Mapping the karst of SW Sarawak

To supplement the paper by Gill, Clucas, and Laverty, the data collected is presented on a variety of base maps here. The file and its data can be downloaded and adapted to taste; the mapping software is Leaflet (a javascript application, specifically version 1.9.4 (released May 2023), with the control.layers.tree, omnivore, and fullscreen plugins).

The data has been assembled into .KML files and interested users are encouraged to download and modify these as required. In particular, the files may be uploaded for display in various versions of Google mapping (eg My Maps and Earth), as well as NASA WorldWind, Cesium among others. Many of these hve the advantage that they allow the data to be draped over the surface and seen in 3D rather than just in a 2D, plan, view.

.KML file for downloadcontentssource
hillsIndicative sketch plans and statistics of hills identified mainly from colonial geological survey maps, or using 3D to guide digitisation in GE Pro
peaksIndicative locations of high points on the hills mainly from NASA SRTM data in QGIS, or as interpolated to contours in online maps
flatsIndicative sketch plans for the limestone flats mainly from colonial geological survey maps
depressionsIndicative sketch plans for karst depressions (dolines) in or adjacent to limestone mainly from NASA SRTM data in QGIS, or as interpolated to contours in online maps
intrusionsIndicative sketch plans for igneous intrusions (in the limestone only) mainly from colonial geological survey maps, or using 3D to guide digitisation in GE Pro
cavesIndicative sketch plans of caves which have been surveyed mainly sketched freehand in QGIS from published survey plans
entrancesIndicative locations of cave entrances mainly estimated but occasionally coordinates edited in from GPS fix
cave nameslabels for some caves mentioned in the paper
place nameslabels for places mentioned in the paper

These notes may help explain how the .kml files were prepared:

KML files - creation, modification, and use

Keyhole Markup Language (KML) files define geographical information in a plain text XML (eXtensible Markup Language) format. It is the native format for Google Earth (which was originally called Keyhole) and has thereby become an accepted format for Geographical Information System data.

Creation

  1. Write direct in a text editor (or wordprocessor provided it saves plain text). Not usually practical for files with much location data. However, generating the code from data held in a database (or spreadsheet) via a bespoke program (or spreadsheet functions) is a good option.
  2. Draw and save with Google Earth Pro. A name field is expected and description, but no other fields, can also be added. Points are easy to add, drawing lines and areas liable to generate too many points. Styling is allowed, but cannot be saved.
  3. QGIS, one of the easiest full GIS systems to use, but initially rather daunting, can create and then export (not ‘save’) files as kml. If you want to save 'extended data' fields other than Google Earth provides, this will do it
  4. Therion can export survey map (from scraps) and centre line (from model) provided the data has been georeferenced
  5. geojson.io (saves to download file only as map.kml)

Editing,

  1. Edit direct in a text editor. This appears to be the only way to modify styling parameters via Style and StyleUrl.
  2. Google Earth Pro. Very good for visual use of 3D, but not always intuitive, sometimes temperamental, and liable to add unnessary data which may even conflict with use in other programs. Existing files are loaded as Network Links. Right-click on name in folder and select Properties to activate edit mode. Save folder with Save Place As (defaults to compressed .kmz format, rather than .kml; the file may have had some extra styling and other default data added, and empty data fields removed). N.B. Changes can be made to the styling in this program but they are NOT saved.
  3. QGIS can load kml files, and update them but you then need to export to a file with a new name (which you can subsequently rename).
  4. geojson.io Easy to use for placing points and drawing lines and areas. Uses only its own simple styling: although styleUrl and icon are treated as data fields, which can be added, updated, or removed easily the Schema, Style, and Folder and SchemaData/schemaUrl elements used by Google Earth are removed on saving. Only saves edited data to a file called map.kml in download folder, which then needs to be moved and renamed.

Use.

  1. Google Earth Pro. Displays in 3D.
  2. Google My Maps. Although Google Maps has a 3D mode in some (but not all) browsers, My Maps is 2D only.
  3. Google Earth on the Web
  4. Cesium JS/Ion - 3D
  5. Leaflet (using omnivore to convert to geoJson). Any KML styling is ignored, so must be coded again.
  6. QGIS.
  7. geojson.io