Chinanews, Xining, July 4 - The water level of the famous Qinghai Lake in Qinghai Province (the biggest lake in China) has kept declining in the past decades. However, scientists estimate that it will start rising again after 2016, and the lake will be restored to the condition of the 1970s in 2030.Qinghai Lake is located 150 km from Xining, 3,197 m above sea level. The lake is 63 km wide north to south, approximately covering 4,583 sq km. The average depth of the lake is 20 m. There are about 75.4 billion cubic meters of water stored in the lake at present.Due to global warming, the water level of the lake has dropped by nearly 3 meters in the last 30 years. However, if global warming goes on, it will send monsoon to the lake from the Indian Ocean. That is to say, the precipitation on the lake will increase.The conclusion is based on careful calculation and precise analysis.