美工圖片   Investigation of Current Status in Wu River System (Water Resources Planning Institute, WRA, MOEA. April, 2006)

 

The purpose of this two-year study was to compile ecological information and current status on the Wu River System in order to provide a basis for its ecological engineering planning and for establishment of its ecological resource database. The second year of the studies focused on its tributaries Fatzu, Tali, Maolo and Peikang. In addition to the compilation of abiotic factors (physical conditions, water quality indices, engineering constructions, and recreation usages), we conducted seasonal biological surveys on algae, aquatic insects, shrimps, crabs and freshwater fishes in aquatic ecosystem , and on riparian vegetations, mammals, birds, reptiles, amphibians, and butterflies in terrestrial ecosystem.
 

The Wu River had an average elevation of 651 m and slop of 1/92 with a drainage basin of  2,025.6 km2. The annual average air temperature of the basin was 21.82℃ and relative humility was 77.33%. Precipitation was strongly influenced by seasonal monsoon and topographic conditions, the raining season in May to October and dry season in November to April. Its average precipitation was 2,087 mm. Water flow differed greatly between the two seasons: Highest in June and lowest in January. There were 25 cities and villages within the boundaries of the Wu River basin covering the three counties Nantou, Taichung and Changhua. Water of the Wu River was primarily for the agricultural use.

The results of the riparian land utilization were: The land along Tali Creek in the section between the Nan Bridge and Shin Bridge was primarily for rice paddies and horticulture, and its small tributary areas were for small orchard gardens, and banana and betel nut plantations. The riparian land along Maolo Creek was primarily for rice paddies and fruit orchards, mixing with small horticultural uses. The land of Peikang Creek was mainly for fruit orchards, vegetable and flower gardens, and betel nut plantations for the downstream section. The recreational uses were

Wu River System

mainly for recreational fishing, particularly at Changping and Pinglin creeks tributary to Maolo Creek, and hiking, fishing, scenery enjoyment for the Peikang Creek. Due to the adversary effects of its upstream section of Maoulo Creek, water recreation was rare.

In the aquatic ecosystem, we collected 26 species of fishes, 9 species of shrimps and crabs, 73 genera of algaes, and 33 genera of aquatic insects. Overall, the species show gradient changes from upstream to downstream.

In the terrestrial ecosystem, there were 18 species of mammals, 117 species of birds, 33 species of reptiles, 18 species of amphibians, and 136 species of butterflies. In general, most of the species were typical animals that represented the ecological status in the region. There are 96 endemic species and subspecies, and 49 conservation species along the Wu River and its tributaries. Some of them, especially birds and butterflies, may be used as indicators for future resource monitoring.

Our work on the current status in the Wu River System is only a beginning for effective management of the natural resources in the region. We expect similar work can be conducted in other rivers of Taiwan in the near future, and these data can be compiled in a well-designed database. These status reviews should provide a starting point for our river management work and, thus, a better environment for future generations.

Wu River