Discussion and Conclusion: 1.The various indicators presented herein before are based on the existing data and reports available form Taoyuan Irrigation Association (TIA), Taiwan. The purpose is to show to what extent these data can be applied to the assessment of irrigation (and drainage) performance. 2.The Taoyuan Main Canal System (TMCS) of TIA receives water from a reservoir (Shihmen Reservoir) to irrigate its service area. However, as the reservoir serves multi-functions (irrigation, water supply, power generation, flood control and tourism), the supplemental water sources are exploited to the greatest extent possible, which consist of local streams and the Association-owned irrigation ponds (287 units in total, capable of impounding 4.6 M^3). 3.In wet or rainy seasons, the TMCS conveys more water than the irrigation requirements, to allow the surplus water to be stored in the ponds, which in turn will supply to their respective service farms when water availability from local streams and the reservoir are limited in dry seasons. This kind of storage adjustment function of the ponds has greatly contributed to the steady irrigation water supply to the area irrigated by TMCS. 4.The aforesaid explain why the water supply amounts are usually greater than the water demands, as shown in tables (1), (2-2) and (3). 5.Data of Table (2-1) shows that in practice the amounts of water delivered to TMCS are much less those planned. This is because the used quantities of rainfalls are greater than the amounts of effective rainfalls given in standard irrigation requirements. 6.In Table (4), as explained above, the amounts of water diverted to TMCS have been adjusted due to use of more effective rainfalls in the fields, whilst irrigation requirements in the fields still based on the standard effective rainfall quantities. 7.In TMCS service area, the rotational irrigation is practiced in dry seasons which fall in the periods of first crop seasons. Each rotational block, which is at the tertiary level, coincides with an irrigation pond’s control area. As the combination of water sources from the pond and TMCS, and local streams where available, are usually sufficient to meet the planned discharges required for rotational distribution, hence either the irrigation times of each due water distribution or the irrigation intervals are dependable or regular. 8.Since TIA is located in the counties where industrial and commercial developments have progressed very fast over the past decade, accompanied with the high increase of local population, therefore not only the non-irrigable farm lands but also the irrigable lands serviced by the Association have been decreasing. The loss of service area has led to desolation of several irrigation ponds and tertiary canals, which land prices have escalated very high due to the fast developments ever made in the surrounding or nearby lands.
計畫主持人
譚義績
Project Director
Yih-Chi Tan
關鍵字
灌溉與排水績效指數、國際灌溉排水協會、ICID、桃園農田水利會
Keywords
Irrigation Permormance、Taoyuan Iirrigation Association
