321 Take-home Midterm 1995 name______________
1. Use the following maps to answer this question. Assume that the "Zero M River" is located on an Earth-like planet, with an Earth-like climate in a landscape that looks remarkably like the Central Appalachians. (In other words, assume it responds like an Appalachian stream... we will change conditions in future questions!)
On a separate page, give a concise explanation of the effects of a 1000 year flood (whatever that means) on this landscape Limit your answer to 500 words. Assume flood water depths reach 8 m in reach A, and 12 m in reach B. These values are twice the depths reached during bank-full discharge. You should draw deposits or other features on this page to assist you with your discussion.
STREAM REACH A
valley wall
10 m terrace
3 m bar
8 m terrace
6 m surface 6 m surface
3 m bar
4 m surface
10 m terrace
valley wall
STREAM REACH B
valley wall
bouldery (BIG)
debris fan
2-5 m
valley wall
3-5 m
gravel alluvial
fan valley wall
2. Describe how vegetation can be used to infer flood frequency over different surfaces in Appalachian river bottoms. (limit your answer to 350 words maximum.)
3. Explain the arguments that support the concept that moderate-magnitude events are the most effective at controlling hydraulic geometry of streams. Give one exception to this concept, and explain why this exception occurs. (limit your answer to 350 words maximum.)
4A. Compare and contrast the types of hydro-meteorological events that create floods in the following regions: Sonora Desert (e.g. Southern Arizona), Pacific Northwest Coast, Northern New England, and the Southern Appalachians. (limit your answer to 250 words maximum.)
4B. How might the flood climatology of the Appalachian Plateau in West Virginia differ from that of the Blue Ridge Mountains of Virginia? (limit your answer to 150 words maximum.)
5. Summarize the Quaternary history of the Monongahela River basin. (limit your answer to 500 words maximum)
6. Calculate the recurrence interval and probability of a 400,000 cfs flood based on the Ohio River data set on the following page. These data may be obtained as an Excel or Lotus 123 file, just ask!
Answer all questions on your own paper. Take the word limits seriously; points will be docked for exceeding these word limits. As always, consider this test to be a writing exercise and expect it to be graded accordingly.
OHIO RIVER AT SEWICKLEY, PA. (Gage # 03086000)
N40:32:57 W080:12:21 19500 mi sq.
water year date cfs stage (ft)
1934 03/06 202000 12.51
1935 03/13 225000 15.70
1936 03/18 574000 34.75
1937 04/27 334000 23.93
1938 12/19 242000 17.07
1939 02/04 222000 15.50
1940 04/21 262000 18.73
1941 06/05 234000 16.68
1942 03/10 194000 13.54
1943 12/31 400000 27.39
1944 03/18 159000 10.95
1945 03/07 331000 23.61
1946 06/03 195000 13.57
1947 04/07 155000 10.68
1948 04/15 277000 19.89
1949 12/17 189000 13.11
1950 03/29 172000 11.86
1951 12/05 259000 18.58
1952 01/28 282000 20.27
1953 06/01 137000 9.80
1954 03/04 137000 9.75
1955 10/16 318000 22.76
1956 03/09 230000 16.34
1957 02/11 168000 12.86
1958 05/09 152000 10.54
1959 01/23 274000 19.67
1960 04/01 246000 17.62
1961 02/27 180000 12.48
1962 03/23 137000 9.84
1963 03/21 232000 16.48
1964 03/11 295000 21.19
1965 01/25 116000 8.95
1966 02/14 249000 17.84
1967 03/07 206000 14.44
1968 05/25 169000 11.66
1969 01/31 133000 9.63
1970 04/03 211000 14.80
1971 02/24 138000 9.85
1972 06/24 370000 24.42
1973 12/10 171000 11.61
1974 01/12 167000 11.36
1975 02/25 171000 11.65
1976 02/18 186000 12.66
1977 04/03 140000 9.95
1978 01/27 174000 11.79
1979 03/06 216000 14.78
1980 04/10 138000
1981 02/21 203000
1982 03/18 137000 9.45
1983 05/05 122000 8.73
1984 02/15 181000 11.83
1985 02/25 163000 10.85
1986 11/06 239000 14.56
1987 04/08 123000 8.77
1988 02/03 130000 8.90
1989 05/11 161000