rainfall report

Author

team 5

title: “Monthly Rainfall Trends in Indian Cities” author: “Team 5” format: pdf execute: echo: true —

Introduction

Rainfall plays a crucial role in understanding climate patterns across different regions.
India experiences significant seasonal variations due to monsoon systems.

This report analyzes monthly rainfall trends across five major Indian cities using data visualization techniques.

Objective

  • Analyze monthly rainfall trends
  • Compare rainfall patterns across cities
  • Identify seasonal variations
  • Visualize trends using area charts

Dataset

The dataset contains monthly rainfall (in millimeters) for five cities: Delhi, Mumbai, Chennai, Kolkata, and Bangalore.

data <- data.frame(
  Month = factor(month.abb, levels = month.abb),
  Delhi = c(20,15,10,5,20,80,180,200,120,40,10,5),
  Mumbai = c(1,1,0,5,50,500,800,700,300,100,20,5),
  Chennai = c(10,5,10,20,50,60,80,100,150,300,350,200),
  Kolkata = c(10,20,30,50,150,300,400,350,250,100,30,10),
  Bangalore = c(5,10,20,40,100,120,150,180,130,80,40,10)
)

data
   Month Delhi Mumbai Chennai Kolkata Bangalore
1    Jan    20      1      10      10         5
2    Feb    15      1       5      20        10
3    Mar    10      0      10      30        20
4    Apr     5      5      20      50        40
5    May    20     50      50     150       100
6    Jun    80    500      60     300       120
7    Jul   180    800      80     400       150
8    Aug   200    700     100     350       180
9    Sep   120    300     150     250       130
10   Oct    40    100     300     100        80
11   Nov    10     20     350      30        40
12   Dec     5      5     200      10        10

Data Transformation

To visualize the data effectively, it is converted from wide format to long format.

library(tidyr)

data_long <- pivot_longer(
  data,
  -Month,
  names_to = "City",
  values_to = "Rainfall"
)

head(data_long)
# A tibble: 6 × 3
  Month City      Rainfall
  <fct> <chr>        <dbl>
1 Jan   Delhi           20
2 Jan   Mumbai           1
3 Jan   Chennai         10
4 Jan   Kolkata         10
5 Jan   Bangalore        5
6 Feb   Delhi           15

Visualization

An area chart is used to visualize rainfall trends across different cities.

library(ggplot2)

ggplot(data_long, aes(x = Month, y = Rainfall, fill = City, group = City)) +
  geom_area(alpha = 0.6, position = "identity") +
  labs(
    title = "Monthly Rainfall Trends in Indian Cities",
    x = "Month",
    y = "Rainfall (mm)"
  ) +
  theme_minimal()

Interpretation

The visualization reveals several important patterns:

  • Mumbai shows extremely high rainfall during June to August due to the Southwest Monsoon
  • Chennai experiences peak rainfall during October and November due to the Northeast Monsoon
  • Delhi shows moderate rainfall with seasonal variation
  • Kolkata also follows strong monsoon rainfall trends
  • Bangalore shows relatively balanced rainfall throughout the year

Insights

  • Coastal cities receive higher rainfall compared to inland cities
  • Monsoon seasons dominate rainfall distribution in India
  • Seasonal patterns vary significantly across regions

Conclusion

The area chart effectively highlights rainfall trends across different cities. The analysis clearly shows the impact of monsoon seasons on rainfall distribution.

This visualization helps in understanding regional climate variations and comparing rainfall patterns efficiently.