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A. Synopsis

Severe weather events impact public health, imparts economic stress, and on a personal level may lead to loss of life and property damage.
The National Oceanic & Atmospheric Administration (NOAA), along with the National Weather Service (NWS) and Department of Commerce, maintains a database that tracks parameters of major storms and weather events in the United States, among them, loss of life, personal injury, and damage to property,

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B. Data Processing

The database contains information for the period beginning in 1950 and ending in November 2011.

B.1 Downloading the data

Set working directory

Important:

Set correct file path below, before the “\Project2”

Create work folder to extract and write data to

if(!file.exists("./Project2")){dir.create("./Project2")}
fileUrl <- "https://d396qusza40orc.cloudfront.net/repdata%2Fdata%2FStormData.csv.bz2"

Download raw data file as data.csv.bz2

download.file(fileUrl,destfile="./Project2/data.csv.bz2")

Unzip & Read the raw data .csv files from the NOAA Storm Database from original folder position as received during unzip procedure into variable noaa_raw.

This line of code will likely take a couple of minutes. Be patient!

library(R.utils)
## Warning: package 'R.utils' was built under R version 3.4.1
## Loading required package: R.oo
## Loading required package: R.methodsS3
## R.methodsS3 v1.7.1 (2016-02-15) successfully loaded. See ?R.methodsS3 for help.
## R.oo v1.21.0 (2016-10-30) successfully loaded. See ?R.oo for help.
## 
## Attaching package: 'R.oo'
## The following objects are masked from 'package:methods':
## 
##     getClasses, getMethods
## The following objects are masked from 'package:base':
## 
##     attach, detach, gc, load, save
## R.utils v2.5.0 (2016-11-07) successfully loaded. See ?R.utils for help.
## 
## Attaching package: 'R.utils'
## The following object is masked from 'package:utils':
## 
##     timestamp
## The following objects are masked from 'package:base':
## 
##     cat, commandArgs, getOption, inherits, isOpen, parse, warnings
noaa_raw <- read.csv(bzfile("./Project2/data.csv.bz2"))

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B.2 Exploratory Data Analysis of Raw Data File

Explored the raw data file using the R elements below. Only showing the summary information below.

object.size(noaa_raw)

dim(noaa_raw)

class(noaa_raw)

str(noaa_raw)

head(noaa_raw)

tail(noaa_raw)

sapply(noaa_raw, class)

summary(noaa_raw)
##     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              :   568   Mean   :451149  
##  Trees were downed.\n                          :   446   3rd Qu.:676723  
##  Large trees and power lines were blown down.\n:   432   Max.   :902297  
##  (Other)                                       :588295

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B.3 Subsetting and manipulate columns for data needed in this analysis

noaa_health_subset <- noaa_raw[ ,c("EVTYPE", "FATALITIES","INJURIES","PROPDMG","PROPDMGEXP","CROPDMG","CROPDMGEXP")]
Page 12 of the STORM DATA PREPARATION document indicate that Damage Estimates are rounded to three significant digits, followed by an alphabetical character signifying the magnitude of the number, i.e., 1.55B for $1,550,000,000. Alphabetical characters used to signify magnitude include: “K” for thousands, “M” for millions, and “B” for billions.
Hence, the cost value data in columns in the noaa_health_subset, i.e. “PROPDMG” &“CROPDMG”, need to be adjusted with the corresponding “K” for thousands, “M” for millions, and “B” for billions multiplier as indicated per columns “PROPDMGEXP” & “CROPDMGEXP”. Two new columns are created containg this actual dollar value information. The column PROPDMG_DV is that for the dollar amounts of property damage and CROPDMG_DV is that for the dollar amounts of crop damages.
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

Add Property Damage actual dollar column

noaa_health_subset2<- mutate(noaa_health_subset, 
                                PROPDMG_DV = ifelse(PROPDMGEXP == "H"|PROPDMGEXP == "h", PROPDMG*100,
                                             ifelse(PROPDMGEXP == "K"|PROPDMGEXP == "k", PROPDMG*1000,
                                             ifelse(PROPDMGEXP == "M"|PROPDMGEXP == "m", PROPDMG*1000000,
                                             ifelse(PROPDMGEXP == "B"|PROPDMGEXP == "b", PROPDMG*1000000000,0)))))

