The impact of different weather events on public health and economy between 1950 and 2011

By Ildar Gabdrakhmanov, 21/10/2015

1. Assignment

The basic goal of this assignment is to explore the NOAA Storm Database and answer some basic questions about severe weather events. You must use the database to answer the questions below and show the code for your entire analysis. Your analysis can consist of tables, figures, or other summaries. You may use any R package you want to support your analysis.

2. Synopsis

In this report we aim to answer the following questions:

  • Across the United States, which types of events (as indicated in the EVTYPE variable) are most harmful with respect to population health?

  • Across the United States, which types of events have the greatest economic consequences?

As we can see later on, the most harmful to the public health was a tornado and the most harmful to the ecomony was a flood. To answer those questions, we obtained Storm database from the U.S. National Oceanic and Atmospheric Administration (NOAA), that tracks characteristics of major storms and weather events in the United States, including when and where they occur, as well as estimates of any fatalities, injuries, and property damage.

3. Data Processing

3.1. Prepare work directory and load the libraries

setwd("~/datasciencecoursera/RepData_PeerAssessment2")
packages <- c("dplyr", "R.cache", "R.utils", "ggplot2")
sapply(packages, require, character.only = TRUE, quietly = TRUE)

3.2. Load the data in R

stormRawDataFileName <- "StormData.csv"
if (file.exists(stormRawDataFileName) == FALSE) {
        stormRawDataFileAddress <- "https://d396qusza40orc.cloudfront.net/repdata%2Fdata%2FStormData.csv.bz2"
        stormRawDataTempFileName <- "StormDataTemp.bz2"
        download.file(stormRawDataFileAddress, stormRawDataTempFileName)
        bunzip2(stormRawDataTempFileName, stormRawDataFileName)
        stormDataDF <- read.csv(stormRawDataFileName)
        stormData <- as.tbl(stormDataDF)
} else {
        stormDataDF <- read.csv(stormRawDataFileName)   
        stormData <- as.tbl(stormDataDF)
}

3.3. Check the loaded data

print(stormData)
## Source: local data frame [902,297 x 37]
## 
##    STATE__           BGN_DATE BGN_TIME TIME_ZONE COUNTY COUNTYNAME  STATE
##      (dbl)             (fctr)   (fctr)    (fctr)  (dbl)     (fctr) (fctr)
## 1        1  4/18/1950 0:00:00     0130       CST     97     MOBILE     AL
## 2        1  4/18/1950 0:00:00     0145       CST      3    BALDWIN     AL
## 3        1  2/20/1951 0:00:00     1600       CST     57    FAYETTE     AL
## 4        1   6/8/1951 0:00:00     0900       CST     89    MADISON     AL
## 5        1 11/15/1951 0:00:00     1500       CST     43    CULLMAN     AL
## 6        1 11/15/1951 0:00:00     2000       CST     77 LAUDERDALE     AL
## 7        1 11/16/1951 0:00:00     0100       CST      9     BLOUNT     AL
## 8        1  1/22/1952 0:00:00     0900       CST    123 TALLAPOOSA     AL
## 9        1  2/13/1952 0:00:00     2000       CST    125 TUSCALOOSA     AL
## 10       1  2/13/1952 0:00:00     2000       CST     57    FAYETTE     AL
## ..     ...                ...      ...       ...    ...        ...    ...
## Variables not shown: EVTYPE (fctr), BGN_RANGE (dbl), BGN_AZI (fctr),
##   BGN_LOCATI (fctr), END_DATE (fctr), END_TIME (fctr), COUNTY_END (dbl),
##   COUNTYENDN (lgl), END_RANGE (dbl), END_AZI (fctr), END_LOCATI (fctr),
##   LENGTH (dbl), WIDTH (dbl), F (int), MAG (dbl), FATALITIES (dbl),
##   INJURIES (dbl), PROPDMG (dbl), PROPDMGEXP (fctr), CROPDMG (dbl),
##   CROPDMGEXP (fctr), WFO (fctr), STATEOFFIC (fctr), ZONENAMES (fctr),
##   LATITUDE (dbl), LONGITUDE (dbl), LATITUDE_E (dbl), LONGITUDE_ (dbl),
##   REMARKS (fctr), REFNUM (dbl)
str(stormData)
## Classes 'tbl_df', 'tbl' and 'data.frame':    902297 obs. of  37 variables:
##  $ STATE__   : num  1 1 1 1 1 1 1 1 1 1 ...
##  $ BGN_DATE  : Factor w/ 16335 levels "1/1/1966 0:00:00",..: 6523 6523 4242 11116 2224 2224 2260 383 3980 3980 ...
##  $ BGN_TIME  : Factor w/ 3608 levels "000","0000","0001",..: 152 167 2645 1563 2524 3126 122 1563 3126 3126 ...
##  $ TIME_ZONE : Factor w/ 22 levels "ADT","AKS","AST",..: 6 6 6 6 6 6 6 6 6 6 ...
##  $ COUNTY    : num  97 3 57 89 43 77 9 123 125 57 ...
##  $ COUNTYNAME: Factor w/ 29601 levels "","5NM E OF MACKINAC BRIDGE TO PRESQUE ISLE LT MI",..: 13513 1873 4598 10592 4372 10094 1973 23873 24418 4598 ...
##  $ STATE     : Factor w/ 72 levels "AK","AL","AM",..: 2 2 2 2 2 2 2 2 2 2 ...
##  $ EVTYPE    : Factor w/ 985 levels "   HIGH SURF ADVISORY",..: 826 826 826 826 826 826 826 826 826 826 ...
##  $ BGN_RANGE : num  0 0 0 0 0 0 0 0 0 0 ...
##  $ BGN_AZI   : Factor w/ 35 levels "","  N"," NW",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ BGN_LOCATI: Factor w/ 54429 levels ""," Christiansburg",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ END_DATE  : Factor w/ 6663 levels "","1/1/1993 0:00:00",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ END_TIME  : Factor w/ 3647 levels ""," 0900CST",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ COUNTY_END: num  0 0 0 0 0 0 0 0 0 0 ...
##  $ COUNTYENDN: logi  NA NA NA NA NA NA ...
##  $ END_RANGE : num  0 0 0 0 0 0 0 0 0 0 ...
##  $ END_AZI   : Factor w/ 24 levels "","E","ENE","ESE",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ END_LOCATI: Factor w/ 34506 levels ""," CANTON"," TULIA",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ LENGTH    : num  14 2 0.1 0 0 1.5 1.5 0 3.3 2.3 ...
##  $ WIDTH     : num  100 150 123 100 150 177 33 33 100 100 ...
##  $ F         : int  3 2 2 2 2 2 2 1 3 3 ...
##  $ MAG       : num  0 0 0 0 0 0 0 0 0 0 ...
##  $ FATALITIES: num  0 0 0 0 0 0 0 0 1 0 ...
##  $ INJURIES  : num  15 0 2 2 2 6 1 0 14 0 ...
##  $ PROPDMG   : num  25 2.5 25 2.5 2.5 2.5 2.5 2.5 25 25 ...
##  $ PROPDMGEXP: Factor w/ 19 levels "","+","-","0",..: 16 16 16 16 16 16 16 16 16 16 ...
##  $ CROPDMG   : num  0 0 0 0 0 0 0 0 0 0 ...
##  $ CROPDMGEXP: Factor w/ 9 levels "","0","2","?",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ WFO       : Factor w/ 542 levels ""," CI","$AC",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ STATEOFFIC: Factor w/ 250 levels "","ALABAMA, Central",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ ZONENAMES : Factor w/ 25112 levels "","                                                                                                                               "| __truncated__,..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ LATITUDE  : num  3040 3042 3340 3458 3412 ...
##  $ LONGITUDE : num  8812 8755 8742 8626 8642 ...
##  $ LATITUDE_E: num  3051 0 0 0 0 ...
##  $ LONGITUDE_: num  8806 0 0 0 0 ...
##  $ REMARKS   : Factor w/ 436781 levels "","\t","\t\t",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ REFNUM    : num  1 2 3 4 5 6 7 8 9 10 ...

