|題名||精進灌溉節水管理技術推動-以嘉南灌區為例成果報告書=Improving Irrigation Water Saving Management Technique :A Case Study In Chia-Nan Irrigation Area
|英文摘要||1. Origin and purpose
The ratio of abundant rainfall to low one is about 9:1 in southern Taiwan, leading to drought in the region from November to May every year. Moreover, recent data show that climate change intensifies its extremity and the frequency of short, delayed, heavy rainfall and other events has been quite significant. Regarding the southern region with high risk of water shortage, the pressure for regional water resources management and scheduling is becoming more and more serious, and the normal or extreme drought problems will continue to exist in the future.
In order to avoid the shortage of water resources affecting economic development and based on innovative thinking and integration of science and technology, this project aims to build the central intelligence management platform by researching and developing of transmission equipment and sensing element technology, and utilizing the Internet of things technology to collect field hydrological and climatic data for a large data statistical decision analysis database. In addition, in the face of the impact of climate change, this project is to use the real-time data of observation and transmission to analyze the water demand of irrigation areas, conduct feedback on and command of the water supply channel control equipment, and achieve the goal of accurately understanding the irrigation water capacity and water allocation, as well as regulate reservoirs to effectively use water resources.
In addition to effective management of water resources, this project intends to verify, test, and develop the function stability and applicability of sensing components and the central intelligence management platform in the demonstration area, and then to expand the modularization of irrigation water-saving equipment and create domestic demand markets, in the hope of exporting technologies, such as developed transmission system integration technology, sensing element products, and intelligent management analysis software to pursue the business opportunities for international water resources technology industry.
2. Selection and planning of test fields
This project selected as the test fields the irrigation areas of Wujia’s small water supply 3-4, 2-1, and 2-2 of the Wushantou branch, with the irrigation area of the experimental fields 55.8 hectares, which meets the requirements of the test plan. The irrigation regions as a replotting area are neat in terms of parcels and are convenient for seting up instruments on site. Divided irrigation channels, small water-supply routes, and complete and simple small drainage channels can help to clarify the objects and key positions of water quantity control. As the surrounding environment is spacious and the view is good, the observation by the weather station set up there is not interfered by the surrounding terrains. Furthermore, the convenient transportation services in the regions are conducive to on-site inspections, testing, and corrections while the impact on the irrigation areas of the lower reaches is slight, which is convenient for testing.
3. Monitoring and planning of operational testing of experimental fields
To compare the effect of gate control on the water efficiency in the experimental fields with no gate control, this project assigned the irrigation area of Wujia’s small water supply 3-4 in the experimental fields to a control group, while that of Wujia’s small water supply 2-4 was allocated to experimental group 1 and 2-2 to experimental group 2. The water sources of the control group and experimental group 1 were derived from the Wushantou branch. Wushantou branch sluice gate no. 2 was responsible for control and allocation, leading some of water sources to Wujia’s small water supply 3 and then separately introducing Wujia’s small water supply 3-4 and 2-1 for all parcels to be irrigated. The water source of experimental group 2 was also derived from the Wushantou branch, which was controlled and allocated by Wushantou branch sluice gate no. 3, leading some of water to Wujia’s small water supply 1 and then introducing Wujia’s small water supply 2-2 for all parcels to be irrigated. Furthermore, the representative parcels were selected among the control group and experimental groups 1 and 2 in the test fields, with a total of six parcels of paddy fields (the white blocks as indicated in the figure with five parcels for experimental groups and one for the control group) and one parcel of dry farmland (the green block as indicated in the figure).
