2.1. Study area
Nansi Lake (NSL) is an important storage hub of the SNWD-ERP. This lake
is located in western Shandong Province (WSD), (34°27′ to 35°20′ N and
116°34′ to 117°21′ E). NSL consists of four sublakes: the Nanyang,
Dushan, Zhaoyang and Weishan sublakes, extending from north to south.
NSL is the largest lake in North China, with a water area of 1,266
km2 and 53 inflowing rivers. NSL is situated in a warm
temperate zone, and the climate is a subhumid continental monsoon
climate with 700 mm of annual precipitation. The evaporites in WSD are
dominated by rock salts and gypsum salts, and gypsum salts (gypsum
mines) are mainly distributed in the southwestern portion of WSD
(Qi, 2010 ).