The registration of springs is fundamental to good hydrogeological studies.

In this article, we will show how information on springs forms the basis for understanding the hydrogeology of a study area, as well as providing a comprehensive and practical review of pre-field, field and data processing activities.

But, after all, what’s the point of registering springs?

This activity is crucial for providing the initial data on which any hydrogeological study is based. During registration, a general hydrological and geological reconnaissance of the study area is carried out, with the identification of geological structures that condition flow.

The data on springs, together with geological data, make it possible to generate preliminary potentiometric maps, which can help in the location of wells and piezometers.

From this, a monitoring network can be established and aquifer tests can be carried out which, in turn, allow conceptual and numerical models to be drawn up. The location, elevation and flow data of springs are also used directly in the models.

In addition, environmental agencies often require certain undertakings to register springs.

We already know what the activity is for, but how should it be done?

Before “how”, it is important to define “when” the registration of springs should be done.

The answer is simple: the action should preferably be carried out during a dry period, to avoid confusion in the registration (such as registering the headwaters of an ephemeral drainage, the result of rain in previous days, as a spring). In this example, the data recorded does not represent the stationary behavior (behavior without considering seasonal variations) of the system.

In order to register the springs, a series of pre-field activities must be carried out. In this regard, it is necessary to review the available data for the area, such as previous hydrogeological records and studies, geological data, hydrography and topography. From this, it is possible to define targets and draw up the maps to be used in the field.

What maps should be taken to the field?

It is important to take the following maps: topographic map, drainage map (preferably generated automatically in a GIS environment, with as much detail as possible – first order drainage onwards), map of previously registered springs, access map, geological map, as well as a watershed map.

Other pre-field activities must be carried out and involve logistics, such as sorting out the equipment (GPS, compass, parameter meters, bucket for measuring flow and geological hammer), printing out the registration forms (with all the fields to fill in), booking a vehicle and sorting out personal protective equipment (boots, leggings, hat, gloves, wellies and others).

Once these steps have been completed, it’s time to go into the field.

But what is the best way to get to the springs to get all the information?

In a springs register, the biggest challenge is precisely getting to each spring. On site, we may encounter some difficulties, such as sloping terrain, closed forest, walking distance and safety risks (venomous animals, falls, among others).

It is therefore essential to adopt a strategic approach to each objective. In the study area, you shouldn’t go around randomly looking for springs. It is imperative to follow the watercourses, either from the watershed or from a point where water is present (downhill or uphill, to put it simply).

When you get to the springs, there are no secrets. All you have to do is fill in the items on the form:

– Write down the coordinates;

– Measure the physical and chemical parameters;

– Give a general description of the area (vegetation, geomorphology, geology, etc.);

– Measure the flow rate*.

*To measure the flow rate using the volumetric method, it is necessary to channel the water from the spring so that it can be collected in a graduated container, and to time how long it takes to fill a certain amount (depending on the flow rate of the spring). We recommend measuring at least three times and calculating the average to reduce errors.

But should we only record the springs?

No, there’s no reason not to take advantage of the field trip and record everything that’s relevant to your study. We can also record other features, such as:

– Springs;

– Users (if contracted);

– Sinks;

– Resurgences;

– Dry drainage;

– Piezometers and wells (if any)**;

– Control points (everything that does not fall into the above categories but is still relevant to hydrology).

**The registration of piezometers and wells is important because the contracting company’s database is not always correct – there may be datum problems, among others.

And what should we call each point?

It is necessary to create standardized codes that summarize as much information as possible in a reasonable number of characters. For example, a spring registered in Florianópolis by a team called “A” could be: FL-NA-01-A.

The first two letters indicate the location of the registration. The second pair indicates that the feature is a spring (NA). It could be a dry drain (DS), a control point (PC) and so on. The number indicates the order of registration and the letter indicates the team. If there is only one team, the code FL-NA-01 would suffice.

Important

In addition to the cards, field book and GPS, it is also recommended to record the points in an app on your cell phone or tablet. There are several options that allow you to record walks, points and photos linked to points.

This is a measure of redundancy with the data: if you somehow lose the cards, your work won’t be lost.

Following the same reasoning, it is advisable to take photos of the sheets and upload the data from the app to the cloud whenever you are in a safe place, such as a hotel or office.

Organizing and processing data

So far, we’ve covered all the pre-field and fieldwork. Once the field stage is complete, the data organization and processing stage begins.

For this, a data management system such as Hydro GeoAnalyst (HGA) is recommended. By importing the data into this software, you can integrate it with the other available project data and handle everything in one place.

In the context of registering springs, the great advantage of HGA is the possibility of generating automated reports. In fact, the spring sheets can be filled in automatically using HGA, avoiding the time-consuming and laborious process of filling them in one by one on the computer.

The forms must be given to the client as an attachment to a technical report on the activities.

And how should the report be drawn up?

The report should be simple: a general description of the activities, with consolidated tables of the registered points, maps of springs and other registered points, as well as a map of walks and a consolidated hydrography map (with the exact starting points of the watercourses, as verified in the field).

The report should also include comparisons between previously registered springs and springs registered in the current study, correlations between parameters and geology, or between flow and geology.

In short, the report should contain all the data and interpretations obtained in the study.

In short, the activity of registering springs:

– Provides fundamental data for hydrogeological studies;

– It is a relatively simple and inexpensive activity, but it must be carried out with planning, strategy and technical rigor;

– Safety is fundamental when carrying out this activity;

– The use of technology facilitates all stages, from pre-fieldwork to data processing and presentation;

– Having a structured database is essential for organizing and optimizing the data obtained.

HGA is an excellent tool for this data management.

Check out the webinar on registering springs, given by the author: