synthesis of hydrograph

例句：

1. 1.The hydrograph of the river shows the flow rate of the water.
   河流的水文学显示了水的流速。
2. 2. The hydrograph of the region is closely related to its climate.
   该地区的水文学与气候密切相关。
3. 3. The hydrograph of the city is used to monitor the water quality.
   城市的水文学被用来监测水质。