4. Test results and management decisions for intelligent irrigation
(1) Water distribution and management of small and medium water supply routes
The experimental results show that, when the farm irrigators were tasked with allocating the water quantity of small and medium water-supply routes in the fields, the water delivery efficiency of small and medium water-supply routes was about 65% to 85%. During the day (from seven a.m. to seven p.m.), the water delivery efficiency was higher. When the electric gates were controlled every ten days according to the current irrigation system of the Irrigation Association, the irrigation and water delivery efficiency increased to 75% to 90%, while the efficiency rose to 85% to 90% when the electric gates were further controlled daily. It was estimated that the 5% to 10% of water consumption by the experimental group in the experimental fields during the second crop season can be balanced
(2) Irrigation management of paddy fields
Based on the theories of aerodynamics and energy balance, this project has constructed an estimation model for crop water requirements and field irrigation water requirements, which can immediately and effectively estimate such requirements for irrigation water management and allocation. According to the water demand characteristics of crop growth stages, this project has also developed the field experiment design of irrigation water management strategies for different paddy fields, setting up Control Group 1 (planting date August 2nd), Experimental Group 1 (three districts with planting dates July 27th, July 24th, and July 24th respectively) and Experimental Group 2 (two districts with planting dates July 24th and July 26th respectively). In addition, this project evaluated and analyzed, on evaluation indexes such as water-saving benefits and yield reduction rates, the effects of the intelligent irrigation management and decision-making system based on Internet of things real-time monitoring on rice yields, agronomic traits, crop water requirements, field irrigation water requirements, and water-saving efficiency, with a view to highlighting the effectiveness of advanced irrigation on precision water allocation and water resources allocation and utilization efficiency, and in the hope of more flexibly and effectively allocating water resources in response to extreme climate or severe water shortage in spring. Since the tests in the paddy fields are still in progress, the results showed that the irrigation water consumption in the experimental fields is lower compared to that in the control group (About 14.47% to 18.01% of savings, i.e. 939m3/ha to 1169 m3/ha), thus demonstrating that the intelligent irrigation management and decision-making system does enhance the allocation and utilization efficiency of water resources.
(3) Dry field irrigation and management
The Intelligent Irrigation System (IIS) modules designed, built, and completed by this study are able to achieve the goals of cloud databases, Internet of things communications, mobile device query, analysis and manipulation, big data analysis, intelligent management and network systems in tandem with information transmission and decision-making data. IIS module hardware and software systems include (1) Internet of things sensors: Internet of things sensors collect data such as on soil moisture, rainfall, and agrometeorology in dry farming areas; (2) Intelligent environment system decision-making platform: transfer in situ data via the Internet of things to the intelligent decision-making platform built under the Chunghwa Telecom Intelligent Environment System (IEN); (3) Big data analysis and intelligent management: the intelligent decision-making platform carries out data analysis according to dry farming control standards, sets the irrigation water quantity and time, and outputs the signals to automatically control the motor and the irrigation valve. According to the research, the intelligent dry farming irrigation system can transform traditional irrigation management into automatic management, and achieve the goal of precise water-saving irrigation.
5. the Central Smart Decision Management Platform
(1) Smart Decision Management Platform - Architecture, Specifications and Data Security
In this project, the cloud computing data center adopted by the smart management platform has passed the ISO500001 energy management certification in 2011. The cloud host can handle a large number of connections simultaneously, and the server is equipped with a supporting structure to ensure continuation of the service. Users can enter the system to perform operations via the Internet anytime and anywhere. The front-end of the system is equipped with a physical firewall to ensure security of the internal system, avoid intrusions or attacks from the Internet, and manage the degree to which an external user shall be able to operate the system through firewall management.
(2) smart decision management platform - Function Display, Alerts
In this project, the smart platform has been equipped with devices for hydrological, climatic and field tests. The data collected in real time will be delivered to the cloud platform via the LoRa communication equipment. In addition to display of the equipment status, the cloud platform can also display the historical observation data, the amount of water flowing into or out of the demonstration field area, and the amount of water required by wet and dry crops in the demonstration field area in each of the observation locations while controlling the electric valves and butterfly valves via remote control. In addition, the smart platform also has an alerting system (sending text messages and Email), a sequential controller and many other functions that can automatically exclude abnormal values arising from noises in the sensor.
(3) smartphone application software
Based on the said services provided by the central smart decision management platform and integration system, the smartphone application software manages to monitor the hydrological information, climate information, gate opening degree, water level and other parameters. The smartphone application software can automatically keep records and design the control interface via platform communications. At the same time, alerts on the water level can be notified in real time based on relevant conditions, which can be monitored in real time on the real-time display screen.
