Synopsis

The goal of this assignment is to explore the NOAA Storm Database and answer some basic questions about severe weather events. This data analysis address’ the following two questions:

The orginal data can be found from here: Storm Data

Data Processing

# downloads and saves NOAA Storm Data in a variable called 'initial.data'
url <- "https://d396qusza40orc.cloudfront.net/repdata%2Fdata%2FStormData.csv.bz2"
download.file(url, destfile = "repdata%2Fdata%2FStormData.csv.bz2")
# creates a master data
initial.data <- read.csv(bzfile("repdata%2Fdata%2FStormData.csv.bz2"))

See the summary of the data

summary(initial.data)
##     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

Results

Question #1

Across the United States, which types of events (as indicated in the 𝙴𝚅𝚃𝚈𝙿𝙴 variable) are most harmful with respect to population health? To solve this problem we will need the following columns from our data: * EVTYPE: The type of the environmental disasters (Tornado, High Wind, Snow, etc.) * FATALITIES: Both direct and indirect fatalities caused by the environmental disaster. * INJURIES: Both direct and indirect injuries caused by the environmental disaster.

# subsets the initial data
health <- initial.data[,c("EVTYPE", "FATALITIES", "INJURIES")]

# shows unique disasters
length(unique(health[,"EVTYPE"]))
## [1] 985
# takes sum of each disaster type for both 'Injuries' and 'Fatalities' and adds them
agg.health <- aggregate(health$FATALITIES + health$INJURIES ~ health$EVTYPE , FUN=sum, na.rm=TRUE)
# sorts from the highest to the lowest and saves top five in "TopH"
sorted.health <- agg.health[order(-agg.health$`health$FATALITIES + health$INJURIES`),]
TopH <- head(sorted.health)

Answer to Question #1

NOAA Storm Data shows us that ‘TORNADO’ is the most harmful environmental disaster in United states with respect to population health. See the graph below to find the full information.

barplot (height = TopH$`health$FATALITIES + health$INJURIES`, 
         names.arg = TopH$`health$EVTYPE`, las = 2, cex.names= 0.7, 
         col = rainbow (30, start=.1, end=0.5))
title ("Top 5 Disasters: Injuries + Fatalities", line=-4)

Question #2

Across the United States, which types of events have the greatest economic consequences? To answer this question we will need all the columns which are related to economics the following columns from the master data: * EVTYPE: The type of the environmental disasters (Tornado, High Wind, Snow, etc.) * PROPDMG: The total property damage rounded to three significant digits used in conjunction with PROPDMGEXP to determine the appropriate size multiplier. * PROPDMGEXP: A letter code indicating the magnitude of the PROPDMG dollar amount {“K”,“M”,“B”} for “thousands”, “millions” and “billions” respectively. * CROPDMG: The total crop damage rounded to three significant digits used in conjunction with CROPDMGEXP to determine the the appropriate size multiplier. * CROPDMGEXP: A letter code indicating the magnitude of the CROPDMG dollar amount {“K”,“M”,“B”} for “thousands”, “millions” and “billions” respectively.

# subsets the initial dataset to choose only the columns we need to answer the second question
economic <- initial.data[,c("EVTYPE", "PROPDMG", "PROPDMGEXP", "CROPDMG", "CROPDMGEXP")]

# how does the dataset look like?
head(economic)
##    EVTYPE PROPDMG PROPDMGEXP CROPDMG CROPDMGEXP
## 1 TORNADO    25.0          K       0           
## 2 TORNADO     2.5          K       0           
## 3 TORNADO    25.0          K       0           
## 4 TORNADO     2.5          K       0           
## 5 TORNADO     2.5          K       0           
## 6 TORNADO     2.5          K       0
# multiplies PROPDMG by PROPDMGEXP
economic[economic$PROPDMGEXP == "K", ]$PROPDMG <- economic[economic$PROPDMGEXP == "K", ]$PROPDMG * 1000
economic[economic$PROPDMGEXP == "K", ]$PROPDMG <- economic[economic$PROPDMGEXP == "K", ]$PROPDMG * 1000
economic[economic$PROPDMGEXP == "M", ]$PROPDMG <- economic[economic$PROPDMGEXP == "M", ]$PROPDMG * 1000000
economic[economic$PROPDMGEXP == "m", ]$PROPDMG <- economic[economic$PROPDMGEXP == "m", ]$PROPDMG * 1000000
economic[economic$PROPDMGEXP == "B", ]$PROPDMG <- economic[economic$PROPDMGEXP == "B", ]$PROPDMG * 1000000000
# multiplies CROPDMG by CROPDMGEXP
economic[economic$CROPDMGEXP == "K", ]$CROPDMG <- economic[economic$CROPDMGEXP == "K", ]$CROPDMG * 1000
economic[economic$CROPDMGEXP == "k", ]$CROPDMG <- economic[economic$CROPDMGEXP == "k", ]$CROPDMG * 1000
economic[economic$CROPDMGEXP == "M", ]$CROPDMG <- economic[economic$CROPDMGEXP == "M", ]$CROPDMG * 1000000
economic[economic$CROPDMGEXP == "m", ]$CROPDMG <- economic[economic$CROPDMGEXP == "m", ]$CROPDMG * 1000000
economic[economic$CROPDMGEXP == "B", ]$CROPDMG <- economic[economic$CROPDMGEXP == "B", ]$CROPDMG * 1000000000
# aggregates cost of damages from crops and properties based on type of disasters 
agg.economic <- aggregate(economic$CROPDMG + economic$PROPDMG ~ economic$EVTYPE , FUN=sum, na.rm=TRUE)
# puts the cost of damages in an descending order
sorted.economic <- agg.economic[order(-agg.economic$`economic$CROPDMG + economic$PROPDMG`),]

# saves top five in a varibale called "TopE"
TopE <- head(sorted.economic)

Answer to Question #2

Across the United States, ‘Flood’ has the greatest economic consequences followed by ‘HURRICANE/TYPHOON’ and ‘STORM SURGE’. See the graph below to find the full information.

barplot (height = TopE$`economic$CROPDMG + economic$PROPDMG`, 
         names.arg = TopE$`economic$EVTYPE`, las = 2, cex.names= 0.7, 
         col = rainbow (30, start=.1, end=0.5))
title ("Top 5 Economical Damages: Crop + Property", line=-4)