Title：An Introduction to Irrigation Management Organizations and Agricultural Water Resources
Speaker：Dr. Chia-Chi Ma
Agricultural Engineering Research Center
Time：06/09（Tue.）14：00
Place：S-325, Science Building 1
Abstract：
This document introduces the basic concepts of the agricultural irrigation management system and the agricultural water resources management framework.
1. Irrigation Management Organizations and Institutions
The primary purpose of irrigation and drainage is to artificially supplement insufficient natural rainfall or remove excess water in order to maintain normal crop growth and improve agricultural productivity. With the development of agriculture, irrigation and drainage have evolved beyond simple production techniques to include multiple environmental functions such as groundwater recharge, microclimate regulation, water resource cycling, and land conservation. These functions are of great significance to the sustainable development of agriculture.
In terms of irrigation management institutions, Taiwan’s irrigation management organizations have gradually developed into a governance structure jointly participated in by the government and farmers. At present, the Irrigation Agency serves as the core institution, with regional management offices responsible for the operation, maintenance, and allocation of major hydraulic facilities. Farmers’ organizations participate in on-farm irrigation management and the operation of irrigation groups, forming a hierarchical management and collaborative governance model. Through the rotational irrigation system and irrigation group system, farmers’ water use can be effectively coordinated, irrigation order can be maintained, and water-use efficiency can be improved.
In addition, under the context of climate change and increasing competition for water resources, the government has promoted related agricultural policies, such as large-scale rotational irrigation in water-competition areas and the promotion of water-saving pipeline irrigation systems. These measures aim to improve agricultural water-saving efficiency during dry seasons and stabilize the overall water supply system.
2. Principles of Agricultural Water Resources and Irrigation Management
The core of agricultural irrigation management lies in understanding crop water requirements and the conditions of water supply. Crop water requirements are generally expressed in terms of evapotranspiration. Estimation is typically based on reference evapotranspiration (ET₀) and crop coefficients (Kc) to calculate crop evapotranspiration (ETcrop). This value is influenced by meteorological conditions, soil characteristics, and crop growth stages, among which solar radiation, temperature, and wind speed are the primary meteorological factors.
When formulating irrigation plans, factors such as reliable water sources, cropping systems, and rainfall conditions must be considered. Water resources in Taiwan are characterized by uneven seasonal distribution, with most rainfall concentrated during the rainy season. Therefore, irrigation systems rely on diversified water sources—including reservoirs, river diversions, and groundwater—to maintain stable water supply.
The calculation of irrigation water volume is generally based on the water balance concept, which includes factors such as crop evapotranspiration, field seepage, rainfall, and return flow. These factors are used to estimate field water requirements and the irrigation demand of the system. In addition, the estimation of effective rainfall is an important basis for irrigation planning and can be analyzed using methods such as the daily water accounting method, the average rainfall method, or the percentage method.
Overall, agricultural water resources management requires accurate estimation of crop water demand, well-designed irrigation systems, and effective management organizations in order to achieve multiple objectives, including agricultural production, efficient water resource utilization, and environmental conservation.
