Japan Geoscience Union Meeting 2023

Presentation information

[E] Online Poster

A (Atmospheric and Hydrospheric Sciences ) » A-HW Hydrology & Water Environment

[A-HW21] Surface and subsurface hydrologic models: Technical advances and applications for water management

Thu. May 25, 2023 1:45 PM - 3:15 PM Online Poster Zoom Room (3) (Online Poster)

convener:Tomochika Tokunaga(Department of Environment Systems, University of Tokyo), Jiaqi Liu(The University of Tokyo ), Philip Brunner(The Centre for Hydrogeology and Geothermics of University of Neuchatel, Switzerland ), Rene Therrien(Laval University)

On-site poster schedule(2023/5/25 17:15-18:45)

1:45 PM - 3:15 PM

[AHW21-P05] Development of a Multi-function Water Depth Sensor in the Irrigated Paddy Fields for Water Resource Management and Precision Agriculture

Chun-Yen Kuo1, Kuang-Peng HSIEH1, *Yung-Cheng HU1, Ruey-Fang YU1 (1.Department of Safety, Health and Environmental Engineering,National United Univ.,Taiwan,R.O.C.)

Keywords:Conductivity, Internet of Things, on-line sensor, water resources, water deep in irrgated paddy

For the coming increasingly serious of extreme weather due to the GHG emissions, water resource management is one of the most critical issues in the worldwide area. Although the annual rainfall in Taiwan is about 3 times of the world average, However, Taiwan area is lack of water resources due to that the rainfall is concentrated in summer seasons and the water storages in rivers and dams are also difficult. In Taiwan, the water consumptions for agricultural purposes are around 71% of the total water use, and the water use for irrigated paddy fields is close 72% of the agricultural water use. Therefore, the water use for irrigated paddy fields is around 50% of the total water use in Taiwan. Similar water consumptions situations were also found in Japan and some southeast Asian countries where rice is the staple food. Therefore, a systematic, real-time and optimal management for the water use in irrigated paddy fields is the most critical issue for the water resource management in Taiwan. The Internet of Things (IoT) connects the physical devices, software, appliances and sensors, which is able to inter-operate within the existing internal infrastructure, which provides the opportunities for more effective, precise and economic benefit of water resource management. Moreover, the Precision Agriculture is a farming management concept based on observing, measuring and responding to inter and intra-field variability in crops to optimize the yields while preserving resources, which was considered as one of the key components of the third wave of modern agricultural revolutions. Indeed, the Precision Agriculture is one of the implementations of the IoT. However, one the most critical points for these applications of IoT is to develop a useable and multi-function sensor.
This research focuses on the development of a multi-function water depth sensor for the irrigated paddy fields based on the concept of continuous conductivity measurements in different depths of the water in the irrigated paddy fields. According to the experimental results, the conductivity profiles can precisely indicate the depths of water level in the irrigated paddy fields. Moreover, a wireless sensor network system (WNS) will also be constructed to detect and collect the conductivity data from different sensors located in different fields and water channels. This information can be used to optimize the water use for the irrigated paddy fields by cooperating a water gate to control the water flow into the field, resulting the saving of water resource for paddy fields. Then a systematic and real-time sensor network can be built using the concepts of IoT for the optimal management of the water use of irrigated paddy fields.
Additionally, the fertilizer substances (for example the nitrogen, phosphate, potash) drawn in the paddy fields will alter the measured conductivities in the fields. This proposed multi-function water depth sensor based on the continuous conductivity measurements can also indicate the approximate concentrations of the fertilizer substances in the fields by evaluating the variations of measured conductivities in the fields. A series of tests were also conducted using the proposed water depth sensor to measure the conductivities of the samples which were added different concentrations of chemical fertilizers into the collected water from the real paddy field. A linear relationship was found between the measured conductivities and the concentrations fertilizer (presented as ammonia nitrogen concentrations) added in the samples. This finding indicates that this proposed depth sensor can also measure the concentrations of the fertilizer substances in the fields, and provides the multiple information in the paddy field for the precision agriculture propose. On the other hand, this proposed sensor can be used as an early warning when the irrigation water was polluted by the discharged wastewater, especially form the industrial wastewater.
Both of the peasants and the governor of the water use of irrigation system can connect to the on-line sensor system. The governor can use this information from the system to optimal the water use for paddy fields even for the other agricultural purposes, and also provide a basis for the development of the Precision Agriculture. The peasants can also more effectively manger the water depth in their paddy fields by using a cell phone to connect to this on-line sensor system.