Aquifer modeling requires understanding and expertise on the different boundary conditions available to represent the physical process related to the groundwater flow regime on determined spatial and temporal discretizations. MODFLOW has a set of boundary conditions of specified head, specified flux and mixed. There is a particular boundary condition created for the representation of the interaction between a river and the surrounding aquifer: the River Package (RIV). This tutorial show the implementation procedure of a River Package (RIV) on a regional model with a discussion on the model output and water balance.Read More
On a normal groundwater modeling workflow the hydraulic parameters, observed data and boundary conditions are preprocessed on a GIS software as QGIS, and then imported on a compatible format (vector or raster) into the modeling software. However, Model Muse has a set of different tools to process point, and tabular data into model parameters increasing the speed in the model construction and simulation. This tutorial show the procedure to interpolate hydraulic conductivity from a table into Modflow from a different set of interpolation methods in Model Muse.Read More
OpenStreeMap (OSM) is a collaborative project to create a world spatial database. This project is motivated by the availability of map information around the world. The database is on continuous growth, it has more than 6.3 thousand million GPS points, around 5 million users and 1 million contributors.
The procedure to download spatial data from OSM has changed from previous QGIS version. Now in QGIS3 there are multiple options to download data from OSM; this tutorial show the installation, and operation of the QuickOSM plugin to perform smart access to the OSM database in QGIS.
QuickOSM works with the Overpass API that was developed to serve up custom selected parts of the OSM map data. This API is optimized for data consumers and it can allow the access millions of elements in some minutes with a specified search criteria (location, object type, tags, proximity or combinations of them).Read More
Hatarilabs is a blog for the knowledge diffusion on open source software in water resources with special focus on groundwater modeling and spatial analysis. However water resources specialists need to eat and to drink, therefore we wanted to give a more plural focus of our blog to cover more common topics for water resources specialist and geoscientists.
From a trip to Santiago de Chile we got a chilean pisco as a gift from a nice group of students from the University of Chile; that pisco was actually elaborated inside the university campus. In Lima we took the chance to compare it with a Pisco from the Tacna region. The comparison deals with the organoleptic (color, smell, taste) and fluid properties as viscosity.Read More
We are sure that in the future most of water resources software will be open source, but somehow there are doubts about the operating system, the platform and some requirements of these future software. It might be that concepts of this article are against the mainstream on the development of water resources evaluations, but we are talking about the future, a interesting stage in our concern for the sustainable management of water resources, and a stage with lots of uncertainties, challenges and trends.Read More
A year ago I had the opportunity to talk about open source software for water resources to several mining professionals. I remenber that I gave the maximum of my communicational skills to describe the complete perpective of the available open source tools for water resources as well as specific applications on the mining industry. Based on my experience as teacher, along the conference development, I knew that there was a problem on the communication process; the language was right, the channel was okay, but it might be that the message was wrong. At the end of the presentation, there was no questions, not even a single commentary about an application of open source software in mining water management.Read More
QGIS 3 has a lot of new features and new tools for geoprocessing and spatial analysis, however there are some tools from QGIS 2 that hasn´t migrated yet. An example of this break was the OpenLayers plugin, one of the most popular and first plugins in QGIS 2 that is not available in the new version of QGIS.
OpenLayers plugin provide maps from Google, OSM and Bing in QGIS 2. Basemaps in QGIS 3 can be inserted as a XYZ Tiles on a process described on this tutorial. However, QuickMapServices plugin allow the search and implementation from a set of basemaps on different formats (TMS, WMS, WFS and GeoJSON) in QGIS 3.Read More
MT3DMS, a three-dimensional transport model, will be used in this tutorial to simulate two-dimensional transport in a radial flow field. The example consists on a well which is injecting a solution in a constant rate of 100 m3/d with a contaminant concentration of 10 g/m3 (10 mg/l). This model will run for a total of 27 days.
The following tutorial will explain how the model was build and the conditions considered.Read More
MODFLOW itself do take into account the spatial referenciation of the groundwater flow regime. Main MODFLOW output are water heads on the cell centre and flow in between cells, additional packages calculate solute transport, zone budgets or pathlines; however on the model construction and simulation it doesnt matter where the model is.Read More
Flood events come from periods of high precipitiation and favourable soil moisture conditions. Based on the basin topography, land cover and precipitation distribution, flood events can be conceptualized as the cummulative sum of a series of peak flows from different affluent rivers.
Flood management involve the prediction of river water elevation and velocitiy from extreme precipitation events. This tutorial shows the procedure to build a unsteady (dynamic) flow simulation of two peak flows with different hydrograms. The channel network configuration for the area of study consists of one main river and a affluent river. Peak flow in the main river is 10 hours ahead of the peak flow in the affluent river.Read More
Flow simulation is an important task for engineering and disaster management. From the free softwares available for flow simulation, HEC-RAS is a strong alternative for its continuous development, the capability to simulate many flow types, and the interaction with other softwares like QGIS or MODFLOW.
