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Most Popular Frameworks for Back-end Web-GIS Development

Most Popular Frameworks for Back-end Web-GIS Development

A lot goes on in the backend of a Web GIS application. In the backend, most of the manipulation and querying of data takes place. Therefore, it is crucial that one chooses the backend wisely. Python programing language is mostly used for the backend of a web GIS application. The main reason is because Python…

Most Popular Libraries for Front-end Web GIS Development

Most Popular Libraries for Front-end Web GIS Development

The onset of the World Wide Web has revolutionized everything around us and GIS is not an exception.  The Web GIS is an advanced type of Geographic Information Systems made available on web platforms. It operates on the Client-server architecture. A GIS server is identified by a uniform resource locator (url). It responds and gives…

Using Landsat 8 Image To Perform Cloud Masking on GEE

Using Landsat 8 Image To Perform Cloud Masking on GEE

Landsat 8 images are widely used for a variety of applications. However, cloud and cloud shadow cover issues are still a challenge. Clouds and cloud shadow decrease accuracy of remote sensing application results because they obscure the land surface, and the brightening effect of clouds and the darkening effect of cloud-shadow’s influence the reflectance capability…

Computation of NDBI in Google Earth Engine

Computation of NDBI in Google Earth Engine

What is NDBI? Normalized Difference Built-up Index (NDBI) is a spectral index used to analyze built-up areas. This index uses two bands: the short-wave infrared (SWIR) and the near infrared (NIR). Areas with more built-up structures reflect shortwave-infrared (SWIR) more while areas with less built-up have a low Near-Infrared (NIR) reflectance. NDBI values range from…

Computing MNDWI using Sentinel 2 on Google Earth Engine

Computing MNDWI using Sentinel 2 on Google Earth Engine

What is MNDWI? Modified Normalized Difference Water Index (MNDWI) is a spectral index used to analyze water bodies such as rivers, lakes and dams especially in built-up areas since it can reduce or even remove built-up land. This index uses two bands:  green and short-wave infrared (SWIR). MNDWI values range from -1 to +1 where…

Google Earth Engine: Applying joins between features

Google Earth Engine: Applying joins between features

Joins are used to combine elements from different collections (e.g. Image Collection or Feature Collection) based on a condition specified by an ee.Filter. The filter is constructed with arguments for the properties in each collection that are related to each other. Specifically, left Field specifies the property in the primary collection that is related to…

Visualize changes over time in GEE

Visualize changes over time in GEE

The area of interest, in this case, is Bungoma region of Kenya, and we would like to visualize changes over time. For this example, we shall focus over the years between 2013 and 2021 in the following steps. Search for the region of interest Add the data layer to the workspace and adjust the date…

Visualization Parameters in Google Earth Engine Explorer

Visualization Parameters in Google Earth Engine Explorer

Visualization parameters enable the user to have a better view of the dataset. On the layers panel of the Modis dataset, there is a visualization dropdown. Clicking on the dropdown results in the image below: In this platform, layers can be visualized in a single band or three-band display. A single-band display is used for viewing a…

Layer Visibility in the Google Earth Engine

Layer Visibility in the Google Earth Engine

This blog is a continuation of the Google Earth Engine Explorer Series, and we focus on the added layer visibility, the date, adding multiple layers, reordering, and removing layers. Layer Visibility The eye-like icon on the right side of the layer that has been added is used for viewing the layer. Toggling it will either…

Google Earth Engine Explorer

Google Earth Engine Explorer

This blog is an introduction to the Google Earth Engine Explorer. The Google Earth Engine Explorer comprises the data catalogue and the workspace. The catalogue is used for searching and import of data to the workspace, while the workspace is used for the viewing of data. Data Catalogue It provides the datasets available in earth…

NDVI Time series in Google Earth Engine.

NDVI Time series in Google Earth Engine.

The Normalized Difference Vegetation Index (NDVI)is a spectral index used to quantify the greenness of vegetation. Earlier on, we had calculated NDVI and this blog will focus on a time series chart of NDVI of a region over a period of time as follows: Define and import the region of interest. This is done using…

Loading data in Jupyter notebooks

Loading data in Jupyter notebooks

A Jupyter notebook is a document that allows one to write code, notes and explanations as well as visualize the output of the code all in a single page. Its uses include data cleaning and transformations, data visualization, machine learning, simulations among others. Its numerous uses allow for working with multiple and varied data-sets from…

Display WMS Layer from GeoServer on Leaflet using Vue.js

Display WMS Layer from GeoServer on Leaflet using Vue.js

The Web Map Service (WMS) is an Open Geospatial Consortium (OGC) specification that defines an HTTP interface used to request a georeferenced map in an image format from a server. GeoServer supports WMS 1.1.1, the most widely used version of WMS, as well as WMS 1.3.0. WMS provides a standard interface for requesting a geospatial…

How to Apply Styled Layer Descriptor (SLD) in GeoServer

How to Apply Styled Layer Descriptor (SLD) in GeoServer

This tutorial will focus on outlining step by step process of applying a style on layer in GeoServer. A Style Layer Descriptor (SLD) file from QGIS will be used to style the layers. Launch QGIS and Export the Styled Layer Descriptor. Firstly, open QGIS and load the vector layer that you want to style. Apply…

How to Publish a Shapefile in GeoServer

How to Publish a Shapefile in GeoServer

This tutorial focuses on how to publish a shapefile in Geoserver assuming that GeoServer is already installed and running via the port assigned, for example, http://localhost:8080/geoserver. Data Preparation. Firstly, prepare the data that you wish to upload on GeoServer,  that is the shapefile. For example, if you want to upload a shapefile for national parks,…

Display GeoJSON Data on Leaflet Map Using Vue JS.

Display GeoJSON Data on Leaflet Map Using Vue JS.

This article will focus on integrating Vue JS with Leaflet and outlining step by step process of displaying geojson data on a leaflet map using Vue Js. Install NPM. Npm is the world’s largest registry used for management of development, sharing and borrowing of packages. Moreover, npm helps to download and use standalone tools. In…

Display Custom Icons using Leaflet and Vue Js.

Display Custom Icons using Leaflet and Vue Js.

Custom icons are a great way to display maps, especially while representing point features. This article focuses on outlining step by step process of displaying custom icons on a leaflet map using Vue Js. Install NPM. Npm is the world’s largest registry used for management of development, sharing and borrowing of packages. Also, npm helps…

Creating a chart in Google Earth Engine

Creating a chart in Google Earth Engine

Charts are used to represent data. They can be in different forms; such as pie charts, bar charts, column charts, line charts, scatter plots, and histograms. This blog will show a simple code for the creation of a bar chart in GEE. The result when the code is run is a bar chart as shown…