## Materials and Methods  
### Development of the DRS System  
For the development of the DRS\({}_{=1}\) simulator, we used the following criteria:  
1. It must have one dripper in the form of a hypodermic needle;
2. It must be relatively cheap:
3. It must be simple to use;4. It must have a precise water flow-regulating system and must endure a hydraulic pressure in the system lower than 0.5 bar. A DRS=1 system is made up of several elements: - Structural support: - Water tank; - Water-moving mechanism; - Mechanism for water flow regulation and simulator operation; - Water tank with a dipper; - Dripper. The structural support of the simulator consists of a wooden platform on which almost all elements are fixed (Figure 1a,c). The water supply is provided from a water tank filled with distilled water. Distilled water is used to avoid the possible formation of scale inside the hydraulic system, especially the dipper. At the bottom of the tank, there is a submersible electric water pump that is supplied with electricity directly from the power grid (Figure 1b). The water pump moves water to the water tank with a dipper through a series of different diameter rubber hoses, syringes, and fittings. They are transparent to enable a visual inspection of the circulation of water and air in the hydraulic system. Water flow is regulated primarily by a switch that is connected directly to the pump. At low power, the pump tends to oscillate, causing an oscillating water flow. Therefore, a secondary flow regulator is added, which compensates for any oscillations and ensures a regular water flow.  
Figure 1: Rainfall simulator with one dipper: (**a**) back side of the structural support, (**b**) water tank with a water pump, (**c**) front side of the structural support with elements of the DRS=1, including transparent hoses, syringes, flow regulators, a water filter, three-pronged taps, pressure gauge, air release chamber, water tank with dipper, dripper, and water drop-measuring equipment such as a NeuLog Drop Counter Logger Sensor NUL-223 (DCLS), mobile stand, NeuLog module-USB module USB-200 (NLU) (NeuLog, 8600 Silkeborg, Denmark), and container for receiving drops during measurement in the form of a plastic cup.  
The simulator elements are mostly taken from a basic medical infusion kit. Therefore, secondary flow regulation is performed by a medical infusion flow regulator. The flow direction is regulated by a series of three-pronged taps. Plastic syringes are used to create an air release chamber and water tank with dripper. There is also a filter that prevents the intrusion of potential water impurities from the water tank. Pressure in the hydraulic system is measured by a pressure gauge (Figure 1c). The dripper is a standard hypodermic needle. We use 11 needles of different diameters and lengths, ranging from 16G to 32G, which were manufactured in accordance with ISO 6009:2016 and ISO 9626:2014(E) and are currently available on the market (Table 1). The dripper is connected to the hydraulic system by a Luer lock fitting (Figure 1c). When the simulations are finished, the hydraulic system is washed and the water pump is turned off and removed from the water tank to prevent rust. Additionally, water is completely pulled out of the system. A detailed description of the simulator design (Figure S1) and function is provided in the Supplementary Material.