Synopsis

This report is aimed at describing severe weather events which are harmful to the population health and that have economic consequences. To analyse the events, the events which caused most fatalities, injuries and economic consequences were plotted. The data is an official publication of the National Oceanic and Atmospheric Administration (NOAA) and the documentation can be found here.

Data Processing

The data was downloaded from the course website, in which is also possible to download the documentation. ###Reading in the Storm Data First, the download was carried using the package downloader. Then, the file is read using the read.csv function. Turn on cache to make the process faster.

library(downloader)
## Warning: package 'downloader' was built under R version 3.1.2
download("http://d396qusza40orc.cloudfront.net/repdata%2Fdata%2FStormData.csv.bz2", dest="stormData.csv.bz2", mode = "wb")
storm <- read.csv("stormData.csv.bz2")

Cleaning the data

Call the head to choose only the info related to the questions (event, harmful, economic consequences).

head(storm)
##   STATE__           BGN_DATE BGN_TIME TIME_ZONE COUNTY COUNTYNAME STATE
## 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
##    EVTYPE BGN_RANGE BGN_AZI BGN_LOCATI END_DATE END_TIME COUNTY_END
## 1 TORNADO         0                                               0
## 2 TORNADO         0                                               0
## 3 TORNADO         0                                               0
## 4 TORNADO         0                                               0
## 5 TORNADO         0                                               0
## 6 TORNADO         0                                               0
##   COUNTYENDN END_RANGE END_AZI END_LOCATI LENGTH WIDTH F MAG FATALITIES
## 1         NA         0                      14.0   100 3   0          0
## 2         NA         0                       2.0   150 2   0          0
## 3         NA         0                       0.1   123 2   0          0
## 4         NA         0                       0.0   100 2   0          0
## 5         NA         0                       0.0   150 2   0          0
## 6         NA         0                       1.5   177 2   0          0
##   INJURIES PROPDMG PROPDMGEXP CROPDMG CROPDMGEXP WFO STATEOFFIC ZONENAMES
## 1       15    25.0          K       0                                    
## 2        0     2.5          K       0                                    
## 3        2    25.0          K       0                                    
## 4        2     2.5          K       0                                    
## 5        2     2.5          K       0                                    
## 6        6     2.5          K       0                                    
##   LATITUDE LONGITUDE LATITUDE_E LONGITUDE_ REMARKS REFNUM
## 1     3040      8812       3051       8806              1
## 2     3042      8755          0          0              2
## 3     3340      8742          0          0              3
## 4     3458      8626          0          0              4
## 5     3412      8642          0          0              5
## 6     3450      8748          0          0              6
stormSlim <- storm[ , c("EVTYPE", "FATALITIES", "INJURIES", "PROPDMG")]

Results

1. Across the United States, which types of events (as indicated in the EVTYPE variable) are most harmful with respect to population health? Aggregate the sum of injuries and the sum of fatalites per event types. Then organise them in decreasing order.

typeInjuries <- aggregate(INJURIES ~ EVTYPE, data = stormSlim, sum)
orderedInj <- typeInjuries[order(typeInjuries$INJURIES, decreasing = TRUE), ]

typeFatalities <- aggregate(FATALITIES ~ EVTYPE, data = stormSlim, sum)
orderedFat <- typeFatalities[order(typeFatalities$FATALITIES, decreasing = TRUE),]

Using ggplot, create 2 histogram of the 4 events with most fatalities and events.

library(ggplot2)

p1 <- ggplot(orderedInj[1:4, ], aes(EVTYPE, INJURIES)) + geom_bar(stat = "identity") + ylab("Injuries") + xlab("Events") + ggtitle("Most Harmful Events: Injuries")

p2 <- ggplot(orderedFat[1:4, ], aes(EVTYPE, FATALITIES)) + geom_bar(stat = "identity") + ylab("Fatalities") + xlab("Events") + ggtitle("Most Harmful Events: Fatalities")

Plot the histograms (using the package gridExtra).

library(gridExtra)
## Loading required package: grid
grid.arrange(p1, p2, nrow=2)

2. Across the United States, which types of events have the greatest economic consequences? Aggregate the sum of property damage per event types. Then organise them in decreasing order.

typeProp <- aggregate(PROPDMG ~ EVTYPE, data = stormSlim, sum)
orderedProp <- typeProp[order(typeProp$PROPDMG, decreasing = TRUE), ]

Using ggplot, create a histogram of property damage versus event types.

ggplot(orderedProp[1:4, ], aes(EVTYPE, PROPDMG)) + geom_bar(stat = "identity") + ylab("Property Damage") + xlab("Events") + ggtitle("Events X Greatest Economic Consequences")