Description Usage Arguments Value Examples
Access USGS databases to retrieve gages and flow data for the specified counties/states or county FIPS codes and the specified date ranges. Flooding at these gage locations are assessed by one of two metrics. Data can be returned at the gage level or the county level.
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county_cd |
Character vector with the county FIPS code(s) |
state |
Character vector of state names. Used to obtain county FIPS codes if county_cd is NULL |
start_date |
Character string with the starting date, using "YYYY-MM-DD" notation. |
end_date |
Character string with the end date, using "YYYY-MM-DD" notation. |
threshold |
Character string of the flood threshold to be used in the analysis (either "Q2" or "NWS"). Defaults to "Q2". |
flood_type |
Character string of the defined flood type based on NWS classifications (one of "action", "flood", "moderate", or "major") |
output |
Character string of output summary type (either "gage", "county", or "both"). Defaults to "both". |
weight |
Character string of variable to be used to scale by river size for weighted averages and scaling point sizes on maps. Options are median annual flood ("Q2") or drainage area ("DA"). Defaults to "Q2". |
A data frame with output at either the gage or county level, depending on the value of "output". If output = "gage" a data frame with the following columns is returned:
Name | Type | Description |
site_no | character | USGS gage ID |
county_cd | character | FIPS code of gage county location |
lat | numeric | Gage latitude |
long | numeric | Gage longitude |
avg_peak | numeric | Mean flood ratio for date range (discharge/flood threshold) |
flood_dur | numeric | Number of days in date range discharge above flood threshold |
max_peak | numeric | Maximum value of flood ratio for date range (discharge/flood threshold) |
num_missing | numeric | Number of days in given date range with no discharge data at that gage |
Q2 | numeric | Median annual discharge (cubic feet per second) |
DA | numeric | Drainage area of the gage (square miles) |
size | numeric | Relative river size, logarithm of either Q2 or DA
depending on user specified weight |
state | character | State name |
county | character | County name |
flood | character | Flood magnitude category based on peak |
If output = "county" a data frame with the following columns is returned:
Name | Type | Description |
county | character | County name |
state | character | State name |
num_gage | numeric | Number of analyzed gages in county |
avg_peak | numeric | Average flood ratio among county gages |
max_peak | numeric | Maximum observed flood ratio |
minor | numeric | Percentage of gages at or above "minor" flood class (flood ratio > 1) |
moderate | numeric | Percentage of gages at or above "moderate" flood class (flood ratio > 1.5) |
major | numeric | Percentage of gages at or above "major" flood class (flood ratio > 2) |
extreme | numeric | Percentage of gages at or above "extreme" flood class (flood ratio > 5) |
max_dur | numeric | Maximum flood duration in county |
avg_dur | numeric | Average flood duration in county |
If threshold = "NWS", the columns "minor", "moderate", "major", and "extreme" are replaced with two columns: "no_flood" and "yes_flood" which show the percentage of gages in the county with or without flooding.
If output = "both" a list containing both data frames is returned. In both cases, if data in counties were requested but not avaialable, these counties are included as additional rows with data values of NA.
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#Use Q2 as flood threshold and get get gage-level output
va_floods <- run_flood(state = "Virginia", start_date = "2015-01-01",
end_date = "2015-12-31", threshold = "Q2",
output = "gage")
#Use NWS flood thresholds and get county-level output
va_floods <- run_flood(state = "Virginia", start_date = "2015-01-01",
end_date = "2015-12-31", threshold = "NWS",
flood_type = "action",
output = "county")
## End(Not run)
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