In this project, for the overall planning of the smartphone application software, we will use the mobile internet technologies and develop data and control network technologies for data interfacing and communication between the mobile devices and the Internet of Things (IoT). With development of mobile technologies, we can use the original programs to access the cloud-based database and physical equipment via remote control. We can also provide customized functional design and integration services. The functional interface design is mainly constructed for the Android-based smartphone system. Only when users log into the system via identity check, can field monitoring and other inquiries on GoogleMap can be activated. The functional architecture for system operation includes the functional design interface for field management and listing, map display and management, the graphical monitoring interface, monitoring record screen and relevant setup.
According to the layout of equipment over the demonstration field area, we will first divide the demonstration area into the control group, the experimental group 1 and the experimental group 2 for data listing design. Those records will be relevant to wet and dry crops in different climatic conditions and fields. The map display function mainly allows users to switch between maps on the screen, make interface between the irrigated area layer data and the monitoring equipment layer data, and inquire about the real-time information on each of the control points. The graphical monitoring interface mainly allows user to monitor the hydrological information, climate information, gate opening degree, water level and other parameters through the service interface.
monitor the hydrological information, climate information, gate opening degree, water level and other parameters. The platform can automatically keep records (including management and monitoring information about fields with wet and dry crops and the automatic gates and butterfly valves within the irrigation channels) and design the control interface via platform communications. The monitoring record screen interface mainly uses the said information to monitor the records and list the data on the screen for its planning and design.
6. R&D of the Sensor Equipment and the Control Equipment
(1) integrated water level sensor
At the present stage, the ultrasounds used in management of fields and channels constitute an application that contain multiple products, which include the ultrasonic transmitter (output 4-20MA), the signal converter, the LORA receiver, solar panels, batteries, chargers and dischargers, and boxes. This project has developed a single product to replace the current product portfolio for field test. Currently, the first version of the development specifications for the project include: Ultrasonic direct digital output which requires no digital transformation of electric current thus reducing output signal differences and contributing to analysis, the built-in LORA module for direct wireless transmission of signals. At the same time, the integrated power will reduce 0.5A in power consumption. The power consumption of solar panels will be reduced from 40w to 5~10w. As the sizes of the batteries and solar panels have been reduced, there is no need for additional covers. In the second edition, we aim to integrate soft solar panels and reduce the weight and size, while adding the low voltage alerting system. The communication board will be extractable, and options like LORA, NB-IoT or RS-485 can be selected for signal output. It is expected that the new version can reduce power consumption, investment costs, and serve the need for diversification of applications in the IOT market in the future.
(2) testing, research and development of the control gate valve
Experiments in the experimental field area show that the electric gates and butterfly valves can improve (or refine) conveyance and use of water via remote control. But if each of small and medium-sized waterways require electric gates (including the power supply, transmission equipment and boxes), each hill will need a set of electric disc valves (including the power supply, transmission equipment and boxes), which may be hard to be popularized. The project attempts to use the solenoid valve to replace the electric disc valve, hoping to achieve lower power consumption, and use the dry cell to replace the solar cell and reduce the cost of solar energy, but the solenoid valve may only be used when the height of the water head is 1.3 meters or more. On the site, we cannot see the conditions be satisfied. Thus, the test results are not good. We design another set of buoyancy automatic gates, and we use the floating bucket to generate buoyancy, which can be exerted on the multi-valve automatic valve to stop the water and realize automatic water refilling for the fields. The water supply will be stopped when the field water is full. Thus, there is no need for power to control water resources in the fields and the cost is lower to be promoted and popularized.
7. Analysis of Potential Economic Benefits and Market Demands at Home and Abroad
The results of this project show that we can conduct real-time observation of the water level to estimate the flow amount of the water. After we grasp water amount into and out of the area, we can send the information back to the hydraulic workers, no matter if the electric valves are controlled every ten days (current irrigation system) or every day. Until October 20th, the statistical results show that the two strategies can enhanced the efficiencies of irrigation water delivery by about 5% to 10% respectively. In addition, via the irrigation estimation model constructed through the project, we can efficiently estimate that the crop water demand and the irrigation water demand for the period can be saved by at least 14.47% or at most 18.01%. In this way, we can conservatively estimate that the application of this smart irrigation system can save 10% to 20% of water consumption in the second-phase cropland (based on the experimental group in the experimental field area). The amount of water to be used by second-phase cropland in the experimental field area is about 524.73 thousand cubic meters. In other words, 79 to 131 thousand cubic meters of water can be saved.
