Analysis of severe weather events and their effect on the health and economic stability of the US population

Synopsis

This project uses the U.S. National Oceanic and Atmospheric Administration’s (NOAA) storm database to analyse the impact of severe weather events on the health and economic stability of the American population.

This analysis concentrates mainly on the number of fatalities and injuries due to severe weather conditions for analysing the health impact and the damage to property and crops to analyse the economic impact.

The results show that the fatalities and injuries are the highest when there is an occurance of a Tornado, Floods are the most damaging to property and draughts for the agriculture.

Downloading and Reading the Data

setwd("C:\\Users\\Intel\\Documents\\Datasets\\Storm Data")
url <- "https://d396qusza40orc.cloudfront.net/repdata%2Fdata%2FStormData.csv.bz2"
#download.file(url, "StormData.csv.bz2")

if(!exists("stormData")) {
    stormData <- read.csv("StormData.csv",header = TRUE)
  }

Basic Exploratory Analysis

Here, we check the summary of the data. We can the see the column names which would be required and plan our analysis accordingly.

summary(stormData)
##     STATE__                  BGN_DATE             BGN_TIME     
##  Min.   : 1.0   5/25/2011 0:00:00:  1202   12:00:00 AM: 10163  
##  1st Qu.:19.0   4/27/2011 0:00:00:  1193   06:00:00 PM:  7350  
##  Median :30.0   6/9/2011 0:00:00 :  1030   04:00:00 PM:  7261  
##  Mean   :31.2   5/30/2004 0:00:00:  1016   05:00:00 PM:  6891  
##  3rd Qu.:45.0   4/4/2011 0:00:00 :  1009   12:00:00 PM:  6703  
##  Max.   :95.0   4/2/2006 0:00:00 :   981   03:00:00 PM:  6700  
##                 (Other)          :895866   (Other)    :857229  
##    TIME_ZONE          COUNTY           COUNTYNAME         STATE       
##  CST    :547493   Min.   :  0.0   JEFFERSON :  7840   TX     : 83728  
##  EST    :245558   1st Qu.: 31.0   WASHINGTON:  7603   KS     : 53440  
##  MST    : 68390   Median : 75.0   JACKSON   :  6660   OK     : 46802  
##  PST    : 28302   Mean   :100.6   FRANKLIN  :  6256   MO     : 35648  
##  AST    :  6360   3rd Qu.:131.0   LINCOLN   :  5937   IA     : 31069  
##  HST    :  2563   Max.   :873.0   MADISON   :  5632   NE     : 30271  
##  (Other):  3631                   (Other)   :862369   (Other):621339  
##                EVTYPE         BGN_RANGE           BGN_AZI      
##  HAIL             :288661   Min.   :   0.000          :547332  
##  TSTM WIND        :219940   1st Qu.:   0.000   N      : 86752  
##  THUNDERSTORM WIND: 82563   Median :   0.000   W      : 38446  
##  TORNADO          : 60652   Mean   :   1.484   S      : 37558  
##  FLASH FLOOD      : 54277   3rd Qu.:   1.000   E      : 33178  
##  FLOOD            : 25326   Max.   :3749.000   NW     : 24041  
##  (Other)          :170878                      (Other):134990  
##          BGN_LOCATI                  END_DATE             END_TIME     
##               :287743                    :243411              :238978  
##  COUNTYWIDE   : 19680   4/27/2011 0:00:00:  1214   06:00:00 PM:  9802  
##  Countywide   :   993   5/25/2011 0:00:00:  1196   05:00:00 PM:  8314  
##  SPRINGFIELD  :   843   6/9/2011 0:00:00 :  1021   04:00:00 PM:  8104  
##  SOUTH PORTION:   810   4/4/2011 0:00:00 :  1007   12:00:00 PM:  7483  
##  NORTH PORTION:   784   5/30/2004 0:00:00:   998   11:59:00 PM:  7184  
##  (Other)      :591444   (Other)          :653450   (Other)    :622432  
##    COUNTY_END COUNTYENDN       END_RANGE           END_AZI      
##  Min.   :0    Mode:logical   Min.   :  0.0000          :724837  
##  1st Qu.:0    NA's:902297    1st Qu.:  0.0000   N      : 28082  
##  Median :0                   Median :  0.0000   S      : 22510  
##  Mean   :0                   Mean   :  0.9862   W      : 20119  
##  3rd Qu.:0                   3rd Qu.:  0.0000   E      : 20047  
##  Max.   :0                   Max.   :925.0000   NE     : 14606  
##                                                 (Other): 72096  
##            END_LOCATI         LENGTH              WIDTH         
##                 :499225   Min.   :   0.0000   Min.   :   0.000  
##  COUNTYWIDE     : 19731   1st Qu.:   0.0000   1st Qu.:   0.000  
##  SOUTH PORTION  :   833   Median :   0.0000   Median :   0.000  
##  NORTH PORTION  :   780   Mean   :   0.2301   Mean   :   7.503  
##  CENTRAL PORTION:   617   3rd Qu.:   0.0000   3rd Qu.:   0.000  
##  SPRINGFIELD    :   575   Max.   :2315.0000   Max.   :4400.000  
##  (Other)        :380536                                         
##        F               MAG            FATALITIES          INJURIES        
##  Min.   :0.0      Min.   :    0.0   Min.   :  0.0000   Min.   :   0.0000  
##  1st Qu.:0.0      1st Qu.:    0.0   1st Qu.:  0.0000   1st Qu.:   0.0000  
##  Median :1.0      Median :   50.0   Median :  0.0000   Median :   0.0000  
##  Mean   :0.9      Mean   :   46.9   Mean   :  0.0168   Mean   :   0.1557  
##  3rd Qu.:1.0      3rd Qu.:   75.0   3rd Qu.:  0.0000   3rd Qu.:   0.0000  
##  Max.   :5.0      Max.   :22000.0   Max.   :583.0000   Max.   :1700.0000  
##  NA's   :843563                                                           
##     PROPDMG          PROPDMGEXP        CROPDMG          CROPDMGEXP    
##  Min.   :   0.00          :465934   Min.   :  0.000          :618413  
##  1st Qu.:   0.00   K      :424665   1st Qu.:  0.000   K      :281832  
##  Median :   0.00   M      : 11330   Median :  0.000   M      :  1994  
##  Mean   :  12.06   0      :   216   Mean   :  1.527   k      :    21  
##  3rd Qu.:   0.50   B      :    40   3rd Qu.:  0.000   0      :    19  
##  Max.   :5000.00   5      :    28   Max.   :990.000   B      :     9  
##                    (Other):    84                     (Other):     9  
##       WFO                                       STATEOFFIC    
##         :142069                                      :248769  
##  OUN    : 17393   TEXAS, North                       : 12193  
##  JAN    : 13889   ARKANSAS, Central and North Central: 11738  
##  LWX    : 13174   IOWA, Central                      : 11345  
##  PHI    : 12551   KANSAS, Southwest                  : 11212  
##  TSA    : 12483   GEORGIA, North and Central         : 11120  
##  (Other):690738   (Other)                            :595920  
##                                                                                                                                                                                                     ZONENAMES     
##                                                                                                                                                                                                          :594029  
##                                                                                                                                                                                                          :205988  
##  GREATER RENO / CARSON CITY / M - GREATER RENO / CARSON CITY / M                                                                                                                                         :   639  
##  GREATER LAKE TAHOE AREA - GREATER LAKE TAHOE AREA                                                                                                                                                       :   592  
##  JEFFERSON - JEFFERSON                                                                                                                                                                                   :   303  
##  MADISON - MADISON                                                                                                                                                                                       :   302  
##  (Other)                                                                                                                                                                                                 :100444  
##     LATITUDE      LONGITUDE        LATITUDE_E     LONGITUDE_    
##  Min.   :   0   Min.   :-14451   Min.   :   0   Min.   :-14455  
##  1st Qu.:2802   1st Qu.:  7247   1st Qu.:   0   1st Qu.:     0  
##  Median :3540   Median :  8707   Median :   0   Median :     0  
##  Mean   :2875   Mean   :  6940   Mean   :1452   Mean   :  3509  
##  3rd Qu.:4019   3rd Qu.:  9605   3rd Qu.:3549   3rd Qu.:  8735  
##  Max.   :9706   Max.   : 17124   Max.   :9706   Max.   :106220  
##  NA's   :47                      NA's   :40                     
##                                            REMARKS           REFNUM      
##                                                :287433   Min.   :     1  
##                                                : 24013   1st Qu.:225575  
##  Trees down.\n                                 :  1110   Median :451149  
##  Several trees were blown down.\n              :   569   Mean   :451149  
##  Trees were downed.\n                          :   446   3rd Qu.:676723  
##  Large trees and power lines were blown down.\n:   432   Max.   :902297  
##  (Other)                                       :588294

