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Evacuation_NewHampshirePDF.Rmd
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Evacuation_NewHampshirePDF.Rmd
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---
title: "Evacuation Risks in New Hampshire"
author: "Marcos Luna and Neenah Estrella-Luna"
date: "`r Sys.Date()`"
output:
bookdown::pdf_document2:
toc: true
toc_depth: 3
number_sections: true
fig_caption: yes
includes:
in_header: my_header.tex
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo=FALSE, message=FALSE, warning=FALSE)
library(tidyverse)
library(sf)
library(tmap)
library(tmaptools)
library(lwgeom)
library(tigris)
options(tigris_use_cache = TRUE, tigris_class = "sf")
```
\pagebreak
# Analysis of evacuation-related risks in New Hampshire
This is an analysis of flood or storm surge-related evacuation risks for priority populations in New Hampshire In the event of significant inland or coastal flooding, evacuation may be required. For individuals and households with limited mobility, either due to inadequate access to transportation options or because of physical limitations, evacuation presents heightened risk. Evacuation may also prove especially difficult for individuals and households due to limited economic resources, difficulty understanding or accessing information, or low trust in official sources of information.
## Analysis of Flood Hazard Exposure in New Hampshire
```{r NFHZAdata, include=FALSE, cache=TRUE}
# Analysis of flooding and hurricane evacuation risks for priority populations in New Hampshire
load("DATA/ne_layers.rds")
# Extract state census units and convert to projected local CRS EPSG:2823: NAD83(HARN) / New Hampshire See https://spatialreference.org/ref/epsg/2823/
nh_blkgrp_2823 <- ne_blkgrp_sf %>%
filter(STATE == "New Hampshire") %>%
st_transform(., crs = 2823)
nh_tracts_2823 <- ne_tracts_sf %>%
filter(STATE == "New Hampshire") %>%
st_transform(., crs = 2823)
# Get rid of empty geometries
empty_geo <- st_is_empty(nh_blkgrp_2823)
nh_blkgrp_2823 <- nh_blkgrp_2823[!empty_geo,]
empty_geo <- st_is_empty(nh_tracts_2823)
nh_tracts_2823 <- nh_tracts_2823[!empty_geo,]
# Extract state boundary
nh_state_sf <- ne_states_sf_cb %>%
filter(NAME == "New Hampshire") %>%
st_transform(., crs = 2823)
# Extract state countiies
nh_counties_sf <- counties(state = "NH", cb = TRUE) %>%
st_transform(., crs = 2823)
# #### Processing in ArcGIS #####
# # Write out block groups for processing in ArcGIS
# nh_blkgrp_2823 %>%
# dplyr::select(GEOID) %>%
# st_write(., "DATA/FEMA/NH/nh_blkgrp_2823.shp", delete_layer = TRUE)
# #
# # repeat for tracts
# nh_tracts_2823 %>%
# dplyr::select(GEOID) %>%
# st_write(., "DATA/FEMA/NH/nh_tracts_2823.shp", delete_layer = TRUE)
#
# # repeat for state boundary
# nh_state_sf %>%
# st_write(., "DATA/FEMA/NH/nh_state_2823.shp", delete_layer = TRUE)
#
# # repeat for state counties
# nh_counties_sf %>%
# st_write(., "DATA/FEMA/NH/nh_counties_2823.shp", delete_layer = TRUE)
# Use dasymetric mapping to calculate populations within flood zones. Approach follows method used by Qiang (2019) to eliminate unpopulated areas of census polygons and then reallocate populations to developed areas as identified in National Land Cover Dataset (NLCD).
# Perform NLCD raster-to-vector conversion, vector erase/difference, and vector intersections in ArcMap because it takes too long in R.
# In ArcMap:
# Convert NLCD raster to shapefile. Clip to state.
# Isolate undeveloped areas (gridcode NOT 22 - 24).
# Erase areas of nh_blkgrp_2823 and nh_tracts_2823 that overlap with undeveloped areas in NLCD shapefiles. Compute OldArea of erased polygons in sqm to identify area of developed polygons remaining.
# Intersect erased nh_blkgrps and erased nh_tracts with NFHZA and Hurricane evacuation zones. Read back into R.
##### Return to working in R ######
# # read in processed nh_blkgrps and nh_tracts
# st_layers(dsn = "DATA/FEMA/NH")
nh_blkgrps_developed <- st_read(dsn = "DATA/FEMA/NH",
layer = "nh_blkgrps_developed") %>%
left_join(., as.data.frame(nh_blkgrp_2823), by = "GEOID") %>%
st_transform(., crs = 2823) %>%
mutate(NewArea = st_area(.)) %>%
st_make_valid() %>%
mutate(Proportion = as.numeric(NewArea/OldArea),
NewPop = totalpopE*Proportion,
NewMinority = minorityE*Proportion,
NewUnder5 = under5E*Proportion,
NewOver64 = over64E*Proportion,
NewUnder18 = under18E*Proportion,
NewEng_limit = eng_limitE*Proportion,
NewPov = num2povE*Proportion,
NewLths = lthsE*Proportion)
nh_blkgrps_nfhza <- st_read(dsn = "DATA/FEMA/NH",
layer = "nh_blkgrps_nfhza") %>%
left_join(., as.data.frame(nh_blkgrp_2823), by = "GEOID") %>%
st_transform(., crs = 2823) %>%
mutate(NewArea = st_area(.)) %>%
st_make_valid()
nh_tracts_nfhza <- st_read(dsn = "DATA/FEMA/NH",
layer = "nh_tracts_nfhza") %>%
left_join(., as.data.frame(nh_tracts_2823), by = "GEOID") %>%
st_transform(., crs = 2823) %>%
mutate(NewArea = st_area(.)) %>%
st_make_valid()
# Apportion populations based on geographic proportion of intersect
nh_blkgrps_nfhza <- nh_blkgrps_nfhza %>%
mutate(Proportion = as.numeric(NewArea/OldArea),
NewPop = totalpopE*Proportion,
NewMinority = minorityE*Proportion,
NewUnder5 = under5E*Proportion,
NewOver64 = over64E*Proportion,
NewUnder18 = under18E*Proportion,
