| dc.description.abstract | Agricultural water accounts for more than 70% of the total water volume in Taiwan, leading to concerns about excessive water usage. Recent research indicates that approximately 40% of irrigation water is replenishing groundwater, making groundwater resources increasingly important as a water supply source. The Tainan region possesses a more mature irrigation system, while the Kaohsiung area′s irrigation system is relatively incomplete. During the dry season, agricultural water availability is often insufficient due to inadequate reservoir and river water levels, leading some areas to excessively extract groundwater to meet agricultural needs.
This study utilizes a System Dynamics model - VENSIM to establish a correlation model between agricultural land and groundwater in the Pingtung Plain, specifically focusing on the Qishan Creek and Laonong Creek watersheds. Hydrological data from 2018 to 2022 are used to analyze aquifer storage, investigating the impact of agricultural water usage on groundwater levels. The aim is to understand the optimal water utilization for agriculture under limited water resources. The validation of the model, with correlation coefficients almost exceeding 0.7, demonstrates a high level of relevance, proving the model′s applicability.
The study simulates and analyzes two scenarios for agricultural land: irrigated and non-irrigated. The irrigated area within the research scope covers approximately 332.64 square kilometers (about 46%). The results indicate that groundwater levels tend to be on average 0.01 to 0.5 meters higher in irrigated areas compared to non-irrigated ones, suggesting that agricultural irrigation has a certain impact on groundwater levels. Moreover, the comparison between non-irrigated simulation results and rainfall data shows that groundwater storage primarily fluctuates based on precipitation when irrigation is not taken into account. | en_US |