The data contains two columns, FATALATIES and INJURIES, which describe the damage to human health.

PART 1 - Processing and Analysing of data for damages to health

The fatalaties and injuries are extracted from the data and combined according to the Event using the tapply function.

deaths <- tapply(stormData$FATALITIES,
                 stormData$EVTYPE,
                 sum)

injuries <- tapply(stormData$INJURIES,
                   stormData$EVTYPE,
                   sum)

These operations produce two tables representing the sum of fatalaties and injuries all over the country according to the event type

Import the required libraries

library(reshape2)
## Warning: package 'reshape2' was built under R version 3.6.3
library(ggplot2)
## Warning: package 'ggplot2' was built under R version 3.6.3

Plot the top 10 weather events which caused the most deaths.

# Sort the fatalities data into descending order
deaths <- deaths[order(deaths, decreasing = TRUE)]
deaths <- deaths[1:10]
deaths <- melt(deaths, "Row.names")

deaths$Row.names <- as.factor(deaths$Row.names)

Results for damages to health

# Plot the fatalities with respect to the event type
deathPlot <- ggplot(deaths, aes(x = Row.names, y = value)) +
    geom_bar(stat = "identity") +
    ylim(0, 6000) +
    theme(plot.title = element_text(hjust = 0.5),
          axis.text.x = element_text(angle=90, vjust=0.5, hjust=1)) +
    ggtitle("Events with Most Fatalities") +
    labs(x = "Event", y = "Number of Deaths")
print(deathPlot)

From the figure, it can be seen that the highest number of deaths were recorded due to Tornados. On some further examination, it can be noted that the number of fatalities is higher than the other events by a hugh margin.

Plot the top 10 weather events which caused the most Injuries.

Here, we use the same method as above

# Sort the Injuries data into descending order
injuries <- injuries[order(injuries, decreasing = TRUE)]
injuries <- injuries[1:10]
injuries <- melt(injuries, "Event")

injuries$Event <- as.factor(injuries$Event)

# Plot the injuries data
injuriesplot <- ggplot(injuries, aes(x = Event, y = value)) +
    geom_bar(stat = "identity") +
    ylim(0, 100000) +
    theme(plot.title = element_text(hjust = 0.5),
          axis.text.x = element_text(angle=90, vjust=0.5, hjust=1)) +
    ggtitle("Events with Most Injuries") +
    labs(x = "Event", y = "Number of Injuries")
print(injuriesplot)

The figure for Injuries shows that Tornados cause the most injuries among all the events.

PART 2 - Processing and Analysing the data for economic damages

The data uses four variables to depict the economic damages -PROPDMG: The overall damage to property -PROPDMGEXP: multiplier for property damage -CROPDMG: Overall damage to crops -CROPDMGEXP: multiplier for crop damage

Analysing and modifying the EXP columns

We first check the number of unique multipliers used for both tyoes of damages using the unique() function

unique(stormData$PROPDMGEXP)
##  [1] K M   B m + 0 5 6 ? 4 2 3 h 7 H - 1 8
## Levels:  - ? + 0 1 2 3 4 5 6 7 8 B h H K m M
unique(stormData$CROPDMGEXP)
## [1]   M K m B ? 0 k 2
## Levels:  ? 0 2 B k K m M