NewEng_limit = eng_limitE*Proportion,
NewPov = num2povE*Proportion,
NewLths = lthsE*Proportion)
nh_tracts_nfhza <- nh_tracts_nfhza %>%
mutate(Proportion = as.numeric(NewArea/OldArea),
NewDisabled = disabledOver18E*Proportion,
NewNoCar = HHnoCarE*Proportion)
# Compute total block group populations within flood zones
nh_flood_blkgrp_df <- nh_blkgrps_nfhza %>%
as.data.frame() %>%
summarize(`Total Pop` = as.integer(sum(NewPop)),
Minority = as.integer(sum(NewMinority)),
`Under 5` = as.integer(sum(NewUnder5)),
`Over 64` = as.integer(sum(NewOver64)),
`Under 18` = as.integer(sum(NewUnder18)),
`Limited English HH` = as.integer(sum(NewEng_limit)),
`Low Income` = as.integer(sum(NewPov)),
`No HS Dip` = as.integer(sum(NewLths))) %>%
gather(key = Group, value = FloodPop)
nh_flood_tracts_df <- nh_tracts_nfhza %>%
as.data.frame() %>%
summarize(`Disabled` = as.integer(sum(NewDisabled)),
`No Car HH` = as.integer(sum(NewNoCar))) %>%
gather(key = Group, value = FloodPop)
# Compute total tract populations within the state for same groups
nh_tract_flood_pops_df <- nh_tracts_2823 %>%
as.data.frame() %>%
summarize(`Disabled` = sum(disabledOver18E),
`No Car HH` = sum(HHnoCarE)) %>%
gather(key = Group, value = NHPop) %>%
left_join(.,nh_flood_tracts_df, by = "Group")
# Compute populations for state,and join with flood pops
nh_FloodPops_df <- nh_blkgrp_2823 %>%
as.data.frame() %>%
summarize(`Total Pop` = sum(totalpopE),
Minority = sum(minorityE),
`Under 5` = sum(under5E),
`Over 64` = sum(over64E),
`Under 18` = sum(under18E),
`Limited English HH` = sum(eng_limitE),
`Low Income` = sum(num2povE),
`No HS Dip` = sum(lthsE)) %>%
gather(key = Group, value = NHPop) %>%
left_join(., nh_flood_blkgrp_df, by = "Group") %>%
rbind(.,nh_tract_flood_pops_df) %>%
mutate(PctFlood = FloodPop/NHPop*100)
nh_towns_sf <- county_subdivisions(state = "NH", cb = TRUE) %>%
st_transform(., crs = 2823)
town_tracts_df <- nh_tracts_2823 %>%
dplyr::select(-GEOID) %>%
st_centroid(.) %>%
st_intersection(nh_towns_sf,.) %>%
as.data.frame() %>%
group_by(NAME) %>%
summarize(TotalDisabled = sum(disabledOver18E, na.rm = TRUE),
TotalOver18 = sum(Over18E, na.rm = TRUE),
TotalNoCar = sum(HHnoCarE, na.rm = TRUE))
townpopsdf <- nh_blkgrp_2823 %>%
dplyr::select(-GEOID) %>%
st_centroid(.) %>%
st_intersection(nh_towns_sf,.) %>%
as.data.frame() %>%
group_by(NAME) %>%
summarize(GEOID = unique(GEOID),
TotalPop = sum(totalpopE, na.rm = TRUE),
TotalHH = sum(householdsE, na.rm = TRUE),
TotalLEH = sum(eng_limitE, na.rm = TRUE),
TotalMin = sum(minorityE, na.rm = TRUE),
TotalLowInc = sum(num2povE, na.rm = TRUE),
TotalNoHS = sum(lthsE, na.rm = TRUE),
TotalOver64 = sum(over64E, na.rm = TRUE),
TotalUnder5 = sum(under5E, na.rm = TRUE),
TotalUnder18 = sum(under18E, na.rm = TRUE)) %>%
left_join(., town_tracts_df, by = "NAME")
nh_state_sf_cb <- ne_states_sf_cb %>%
filter(NAME == "New Hampshire") %>%
st_transform(., crs = st_crs(nh_blkgrp_2823))
# save data for later analysis
save(nh_blkgrps_nfhza,nh_tracts_nfhza,
nh_FloodPops_df,
file = "DATA/FEMA/NH/nfhza_census.Rds")
```
As a humid, coastal state, a significant portion of New Hampshire's land area and population are exposed to the risk of flooding from overbanking of inland water bodies (e.g., ponds and rivers) or from coastal storm surge and sea level rise.
The analysis of flood exposure presented here is based on the Federal Emergency Management Agency's (FEMA) National Flood Hazard Layer (NFHL), a digital version of FEMA's most recent flood maps.[^NFHL] FEMA identifies areas subject to varying levels of flood risk through its Flood Insurance Rate Maps (FIRMs), which are produced for most parts of the country to identify areas subject to flooding. FEMA's FIRMs are a national standard used by all federal agencies for the purposes of requiring and rating the purchase of flood insurance and regulating new development. Population data comes from the American Community Survey (ACS) 2018 5-year estimates at the census tract and block group levels.
A significant proportion of New Hampshire's population lives near the coast or near inland water bodies. As a result, a significant proportion of the population lives near or within known flood zones. Figure \@ref(fig:mapNFHZAPop) below shows the population distribution and areas subject to floods with an Annual Exceedance Probability (AEP) of 1% (also known as a '100-year' flood) and areas subject to 0.2% AEP (also known as a '500-year' flood). Areas within the 1% AEP flood zone are designated by FEMA as Special Flood Hazard Areas, and development within those zones must be covered by flood insurance. Areas within the 0.2% AEP are not currently regulated, but these areas are nevertheless subject to flood risk under more extreme, albeit less frequent, flooding circumstances. Coastal areas within the 0.2% AEP zone are a reasonable proxy measure for the risks of sea level rise. Note that portions of northwest and northeast New Hampshire are not currently mapped for flooding risk by FEMA.
```{r mapNFHZAdata, include=FALSE, cache=TRUE}
# Process data for mapping
# Create point layer of major cities for context
# Note cb=FALSE is necessary for extracting centroids from town polygons. Otherwise, if cb=TRUE, cannot extract centroids from multipolygon features.
