How to query the hydrological data of Hunan Province in recent 20 days

First of all, you should find the distribution map of hydrological station network in the nearby area, select the corresponding hydrological station, and then apply to the local hydrological bureau or the competent hydrological department for using hydrological data. After calculating the price, you can receive paper and electronic hydrological data by paying the money. Please consult the Hydrological Bureau for flow data, water level data, rainfall and evaporation data.