Multipliers used in the data: - “?”: 0 USD - " “: 1 USD -”0“: 10^0 USD -”1“: 10^1 USD -”2“: 10^2 USD -”3“: 10^3 USD -”4“: 10^4 USD -”5“: 10^5 USD -”6“: 10^6 USD -”7“: 10^7 USD -”8“: 10^8 USD -”h" or “H”: 10^2 USD - “k” or “K”: 10^3 USD - “m” or “M”: 10^6 USD - “B”: 10^9 USD

Converting the multipliers for property damage into proper numbers and finding the real damage to property in USD

library(plyr)
## Warning: package 'plyr' was built under R version 3.6.3
stormData$PROPDMGEXP <- mapvalues(warn_missing = F,
                                  stormData$PROPDMGEXP,
                                  from = c("K", "M","", "B", "m", "+",
                                           "0", "5", "6", "?", "4", "2", "3", "h",
                                           "7", "H", "-", "1", "8"),
                                  to = c(10^3, 10^6, 1, 10^9, 10^6, 0,
                                         1,10^5, 10^6, 0, 10^4, 10^2, 10^3,
                                         10^2, 10^7, 10^2, 0, 10, 10^8))

stormData$PROPDMGEXP <- as.numeric(as.character(stormData$PROPDMGEXP))
propertyDamage <- data.frame(stormData$EVTYPE,
                             (stormData$PROPDMG * stormData$PROPDMGEXP)/10^9)
colnames(propertyDamage) <- c("Event", "Damages")

Aggregating the damage to property according to the event type

propDamageAgg <- tapply(propertyDamage$Damages,
                        propertyDamage$Event,
                        sum)

propDamageAgg <- propDamageAgg[order(propDamageAgg, decreasing = TRUE)]
propDamageAgg <- propDamageAgg[1:10]
propDamageAgg <- melt(propDamageAgg, "Event")
propDamageAgg$Event <- as.factor(propDamageAgg$Event)

Converting the multipliers for crop damage into proper numbers and finding the real damage to crops in USD

stormData$CROPDMGEXP <- mapvalues(warn_missing = F,
                                  stormData$CROPDMGEXP,
                                  from = c("","M", "K", "m", "B",
                                           "?", "0", "k","2"),
                                  to = c(1,10^6, 10^3, 10^6, 10^9,
                                         0, 1, 10^3, 10^2))

stormData$CROPDMGEXP <- as.numeric(as.character(stormData$CROPDMGEXP))
cropDamage <- data.frame(stormData$EVTYPE,
                             (stormData$CROPDMG * stormData$CROPDMGEXP)/10^9)
colnames(cropDamage) <- c("Event", "Damages")

Aggregating the damage to crops according to the event type

cropDamageAgg <- tapply(cropDamage$Damages,
                        cropDamage$Event,
                        sum)

cropDamageAgg <- cropDamageAgg[order(cropDamageAgg, decreasing = TRUE)]
cropDamageAgg <- cropDamageAgg[1:10]
cropDamageAgg <- melt(cropDamageAgg, "Event")
cropDamageAgg$Event <- as.factor(cropDamageAgg$Event)

Results for Damages to the economy

Plotting the damage to property with respect to the event type

propDamagePlot <- ggplot(propDamageAgg, aes(x = Event, y = value)) +
    geom_bar(stat = "identity") +
    theme(plot.title = element_text(hjust = 0.5),
          axis.text.x = element_text(angle=90, vjust=0.5, hjust=1)) +
    ggtitle("Events with Most Property Damage") +
    labs(x = "Event", y = "Property Damage in Billion USD")
print(propDamagePlot)

It can be seen from the figure that floods cause the most damage to property

Plotting the damage to crops with respect to the event type

cropDamagePlot <- ggplot(cropDamageAgg, aes(x = Event, y = value)) + 
  geom_bar(stat = "identity") +
  ylim(0, 15) +
  theme(plot.title = element_text(hjust = 0.5),
        axis.text.x = element_text(angle=90, vjust=0.5, hjust=1)) +
  ggtitle("Events with Most Crop Damage") +
  labs(x = "Event", y = "Crop Damage in Billion USD")
print(cropDamagePlot)

It can be seen from the figure that Droughts cause the most damage to crops