U.S. NOAA Storm Data Analysis

Synopsis

Severe weather conditions can cause both public health and economic problems for communities and municipalities across the U.S..In this research project, we are aiming to analyze the storm data from U.S. National Oceanic and Atmospheric Administration’s (NOAA) storm database, which tracks characteristics of major storms and weather events. We will look to address two questions using this data: 1. Across the U.S., which type of events (as indicated in the EVTYPE variable) are most harmful with respect to population health? 2. Across the United States, which types of events have the greatest economic consequences?

Data Processing

This section will process the dataset and read it into environment to prepare for analysis

setwd("C:/Users/Charlie/Desktop/Data Science/Reproducible Research")
library(plyr)
library(reshape2)
library(R.utils)
#bunzip2("repdata-data-StormData.csv.bz2", "stormData.csv", remove=FALSE)
stormData <- read.csv("stormData.csv", sep = ",")
head(stormData)
##   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

Exploratory Analysis

We will look at the data first to see what variables are in the dataset, and in particular for the fields that will be used to answer our two questions.

str(stormData)
## 'data.frame':    902297 obs. of  37 variables:
##  $ STATE__   : num  1 1 1 1 1 1 1 1 1 1 ...
##  $ BGN_DATE  : Factor w/ 16335 levels "1/1/1966 0:00:00",..: 6523 6523 4242 11116 2224 2224 2260 383 3980 3980 ...
##  $ BGN_TIME  : Factor w/ 3608 levels "00:00:00 AM",..: 272 287 2705 1683 2584 3186 242 1683 3186 3186 ...
##  $ TIME_ZONE : Factor w/ 22 levels "ADT","AKS","AST",..: 7 7 7 7 7 7 7 7 7 7 ...
##  $ COUNTY    : num  97 3 57 89 43 77 9 123 125 57 ...
##  $ COUNTYNAME: Factor w/ 29601 levels "","5NM E OF MACKINAC BRIDGE TO PRESQUE ISLE LT MI",..: 13513 1873 4598 10592 4372 10094 1973 23873 24418 4598 ...
##  $ STATE     : Factor w/ 72 levels "AK","AL","AM",..: 2 2 2 2 2 2 2 2 2 2 ...
##  $ EVTYPE    : Factor w/ 985 levels "   HIGH SURF ADVISORY",..: 834 834 834 834 834 834 834 834 834 834 ...
##  $ BGN_RANGE : num  0 0 0 0 0 0 0 0 0 0 ...
##  $ BGN_AZI   : Factor w/ 35 levels "","  N"," NW",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ BGN_LOCATI: Factor w/ 54429 levels "","- 1 N Albion",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ END_DATE  : Factor w/ 6663 levels "","1/1/1993 0:00:00",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ END_TIME  : Factor w/ 3647 levels ""," 0900CST",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ COUNTY_END: num  0 0 0 0 0 0 0 0 0 0 ...
##  $ COUNTYENDN: logi  NA NA NA NA NA NA ...
##  $ END_RANGE : num  0 0 0 0 0 0 0 0 0 0 ...
##  $ END_AZI   : Factor w/ 24 levels "","E","ENE","ESE",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ END_LOCATI: Factor w/ 34506 levels "","- .5 NNW",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ LENGTH    : num  14 2 0.1 0 0 1.5 1.5 0 3.3 2.3 ...
##  $ WIDTH     : num  100 150 123 100 150 177 33 33 100 100 ...
##  $ F         : int  3 2 2 2 2 2 2 1 3 3 ...
##  $ MAG       : num  0 0 0 0 0 0 0 0 0 0 ...
##  $ FATALITIES: num  0 0 0 0 0 0 0 0 1 0 ...
##  $ INJURIES  : num  15 0 2 2 2 6 1 0 14 0 ...
##  $ PROPDMG   : num  25 2.5 25 2.5 2.5 2.5 2.5 2.5 25 25 ...
##  $ PROPDMGEXP: Factor w/ 19 levels "","-","?","+",..: 17 17 17 17 17 17 17 17 17 17 ...
##  $ CROPDMG   : num  0 0 0 0 0 0 0 0 0 0 ...
##  $ CROPDMGEXP: Factor w/ 9 levels "","?","0","2",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ WFO       : Factor w/ 542 levels ""," CI","$AC",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ STATEOFFIC: Factor w/ 250 levels "","ALABAMA, Central",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ ZONENAMES : Factor w/ 25112 levels "","                                                                                                                               "| __truncated__,..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ LATITUDE  : num  3040 3042 3340 3458 3412 ...
##  $ LONGITUDE : num  8812 8755 8742 8626 8642 ...
##  $ LATITUDE_E: num  3051 0 0 0 0 ...
##  $ LONGITUDE_: num  8806 0 0 0 0 ...
##  $ REMARKS   : Factor w/ 436774 levels "","-2 at Deer Park\n",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ REFNUM    : num  1 2 3 4 5 6 7 8 9 10 ...

