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I I I I I I I I I I I I I I I I I I I BEND NO.* 1 2 3 4 5 6 7 8 9 10 11 12 13 NOTES: DOlOIO PLANFORM OF BENDS RADIUS OF CURVATURE (FT) 440 540 400 440 640 370 290 580 800 1,130 2,530 330 1,630 DEF LECTI ON ANGLE (DEG.) 135 95 80 125 50 90 100 110 60 50 35 135 60 MATERIAL ON CONCAVE BANK Terrace Floodplain Terrace Terrace, Floodplain Terrace, Floodplain Terrace Terrace Floodplain Terrace Floodplain Floodplain Hi gh Terrace 8ridge, Terrace 1. Bend numbers are shown in Figure-3 2. Deflection angles have been rounded to the nearest 5 degrees. Bends with small radii of curvature and large deflection angles have chutes. 8ends with large radii of curvature and small deflection angles have very small or no point bars. Bends eroding into recent floodplain material, mainly sand, migrate rapidly downstream. The two most upstream bends are this type. Bends with concave (outside) banks in older floodplain alluvium erode more slowly. Terrace materials erode more slowly than floodplain materials. Bankline movements are illustrated in Figure-3 and are described in the next section. 8. River Alignment The planform of the active bed in 1937 and 1983 are compared in Figure-3. These were obtained from aerial photographs taken in July, 1937 and October, 1983. The prints are with scale of 1 inch = 400 feet, approximately. The main features are: 1. 8ends No.1, 2, and 3 have migrated downstream distances of approxi- mately 1100, 500, and 1200 feet, respectively. The river can move rapidly here because it is cutting into low banks of sand. -18-