By Alexander Ariza

“Contour lines are an important way to show the rise and fall of the terrain on a map. They show all places that are at the same height above sea level. They also tell us about the slope of the terrain and are a layer information base in engineering projects “

Contour lines generated from 30 m ALOS PALSAR DEM (Jaxa, 2020) on Google Earth Engine and QGIS platform in a central area of NEPAL

Contour lines are the most distinctive feature of a topographic map. Contour lines are lines drawn on a map that connect points of equal elevation, which means that if you physically followed a contour line, the elevation would remain constant. …


A guest blog post by Alexander Ariza

Foreword by Sentinel Hub

This post is part of a series of guest blog posts written by script authors, talking about their entries to the Sentinel Hub Custom Script Contest. Alexander Ariza and Norma Davila are among the winners in the third round of the Contest. Their winning script with detailed description is available on our GitHub repository.

In this blog post, authors are explaining their winning custom script for detecting landslides using space-based data provided by the Sentinel-2 satellite in Sentinel Playground and EO Browser. …


This repository is a collection of basic scripts — explained in English and Spanish — for analysing landslides using space-based data in Google Earth Engine (GGE). It aims to facilitate working with big data in the cloud as an alternative to using desktop software

“According to the United Nations Office for Disaster Risk Reduction (UNDRR), landslides are a a “variety of processes that result in the downward and outward movement of slope-forming materials, including rock, soil, artificial fill, or a combination of these. The materials may move by falling, toppling, sliding, spreading, or flowing.”

Landslides are a geological hazard that…

Alexander Ariza

Phd in Geographic Information Technologies and Visiting Scientist. Bonn Office, UN-SPIDER Programme United Nations Office for Outer Space Affairs (UNOOSA)

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