# Read in NFHL for NH. Data comes from FEMA.
# List available layers in geodatabase
# st_layers("DATA/FEMA/NH/NFHL_33_20190723.gdb")
# # Read in flood hazard areas
# nh_nfhza_2823 <- st_read(dsn = "DATA/FEMA/NH/NFHL_33_20190723.gdb", layer = "S_Fld_Haz_Ar", quiet = TRUE) %>%
# filter(!FLD_ZONE %in% c("OPEN WATER","AREA NOT INCLUDED","D") &
# !ZONE_SUBTY %in% c("AREA OF MINIMAL FLOOD HAZARD",
# "AREA WITH REDUCED FLOOD RISK DUE TO LEVEE")) %>%
# mutate(FLD_ZONE = as.character(FLD_ZONE)) %>% # omit unused factor levels
# st_transform(., crs = 2823) %>%
# st_make_valid() %>%
# group_by(FLD_ZONE) %>% # aggregate flood zone polygons
# summarize(count = n()) %>%
# mutate(Area = st_area(.),
# Interval = case_when(
# FLD_ZONE == "A" ~ "100-year",
# FLD_ZONE == "AE" ~ "100-year",
# FLD_ZONE == "AH" ~ "100-year",
# FLD_ZONE == "AO" ~ "100-year",
# FLD_ZONE == "VE" ~ "100-year",
# FLD_ZONE == "X" ~ "500-year"))
#
# # get rid of empty geometries
# empty_geo <- st_is_empty(nh_nfhza_2823)
# nh_nfhza_2823 <- nh_nfhza_2823[!empty_geo,]
#
# # save this layer since it takes more than 30 mins to load
# saveRDS(nh_nfhza_2823,"DATA/FEMA/NH/nh_nfhza_2823.Rds")
# load previously process flood layer
nh_nfhza_2823 <- readRDS("DATA/FEMA/NH/nh_nfhza_2823.Rds")
# download Census TIGERLine hydrography for NH
# # First, extract list of county names to use with tigris::water
# nh_counties <- counties("NH") %>%
# pull(NAME)
# # Next, download water features for each county and rbind to one layer
# nh_awater_sf <- rbind_tigris(
# lapply(
# nh_counties, function(x) area_water(state = "NH", county = x)
# )
# ) %>%
# st_union() %>%
# st_as_sf() %>%
# st_transform(., crs = 2823)
#
# # save time by loading file
# saveRDS(nh_awater_sf, "DATA/FEMA/NH/nh_awater_sf.Rds")
# load water features
nh_awater_sf <- readRDS("DATA/FEMA/NH/nh_awater_sf.Rds")
# # crop flood zones to land areas only
# start_time <- Sys.time()
# nh_nfhza_2823_land <- nh_nfhza_2823 %>%
# crop_shape(., nh_state_sf, polygon = TRUE) %>%
# st_difference(., nh_awater_sf) %>%
# mutate(Area = st_area(.)) %>%
# st_make_valid() # takes about 12 mins
# end_time <- Sys.time()
# end_time - start_time
# # save time by just loading file
# saveRDS(nh_nfhza_2823_land, file = "DATA/FEMA/NH/nh_nfhza_2823_land.Rds")
# load cropped flood zones
nh_nfhza_2823_land <- readRDS("DATA/FEMA/NH/nh_nfhza_2823_land.Rds")
# Create a dot density map of total populations and overlay on flood zones
# Create point layer of major cities for context
# Note cb=FALSE is necessary for extracting centroids from town polygons. Otherwise, if cb=TRUE, cannot extract centroids from multipolygon features.
nh_towns_sf_pts <- county_subdivisions(state = "NH", cb = TRUE) %>%
filter(NAME %in% c("Nashua",
"Portsmouth",
"Manchester",
"Concord",
"Laconia",
"Lebanon",
"Conway",
"Woodstock",
"Franconia",
"Berlin",
"Lancaster",
"Pittsburg",
"Keene")) %>%
st_transform(., crs = 2823) %>%
st_centroid(of_largest_polygon = TRUE)
# Create road layer for context
nh_highways <- primary_roads() %>%
filter(FULLNAME %in% c("I- 89","I- 91","I- 93","I- 95")) %>%
tmaptools::crop_shape(., ne_states_sf_cb) %>%
st_transform(., crs = 2823)
# nh_highways2nd <- primary_secondary_roads("NH") %>%
# filter(FULLNAME %in% c("US Hwy 202","Presidential Hwy","US Hwy 2")) %>%
# st_transform(., crs = 2823)
# Extract highway segments for labeling
I89roadSegment <- nh_highways %>%
filter(LINEARID == "1105281262324")
I91roadSegment <- nh_highways %>%
filter(LINEARID == "110373954766")
I95roadSegment <- nh_highways %>%
filter(LINEARID == "1105569136123")
I93roadSegment <- nh_highways %>%
filter(LINEARID == "1105598909781")
# Create custom icons of highway shields
I89 <- tmap_icons(file = "https://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/I-89.svg/200px-I-89.svg.png")
I91 <- tmap_icons("https://upload.wikimedia.org/wikipedia/commons/thumb/9/90/I-91.svg/200px-I-91.svg.png")
I95 <- tmap_icons(file = "https://upload.wikimedia.org/wikipedia/commons/thumb/6/61/I-95.svg/200px-I-95.svg.png")
I93 <- tmap_icons("https://upload.wikimedia.org/wikipedia/commons/thumb/0/0d/I-93.svg/200px-I-93.svg.png")
# # Bring in outline of New York for western boundary
# ny_state_sf <- tigris::states(cb = TRUE) %>%
# filter(NAME == "New York")
# # Create polygons to show where there are no FEMA maps
# start_time <- Sys.time()
# nofemapolys <- st_read(dsn = "DATA/FEMA/NH/NFHL_33_20190723.gdb",
# layer = "S_Fld_Haz_Ar", quiet = TRUE) %>%
# filter(FLD_ZONE != "AREA NOT INCLUDED") %>%
# group_by() %>%
# summarize() %>% # aggregate all flood zone polygons into one
# st_transform(., crs = st_crs(nh_state_sf)) %>%
# st_make_valid() %>%
# st_difference(nh_state_sf,.) %>% # extract areas with no flood coverage
# st_cast(., "POLYGON") %>% # disaggregate multipolygon feature
# mutate(Area = st_area(.),
# LABEL = "No FEMA\nFlood Data") %>% # calc area of each polygon
# filter(as.numeric(Area)/10^6 > 1000) # remove polygons < 1000km2
# end_time <- Sys.time()
# end_time - start_time #takes about 2.4mins
#
# # save time by loading previously processed file
# saveRDS(nofemapolys,"DATA/FEMA/NH/nofemapolys.Rds")
# load data
nofemapolys <- readRDS("DATA/FEMA/NH/nofemapolys.Rds")
# # Create random points, with 1 point for every 500 people
# nh_totalpop_pts <- nh_blkgrps_developed %>%
# select(NewPop) %>%
# filter(NewPop >= 500) %>%
# st_sample(., size = round(.$NewPop/500)) %>% # create 1 random point for every 500 people
# st_sf(.) %>%
# group_by() %>%
# summarize() # reduce to one multipoint object
# Create a simplified version of NFHZA polygons to speed up mapping
# start_time <- Sys.time()
nh_nfhza_2823_land_simple <- nh_nfhza_2823_land %>%
select(Interval) %>%
st_cast(., "MULTIPOLYGON") %>% # homogenize type
st_cast(., "POLYGON") %>%
st_simplify(., dTolerance = 100) %>% # reduce vertices
st_make_valid() %>%
group_by(Interval) %>%
summarize() %>%
mutate(Area = st_area(.))
