The surface water forecast is divided into three periods: the high water period, the normal water period and the dry water period.
1. Flood Period: Refers to a time when river flow relies primarily on precipitation or snowmelt for recharge. This is a time in the rainy season or spring when the temperature continues to rise. , the river water is abundant and lasts a long time.
2. Flat water period: It is divided according to the climate of the hydrographic zone and is mainly fed by rainwater.
3. Dry season: Refers to the period when the surface water flow in the basin is exhausted and the water supply depends mainly on groundwater. The dry season lasts a long time in the year and varies depending on the season. natural geography and weather conditions of the basin.