Synopsis

Storms and other severe weather events can cause both public health and economic problems for communities and municipalities. Many severe events can result in fatalities, injuries, and property damage, and preventing such outcomes to the extent possible is a key concern.

This project involves exploring the U.S. National Oceanic and Atmospheric Administration’s (NOAA) storm database. 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.

The basic goal of this assignment is to explore the NOAA Storm Database and answer some basic questions about severe weather events.

The followong analysis investigates Fatalities to: - Health (injuries and fatalities) - Properties and Crops (economic consequences)

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

Data Processing

#importing library for plot
library(ggplot2)
Url<-"https://d396qusza40orc.cloudfront.net/repdata%2Fdata%2FStormData.csv.bz2"
#Downloading the Data
download.file(Url,destfile = "storm_data.csv")
storm_data<-read.csv("storm_data.csv")
head(storm_data)

Exploring Columns

colnames(storm_data)
##  [1] "STATE__"    "BGN_DATE"   "BGN_TIME"   "TIME_ZONE"  "COUNTY"    
##  [6] "COUNTYNAME" "STATE"      "EVTYPE"     "BGN_RANGE"  "BGN_AZI"   
## [11] "BGN_LOCATI" "END_DATE"   "END_TIME"   "COUNTY_END" "COUNTYENDN"
## [16] "END_RANGE"  "END_AZI"    "END_LOCATI" "LENGTH"     "WIDTH"     
## [21] "F"          "MAG"        "FATALITIES" "INJURIES"   "PROPDMG"   
## [26] "PROPDMGEXP" "CROPDMG"    "CROPDMGEXP" "WFO"        "STATEOFFIC"
## [31] "ZONENAMES"  "LATITUDE"   "LONGITUDE"  "LATITUDE_E" "LONGITUDE_"
## [36] "REMARKS"    "REFNUM"

Extracting Necessary columns

storm_event<-storm_data[, c("BGN_DATE", "EVTYPE", "FATALITIES", "INJURIES", "PROPDMG", "PROPDMGEXP", "CROPDMG", "CROPDMGEXP")]
summary(storm_event)
##    BGN_DATE            EVTYPE            FATALITIES          INJURIES        
##  Length:902297      Length:902297      Min.   :  0.0000   Min.   :   0.0000  
##  Class :character   Class :character   1st Qu.:  0.0000   1st Qu.:   0.0000  
##  Mode  :character   Mode  :character   Median :  0.0000   Median :   0.0000  
##                                        Mean   :  0.0168   Mean   :   0.1557  
##                                        3rd Qu.:  0.0000   3rd Qu.:   0.0000  
##                                        Max.   :583.0000   Max.   :1700.0000  
##     PROPDMG         PROPDMGEXP           CROPDMG         CROPDMGEXP       
##  Min.   :   0.00   Length:902297      Min.   :  0.000   Length:902297     
##  1st Qu.:   0.00   Class :character   1st Qu.:  0.000   Class :character  
##  Median :   0.00   Mode  :character   Median :  0.000   Mode  :character  
##  Mean   :  12.06                      Mean   :  1.527                     
##  3rd Qu.:   0.50                      3rd Qu.:  0.000                     
##  Max.   :5000.00                      Max.   :990.000

5 Events that contributes to most injuries and Fatalities

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
Total_injuries<-storm_event %>% group_by(EVTYPE) %>% summarise(FATALITIES = sum(FATALITIES), 
            INJURIES = sum(INJURIES), totals = sum(FATALITIES) + sum(INJURIES))

Total_injuries<-Total_injuries[order(-Total_injuries$FATALITIES),]
head(Total_injuries,5)

Reshaping The data for plots

library(reshape)
## Warning: package 'reshape' was built under R version 4.3.2
## 
## Attaching package: 'reshape'
## The following object is masked from 'package:dplyr':
## 
##     rename
New_data<-as.data.frame(head(Total_injuries,5))
#Reshaping the dataset for plot
df<-melt(New_data, id.vars="EVTYPE")
colnames(df)
## [1] "EVTYPE"   "variable" "value"

Results

# Create chart
ggplot(df,aes(x=reorder(EVTYPE,-value),y=value, fill=variable))+
    geom_bar( stat = "identity",position="dodge")+ylab("Frequency Count")+ theme(plot.title = element_text(hjust = 0.5))+xlab("Event Type")+theme(axis.text.x = element_text(angle=45, hjust=1))+
  ggtitle("Top 5 US Calamities") + theme(plot.title = element_text(hjust = 0.5))

- The bar chart clearly shows that tornadoes are the primary cause of injuries and fatalities resulting from natural disasters in the US.

2. Which types of events have the greatest economic consequences in US?

Filtering DATA

unique(storm_event$PROPDMGEXP)
##  [1] "K" "M" ""  "B" "m" "+" "0" "5" "6" "?" "4" "2" "3" "h" "7" "H" "-" "1" "8"
unique(storm_event$CROPDMGEXP)
## [1] ""  "M" "K" "m" "B" "?" "0" "k" "2"
# Map property damage alphanumeric exponents to numeric values.
storm_event$PROPDMGEXP_number <-  recode(storm_event$PROPDMGEXP,
                 " " = 10^0,
                 "-" = 10^0, 
                 "+" = 10^0,
                 "0" = 10^0,
                 "1" = 10^1,
                 "2" = 10^2,
                 "3" = 10^3,
                 "4" = 10^4,
                 "5" = 10^5,
                 "6" = 10^6,
                 "7" = 10^7,
                 "8" = 10^8,
                 "9" = 10^9,
                 "H" = 10^2,
                 "K" = 10^3,
                 "M" = 10^6,
                 "B" = 10^9,
                 .default = 10^0)

# Map crop damage alphanumeric exponents to numeric values
storm_event$CROPDMGEXP_number <-  recode(storm_event$CROPDMGEXP,
                                  " " = 10^0,
                                  "?" = 10^0, 
                                  "0" = 10^0,
                                  "K" = 10^3,
                                  "M" = 10^6,
                                  "B" = 10^9,
                                  .default = 10^0)

#Cost of Damaged Property and Crop 
storm_event$PropCost<-storm_event$PROPDMG * storm_event$PROPDMGEXP_number
storm_event$CropCost<-storm_event$CROPDMG * storm_event$CROPDMGEXP_number

Preparing Dataset for plotting

TotalCost<-storm_event %>% group_by(EVTYPE) %>% summarise(PropCost = sum(PropCost), 
            CropCost = sum(CropCost), total_cost = sum(PropCost) + sum(CropCost))

TotalCost<-TotalCost[order(-TotalCost$total_cost),]
New_cost<-as.data.frame(head(TotalCost,5))
df_cost<-melt(New_cost, id.vars="EVTYPE")
colnames(df_cost)
## [1] "EVTYPE"   "variable" "value"

Results

ggplot(df_cost,aes(x=reorder(EVTYPE,-value),y=value, fill=variable))+
    geom_bar( stat = "identity",position="dodge")+ylab("Frequency Count")+ theme(plot.title = element_text(hjust = 0.5))+xlab("Event Type")+theme(axis.text.x = element_text(angle=45, hjust=1)) + ggtitle("Top 5 US Storm Events causing Economic Consequences")+
  theme(plot.title = element_text(hjust = 0.5))

-In the United States, floods cause the most financial damage from natural disasters, with hurricanes or typhoons coming in a close second.