2.1 Overview of the study area
This study selected Shahe Reservoir (118°07′ − 118°15′E, 32°20′ −
32°26′N), Huanglishu Reservoir (118°01′ − 118°07′E, 32°11′ − 32°16′N),
and Chengxi Reservoir (118°15′ − 118°18′E, 32°19′ − 32°22′N) as the
research objects in Chuzhou City (Fig. 1). Shahe Reservoir is located in
Shahe Town, Nanqiao District, Chuzhou City, was built in September 1958,
has been reinforced and expanded for five times, reached the current
scale in 1979. The reservoir has a catchment area of 300
km2 and a total capacity of 197 million
m3, as a large (Ⅱ) type reservoir, it is mainly used
for irrigation and has the comprehensive benefits of flood control,
urban water supply, aquaculture, and so on. Huanglishu Reservoir is
situated in Chuzhou City, Quanjiao County, started construction in
September 1959, and in December 1965 was completed. With a control basin
area of 262 km2 and a total reservoir capacity of 315
million m3, it is a large (Ⅱ) type reservoir that is
mainly used for irrigation, taking into account the comprehensive roles
of flood control, water supply, power generation, and aquaculture. Now
renamed Biyun Lake, the surrounding area has become very popular for
tourism. Chengxi Reservoir lies in the upper reaches of the tributaries
of the Qingliu River in Chuzhou City, constructed in 1958 and put into
operation in 1965. Reinforcement was carried out in 2010 and is now
completed. The control basin area of the reservoir is 168
km2 and the corresponding capacity is 85.25 million
m3, which has the functions of flood control and
security, urban water supply, agricultural irrigation, power generation,
and so on. The average annual water supply is about 29 million
m3 to the city and 9 million m3 to
agriculture. It can be clear that guaranteeing the domestic water needs
of Chuzhou residents is the major task of the Chengxi Reservoir.