美工圖片   Investigation of Current Status in Er-jen River System (The 6th River Management Office, WRA, MOEA. June, 2007)

 

To enhance river management and provide essential information of river regulation, this project completes river environment investigations, including cultural, geography, hydrology, biological resources and land use. The study area covers the main stream of Er-Jen stream and three tributaries, Shen-Keng-Zih creek, Song-Zih-Jiao creek and Niou-Chou-Pu creek. The study stream is distinguished into upper reaches and low reaches at Chong-De Bridge, according to bottom slope. The patterns of pool and run occupy most reaches of Er-Jen stream and Niou-Chou-Pu creek, and the patterns of glide and pool appear in Song-Zih-Jiao creek and Shen-Keng-Zih creek. The present land use along river side is mainly the orchard, bamboo grove, factory and house.

This project evaluates water quality in four seasons, and the results show serious pollution along full reach of Niou-Chou-Pu creek, and the low reach of Shen-Keng-Zih creek especially in dry season. The flora and fauna found in the Er-Jen river system are 13 fish species, 2 crab species, 4 shrimp species, 17 benthos species, 190 Terrestrial species and 222 flora species.

The boat for the Environment Protection
The boat for the Environment Protection

 

On stream habitat structure and restoration, this project takes advantages of multiple component method to analyze water quality data monitored by environmental protection agency. The results indicate the river pollution of Er-Jen stream has no obviously variation in the past five years, and the benthic component changes significantly in different seasons.

To introduce preliminary plan of environment improvement, this project carries on rainfall frequency analysis and one dimensional hydraulic computation. Hydraulic computaions show that it requires constructing embankment to reduce the flood risk in the low reach of Er-Jen stream.

Questionnaire investigation with resident along river side has finished and 83 copies are taken into account. It responses that most of people feel the worst river environment and water purification is expected. According to the integrated investigations, the river development planning is proposed to different reach: the low reach is suggested to flood control and river side activity, the middle reach is stressed on water purification and stream restoration, and the upper reach is advised in landscape development. In water purification planning, underground filter tank is suggested to install at the low reach of tributary or the upper reach of Er-Jen stream, but river sediment must be taken into consideration. At river mouth of Er-Jen stream, the construct wetland is suggested to habitat restoration and improve landscape and river side activity.

Er-jen River Environment