0 2.0 3.0-6.0 3.2-4.5 2.5-4.0 2.0-3.6 1.0-4.0 3.0-6.0* |
Max. Boulder (A-axis) (m) 5.1-12.0 1.0-5.6 0.2-0.4 2.7-4.1 1.7-2.7 1.8-7.5 2.5-9.5 3.2-5.3 3.2-7.1 |
Velocity (m/s) 5.8 N/A 4.2-7.0 N/A 3.5-13.6 3.3 3.2-5.2 4.4 4.1-5.8 |
Fabric
Matrix supported-grain to grain support Grain
to grain support Graded Grain
to grain support Matrix
supported Grain
to grain support, partially imbricated Matrix
supported Grain
to grain support N/A |