Drought Conditions in the US

Jo Hardin

6/14/2022

Data

The data this week comes from the National Integrated Drought Information System.

This web page provides more information about the drought conditions data.

drought_county <- read_csv("drought-fips.csv")
drought_state <- read_csv("drought.csv")

ggridges by state

h/t to @adambushman for the ggridges idea and @nrennie for the formatting of the facet_geo.

drought_county_state <- drought_county %>% group_by(State) %>% 
  summarize(State = first(State))

drought_county %>%
  #dplyr::filter(State == "CA") %>%
  mutate(year = year(ymd(date))) %>%
  ggplot(aes(x = DSCI, y = year, group = year, fill = stat(x))) + 
  ggridges::geom_density_ridges_gradient(rel_min_height = 0.01, color = "#ffffff") + 
  facet_geo(~State, grid = "us_state_contiguous_grid1") +
  scale_fill_gradient(high = '#d0162e', low = '#fcc425') +
  labs(title = 'Drought Severity by Year',
       subtitle = 'Since Year 2000', 
       y = '', 
       x = 'DSCI Score [Drought Severity]', 
       fill = 'DSCI',
       caption = "Tidy Tuesday Plot: @hardin47 | Data: National Integrated Drought Information System") +
  theme_minimal() +
  coord_cartesian(expand = FALSE) +
  theme(
    plot.background = element_rect(fill = '#ffffff'), 
    text = element_text(color = '#808080'),
    axis.text = element_text(color = '#808080'), 
    panel.grid.major = element_line(color = '#efefef'), 
    panel.grid.minor = element_line(color = '#efefef'), 
    plot.title = element_text(size = 18, hjust = 0.5, face = 'bold'), 
    plot.subtitle = element_text(size = 12, hjust = 0.5),
    legend.position = "bottom",
    legend.title = element_blank(),
    panel.grid = element_blank(),
    axis.text.x = element_blank(),
    axis.text.y = element_text(size = 6),
    axis.ticks = element_blank(),
    strip.background = element_blank(),
    strip.text = element_text(hjust = 0, size = 10)
  )

A separate ridge plot is given for each state where the x-axis is the drought severity score and the y-axis is the year. We can see that in the west, there has been much more severe drought than in other parts of the country, although there is no clear pattern over the time period from 2000 to 2020.