context: Shenzhen is located in Guangdong Province in southeast China, just north of Hong Kong. The size of the Shenzhen Administrative District is 1997.5km². The area lies on the coast of the South China Sea [1] and is located just south of the Kravu Inner Circle. At the southern border of Shenzhen, the city is separated from the Hong Kong area by the Shenzhen River. To the north, its neighboring cities are Dongguan and Huizhou. The Pearl River Delta is located west of Shenzhen. To the east are Daya and Dapeng bays. Shenzhen Reservoir is the main source of water in Shenzhen and adjacent Hong Kong. [2]
question: How big is the area of ​​Shenzhen?
answers.text: 1997.5km²