# end_time <- Sys.time()
# end_time - start_time
# Create a simplified version of nh_awater_sf to speed up mapping
nh_awater_sf_simple <- nh_awater_sf %>%
st_cast(., "MULTIPOLYGON") %>% # homogenize type
st_cast(., "POLYGON") %>%
st_simplify(., dTolerance = 100) %>% # reduce vertices
st_make_valid() %>%
group_by() %>%
summarize()
# read in Canadian province boundary files for background
canada <- st_read(dsn = "DATA/FEMA/NH", layer = "lpr_000b16a_e") %>%
filter(PRENAME == "Quebec") %>%
st_transform(., crs = 2823) %>%
st_simplify(., dTolerance = 100) %>%
st_make_valid()
```
```{r mapNFHZAPop, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="FEMA flood zones across New Hampshire."}
# Create a dot density map of total populations and overlay on flood zones
# Map totalpop and flood zones
m1 <- tm_layout(bg.color = "#e6f3f7") +
tm_shape(nh_blkgrp_2823, unit = "mi") + tm_fill(col = "white") +
tm_shape(ne_states_sf_cb) + tm_fill(col="white") +
tm_shape(canada) + tm_fill(col = "white") +
# tm_shape(ny_state_sf) + tm_fill(col="white") +
tm_shape(nh_awater_sf_simple) + tm_fill(col = "#e6f3f7") +
# tm_shape(ne_states_sf_cb) + tm_borders() +
# tm_shape(ny_state_sf) + tm_borders() +
# tm_shape(nh_totalpop_pts) + tm_dots(col = "darkgoldenrod3",
# labels = "1 dot = 500 people",
# alpha = 0.6) +
tm_shape(nh_nfhza_2823_land_simple) +
tm_fill(col = "Interval",
palette = c("dodgerblue", "blueviolet"),
labels = c("1% AEP (100-year)", "0.2% AEP (500-year)"),
title = "FEMA Flood Zones",
alpha = 0.6,
border.alpha = 0) +
tm_shape(ne_states_sf_cb) + tm_borders(lwd = 0.2, alpha = 0.8) +
# tm_shape(ny_state_sf) + tm_borders(lwd = 0.8) +
tm_shape(nh_highways) + tm_lines(col = "seashell4", lwd = 1.5) +
# tm_shape(nh_highways2nd) + tm_lines(col = "seashell4", lwd = 1.5) +
tm_shape(I89roadSegment) +
tm_symbols(shape = I89, border.lwd = NA, size = 0.15) +
tm_shape(I91roadSegment) +
tm_symbols(shape = I91, border.lwd = NA, size = 0.15) +
tm_shape(I93roadSegment) +
tm_symbols(shape = I93, border.lwd = NA, size = 0.15) +
tm_shape(I95roadSegment) +
tm_symbols(shape = I95, border.lwd = NA, size = 0.15) +
tm_shape(nh_towns_sf_pts) + tm_dots() +
tm_text("NAME", size = 0.5, col = "black",
xmod = 0.7, ymod = 0.2, shadow = TRUE) +
tm_shape(nofemapolys) + tm_fill(col = "gray", alpha = 0.4) +
tm_text("LABEL", alpha = 0.5, size = .7) +
tm_scale_bar(breaks = c(0, 10, 20), text.size = 0.5,
position = c("left","TOP")) +
# tm_add_legend(type = "fill", col = "darkgoldenrod3",
# alpha = 0.6,
# border.col = "white", border.alpha = 0,
# labels = "1 dot = 500 people",
# title = "Total Population") +
tm_layout(title = "FEMA\nFlood Zones",
frame = TRUE, main.title.size = 0.8,
legend.outside = TRUE,
legend.title.size = 0.8,
legend.outside.position = c("right", "top"))
tmap_save(m1, "DATA/FEMA/NH/nh_flood.png",
height = 8, width = 8, units = "in", dpi = 600)
knitr::include_graphics("DATA/FEMA/NH/nh_flood.png")
```
Approximately 5% of New Hampshire's land area falls within FEMA flood zones. The breakdown by type of flood zone is presented in Table \@ref(tab:tabNFHZAarea) below.
```{r tabNFHZAarea, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="New Hampshire Land Area within Flood Zones."}
# Total land in NH
nh_area <- as.numeric(nh_state_sf$ALAND)
# Total and percentage of land area of RI within flood zones
nh_nfhza_2823_land %>%
as.data.frame() %>%
group_by(Interval) %>%
summarize(SqKm = round(as.numeric(sum(Area)/10^6),1),
SqMi = round(as.numeric(SqKm/2.59),1),
PctArea = paste0(as.character(round(as.numeric(sum(Area)/nh_area*100),1)),"%")) %>%
kableExtra::kable(longtable = T, booktabs = T,
format.args = list(big.mark = ','),
caption = "New Hampshire Land Area within Flood Zones",
digits = 0, align = "r") %>%
kableExtra::kable_styling(latex_options = c("repeat_header"))
```
These percentages approximate the proportion of the total population in the state that are living within these flood zones. However, exposure varies significantly by population subgroup. Table \@ref(tab:tabNFHZApop) below shows the total and percentages of the general population and various subgroups living within flood zones. Aside from the total population, the largest absolute numbers of subpopulations living within a flood zone are low income persons followed by people under 18 or over 64. The latter groups are priority populations who may have limited mobility in the event of an evacuation.
```{r tabNFHZApop, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="New Hampshire Populations Living within Flood Zones."}
# Show table of pops within flood zones
nh_FloodPops_df %>%
mutate(PctFlood = paste0(as.character(round(PctFlood,1)),"%")) %>%
arrange(-FloodPop) %>%
mutate(Group = recode(Group, "Minority" = "People of Color",
"No HS Dip" = "No HS Diploma")) %>%
kableExtra::kable(longtable = T, booktabs = T,
format.args = list(big.mark = ','),
caption = "New Hampshire Populations Living within Flood Zones",
digits = 0, align = "r") %>%
kableExtra::kable_styling(latex_options = c("repeat_header"))
```
Some groups are disproportionately exposed to these flood hazards. While approximately 5.8% of the general population are living within flood zones, households without access to a car, people with disabilities, people in low income households, and other priority populations, exceed the population average living within flood zones. These priority populations are disproportionately exposed to flood risk (see Figure \@ref(fig:chartNFHZApop) below).
