Spatio-temporal variations and cause analysis of headwater quality in forest area of Taihuyuan

Key words: 
• water resources /
• water quality /
• bamboo plantation /
• forest tourism /
• nitrogen /
• Taihu Region

Abstract: The headwaters of Tiaoxi River，located in Taihu Headwaters （THH） Township of Lin’an City，Zhejiang Province，serve as a source of drinking water for people living in the Tiaoxi River watershed area comprised of Hang-Jia-Hu Plain in northern Zhejiang Province and a region along Taihu Lake in Jiangsu Province. Maintenance with high water quality to the headstreams therefore is of great importance. In recent years，however，with the fast development of heavily fertilized bamboo plantations for edible bamboo shoots and flourishing forest tourism，soil runoff and waste output due to improper deposition and discharge have imposed remarkable risk of water pollution. Protection of the headwater quality in the catchment of THH Township has become more serious than ever. This research project is therefore carried out to monitor water quality of the headwaters down to the lower part of the Tiaoxi River in metropolitan area of Lin’an City； sources of pollutants are also under investigation. The present paper summarizes our primary results based on monthly water monitoring from May 2006 until March 2007. The results show that water quality varies greatly over the distance from the headwaters to the lower part. Nitrogen （N） is the most serious pollutant. Concentrations of ammonium，organic matter（OM） and phosphorus（P） in the water also change remarkably over time. The results imply that water pollution is closely related to output of organic wastes including household refuse and human waste where tourism is heavily increasing in the headwaters areas. Additionally，the pollution is heavy in the metropolitan area of Lin’an City and the area of bamboo plantations. ［Ch，2 fig. 2 tab. 12 ref.］