July 02, 2017

Tutorial to Georeference Google Searches with Python and QGIS

July 02, 2017/ Saul Montoya

To carry out a series of studies and investigations we have to know both name and location of certain places. This may be available through some web pages, however the use of data is limited and advance geoprocessing tools on softwares as QGIS can not be used. There are several services or APIs that can bring you the spatial location of Google searches. In this tutorial we will use the Google Maps API for the location of Hospitals in a radius of 5 kilometers from a point in Miraflores, Lima. Only open source software tools have been used for this tutorial.

June 24, 2017

Recharge Estimation by Daily Precipitation with MODFLOW UZF and Python

June 24, 2017/ Saul Montoya

The processes of the superficial and groundwater water cycle are related to the precipitation (shape and intensity) and the dynamic of soil moisture. This dynamic of soil moisture is determined by the type of soil and the root zone in a daily, or even hourly, temporal scale. These phenomena have not been considered or studied in conventional hydrogeology text books, maybe because of their intensive use of modeling tools and complex conceptualizations and validations.

June 19, 2017

Modeling of Soil Erosion with Landlab in Python – Open Source Software

June 19, 2017/ Saul Montoya

Soil erosion is the movement of the upper soil layers caused by processes related to water or wind. Soil erosion can occur slowly on the surface, however, soil alterations caused by human activity can increase this rate in 10 to 40 times. The evaluation of soil erosion is important to estimate the impact of human activities and the planning of remediation plans.

This article introduces the Landlab environment, which is developed in Python, as well as a practical example of soil erosion modeling on slopes over time.

June 08, 2017

Determination of Mining Projects Areas with Satellite Imagery and QGIS

June 08, 2017/ Saul Montoya

Our current working conditions require access to spatial information in short periods of time. Work planning tasks or quoting of services require data of distances, areas, proximities, medium elevations, among others. The data can be given by clients, organizations or by field monitoring, but they may not be available at the required moment. The use of geoprocessng tools of satellite imagery reduces the required time to have this information. Since QGIS is open source and the Landsat, MODIS and Aster images are free, this type of geoprocessing is versatile, economic and friendly for any user with basic/intermediate QGIS knowledge.

May 29, 2017

Tutorial: How to convert MODFLOW-2005 files to MODFLOW-6 format

May 29, 2017/ Saul Montoya

The United States Geological Survey (USGS) has just released a new MODFLOW version: MODFLOW-6. This one comes with new functionalities to make it easier to create input files and perform simulations. Among the downloaded MODFLOW-6 files, there is an executable file to convert MODFLOW-2005 files to the new MODFLOW-6 format. In this tutorial we will show you how to do this.

May 29, 2017

How to generate a legend on map canvas in QGIS with PyQGIS - Tutorial

May 29, 2017/ Saul Montoya

QGIS is a powerful and user friendly GIS software. The user can represent points and style them according to the measured values. This tutorial deals with the legend representation on map canvas for a better geospatial data analysis.
Legend representation is done with just 6 lines of code on PyQGIS, the Python tool of QGIS.

May 17, 2017

Tutorial to Generate Orthophotos from Drone Images with WebODM

May 17, 2017/ Saul Montoya

Drone imagery is a powerful for geospatial analysis on small scales and high resolutions. The availability to take drone images and the open source tools available allow the user to generate orthophotos with resolutions of less than 1 meter and fully compatible with SIG softwares as QGIS.

This tutorial show the procedure to make an orthophoto with WebODM based on drone images from a pinneapple field.

May 16, 2017

How to install Web OpenDroneMap (WebODM) in Windows with Docker

May 16, 2017/ Saul Montoya

WebOpenDroneMap is a friendly Graphical User Interfase (GUI) of OpenDroneMap. It enhances the capabilities of OpenDroneMap by providing a easy tool for processing drone imagery with bottoms, process status bars, and a new way to store images. WebODM allows to work by projects, so the user can create different projects and process the related images.

As a whole, WebODM in Windows is a implementation of PostgresSQL, Node, Django and OpenDroneMap and Docker. The software instalation requires 6gb of disk space plus Docker. It seem huge but it is the only way to process drone imagery in Windows using just open source software. We definitely see a huge potential of WebODM for the image processing, therefore we have done this tutorial for the installation and we will post more tutorial for the application of WebODM with drone images.