```{r chartNFHZApop, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="New Hampshire Populations Living within Flood Zones."}
# Create lollipop plot of pops within flood zones
nh_FloodPops_df %>%
mutate(Group = recode(Group, "Minority" = "People of Color",
"No HS Dip" = "No HS Diploma")) %>%
ggplot(aes(x = reorder(Group,PctFlood),
y = PctFlood)) +
geom_segment(aes(x = reorder(Group,PctFlood),
xend = reorder(Group,PctFlood),
y = nh_FloodPops_df[1,4], yend = PctFlood),
color = "skyblue") +
geom_point(color = "blue", size = 4, alpha = 0.8) +
coord_flip() + xlab("") + ylab("") +
ggtitle("New Hampshire Populations Living within Flood Zones") + theme_light() +
theme(panel.grid.major.y = element_blank(),
panel.border = element_blank(),
axis.ticks.y = element_blank()) +
geom_text(aes(x = Group, y = PctFlood + 0.2 * sign(PctFlood),
label = paste0(round(PctFlood,1),"%")),
hjust = 1.8, vjust = -1, size = 3,
color=rgb(100,100,100, maxColorValue=255)) +
scale_y_continuous(labels = function(x) paste0(x, "%")) +
geom_hline(yintercept = nh_FloodPops_df[1,4], linetype = "dashed") +
geom_text(aes(x = "Over 64", y = 7, label = "Above state\naverage"),
color = "gray48") +
geom_text(aes(x = "Over 64", y = 5, label = "Below state\naverage"),
color = "gray48") +
expand_limits(y=c(4.5,8))
ggsave("images/NH_FEMA_graph.png")
# geom_segment(aes(x = "Total Pop", xend = "Total Pop", y = 5.9, yend = 6.6),
# arrow = arrow(length = unit(0.3,"cm")))
```
The maps below (Figures \@ref(fig:mapNFHZAPopConcern1) and \@ref(fig:mapNFHZAPopConcern2)) show households without a car and disabled persons who are disproportionately exposed to flood risk. Maps for other priority populations can be found in Figures \@ref(fig:mapNFHZAPopConcern3) to \@ref(fig:mapNFHZAPopConcern9) and breakdowns by municipality in Tables \@ref(tab:tabNFHZANoCar) to \@ref(tab:tabNFHZAU5) in Appendix B.
```{r mapNFHZAPopConcern, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="New Hampshire Populations Living within Flood Zones."}
# Create a dot density map of transit-dependent populations in flood zone
# # create a function to select variable, filter records, and create sample points
# pop2points <- function(sf, x, group){
# x <- enquo(x)
# sf %>%
# select(!!x) %>%
# filter(!!x >= 10) %>%
# st_sample(., size = round(.[[as_label(x)]]/10)) %>%
# st_sf(.) %>%
# mutate(Group = group)
# }
#
# LimitEngHH_nfhza_pts <- pop2points(nh_blkgrps_nfhza,NewEng_limit,"Limited English HH")
#
# NoCarHH_nfhza_pts <- pop2points(nh_tracts_nfhza,NewNoCar,"No Car HH")
#
# NoHSdip_nfhza_pts <- pop2points(nh_blkgrps_nfhza,NewLths,"No HS Dip")
#
# LowInc_nfhza_pts <- pop2points(nh_blkgrps_nfhza,NewPov,"Low Income")
#
# Disabled_nfhza_pts <- pop2points(nh_tracts_nfhza,NewDisabled,"Disabled")
#
# Minor_nfhza_pts <- pop2points(nh_blkgrps_nfhza,NewMinority,"Minority")
#
# Under5_nfhza_pts <- pop2points(nh_blkgrps_nfhza,NewUnder5,"Under 5")
#
# Over64_nfhza_pts <- pop2points(nh_blkgrps_nfhza,NewOver64,"Over 64")
#
# Under18_nfhza_pts <- pop2points(nh_blkgrps_nfhza,NewUnder18,"Under 18")
#
# # Bring them together
# nh_nfhza_vulnerable <- rbind(NoCarHH_nfhza_pts,
# LimitEngHH_nfhza_pts,
# Disabled_nfhza_pts,
# LowInc_nfhza_pts,
# Minor_nfhza_pts,
# Over64_nfhza_pts,
# Under5_nfhza_pts,
# Under18_nfhza_pts,
# NoHSdip_nfhza_pts) %>%
# # slice(sample(1:n())) %>% # randomise order to avoid bias in plotting order
# group_by(Group) %>%
# summarize()
#
# # clean up pts layers
# rm(list = ls(pattern = "_nfhza_pts"))
#
# # save time by just loading file
# saveRDS(nh_nfhza_vulnerable, file = "DATA/FEMA/NH/nh_nfhza_vulnerable.Rds")
# load vulnerable point file
nh_nfhza_vulnerable <- readRDS("DATA/FEMA/NH/nh_nfhza_vulnerable.Rds")
```
```{r mapNFHZAPopConcern1, fig.align = "center", fig.cap="Households without a Car Living within Flood Zones."}
# create pop subset
nfhza_sub <- nh_nfhza_vulnerable %>%
filter(Group == "No Car HH")
# Map over-represented pops and flood zones
m <- tm_layout(bg.color = "#e6f3f7") +
tm_shape(nh_blkgrp_2823, unit = "mi") + tm_fill(col = "white") +
tm_shape(ne_states_sf_cb) + tm_fill(col="white") +
tm_shape(canada) + tm_fill(col = "white") +
# tm_shape(ny_state_sf) + tm_fill(col="white") +
tm_shape(nh_awater_sf_simple) + tm_fill(col = "#e6f3f7") +
tm_shape(nfhza_sub) +
tm_dots(col = "darkgoldenrod3",
labels = "1 dot = 10 people",
alpha = 0.8) +
# tm_facets(by = "Group",
# ncol = 2,
# free.coords = FALSE) +
tm_shape(nh_nfhza_2823_land_simple) +
tm_fill(col = "Interval",
palette = c("dodgerblue", "blueviolet"),
labels = c("1% AEP (100-year)", "0.2% AEP (500-year)"),
title = "FEMA Flood Zones",
alpha = 0.6,
border.alpha = 0) +
tm_shape(ne_states_sf_cb) + tm_borders(lwd = 0.6) +
# tm_shape(ny_state_sf) + tm_borders(lwd = 0.6) +
tm_shape(nh_highways) + tm_lines(col = "seashell4", lwd = 1) +
tm_shape(I89roadSegment) +
tm_symbols(shape = I89, border.lwd = NA, size = 0.1) +
tm_shape(I91roadSegment) +
tm_symbols(shape = I91, border.lwd = NA, size = 0.1) +
tm_shape(I93roadSegment) +
tm_symbols(shape = I93, border.lwd = NA, size = 0.1) +
tm_shape(I95roadSegment) +
tm_symbols(shape = I95, border.lwd = NA, size = 0.1) +
tm_shape(nh_towns_sf_pts) + tm_dots() +
tm_text("NAME", size = 0.5, col = "black",
xmod = 0.7, ymod = 0.2, shadow = TRUE) +
tm_shape(nofemapolys) +
tm_fill(col = "gray", alpha = 0.4) +
tm_text("LABEL", alpha = 0.5, size = 0.6) +
tm_scale_bar(breaks = c(0, 10, 20), text.size = 0.5,
position = c("left","TOP")) +
tm_add_legend(type = "fill", col = "darkgoldenrod3",
alpha = 0.6,
border.col = "white", border.alpha = 0,
labels = "1 dot = 10 people") +
tm_layout(title = "Households\nwithout a Car\nLiving within\nFlood Zones",
frame = TRUE, main.title.size = 0.8,
