The history of irrigation in Taiwan has already four hundred years, The successive dynasties burdened with the economical development of the weighty responsibility. Since the center government of Republic of China from the main land of china move to the island, at the first stage (1941~1960), for the stabilization of economy and food supply, the enterprises of irrigation and drainage are constructed more positively, then, all of the facilities that are constructed in the period of 1941 to 1960 have been used over 50 years. The most part of canals are older near to the use limit period of construction, So that it should be renewed or improved.
Before 1971, Agriculture is the main economical enterprise in Taiwan, but in recent of 30 years period, the conditions of society and economy are changed, now the industry and business become the main economical action, in the same time population are increased so many too. There are many new urban communities and industry demonstration districts have been constructed. It distributed in the side of irrigation canal. Because of the social district developed rapidly, and drain systems of urban communities are not constructed by same time, Residents used irrigation canals for drain in most part of urban communities, and used the both sides of patrol road for the country roads, so that the relations between irrigation system and urban communities become intimater. People in the urban communities expect that the canals of irrigation and drainage would be green area and have diversified functions to supply the place used for residents relaxing, and have big capacity for drain when storm occur, and have sufficient safety facilities for avoid danger of some pedestrian fall down into canal. But wasted water drain from urban communities and industry demonstration districts polluted the irrigation water, and getting ride of garbage by resident as one please etc., that hinder the irrigation management.
All of above problems have to solve by renewed or improved the structure of canals. Otherwise, after Taiwan entered the WTO organization, owing to free trade Agriculture products in the island are struck against seriously by products of other countries. In order to solve the problem, agriculture policy in Taiwan Change the objective of development from only production to three-generation (I.e. production, ecology and living environment), Therefore, irrigation canal system have to adjust the original simple function to multiple functions to approach the new agriculture development objective. Stabilization of food production, beautification of living environment, and maintenance of natural ecology system are new functions of irrigation canal system. According to above reason, most part of canals that are older or function change have to renew or improve in near years.
The study analyze some practice cases of Tao-Yuan main canal system that renewed and improved by recent, finds that for avoiding the negative influence from urban communities and industry, and creating the plus function of canal to urban communities can use the following models:
A: Avoidance of irrigation water polluted by urban communities or industry: Separating irrigation canal from wasted water way.
B: Increase the canal capacity for drain flood and safety facilities: Renew the structure of canal by changing the cross section from original trapezoid type to double rectangular type, using the model can reduce the water depth and increase the water conveyance area, therefore, it can satisfy the need of flood drain in storm days and decrease the danger of people fall down into canal on usual days.
C: Diversification canal functions of green and beautify living environment and maintenance the natural ecology systems for supply people relaxing area: construct a creeping irrigation canal that can maintain the natural ecology environment, and using the quasi-natural construction method to improve drainage canal that can not only maintain natural ecology but also have beautiful landscape, otherwise, farm ponds can coordinate with the near series space of relaxation action, it will become a continuous complete space used for people relaxing.
Above three models are analyzed and checked by the study, its effect is excellent and quickly that are certified. And the technic of design and plane, the methods of effect estimation and rule of operation and maintenance etc; are explained by case study of Tao-Yuan main canal in this paper. Expect it can be some reference in other case.
計畫主持人
陳獻、李總集
Project Director
Shinne Chen, Tsung-Che Lee
關鍵字
桃園大圳、灌溉、水質、渠道更新改善、水路安全、休閒遊憩
Keywords
Tao-Yuan main canal、 Irrigation、 Water quality、renewal and improvement for canal、afety of canal、play