According to the estimation of equipment layout in the experimental field area: the waterways will be monitored but will not be controlled (small and medium-sized waterways do not have electric gates, so the hydraulic workers will be in control of water division). The cost per hectare is between about $ 10,173 and $ 13,035. If the waterways will be monitored and controlled, the cost per hectare will be between $ 47,415 and $ 49,661. The cost of the paddy field per hectare is about $ 48,200 if the waterways will be monitored but will not be controlled. The cost of the paddy field per hectare will be increased to $ 117,700 if the waterways will be monitored and controlled. If the waterways will be monitored and controlled, the cost of the waterways will be between $ 41,100 and $ 45,693. The cost of the paddy field per hectare will be about $ 48,200 if the waterways will be monitored but will not be controlled. The cost of the paddy field per hectare will be about $57,200 if the waterways will be monitored and controlled.
On the whole, if we conduct estimation based on the monitoring and development equipment in this project, the cost of the paddy field and waterways per hectare will range between $ 30,105 and $ 30,621 per hectare if the waterways and paddy field will be monitored but will not be controlled. And the cost of waterways and paddy fields will range between $ 93,552 to $ 98,155 per hectare if the waterways and paddy field will be monitored and controlled. In this regard, we may conduct estimation based on the estimated irrigation area of 67395 hectares for the existing paddy field in 2017 (Jialan Water Conservancy - Double-cropped fields: 22,952 hectares; Single-cropped fields: 9178 hectares; 2 crops in 3 years: 34919 hectares; and Rotation field: 346 hectares). In this project, if the smart irrigation management system is promoted to all parts of JiaNan Water Conservancy (waterway monitoring equipment: a single small and medium-sized waterway as the unit for equipment layout; paddy field monitoring equipment: irrigation per hectare for equipment layout), it may cost $3.67 to $3.70 billion when he waterways and paddy field will be monitored but will not be controlled, while it may cost $6.9 to $6.9 billion when he waterways and paddy field will be monitored and controlled.
8. Directions for Future Research
Effective use of water resources and food security will surely become important issues around the globe in the future, especially when human beings are faced with more frequent and powerful extreme climates in the current stage. As this project aims to promote water use efficiency and acceptable farming and irrigation methods, we use the Internet real-time monitoring function to establish a smart irrigation decision-making system that can achieve accurate water distribution and effective use of water resources. This study was conducted on two crops in 2016. However, it is recommended that this study be continued to establish better and reliable information for future reference.
Regarding water distribution, this project uses the small and medium waterways for the irrigation area as the unit to control water. In the future, we may try to expand the range of the monitoring unit (single crop area, rotation area, groups). We hope that we can reduce the investment cost while keeping high efficiency for water transmission and distribution. Also, we may further study a series of interlocking gate control strategy under the current water conservancy farming system to ensure that the surplus water can be effectively stored in Wushan Tau reservoir. In addition, under the system set up by the Jialan Water Conservancy, as we consider that Wushantou line is a branch outside of the north and south lines, the test will have a small impact on the farming system set up by the water conservancy. And thus, it is recommended that the demonstration field areas be expanded to all the irrigation areas along the Wushantou line for further promotion and popularization.
Regarding paddy field irrigation, in the future, we can study adjustment to the planting period and the System of Rice Intensification (SRI). We can use the modified growing degree days (MGDD) to collect temperature data and establish rice growth period and the cumulative fertility degree of the paddy rice in each growth period. And we can more timely and accurately decide the crop coefficient and set the monitoring level that can help estimation of the crop water demand and improvement of the central smart irrigation management decision system.
Regarding irrigation of dry fields, it is hoped that the Dryland Smart Irrigation System can be applied to the highly economic dry irrigation area and other dry crop lands and irrigation areas that are deficient of water and receive less irrigation from the Farmland Water Conservancy for higher efficiency of irrigation.