legend.outside = TRUE,
legend.title.size = 0.8,
legend.outside.position = c("right", "top"))
tmap_save(m, "DATA/FEMA/NH/NH_nhfza_vulnerable1.png",
height = 8, width = 8, units = "in", dpi = 600)
knitr::include_graphics("DATA/FEMA/NH/NH_nhfza_vulnerable1.png")
```
```{r mapNFHZAPopConcern2, fig.align = "center", fig.cap="Disabled Persons Living within Flood Zones."}
# create pop subset
nfhza_sub <- nh_nfhza_vulnerable %>%
filter(Group == "Disabled")
# Map over-represented pops and flood zones
m <- tm_layout(bg.color = "#e6f3f7") +
tm_shape(nh_blkgrp_2823, unit = "mi") + tm_fill(col = "white") +
tm_shape(ne_states_sf_cb) + tm_fill(col="white") +
tm_shape(canada) + tm_fill(col = "white") +
# tm_shape(ny_state_sf) + tm_fill(col="white") +
tm_shape(nh_awater_sf_simple) + tm_fill(col = "#e6f3f7") +
tm_shape(nfhza_sub) +
tm_dots(col = "darkgoldenrod3",
labels = "1 dot = 10 people",
alpha = 0.8) +
# tm_facets(by = "Group",
# ncol = 2,
# free.coords = FALSE) +
tm_shape(nh_nfhza_2823_land_simple) +
tm_fill(col = "Interval",
palette = c("dodgerblue", "blueviolet"),
labels = c("1% AEP (100-year)", "0.2% AEP (500-year)"),
title = "FEMA Flood Zones",
alpha = 0.6,
border.alpha = 0) +
tm_shape(ne_states_sf_cb) + tm_borders(lwd = 0.6) +
# tm_shape(ny_state_sf) + tm_borders(lwd = 0.6) +
tm_shape(nh_highways) + tm_lines(col = "seashell4", lwd = 1) +
tm_shape(I89roadSegment) +
tm_symbols(shape = I89, border.lwd = NA, size = 0.1) +
tm_shape(I91roadSegment) +
tm_symbols(shape = I91, border.lwd = NA, size = 0.1) +
tm_shape(I93roadSegment) +
tm_symbols(shape = I93, border.lwd = NA, size = 0.1) +
tm_shape(I95roadSegment) +
tm_symbols(shape = I95, border.lwd = NA, size = 0.1) +
tm_shape(nh_towns_sf_pts) + tm_dots() +
tm_text("NAME", size = 0.5, col = "black",
xmod = 0.7, ymod = 0.2, shadow = TRUE) +
tm_shape(nofemapolys) +
tm_fill(col = "gray", alpha = 0.4) +
tm_text("LABEL", alpha = 0.5, size = 0.6) +
tm_scale_bar(breaks = c(0, 10, 20), text.size = 0.5,
position = c("left","TOP")) +
tm_add_legend(type = "fill", col = "darkgoldenrod3",
alpha = 0.6,
border.col = "white", border.alpha = 0,
labels = "1 dot = 10 people") +
tm_layout(title = "Disabled\nPersons\nLiving within\nFlood Zones",
frame = TRUE, main.title.size = 0.8,
legend.outside = TRUE,
legend.title.size = 0.8,
legend.outside.position = c("right", "top"))
tmap_save(m, "DATA/FEMA/NH/NH_nhfza_vulnerable2.png",
height = 8, width = 8, units = "in", dpi = 600)
knitr::include_graphics("DATA/FEMA/NH/NH_nhfza_vulnerable2.png")
```
\pagebreak
## Analysis of Hurricane Evacuation Risk
```{r HEVACdata, include=FALSE}
# read in hurricane evacuation zone layer
nh_hea_sf <- st_read(dsn = "DATA/FEMA/NH",layer = "nh_hevac") %>%
mutate(Zone = as.character(Zone)) %>%
filter(Zone %in% c("A","B")) %>%
st_transform(., crs = 2823) %>%
st_make_valid() %>%
mutate(Area = st_area(.))
# read in processed nh_blkgrps and nh_tracts
nh_blkgrps_hevac <- st_read(dsn = "DATA/FEMA/NH",
layer = "nh_blkgrps_hevac") %>%
left_join(., as.data.frame(nh_blkgrp_2823), by = "GEOID") %>%
st_transform(., crs = 2823) %>%
mutate(NewArea = st_area(.)) %>%
st_make_valid()
nh_tracts_hevac <- st_read(dsn = "DATA/FEMA/NH",
layer = "nh_tracts_hevac") %>%
left_join(., as.data.frame(nh_tracts_2823), by = "GEOID") %>%
st_transform(., crs = 2823) %>%
mutate(NewArea = st_area(.)) %>%
st_make_valid()
# Apportion populations based on geographic proportion of intersect
nh_blkgrps_hevac <- nh_blkgrps_hevac %>%
mutate(Proportion = as.numeric(NewArea/OldArea),
NewPop = totalpopE*Proportion,
NewMinority = minorityE*Proportion,
NewUnder5 = under5E*Proportion,
NewOver64 = over64E*Proportion,
NewUnder18 = under18E*Proportion,
NewEng_limit = eng_limitE*Proportion,
NewPov = num2povE*Proportion,
NewLths = lthsE*Proportion)
nh_tracts_hevac <- nh_tracts_hevac %>%
mutate(Proportion = as.numeric(NewArea/OldArea),
NewDisabled = disabledOver18E*Proportion,
NewNoCar = HHnoCarE*Proportion)
# Compute total populations within hurricane evac zones
nh_hevac_blkgrp_df <- nh_blkgrps_hevac %>%
as.data.frame() %>%
summarize(`Total Pop` = as.integer(sum(NewPop)),
Minority = as.integer(sum(NewMinority)),
`Under 5` = as.integer(sum(NewUnder5)),
`Over 64` = as.integer(sum(NewOver64)),
`Under 18` = as.integer(sum(NewUnder18)),
`Limited English HH` = as.integer(sum(NewEng_limit)),
`Low Income` = as.integer(sum(NewPov)),
`No HS Dip` = as.integer(sum(NewLths))) %>%
gather(key = Group, value = HevacPop)
nh_hevac_tracts_df <- nh_tracts_hevac %>%
as.data.frame() %>%
summarize(`Disabled` = as.integer(sum(NewDisabled)),
`No Car HH` = as.integer(sum(NewNoCar))) %>%
gather(key = Group, value = HevacPop)
# Compute total tract populations within the state for same groups
nh_tranh_hevac_pops_df <- nh_tracts_2823 %>%
as.data.frame() %>%
summarize(`Disabled` = sum(disabledOver18E),
`No Car HH` = sum(HHnoCarE)) %>%
gather(key = Group, value = NHPop) %>%
left_join(.,nh_hevac_tracts_df, by = "Group")
# Compute populations for state, and join with hurricane evac pops
nh_HevacPops_df <- nh_blkgrp_2823 %>%
as.data.frame() %>%
summarize(`Total Pop` = sum(totalpopE),
Minority = sum(minorityE),
`Under 5` = sum(under5E),
`Over 64` = sum(over64E),
`Under 18` = sum(under18E),
`Limited English HH` = sum(eng_limitE),
`Low Income` = sum(num2povE),
`No HS Dip` = sum(lthsE)) %>%
gather(key = Group, value = NHPop) %>%
left_join(., nh_hevac_blkgrp_df, by = "Group") %>%
rbind(.,nh_tranh_hevac_pops_df) %>%
mutate(PctHevac = HevacPop/NHPop*100)
# save data for later analysis
save(nh_blkgrps_hevac, nh_tracts_hevac,
nh_HevacPops_df,
file = "DATA/FEMA/NH/hevac_census.Rds")
```
