Arduino system and ultrasonic sensor for automation of the determination of water infiltration rate in soil

Marcos Cleve Alves Da Silva,Marcelo Dos Santos Targa,Vicente Rodolfo Santos Cezar

doi:10.4136/ambi-agua.2543

Marcos Cleve Alves Da Silva, Marcelo Dos Santos Targa + Show 1 more

Open Access

https://doi.org/10.4136/ambi-agua.2543

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Abstract

The velocity of water infiltration in soil is important for the design of irrigation systems, drainage, septic tanks, sanitary landfills, dams, channels for water distribution, soil and water management to control erosion and estimate surface runoff. Infiltration tests are generally done with rulers and visual reading, which can lead to errors. The present study therefore aimed to determine the Infiltration Velocity (IV) curves of water in the soil by the concentric ring infiltrometer method, using an Arduino microcontroller and an ultrasonic sensor to measure the lowering of the water depth. For that, in the same infiltration test, four readings in Automatic mode (AT) and four readings in Manual mode (MN) were performed simultaneously, in a red-yellow Argisol type soil, in the Areal Basin, located in the southeastern region of Brazil. municipality of Taubaté, Vale do Paraíba, in the state of São Paulo. Adjustments of kostiakov curves and their equations were made from the data obtained in the field, and the values of R² were determined, as well as the values of Basic Infiltration Velocities (BIV), Accumulated Infiltration (AI) and the Average Percentage Error (APE) of the calculated IS values and those estimated by the equations. The results show that the number of readings in the same test time in Automatic mode (AT) was 2.3 times higher than in the manual (MN). All tests showed that the Red-Yellow Argisol showed a high infiltration speed, and in the pasture area the BIV values were 1.9 times higher than those obtained in the forest area. The R² determination coefficients for all curves are 0.99 in all tests and demonstrate the strong correlation between the data. The APE of the calculated and estimated IS values were low, and the biggest discrepancies that occurred were (APE = 0.30%) in the MN - 4 test and (APE = -0.01%) in the AT - 4. APE of MN mode BIVs for AT was 2.7%. These differences in IS values are reflected in the accumulated infiltration (AI) in the soil over time, and in this study the AI of the ATs tests was on average 4.1mm higher than in the MN tests, which corresponds to a difference of 41m³ ha-1. It was concluded that the use of the Arduino microcontroller with the ultrasonic sensor installed in the ring infiltrometer proved to be efficient in the field measurements and made the determination of the accumulated infiltration and the infiltration speed practical, proving to be an economical and technically viable alternative mainly due to the quantity of possible points to collect for each test and the greater reliability added to the low error values when compared to the manual.

Highlights

The rate of water infiltration into the soil is influenced by several factors, such as the type of soil, management, cultivation, physical properties and the moisture content of the soil
The tests were carried out in August, the driest period in the region of Taubaté, SP, with only 31 mm of average monthly precipitation (1964 to 2011) as (São Paulo, 2019), which is excellent for determining infiltration tests, because the infiltration curve can be produced in its entirety from the driest point to the saturation of the soil, depending only on the water that is placed in the test
The data obtained in the field from the performance of four infiltration tests in four different locations in Red-yellow Argisol in the Areal Basin, in an automatic and manual way, were plotted in a Microsoft Excel spreadsheet in order to obtain the speed graphs

Summary

Introduction

The rate of water infiltration into the soil is influenced by several factors, such as the type of soil, management, cultivation, physical properties (texture, structure, degree of compaction) and the moisture content of the soil. It is a process of great relevance, as it directly affects the runoff of water on the soil surface, which is the component of the hydrological cycle responsible for the processes of erosion and flooding in cities. Knowledge of the infiltration speed is important for the design of irrigation systems, drainage, septic tanks, sanitary landfills, dams, channels for water distribution, soil and water management for erosion control and estimation runoff, etc.

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