3.4. Get close look to the multipliers and coerse to chatacter

levels(stormData$PROPDMGEXP)
##  [1] ""  "+" "-" "0" "1" "2" "3" "4" "5" "6" "7" "8" "?" "B" "H" "K" "M"
## [18] "h" "m"
levels(stormData$CROPDMGEXP)
## [1] ""  "0" "2" "?" "B" "K" "M" "k" "m"
stormData$PROPDMGEXP <- as.character(stormData$PROPDMGEXP)
stormData$CROPDMGEXP <- as.character(stormData$CROPDMGEXP)

3.5. Process the multipliers to the

multiplier <- list("\\-|\\+|\\?" = "0", "B|b" = "9", "M|m" = "6", "K|k" = "3", "H|h" = "2")

for (i in 1:length(names(multiplier))) {
        
        stormData$PROPDMGEXP = gsub(names(multiplier)[i], multiplier[i][[1]], stormData$PROPDMGEXP)  
        stormData$CROPDMGEXP = gsub(names(multiplier)[i], multiplier[i][[1]], stormData$CROPDMGEXP)
}

stormData$PROPDMGEXP <- as.integer(stormData$PROPDMGEXP)
stormData$CROPDMGEXP <- as.integer(stormData$CROPDMGEXP)
stormData$PROPDMGEXP[is.na(stormData$PROPDMGEXP)] <- 0
stormData$CROPDMGEXP[is.na(stormData$CROPDMGEXP)] <- 0

3.6. Find the sum of the variables.

PUBHEALTHDMG shows total public health damage (INJURIES, FATALITIES). ECONOMYDMG shows total economy damage (PROPDMG + CROPDMG, considering the multipliers PROPDMGEXP and CROPDMGEXP respectively).

stormData <- stormData %>% 
        select(EVTYPE, INJURIES, FATALITIES, PROPDMG, PROPDMGEXP, CROPDMG, CROPDMGEXP) %>%
        mutate(PUBHEALTHDMG = INJURIES + FATALITIES) %>%
        mutate(ECONOMYDMG = PROPDMG * 10^PROPDMGEXP + CROPDMG * 10^CROPDMGEXP) %>%
        select(EVTYPE, PUBHEALTHDMG, ECONOMYDMG) %>%
        group_by(EVTYPE) %>% 
        summarise_each(funs(sum)) 

3.7. Find the most damaging events.

Get top 5 for public health damage and for ecomomy damage.

stormDataPubHealthDmg <- stormData %>% 
        select(EVTYPE, PUBHEALTHDMG) %>%
        top_n(5, PUBHEALTHDMG)
stormDataEconomyDmg <- stormData %>% 
        select(EVTYPE, ECONOMYDMG) %>%
        top_n(5, ECONOMYDMG)

4. Results.

As we can see from the plots, TORNADO has the most impact an public health and FLOOD has the most impact on ecomony.

ggplot(stormDataPubHealthDmg, aes(EVTYPE, PUBHEALTHDMG), color = EVTYPE) + geom_bar(stat = "identity", aes(fill = EVTYPE)) + labs(title = "", x = "Type of event", y = "Damage")

ggplot(stormDataEconomyDmg, aes(EVTYPE, ECONOMYDMG), color = EVTYPE) + geom_bar(stat = "identity", aes(fill = EVTYPE)) + labs(title = "", x = "Type of event", y = "Damage")