New Hampshire is subject to hurricane risk. Since 1900, New Hampshire has been struck by hurricanes twice. The most recent hurricane to hit New Hampshire directly was [Hurricane Bob in 1991](https://www.mass.gov/service-details/the-worst-New Hampshire-hurricanes-of-the-20th-century),[^HurricaneBob] a Category 2 storm when it struck the south shore of New Hampshire. The latter caused over \$2.3 million in damages in New Hampshire alone and left 20% of the state without power. Hurricane Sandy in 2012 did not hit New Hampshire directly, but nevertheless resulted in flooding of New Hampshire coastal communities that resulted in over \$1.6 million in damanges. In general, New Hampshire is subject to a [hurricane return period of approximately 30 years](https://www.nhc.noaa.gov/climo/#returns).[^HurricaneReturn]
Hurricane intensity is ranked from 1 to 5 on the Saffir-Simpson scale, which is based on sustained wind speeds. However the most destructive and deadly aspects of hurricanes are due to storm surge - ocean water pushed inland by the high winds. This coastal storm surge may be combined with intense rainfall which can exacerbate flooding. As a result, coastal evacuation may be necessary as a hurricane approaches.
The analysis of hurricane evacuation risk presented here is based on [storm surge modeling by the National Weather Service's National Hurricane Center](https://www.nhc.noaa.gov/nationalsurge/) using the hydrodynamic Sea, Lake, and Overland Surges from Hurricanes (SLOSH) model to simulate storm surge from tropical cyclones. These data products are provided to federal, state, and local government agencies to assist in planning, risk assessment studies, and operational decision-making.[^SurgeModel] Population data comes from the American Community Survey (ACS) 2018 5-year estimates at the census tract and block group levels.
A significant proportion of New Hampshire's population lives near the coast and is therefore within areas subject to inundation due to hurricane storm surge. Figure \@ref(fig:mapHEVACPop) below shows the population distribution and areas subject to hurricane inundation. Zone “A” is recommended to be evacuated prior to an expected category 1 or 2 hurricane. Zone “B” is recommended to be evacuated prior to an expected category 3 or 4 hurricane.
```{r mapHEVACPop, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="Hurricane flood zones across New Hampshire."}
# Create a simplified version of hea polygons to speed up mapping
empty_geo <- st_is_empty(nh_hea_sf)
nh_hea_sf <- nh_hea_sf[!empty_geo,]
nh_hea_sf_simple <- nh_hea_sf %>%
select(Zone) %>%
# st_buffer(., dist = 0) %>%
# st_set_precision(1e6) %>%
# st_cast(., "MULTIPOLYGON") %>% # homogenize type
# st_cast(., "POLYGON") %>%
st_simplify(., dTolerance = 100) %>% # reduce vertices
group_by(Zone) %>%
summarize() %>%
st_make_valid() %>%
mutate(Area = st_area(.))
# create tailored labels for close-up of hurricane areas
I95roadSegment2 <- nh_highways %>%
filter(LINEARID == "1105569136123")
# add labels for towns for close-up of hurricane areas
nh_towns_sf_pts2 <- county_subdivisions(state = "NH", cb = TRUE) %>%
filter(NAME %in% c("Seabrook",
"Hampton",
"Hampton Falls",
"North Hampton",
"Rye",
"Portsmouth",
"Newington",
"Greenland",
"Durham",
"Dover")) %>%
st_transform(., crs = 2823) %>%
st_centroid(of_largest_polygon = TRUE)
# clip water to area of focus for faster mapping
coastalWater <- nh_counties_sf %>%
filter(NAME %in% c("Rockingham","Strafford")) %>%
crop_shape(nh_awater_sf,.,polygon = TRUE)
# Map totalpop and hurricane evacuation zones
m <- tm_layout(bg.color = "#e6f3f7") +
tm_shape(nh_hea_sf_simple, unit = "mi") + tm_fill(col = "white") +
tm_shape(nh_blkgrp_2823, unit = "mi") + tm_fill(col = "white") +
tm_shape(ne_states_sf_cb) + tm_fill(col="white") +
# tm_shape(ny_state_sf) + tm_fill(col="white") +
tm_shape(coastalWater) + tm_fill(col = "#e6f3f7") +
tm_shape(ne_states_sf_cb) + tm_borders() +
# tm_shape(ny_state_sf) + tm_borders() +
tm_shape(nh_hea_sf) +
tm_fill(col = "Zone",
palette = c("deeppink", "purple3"),
labels = c("A: Category 1 - 2",
"B: Category 3 - 4"),
title = "Inundation Zone and\nHurricane Category",
alpha = 0.6,
border.alpha = 0) +
# tm_shape(nh_totalpop_pts) +
# tm_dots(col = "springgreen3",
# labels = "1 dot = 500 people",
# alpha = 0.8) +
tm_shape(ne_states_sf_cb) + tm_borders(lwd = 0.8) +
# tm_shape(ny_state_sf) + tm_borders(lwd = 0.8) +
tm_shape(nh_highways) + tm_lines(col = "seashell4", lwd = 1) +
# tm_shape(nh_highways2nd) + tm_lines(col = "seashell4", lwd = 1.5) +
tm_shape(I89roadSegment) +
tm_symbols(shape = I89, border.lwd = NA, size = 0.1) +
tm_shape(I91roadSegment) +
tm_symbols(shape = I91, border.lwd = NA, size = 0.1) +
tm_shape(I93roadSegment) +
tm_symbols(shape = I93, border.lwd = NA, size = 0.1) +
tm_shape(I95roadSegment2) +
tm_symbols(shape = I95, border.lwd = NA, size = 0.1) +
tm_shape(nh_towns_sf_pts2) + tm_dots() +
tm_text("NAME", size = 0.5, col = "black",
xmod = 0.7, ymod = 0.2, shadow = TRUE) +
tm_scale_bar(breaks = c(0, 5, 10), text.size = 0.5,
position = c("left","TOP")) +
# tm_add_legend(type = "fill", col = "springgreen3",
# alpha = 0.6,
# border.col = "white", border.alpha = 0,
# labels = "1 dot = 500 people",
# title = "Total Population") +
tm_layout(title = "Hurricane\nInundation Zones",
frame = TRUE, main.title.size = 0.8,
legend.outside = TRUE,
legend.title.size = 0.8,
legend.outside.position = c("right", "top"))
tmap_save(m, "DATA/FEMA/NH/NH_hevac.png",
height = 8, width = 8, units = "in", dpi = 600)
knitr::include_graphics("DATA/FEMA/NH/NH_hevac.png")
```
Approximately 0.3% of New Hampshire's land area falls within areas subject to hurricane inundation. The breakdown by hurricane inundation zone is presented in Table \@ref(tab:tabHEVACarea) below.