May 10, 2017

VIDEO: Webminar on Satellite Imagery Analysis with QGIS - May 10, 2017

May 10, 2017/ Saul Montoya

Satellite Imagery has developed a new dimension in the evaluation of water resources, environment, land planning, atmosphere and climate change. There are many satellites and imagery available, many of them being free of cost. At the same time, powerful open source tools for spatial analysis and representation are available.

This webminar wants to give a perspective on search, manage and interpretation of satellite imagery, through practical exercises using QGIS.

April 12, 2017

Parameter Optimization Simulation for a Basin Model with HEC HMS

April 12, 2017/ Saul Montoya

Model optimization involves adjusting parameter values so that the simulated results match stream flows as closely as posible. The software have two different search algorithms for the optimization as well as a variety of objective functions to measure the goodness of fit between simulated and observed stream flow.

Optimization trials are quite simple to set up and compute. This tutorial show the complete procedure to run a optimization for a hydrological model on a andean basin.

April 11, 2017

How to create contours from a Raster File - Example on a NDVI Layer

April 11, 2017/ Saul Montoya

This tutorial show the procedure to create contours from a raster file considering interval definition. The example is made from a NDVI raster file.

April 11, 2017

How to cut a Raster File on QGIS - Example on a NDVI Layer

April 11, 2017/ Saul Montoya

This tutorial show the procedure to cut a NDVI Raster File calculated from a Sentinel 2 Granule on QGIS.

April 11, 2017

How to calculate the NDVI Index from a Sentinel 2 Image

April 11, 2017/ Saul Montoya

This tutorial show the prodecure to calculate the NDVI from Sentinel 2 bands on QGIS.

April 11, 2017

How to represent Sentinel 2 Bands in a False Color Image with QGIS

April 11, 2017/ Saul Montoya

False color images are used to enhance certain cover types as vegetation on the image representation. This tutorial show the procedure represent the bands of a False Color image from Sentinel 2 bands in QGIS.

April 11, 2017

How to represent Sentinel 2 Bands in a True Color Image with QGIS

April 11, 2017/ Saul Montoya

This tutorial show the procedure represent the bands of a Sentinel 2 Granule (Image) in QGIS. The representation of the image is True Color (Red, Green and Blue)

April 07, 2017

How to Download Specific Granules from ESA Sentinel 2 Images

April 07, 2017/ Saul Montoya

Sentinel-2 carries an innovative wide swath high-resolution multispectral imager with 13 spectral bands for a new perspective of our land and vegetation. The mission is based on a constellation of two identical satellites in the same orbit, 180° apart for optimal coverage and data delivery. Together they cover all Earth’s land surfaces, large islands, inland and coastal waters every five days at the equator (source ESA).

This tutorial show the procedure to download especific granules from a ESA Sentinel 2 Image using the website: https://scihub.copernicus.eu/

April 07, 2017

How to Download ESA Sentinel 2 Satellite Images

April 07, 2017/ Saul Montoya

This tutorial show the procedure to download images of ESA Sentinel 2 from the website: https://scihub.copernicus.eu/

April 06, 2017

Evaporation and Homogeneous Redox Reactions Simulation with Phreeqc

April 06, 2017/ Saul Montoya

Evaporation is accomplished by removing water from the chemical system. Water can be removed as an irreversible reactant with a negative reaction coefficient in the REACTION keyword input. This example uses this method; the REACTION data block is used to simulate concentration of rain water by approximately 20 fold by removing 95 percent of the water. The resulting solution contains only about 0.05 kg of water. In a subsequent simulation, the MIX keyword is used to generate a solution that has the same concentrations as the evaporated solution, but has a total of mass of water of approximately 1 kg.

April 04, 2017

Geochemical Simulation Tutorial of Water Mixing with Phreeqc

April 04, 2017/ Saul Montoya

This example demonstrates the capabilities of PHREEQC to perform a series of geochemical simulations, with the final simulations relying on results from previous simulations within the same run. The example investigates diagenetic reactions that may occur in zones where seawater mixes with carbonate ground water. This example is take from the Phreeqc documentation that can be found here:

https://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/html/final-72.html