## Analysing and Visualizing Water Quality data using R-programming
## Coded by - Debarghya De (203001170001)
## Branch - B.Tech Agriculture_6th Semester

# Load necessary packages
library(tidyverse) # for data manipulation and plotting
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library(lubridate) # for handling dates and times
library(leaflet)   # for creating interactive maps
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library(reshape2)
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library(ggplot2)

# Load and pre-process water quality data from multiple stations
water_data <- read.csv("water_quality_data.csv")
water_data$date <- ymd(water_data$date) # convert date column to proper date format
## Warning: All formats failed to parse. No formats found.
# Calculate descriptive statistics of the water quality parameters
water_stats <- water_data %>%
  summarize(mean_pH = mean(pH),
            mean_DO = mean(dissolved_oxygen),
            mean_turbidity = mean(turbidity),
            sd_pH = sd(pH),
            sd_DO = sd(dissolved_oxygen),
            sd_turbidity = sd(turbidity))

# Plot barplots of the water quality parameters by station and by month
ggplot(water_data, aes(x = station, y = pH)) +
  geom_bar(stat = "summary", fun = "mean") +
  labs(x = "Station", y = "pH") +
  ggtitle("Mean pH by Station") +
  theme_bw()

ggplot(water_data, aes(x = station, y = dissolved_oxygen)) +
  geom_bar(stat = "summary", fun = "mean") +
  labs(x = "Station", y = "Dissolved Oxygen") +
  ggtitle("Mean Dissolved Oxygen by Station") +
  theme_bw()

ggplot(water_data, aes(x = station, y = turbidity)) +
  geom_bar(stat = "summary", fun = "mean") +
  labs(x = "Station", y = "Turbidity") +
  ggtitle("Mean Turbidity by Station") +
  theme_bw()

# Perform correlation analysis to identify relationships between the water quality parameters
cor_data <- water_data %>%
  select(pH, dissolved_oxygen, turbidity) %>%
  cor()

# Create a heatmap of the correlations
ggplot(data = melt(cor_data), aes(x = Var1, y = Var2, fill = value)) +
  geom_tile() +
  scale_fill_gradient2(low = "blue", mid = "white", high = "red", midpoint = 0) +
  labs(title = "Correlation Heatmap of Water Quality Parameters") +
  xlab("") +
  ylab("") +
  theme_bw()

# Create a map of the study area and plot the spatial distribution of the water quality parameters
water_map <- leaflet(water_data) %>%
  addProviderTiles("CartoDB.Positron") %>%
  addCircleMarkers(lng = ~long, lat = ~lat, weight = 1, radius = 100, 
                   color = ~turbidity, opacity = 0.7, fillOpacity = 0.7, 
                   label = ~paste("Station:", station, "<br>", "Turbidity:", turbidity)) %>%
  addLegend(pal = colorNumeric(palette = "YlOrRd", domain = water_data$turbidity),
            values = water_data$turbidity,
            title = "Turbidity",
            opacity = 1)

# Show map
water_map