Outdoors – r.iresmi.net

Author

Michaël

Published

2023-11-20

Modified

2023-11-22

A photo of the Porcupine River in the Yukon Flats — Porcupine River – public domain by David Spencer, FWS

Day 20 of 30DayMapChallenge: « Outdoors » (previously). Get some fresh air in Alaska!

Setup

library(terra)
library(viridis)

Data

You can browse several DEM datasets on https://elevation.alaska.gov/#66.53733:-145.25385:13. Yukon Flats by Lidar look promising…

dtm_file <- "yukon_flats_usgs_2pt5_dtm.tif"

if (!file.exists(dtm_file)) {
  download.file("https://elevation.alaska.gov/download?geojson=%7B%22type%22%3A%22Polygon%22%2C%22coordinates%22%3A%5B%5B%5B-145.4186%2C66.5036%5D%2C%5B-145.4186%2C66.5710%5D%2C%5B-145.0891%2C66.5710%5D%2C%5B-145.0891%2C66.5036%5D%2C%5B-145.4186%2C66.5036%5D%5D%5D%7D&ids=134",
                "custom_download.zip")
  unzip("custom_download.zip")
  unzip("dds4/yukon_flats_usgs/dtm/yukon_flats_usgs_2pt5_dtm.zip")
}

Map

rast(dtm_file) |> 
  crop(ext(572000, 582000, 7370000, 7380000)) |> 
  plot(col = rev(magma(256)), axes = FALSE, smooth = TRUE, legend = FALSE)

Colorized Digital Elevation Model of Yukon Flats. — Figure 1: Yukon Flats. Data: USGS/Aero-Metric

---
title: "Outdoors"
description: "Day 20 of 30DayMapChallenge"
author: "Michaël"
date: "2023-11-20T08:00:00"
date-modified: last-modified
categories:
  - R
  - 30DayMapChallenge
  - spatial
  - datavisualization
draft: false
freeze: true
editor_options:
  chunk_output_type: console
chunk_output_type: console
execute:
  eval: true
---

[![Porcupine River -- public domain by David Spencer, FWS](images/Porcupine_River_YFNWR.jpg){fig-alt="A photo of the Porcupine River in the Yukon Flats"}](https://commons.wikimedia.org/wiki/File:Porcupine_River_YFNWR.jpg)

Day 20 of [30DayMapChallenge](https://30daymapchallenge.com/): « Outdoors » ([previously](/#category=30DayMapChallenge)). Get some fresh air in Alaska!

## Setup

```{r}
#| label: setup

library(terra)
library(viridis)
```

## Data

You can browse several DEM datasets on <https://elevation.alaska.gov/#66.53733:-145.25385:13>. Yukon Flats by [Lidar](https://en.wikipedia.org/wiki/Lidar) look promising...

```{r}
dtm_file <- "yukon_flats_usgs_2pt5_dtm.tif"

if (!file.exists(dtm_file)) {
  download.file("https://elevation.alaska.gov/download?geojson=%7B%22type%22%3A%22Polygon%22%2C%22coordinates%22%3A%5B%5B%5B-145.4186%2C66.5036%5D%2C%5B-145.4186%2C66.5710%5D%2C%5B-145.0891%2C66.5710%5D%2C%5B-145.0891%2C66.5036%5D%2C%5B-145.4186%2C66.5036%5D%5D%5D%7D&ids=134",
                "custom_download.zip")
  unzip("custom_download.zip")
  unzip("dds4/yukon_flats_usgs/dtm/yukon_flats_usgs_2pt5_dtm.zip")
}
```

## Map

```{r}
#| label: fig-map
#| fig-cap: "Yukon Flats. Data: USGS/Aero-Metric"
#| fig-alt: Colorized Digital Elevation Model of Yukon Flats.
#| dev: png
#| out-width: "100%"
#| dev.args:
#|   bg: transparent
#| fig-width: 7
#| fig-height: 7
rast(dtm_file) |> 
  crop(ext(572000, 582000, 7370000, 7380000)) |> 
  plot(col = rev(magma(256)), axes = FALSE, smooth = TRUE, legend = FALSE)
```