Synopsis

In this project, the storm database from the US National Weather service was analyzed with the goal of determining which event had done the most harm to population health and the economy. Our analysis on Fatalities and Injuries, collated as Heath statistics, conclude that the Tornado is the most harmful event in respect to population health. While, based on Property and Crop damages, the data showed that Floods had the greatest economic impact, with total damage costs reaching billions of dollars.

Data Processing

The data was first extracted from a zip file into csv format.
The csv file is then loaded into Rstudio from a preset working directory.

setwd("/Users/DrEmmanuelMeribole/Desktop/Coursera")
StormData1<-read.csv("repdata_data_StormData.csv", stringsAsFactors = T)
summary(StormData1)
##     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

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

The parameter used to describe harm to the health of the population would be the sum of the fatalities and Injuries. This involves the creation of a new column, called Health Statistics.
That is, HealthStats= Fatalities + Injuries

StormData1$HealthStats<- StormData1$FATALITIES + StormData1$INJURIES

Summarize HealthStats by EVTYPE

Since we’re interested in the “most” harmful, the focus would be on the health statistics related to the event type. A Data frame will be generated displaying the total health impact by event. Then we will get the Top 10 events with the most harm to population health.

# Total health impact by event
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
EVhealthStats<- StormData1 %>% group_by(EVTYPE) %>% 
    summarise( HealthStats = sum(HealthStats, na.rm = TRUE)) 
EVhealthStats <- arrange(EVhealthStats, desc(HealthStats))
Top10health<- head(EVhealthStats, 10)
print(Top10health)
## # A tibble: 10 × 2
##    EVTYPE            HealthStats
##    <fct>                   <dbl>
##  1 TORNADO                 96979
##  2 EXCESSIVE HEAT           8428
##  3 TSTM WIND                7461
##  4 FLOOD                    7259
##  5 LIGHTNING                6046
##  6 HEAT                     3037
##  7 FLASH FLOOD              2755
##  8 ICE STORM                2064
##  9 THUNDERSTORM WIND        1621
## 10 WINTER STORM             1527

The Top10health data frame above shows the top 10 event types with the highest impact on population health.

2. Across the United States, which types of events have the greatest economic consequences? .
The economic consequences of the storm events can be summarized by the property damage and crop damage columns, i.e: PROPDMG and CROPDMG.
These columns have multipliers called PROPDMGEXP and CROPDMGEXP, with variables like “K”, “M”, and “B” translating to a multiple of a thousand, a million and a billion respectively.
These multipliers would be applied to the property and crop damage columns, for a complete view of the cost of damages.

library(stringr)
#Property Damage
StormData1$PROPDMGEXP <- str_replace(StormData1$PROPDMGEXP, "K", "1000")
StormData1$PROPDMGEXP <- str_replace(StormData1$PROPDMGEXP, "M", "1000000") 
StormData1$PROPDMGEXP <- str_replace(StormData1$PROPDMGEXP, "B", "1000000000")
#applying the multipliers
StormData1$PROPDMG <- StormData1$PROPDMG * as.numeric(StormData1$PROPDMGEXP)
## Warning: NAs introduced by coercion
# Crop damage
StormData1$CROPDMGEXP <- str_replace(StormData1$CROPDMGEXP, "k", "1000")
StormData1$CROPDMGEXP <- str_replace(StormData1$CROPDMGEXP, "K", "1000")
StormData1$CROPDMGEXP <- str_replace(StormData1$CROPDMGEXP, "m", "1000000") 
StormData1$CROPDMGEXP <- str_replace(StormData1$CROPDMGEXP, "M", "1000000") 
StormData1$CROPDMGEXP <- str_replace(StormData1$CROPDMGEXP, "B", "1000000000")
#applying the multipliers
StormData1$CROPDMG<- StormData1$CROPDMG * as.numeric(StormData1$CROPDMGEXP)
## Warning: NAs introduced by coercion

Total economic impact would now be the sum of property and crop damage, and this sum(Economic Impact, aka EconImpact) would be grouped according to the event type.

StormData1$EconImpact<- StormData1$PROPDMG + StormData1$CROPDMG

EVEconImpact<- StormData1 %>% group_by(EVTYPE) %>% 
    summarise( EconImpact = sum(EconImpact, na.rm = TRUE)) 
EVEconImpact <- arrange(EVEconImpact, desc(EconImpact))
Top10Econ<- head(EVEconImpact, 10)
print(Top10Econ)
## # A tibble: 10 × 2
##    EVTYPE              EconImpact
##    <fct>                    <dbl>
##  1 FLOOD             138007444500
##  2 HURRICANE/TYPHOON  29348167800
##  3 TORNADO            16570326150
##  4 HURRICANE          12405268000
##  5 RIVER FLOOD        10108369000
##  6 HAIL               10045596740
##  7 FLASH FLOOD         8715885162
##  8 ICE STORM           5925150800
##  9 STORM SURGE/TIDE    4641493000
## 10 THUNDERSTORM WIND   3813647990

The Top10Econ data frame above shows the top 10 event types with the highest economic impact.

RESULTS

1. Answer to Question 1: Events that are most harmful with respect to population health

To answer this,The top 10 harmful events will be visually represented on a bar chart.

library(ggplot2)
ggplot(Top10health, aes(EVTYPE, HealthStats)) + 
    geom_bar(stat = "identity") + 
  theme(axis.text.x = element_text(angle = 45, hjust=1)) + 
    xlab("") +
    ylab("population health stats") +
    ggtitle("Top 10 events impacting population health")

From the bar chart above, we can see the events that have caused the most harm to the population and can infer that the most impactful event is the Tornado.

2. Answer to Question 2: Events that have the greatest economic consequences

library(ggplot2)
ggplot(Top10Econ, aes(EVTYPE, y=EconImpact/1e9)) + 
    geom_bar(stat = "identity") +
  theme(axis.text.x = element_text(angle = 45, hjust=1)) + 
    xlab("") +
    ylab("Damage Costs(in billion USD)") +
    ggtitle("Top 10 events with highest economic impact")

From the chart above, we can infer that the highest economic impact is dealt by floods.