Abstract
The variation of seasonal rainfall pattern is very obvious in Taiwan. In recent, the climate and water resource reliability is decreasing with global warming. The irrigation water demand is 70% of total yearly water usage. It also exists highly risk of hazards under climate change. Therefore, efficient and flexible water resource allocation management to reduce hazard risk is an important issue. The study area includes whole Taoyuan Channel irrigation area and particularly its 2-nd branch system. The Mann-Kendall tests showed significant change of long-term rainfall in the study area. When spring rainfall and plum rainfall increased, the water supply increased during the first paddy period. The decreasing trend of dry season rainfall may indirectly increase the risk of irrigation water supply. The long-term seasonal forecast of three-month future rainfall probability prediction was provided by Central Weather Bureau (CWB). The objective of this research was to investigate the influence of irrigation water requirement with pond irrigation operation. In this study, rotation irrigation method and pond irrigation system condition was input into Vensim model operation basement of Taoyuan Channel irrigation area. The long-term seasonal forecast probability was used to generate the future rainfall data with Weather Generator (WGEN). To gather statistics the historical rainfall data of both Taipei rainfall station and fourteen Taoyuan Channel irrigation area rainfall stations. The rainfall shooting averages were all above 0.61 in three shooting zones. It suggested that the long-term seasonal forecast data of Taipei station can be applied to Taoyuan area. However, the analysis of Taipei station prediction ability was not very stable. The future 3 month rainfall data sets simulation was formulated into three cases: (1) pond operated, (2) pond partial operated, and (3) pond closed irrigation system. For cases of insufficient water supply, the results showed that pond irrigation system can reduce the burden of canal supply and the risk of shortage significantly. The performance of pond operated was better than pond partial operated.
Original language | English |
---|---|
Pages (from-to) | 74-86 |
Number of pages | 13 |
Journal | Taiwan Water Conservancy |
Volume | 61 |
Issue number | 3 |
State | Published - 2013 |
Keywords
- Mann-Kendall tests
- Pond irrigation system
- Rotation irrigation
- Seasonal long-term forecast
- Weather genterator