Add Crop Damage actual dolloar column

noaa_health_subset3<- mutate(noaa_health_subset2,                              
                                CROPDMG_DV = ifelse(CROPDMGEXP == "H"|CROPDMGEXP == "h", CROPDMG*100,
                                             ifelse(CROPDMGEXP == "K"|CROPDMGEXP == "k", CROPDMG*1000,
                                             ifelse(CROPDMGEXP == "M"|CROPDMGEXP == "m", CROPDMG*1000000,
                                             ifelse(CROPDMGEXP == "B"|CROPDMGEXP == "b", CROPDMG*1000000000,0)))))

Check new entries

head(noaa_health_subset3)
##    EVTYPE FATALITIES INJURIES PROPDMG PROPDMGEXP CROPDMG CROPDMGEXP
## 1 TORNADO          0       15    25.0          K       0           
## 2 TORNADO          0        0     2.5          K       0           
## 3 TORNADO          0        2    25.0          K       0           
## 4 TORNADO          0        2     2.5          K       0           
## 5 TORNADO          0        2     2.5          K       0           
## 6 TORNADO          0        6     2.5          K       0           
##   PROPDMG_DV CROPDMG_DV
## 1      25000          0
## 2       2500          0
## 3      25000          0
## 4       2500          0
## 5       2500          0
## 6       2500          0

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C.1 Results

Q1. Across the United States, which types of events (as indicated in the EVTYPE variable) are most harmful with respect to population health?

Create subset for fatalities

fatalities_subset <- aggregate(FATALITIES~EVTYPE,noaa_health_subset3, sum )
fatalities_subset2 <- fatalities_subset[order(-fatalities_subset$FATALITIES),][1:10,]

Create subset for injuries

injuries_subset <- aggregate(INJURIES~EVTYPE,noaa_health_subset3, sum )
injuries_subset2 <- injuries_subset[order(-injuries_subset$INJURIES),][1:10,]

Create panel with 2 bar plots showing the distribution of fatalities and injuries as a result of severe weather event

par(mfrow=c(1,2), mar = c(11, 5, 3, 2), mgp = c(3, 1, 0), cex = 0.7)
with(fatalities_subset2, barplot(FATALITIES, names.arg = EVTYPE, las=3, main = "Fatalities due to Weather Events",  ylab = "Fatalities", cex.lab = 1.5))
with(injuries_subset2, barplot(INJURIES, names.arg = EVTYPE, las=3, main = "Injuries due to Weather Events",  ylab = "Injuries", cex.lab = 1.5 ))

Q2. Across the United States, which types of events have the greatest economic consequences?

Create subset for property damage

propertydamage_subset <- aggregate(PROPDMG_DV~EVTYPE,noaa_health_subset3, sum )
propertydamage_subset2 <- propertydamage_subset[order(-propertydamage_subset$PROPDMG_DV),][1:10,]

Create subset for crop damage

cropdamage_subset <- aggregate(CROPDMG_DV~EVTYPE,noaa_health_subset3, sum )
cropdamage_subset2 <- cropdamage_subset[order(-cropdamage_subset$CROPDMG_DV),][1:10,]

Create panel with 2 bar plots showing the distribution of property and crop damage as a result of severe weather event

par(mfrow=c(1,2), mar = c(11, 5, 3, 2), mgp = c(3, 1, 0), cex = 0.7)
with(propertydamage_subset2, barplot(PROPDMG_DV/(10^9), las = 3, names.arg = EVTYPE, main = "Property $ Damage due to Weather Events",  ylab = "Property Damage ($ billion)" ))
with(cropdamage_subset2, barplot(CROPDMG_DV/(10^9), las = 3, names.arg = EVTYPE, main = "Crop $ Damage due to Weather Events",  ylab = "Crop Damage ($ billion)" ))

Close the screen device

dev.off()
## null device 
##           1

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D.1 Conclusions

From the graphical presentations in the Results section above it is clear that Tornados by far caused the greatest number of fatalities and injuries. Heat exposure, and floods also play a significant roll.
The maximum dollar impact as a result of severe weather, measured as a function of property and crop damage, is the result of flooding and drought, respectively. Tornados, hurricanes and storm surges also significantly contributes to the former, while flooding, ice storms and hail severely impact crop losses.