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uϤ   Investigation of Current Status in Tan-shui River System (The 10th River Management Office, WRA, MOEA. December, 2005)

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River Investigations projects were started in 2002 aiming at establishing ecological environment database of the primary rivers in Taiwan. 10th River Management Office, WRA, is processing the investigations in Tanshui River system in 2004 and 2005.

The data of hydrological and biological status in the Tanshui River system has been surveyed and collected in the two-year project. Based on the data, integration workof the ecological and engineering investigating results were made to provide as suggestions for ecological and hydro-engineering communities. The main survey sites were located on the main river section in the first year, and tributaries, Da-Han Stream, Xin-Dian Stream, Jing-Mei Stream, Ji-Long River in the second year.

By analyzing the characteristics of river morphology, hydraulics, and sediment,, Tanshui River was classified as 12 modules, namely, bands aggradations, bands degradation, bridge, wetland, influx, flood plain, wide-straight reach, narrow-straight reach, v-shaped valley, pool, riffle, and reservoir. The categories obtained were then used to describe the habitat of the creature.

From the biological survey, the fauna and flora recorded in the Tanshui River watershed are as follows:

1.Aquatic creature: 35 genera of aquatic insects, 27 species of fishes, and 16 species of amphibians.

2.Territorial creature: 16 species of reptiles, 118 species of birds, 10 species of mammal, and 480 species of plants.

According to the investigation, we have found the phenomenon that much habitat is destroyed by artificial constructions, many exotic species are dominant the river corridor, and the biodiversity are low. It is implied that the natural environment of river is greatly unbalanced by human disturbances. In this report, each profrssional team has proposed the advice for improving the degraded river situations.

All of the collected data, including biotic and abiotic attributes of Tanshui River system, was digitized and compiled by the GIS technology. Users can access this information from the website easily in the future.

Our work on the current status of Tanshui River is a beginning for different fields cooperating to figure out the natural resources in this region. We expect the similar projects can be continued on the other river systems to provide more information and a macroscopic perspective for watershed management. Therefore, we can leave a better aquatic environment for the coming generations.

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