A streamlined method for collecting, validating, and storing costly geoscientific data in 2022
In early August 22 I wrote an article about the use of portable GIS solutions in Mineral Exploration, and how incredibly useful it can be at bridging the gap between field work and data management. Whether you are a geologist sampling and mapping, or a field technician sampling, but perhaps less concerned about the dirt or the rock around, having a streamlined workflow for collecting your samples is a must have in 2022. [paragraph 1/8]
QField is my preferred app for carrying out field work as it is open-source, offers almost full GIS capabilities and is a real competitor against the proprietary Collector for ArcGIS app. The process of getting a project set-up for use is simple but requires careful planning so your app is optimised for your use. [2/8]
A wise bearded geo once told me:
“Make it fit for purpose” – (Edward Keys, mentor and friend).
Creating your sampling forms:
This is basically like creating a standard GIS database file. QField works best using geopackage file types. Each field you create must have pre-defined attributes, ideally all in phase with your database architecture. Since the aim of using the app is to collect and validate data on the fly, your fields must be in the appropriate format
Default pre-filled values applied to metadata fields such as sample ID’s, coordinates, CRS ID, creation and modification dates, sampler name, project ID, etc;
Enforcement of ‘not-null’, ‘Unique’, and specific expression constrains to critical fields like Sample ID and coordinates. [3/8]
The next step is to set up your other fields concerning the sample you are collecting. This is where the fit for purpose comes into play. Think carefully about the attributes you want to capture in the field when sampling. Ask yourself what you need to collect, what you want to collect, and how practical is it to include all the fields you are planning to include in your form. [4/8]
If you are planning a soil survey to be carried out by field technicians, your form will likely be very different than if you want a geologist to go and collect rock chip samples; e.g. vein dimensions, orientation, composition, type, etc if it is a vein; as opposed to different attributes for other material; soil type, sample depth, horizon name, and maybe a confidence value if you are collecting soil. Either way any field you include must be as practical as possible. This is done by displaying the fields as check boxes or drop-down lists in your form, which you can make selective to further improve practicality (drill-down lists). [5/8]
For complex sampling forms, it is easy to be overwhelmed by an endless list of fields and attributes. This is easily tackled by implementing dynamic forms that adapt to the user as information is entered. I will be going into details on how to do that in a future post. Cutting down on rock types and mineralogy fields is also a plus. We are doing exploration after all and not academic research, and I doubt that anorthosite will be useful in most cases. Again, the great thing about using these forms is that there are no rules, you can design it the way you want and make it fit for your purpose. If there is anorthosite where you are going sampling, go for your life! [6/8]
Prepare your base map
And this is it. Almost. If you made it this far you are probably itching to go to the field and try your app! Well dot that but only with a great base map. A combination of high-resolution imagery, some geophysics and existing geological maps will not only help you navigate better but also help you generate your interpretation. I found quality satellite imagery to be a real time saver when going out bush with vehicles, as you can quickly know where to go and anticipate larger obstacles like dense impassable bush. Below is an example of what I call ‘quality imagery’. If you can see individual trees, then you have it. This type of imagery is very easily extractable from various web services. Once extracted you can save it as a Tiff, and it works fine with the app. The only thing you require is a lot of internal memory to store such geo Tiff files. You should be ok on RAM as most smartphones today work like thunder, even the cheap ones. [7/8]
Choose your device
To be perfectly honest, RAM and storage memory are a given nowadays, and you do not need the latest and greatest to run QField, even with large vector datasets and Tiff rasters loaded in your project. I will be going over what devices are best for this kind of work in a future post. But for now, know that a good quality screen is a plus when working outside, so choose something that has plenty of brightness. The most important though is your battery. A minimum of 6000 mAh for tablets and 5000 mAh for phones should keep you going for the day. You also have the option to recharge on the go with a power bank, or to use devices with removable batteries so you can buy two and switch them when you run out. The Samsung galaxy active tabs are great rugged products with easily removable batteries. Go here if you want to search and compare devices. [8/8]
So there you have it, you are all set up for field work! No time-wasting, no more data entry errors, and last but not least, some recognition from your database admin! If you need some assistance with it, click here to learn how you can get help to get set up for field work.
Enjoy your field work and stay safe out there!
Dimitri
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