We found that the following columns are of interest to us when trying to answer these questions: EVTYPE, FATALITIES, INJURIES, PROPDMG, PROPDMGEXP, CROPDMG, CROPDMGEXP. Thus, we will take this subset of data and look at it more closely.

col <- c("EVTYPE", "FATALITIES", "INJURIES", "PROPDMG", "PROPDMGEXP", "CROPDMG", "CROPDMGEXP")
storm2 <- stormData[,col]

Weather Event Impact on Public Health

We will take a look at the type of weather event that has had major impact on public health by looking at EVTYPE, FATALITIES, INJURIES variables in the dataset.

fatal <- aggregate(FATALITIES ~ EVTYPE, data = storm2, FUN = sum)
injury <- aggregate(INJURIES ~ EVTYPE, data = storm2, FUN = sum)
# rank the top 10 weather events in terms of fatalities and injuries
topfatal <- fatal[order(-fatal$FATALITIES), ][1:10, ]
topinjury <- injury[order(-injury$INJURIES), ][1:10, ]
par(mfrow = c(1, 2), mar = c(12, 4, 3, 2), mgp = c(3, 1, 0), cex = 0.9)
barplot(topfatal$FATALITIES, las = 3, names.arg = topfatal$EVTYPE, main = "Weather Events With The Top 10 Highest Fatalities", ylab = "number of fatalities", col = "gray")
barplot(topinjury$INJURIES, las = 3, names.arg = topinjury$EVTYPE, main = "Weather Events With the Top 10 Highest Injuries", ylab = "number of injuries", col = "blue")

Weather Event Impact on Economy

Impact on Properties

We will prepare the PROPDMG, PROPDMGEXP data for our analysis on weather events’ impact that causes property damages.

unique(storm2$PROPDMGEXP)
##  [1] K M   B m + 0 5 6 ? 4 2 3 h 7 H - 1 8
## Levels:  - ? + 0 1 2 3 4 5 6 7 8 B h H K m M
# convert data in PROPDMGEXP to quantitative values
storm2$PROPEXP[storm2$PROPDMGEXP == "K"] <- 1000
storm2$PROPEXP[storm2$PROPDMGEXP == "M"] <- 1000000
storm2$PROPEXP[storm2$PROPDMGEXP == ""] <- 1
storm2$PROPEXP[storm2$PROPDMGEXP == "B"] <- 1000000000
storm2$PROPEXP[storm2$PROPDMGEXP == "m"] <- 1000000
storm2$PROPEXP[storm2$PROPDMGEXP == "0"] <- 1
storm2$PROPEXP[storm2$PROPDMGEXP == "5"] <- 100000
storm2$PROPEXP[storm2$PROPDMGEXP == "6"] <- 1000000
storm2$PROPEXP[storm2$PROPDMGEXP == "4"] <- 10000
storm2$PROPEXP[storm2$PROPDMGEXP == "2"] <- 100
storm2$PROPEXP[storm2$PROPDMGEXP == "3"] <- 1000
storm2$PROPEXP[storm2$PROPDMGEXP == "h"] <- 100
storm2$PROPEXP[storm2$PROPDMGEXP == "7"] <- 10000000
storm2$PROPEXP[storm2$PROPDMGEXP == "H"] <- 100
storm2$PROPEXP[storm2$PROPDMGEXP == "1"] <- 10
storm2$PROPEXP[storm2$PROPDMGEXP == "8"] <- 100000000
storm2$PROPEXP[storm2$PROPDMGEXP == "+"] <- 0
storm2$PROPEXP[storm2$PROPDMGEXP == "-"] <- 0
storm2$PROPEXP[storm2$PROPDMGEXP == "?"] <- 0
# Computing the amount of total property damage for each weather event
storm2$PROPDMGVAL <- storm2$PROPDMG * storm2$PROPEXP

Impact on Crops

unique(storm2$CROPDMGEXP)
## [1]   M K m B ? 0 k 2
## Levels:  ? 0 2 B k K m M
# convert data in CROPDMGEXP to quantitative values
storm2$CROPEXP[storm2$CROPDMGEXP == "M"] <- 1000000
storm2$CROPEXP[storm2$CROPDMGEXP == "m"] <- 1000000
storm2$CROPEXP[storm2$CROPDMGEXP == "K"] <- 1000
storm2$CROPEXP[storm2$CROPDMGEXP == "k"] <- 1000
storm2$CROPEXP[storm2$CROPDMGEXP == "B"] <- 1000000000
storm2$CROPEXP[storm2$CROPDMGEXP == "0"] <- 1
storm2$CROPEXP[storm2$CROPDMGEXP == "2"] <- 100
storm2$CROPEXP[storm2$CROPDMGEXP == "?"] <- 0
# Compute total damage to crops
storm2$CROPDMGVAL <- storm2$CROPDMG * storm2$CROPEXP

Now, we quantify and visualize the total amount damage in $ to crops and properties

propdmg <- aggregate(PROPDMGVAL ~ EVTYPE, data = storm2, FUN = sum)
cropdmg <- aggregate(CROPDMGVAL ~ EVTYPE, data = storm2, FUN = sum)
# ranking top 10 events with highest amount in property damage
toppropdmg <- propdmg[order(-propdmg$PROPDMGVAL), ][1:10, ]
# ranking top 10 events with highest amount in crop damage
topcropdmg <- cropdmg[order(-cropdmg$CROPDMGVAL), ][1:10, ]
par(mfrow = c(1, 2), mar = c(12, 4, 3, 2), mgp = c(3, 1, 0), cex = 0.8)
barplot(toppropdmg$PROPDMGVAL/(10^9), las = 3, names.arg = toppropdmg$EVTYPE, main = "Top 10 Events with Highest Amount of Damages to Properties", ylab = "Total Cost of damages in billions", col = "lightblue1")
barplot(topcropdmg$CROPDMGVAL/(10^9), las = 3, names.arg = topcropdmg$EVTYPE, main = "Top 10 Events With Highst Amount Damages to Crops", ylab = "Total Cost of damages in billions", col = "lightblue4")

Results

From the research above, we can conclude the following weather events that are most harmful (cause the most damages) to public health are:

Tornado, Excessive Heat, Flood

Also derived from our research, we can conclude that the following weather events have the greatest economic consequences:

Flood, Drought, Tornado and Hurricanes