QGIS is a free and open source software Geographical Information System (GIS) application. There is a environment of available plugins in QGIS that perform specific tasks of analysis, representation and preprocessing. There are QGIS plugins related to HEC-RAS, in this tutorial we will use the Q-RAS plugin to develop a basic example of flow model geometry construction in QGIS and steady flow simulation in HEC-RAS.Read More
Aquifer response to pumping is one of the most popular interactions between human and the groundwater flow regimen. On the complexity of the hydrogeological studies, pumping tests are the most controlled environments since the well construction details are known, geological logs are available and pumping rates and drawndows can be measured. There are uncertainties on this hydraulic test and these are mostly related to the aquifer heterogeneity, however, it is expected that a pumping test can be fully recreated on a numerical model.
MODFLOW is the groundwater flow model developed by the USGS based on finitRead More
With current technology and the availability of remote sensing tools through different servers makes it possible to determine or estimate the areas that are flooded or could be, the focus of this tutorial in which a methodology to determine flood zones will be described from the calculation of the NDVI and compare the results with the use of two servers, Sentinel 2 and Landsat 8.Read More
The vegetation indices are obtained from area and satellite images and can be used to estimate changes in the state of vegetation, biomass, leaf area index and chlorophyll concentration. The determination of vegetation indices is calculated from the relationship between the reflectance of the electromagnetic spectrum. While biomass presents various methodologies to be able to estimate that they are based on field measurements that despite being a direct method are still very limited. Currently, the use of remote sensors provides a method to generate information on biomass.
In this tutorial the estimation and relationship of the biomass of a study area with the Normalized Difference Vegetation Index (NDVI) and the Normalized Red-Green Difference Index (NGRDI) will be carried out.Read More
Mining and the treatment of metals are a significant source for the contribution of pollutants in various natural resources such as lakes. The impact of a pollutant on the lakes depends on the physical and chemical conditions that affect its toxicity and the degree of exposure related to concentration and time. The contribution of metals can be incorporated by precipitation, mine filtration, soil washing, leaching and percolation.Read More
Remote sensing allows the interpretation of dynamic processes in a study area at a spatial and temporal level. This information is collected from the surface that is captured by a sensor located on board a satellite in orbit around the earth. In this way, you can compare images and analyze the changes of a study area.
Different space agencies have facilitated access to information provided by satellites through servers and web portals, where satellite images can be downloaded for the analysis and interpretation of resources, for this instance, the quality of seawater can be analyzed through the classification of specific footprints using geographic information systems tools such as QGIS 3 and the Semi-Automatic Classification plugin.Read More
MODFLOW 6 is the last version of MODFLOW that brings a set of new tools and a complete rearrange of the model file system. To the date of this post (July 2018) there are limited options for MODFLOW 6 preprocessors and postprocessors; so, whether you construct the MODFLOW 6 files as text files or you use the Flopy options to build, run and visualize groundwater models in MODFLOW 6.
Flopy is the Python package to create, run and post-process MODFLOW models. Flopy supports MODFLOW-2005 and MODFLOW 6 modeling codes and MODFLOW-based models as MODPATH (for particle tracking) and MT3D-USGS (for contaminant transport).
This tutorial show the complete procedure to setup, run and visualize a basic groundwater model in MODFLOW 6 with Flopy.Read More
Image from earth surface are available from satellite images and unmanned aerial vehicules (UAV). Image resolution ranges from 10 meters on free available datasets as Sentinel2, less than 1 meter on commercial satellite imagery to 0.05m (or even less) from UAVs.
Scikit-image is a library for image processing in Python. Currently there are few QGIS plugins that run Scikit-image, we found one that extracts geological features as fractures and represent fault dip, dip direction, and strike in stereonets and rose diagrams. This tutorial show the procedure to install GeoTrace on QGIS 3 with its dependencies, runs a geological fault trace on a modified raster, calculate fault strike azimuths as a separate attribute field represent them as a strike rose.Read More
For a normal GIS user, QGIS 3 brings a lot of new tools, new forms to perform spatial analysis but also it doesn´t bring (yet) some options available in QGIS 2. This is the case for the representation of HDF raster files that is not available in QGIS 3 but it is available in QGIS 2. Research have been performed to address this issue and many options were evaluated to open the HDF files and perform a geotransformation from Sinusoidal Coordinate System to Geographical Coordinate System.
The solution came from the powerful gdal library and some core Python functions. This tutorial show the procedure to open a layer of a MOD13A2, a MODIS data product for vegetation evaluation and reproject it to geographical coordinate system (lat/lon).Read More
There are several satellites with different characteristics that acquire multispectral images of the surface of the earth. In this case, the Sentinel 2 images are particularly useful for the monitoring of land cover and can be provided free of charge from SCP.
In this tutorial we will perform the evaluation of spectral signatures using the Semi-automatic Classification complement in version 6, which is a free open source plugin for QGIS 3 that allows the supervised and unsupervised classification of remote sensing images.Read More