```{r tabHEVACarea, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="New Hampshire Populations within Hurricane Inundation Zones."}
# Total and percentage of land area within hurricane evacuation zones
nh_hea_sf %>%
as.data.frame() %>%
group_by(Zone) %>%
summarize(SqKm = round(as.numeric(sum(Area)/10^6),1),
SqMi = round(as.numeric(SqKm/2.59),1),
PctArea = paste0(as.character(round(as.numeric(sum(Area)/nh_area*100),1)),"%")) %>%
kableExtra::kable(longtable = T, booktabs = T,
format.args = list(big.mark = ','),
caption = "New Hampshire Land Area within Hurricane Inundation Zones",
digits = 0, align = "r") %>%
kableExtra::kable_styling(latex_options = c("repeat_header"))
```
These percentages belie the proportion of the population in the state that are living within these inundation zones. Exposure varies significantly by population subgroup. Table \@ref(tab:tabHEVACpop) below shows the total and percentages of the general population and various subgroups living within hurricane inundation zones. Aside from the total population, the largest subpopulation living within an inundation zone are individuals over age 64 and low income individuals. The latter groups are priority populations who may have limited mobility in the event of an evacuation.
```{r tabHEVACpop, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="New Hampshire Populations Living within Hurricane Evacuation Zones."}
# Show table of pops within hurricane evacuation zones
nh_HevacPops_df %>%
mutate(PctHevac = paste0(as.character(round(PctHevac,1)),"%")) %>%
arrange(-HevacPop) %>%
mutate(Group = recode(Group, "Minority" = "People of Color",
"No HS Dip" = "No HS Diploma")) %>%
kableExtra::kable(longtable = T, booktabs = T,
format.args = list(big.mark = ','),
caption = "New Hampshire Populations Living within Hurricane Inundation Zones",
digits = 0, align = "r") %>%
kableExtra::kable_styling(latex_options = c("repeat_header"))
```
Some groups are disproportionately exposed to these hurricane evacuation hazards. While approximately 1.1% of the general population are living within hurricane inundation zones, individuals over age 64 and households without access to a car exceed the population average living within hurricane inundation zones. These priority populations are disproportionately exposed to the risk of hurricane inundation (see Figures \@ref(fig:chartHEVACpop) and \@ref(fig:mapHEVACPopConcern1) below).
```{r chartHEVACpop, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="New Hampshire Populations Living within Hurricane Evacuation Zones."}
# Create lollipop plot of pops within flood zones
nh_HevacPops_df %>%
mutate(Group = recode(Group, "Minority" = "People of Color",
"No HS Dip" = "No HS Diploma")) %>%
ggplot(aes(x = reorder(Group,PctHevac),
y = PctHevac)) +
geom_segment(aes(x = reorder(Group,PctHevac),
xend = reorder(Group,PctHevac),
y = nh_HevacPops_df[1,4], yend = PctHevac),
color = "skyblue") +
geom_point(color = "blue", size = 4, alpha = 0.8) +
coord_flip() + xlab("") + ylab("") +
ggtitle("New Hampshire Populations Living within Hurricane\nInundation Zones") + theme_light() +
theme(panel.grid.major.y = element_blank(),
panel.border = element_blank(),
axis.ticks.y = element_blank()) +
geom_text(aes(x = Group, y = PctHevac + 0.2 * sign(PctHevac),
label = paste0(round(PctHevac,1),"%")),
hjust = 1.7, vjust = -0.7, size = 3,
color=rgb(100,100,100, maxColorValue=255)) +
scale_y_continuous(labels = function(x) paste0(x, "%")) +
geom_hline(yintercept = nh_HevacPops_df[1,4], linetype = "dashed") +
geom_text(aes(x = "Total Pop", y = 1.5, label = "Above state\naverage"),
color = "gray48") +
geom_text(aes(x = "Total Pop", y = .8, label = "Below state\naverage"),
color = "gray48")
ggsave("images/NH_HEVAC_graph.png")
# geom_segment(aes(x = "Total Pop", xend = "Total Pop", y = 1.3, yend = 2),
# arrow = arrow(length = unit(0.3,"cm")))
```
The maps below (Figures \@ref(fig:mapHEVACPopConcern1) and \@ref(fig:mapHEVACPopConcern2)) show persons over 64 and households without a car who are disproportionately exposed to hurricane evacuation risk. Maps for other priority populations can be found in Figures \@ref(fig:mapHEVACPopConcern3) to \@ref(fig:mapHEVACPopConcern7) and breakdowns by municipality in Tables \@ref(tab:tabHEVACO64) to \@ref(tab:tabHEVACLEH) in Appendix B.
```{r mapHEVACPopConcern, echo=FALSE, message=FALSE, warning=FALSE, fig.align = "center", fig.cap="New Hampshire Populations Living within Hurricane Evacuation Zones."}
# # Create a dot density map of over-represented populations in hurricane evacuation zones
#
# # LimitEngHH_hevac_pts <- pop2points(nh_blkgrps_hevac,NewEng_limit,"Limited English HH") # no blkgrps >= 10
#
# NoCarHH_hevac_pts <- pop2points(nh_tracts_hevac,NewNoCar,"No Car HH")
#
# NoHSdip_hevac_pts <- pop2points(nh_blkgrps_hevac,NewLths,"No HS Dip")
#
# LowInc_hevac_pts <- pop2points(nh_blkgrps_hevac,NewPov,"Low Income")
#
# Disabled_hevac_pts <- pop2points(nh_tracts_hevac,NewDisabled,"Disabled")
#
# Minor_hevac_pts <- pop2points(nh_blkgrps_hevac,NewMinority,"Minority")