In CAopenwater/sdwisard: R wrapper for accessing a pretend API for SDWIS

knitr::opts_chunk$set(warnings = FALSE, message = FALSE, out.width = '100%')

library(sdwisard)
library(dplyr)
library(ggplot2)

Make sure the package is installed. See installation instructions here.

Basic Query

The PSID (public water system ID number) of a water system is the only mandatory argument to get_data(). Use the PSID of a system to get all the water quality data for that system.

For example, Alameda County Water District is PSID 0110001:

alameda_all <- get_data(psid = "0110001")
glimpse(alameda_all)

Helper Functions

sdwisard includes three helper functions:

• get_water_system() - Find PSID by county name
• get_analyte_summary() - Summary about available data for a water system
• get_storet_id() - Find storet id with common chemical name

Supply a county to get_water_system() to return PSIDs and water system names within that county.

get_water_system(county = "Alameda")

Supply a PSID to get_analyte_summary() to view a summary of a water system's available analyte data.

get_analyte_summary(psid = "0110001") 

Use the function get_storet_id to search for storet IDs by common names of an analytes.

nitrate_ids <- get_storet_id("nitrate")
nitrate_ids

Provide the storet ID to query for a specific analyte. The following query return all nitrate data (storet ID = A-029) for Alameda county Water District.

alameda_nitrate <- get_data(psid = "0110001", storet = "A-029")

We can plot these results with ggplot as follows:

alameda_nitrate %>% 
  mutate(date = as.Date(SAMP_DATE)) %>% 
  ggplot(aes(date, FINDING)) +
  geom_point() +
  geom_smooth(se = FALSE) +
  labs(title = "NITRATE + NITRITE (AS N) at Alameda County Water District",
       y = "(MG/L)") +
  theme_minimal()

To query a specific date range provide a start_date and/or end_date argument(s) in YYYY-MM-DD format.

alameda_09_2018 <- get_data(psid = "0110001", start_date = "2018-09-01", end_date = "2018-09-30")

Built-in package objects

Full tables of metadata are also available:

water_systems

psid_analyte

analytes

CAopenwater/sdwisard documentation built on Jan. 27, 2021, 5:57 p.m.