time_series_flood: Return a time series of flood metrics by county codes or...
In countyfloods: Quantify United States County-Level Flood Measurements

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 on timing and magnitude of flooding will be returned at the gage level or the county level.

1
2
3

time_series_flood(county_cd = NULL, state = NULL, start_date, end_date,
  threshold = "Q2", flood_type = "flood", weight = "Q2",
  Q2_magnitude = "Moderate", filter_data = TRUE)

`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")
`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".
`Q2_magnitude`	Character string of ratio of daily streamflow to Q2 used as a binary flood threshold. One of "Minor" (1 < Flow / Q2 < 1.5), "Moderate" (< 2), "Major" (< 5), and "Extreme" (> 5). Defaults to "Moderate".
`filter_data`	Logical. If TRUE only dates with a flood occurring are returned for both gage and county-level data. If FALSE, all dates are returned.

A list with two data frames, summarizing the results by gage and by county:

Gage:

Name	Type	Description
site_no	character	USGS gage ID
date	date	Date of observation
lat	numeric	Gage latitude
long	numeric	Gage longitude
county_cd	character	FIPS code of gage county location
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`
discharge	numeric	Observed mean daily discharge (cubic feet per second)
flood_val	numeric	Selected threshold flood value. Either Q2 or an NWS flood threshold.
flood_ratio	numeric	Ratio of the observed discharge divided by the defined flood threshold
state	character	State name
county	character	County name
flood	character	Flood magnitude category based on peak

County:

Name	Type	Description
date	date	Date of observation
county	character	County name
state	character	State name
num_gage	numeric	Number of analyzed gages in county
max_peak	numeric	Maximum observed flood ratio
avg_peak	numeric	Average flood ratio among county gages
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)
flood_metric	numeric	Fraction of gages in county experiencing a flood, weighted by river size (`size` from gage-level output)

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.

## Not run: 
#Use Q2 as flood threshold
va_time_series <- time_series_flood(state = "Virginia", start_date = "2015-01-01",
                      end_date = "2015-12-31", threshold = "Q2")

#Use NWS flood thresholds
va_time_series <- time_series_flood(state = "Virginia", start_date = "2015-01-01",
                      end_date = "2015-12-31", threshold = "NWS",
                      flood_type = "action")

## End(Not run)