Analysis of the adverse impacts caused by storms in the U.S.

1. Synopsis

The goal of the assignment is to study the effects of severe weather events on both the U.S. population and the economy. To carry out the task, the National Oceanic and Atmospheric Administration’s (NOAA) storm database is going to be explored. This database 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.

Thus, key questions addressed by the report are as follows:

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

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

RStudio is going be used to answer these questions.

2. Loading and reading the data into R

First, we’ll download and read the data into R.

# Loading the data (the file has preliminarily been downloaded))
StormData <- read.csv("repdata%2Fdata%2FStormData.csv")
# A quick glance to the structure of this data set
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

3. Subset the data required for the analysis

In the second step, we’ll summarise and filter the required data.

3.1. Selection of the human population damage data: fatalities and injuries (variables “FATALITIES”, “INJURIES”, “INCIDENTS”), removal of the small outliers.

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
population_damage <- StormData %>% 
group_by(EVTYPE) %>% 
mutate(INCIDENTS=max(INJURIES, FATALITIES)) %>%
                  summarise(injur = max(INJURIES),
                            fatal = max(FATALITIES),
                            incid = max(INCIDENTS)) %>%
                  arrange(incid) %>%
                  filter(incid > 500)
health_type <- order(population_damage$incid, decreasing=TRUE)

3.2. Selection of the property damage data to estimate impact on the ecomomy: (variable “CROPDMG”, “PROPDMG”), removal of the small outliers.

economy_damage <- StormData %>%
              group_by(EVTYPE) %>%
              summarise(crops = max(CROPDMG),
                        properties = max (PROPDMG)) %>%
              mutate(total_damage=crops+properties) %>%
              filter(total_damage > 3000) %>%
              arrange(total_damage)
damage_type <- order(economy_damage$total_damage, decreasing=TRUE)

4. Visual presentation of the results

4.1. Creating a barplot for the human population damage:

population_damage$names <- as.character(population_damage$EVTYPE)

for (i in 1:length(population_damage$names)) {
    lsname <- strsplit(population_damage$names[i], split=" ")
    population_damage$names[i] = paste(unlist(lsname), collapse="\n")
}

barplot(names.arg=tolower(as.character(factor(population_damage$names[health_type]) )),
        height=t(as.matrix(population_damage[health_type,2:3])),
        xlab="Event",
        ylab="Number of incidents",
        main="U.S. human population damage", col = c("blue", "red"), beside=TRUE)

legend("topright", lty= c(1,1), lwd = c(3,3), c("Injuries", "Fatalities"), col=c("blue", "red"))

Arrange the most harmful events by the number of maximum number of incidents

head(arrange(population_damage, desc(incid)), 6)
## # A tibble: 6 x 5
##   EVTYPE            injur fatal incid names            
##   <fct>             <dbl> <dbl> <dbl> <chr>            
## 1 TORNADO            1700   158  1700 TORNADO          
## 2 ICE STORM          1568     6  1568 "ICE\nSTORM"     
## 3 FLOOD               800    15   800 FLOOD            
## 4 HURRICANE/TYPHOON   780    15   780 HURRICANE/TYPHOON
## 5 HEAT                230   583   583 HEAT             
## 6 EXCESSIVE HEAT      519    99   519 "EXCESSIVE\nHEAT"

4.2. Creating a barplot presenting the damage for economy (crops and property):

economy_damage$names <- as.character(economy_damage$EVTYPE)
for (i in 1:length(economy_damage$names)) {
    lsname <- strsplit(economy_damage$names[i], split=" ")
    economy_damage$names[i] = paste(unlist(lsname), collapse="\n")
}

barplot(names.arg=tolower(as.character(factor(economy_damage$names[damage_type]) )),
        height=t(as.matrix(economy_damage[damage_type,2:3])),
        xlab="Event",
        ylab="Damage USD",
        main="Damage to the economy", col = c("yellow", "green"))

legend("topright", lty= c(1,1), lwd = c(3,3), c("Property damage", "Crop damage"), col=c("yellow", "green"))

Arrange the most harmful events by the most financial impact on the economy^:

head(arrange(economy_damage, desc(total_damage)), 6)
## # A tibble: 6 x 5
##   EVTYPE            crops properties total_damage names               
##   <fct>             <dbl>      <dbl>        <dbl> <chr>               
## 1 FLASH FLOOD         950       5000         5950 "FLASH\nFLOOD"      
## 2 THUNDERSTORM WIND   800       5000         5800 "THUNDERSTORM\nWIND"
## 3 TORNADO             900       4410         5310 TORNADO             
## 4 WATERSPOUT            0       5000         5000 WATERSPOUT          
## 5 LANDSLIDE            20       4800         4820 LANDSLIDE           
## 6 FLOOD               978       3000         3978 FLOOD

5. Conclusion

  1. According to the National Oceanic and Atmospheric Administration’s (NOAA) storm database we can conlcude that tornadoes had the most harmful effect with respect to population health (injuries), and so had heat to deaths.

  2. According to the National Oceanic and Atmospheric Administration’s (NOAA) storm database we can conlcude that flash floows had the most harmful effect with respect to the economy.