**4.2 Losing stream or influent stream**

In this connection, given the level of GW is lower than the streambed, hence, SW recharges the GW. Losing streams connection divided into two types in which it is either connected or disconnected with the GW table. The term "transition" is used to define the condition of connected and disconnected streams. As shown in (**Figure 7B**), the unsaturation zone is presented in transition with a shallow GW table between riverbed. Note, there are distinguished interactions of the disconnected stream with shallow and deep water table [20].

## **4.3 Losing disconnected stream**

In this connection, the unsaturation zone of sediments exists between the channel and regional water table hence it can be said that the system may be hydraulically disconnected (**Figure 7C**). The term disconnected has been criticized because it can suggest a system where there is no exchange of recharge and discharge of the GW system [21]. Therefore, the rate of infiltration of a disconnected system has been referred to as a "maximum losing condition"—stream discharge mechanism. Thus, the water table occurs at greater depth in the disconnected system and at shallow depth in the transition zone.

#### **4.4 Losing connected stream**

A stream is a stream that loses water while it flows downstream. The water penetrates the ground and recharges the local GW flow as the water table lies below the level of the channel with the absence of an unsaturation zone (**Figure 7D**).

## **4.5 Parallel stream**

This interaction occurs when the stage of the stream and the head of the groundwater is equal (**Figure 7E**).

#### **4.6 Flow-through stream**

Where the stage of the channel is less than the head in the groundwater on one bank side and larger than the head in the groundwater on the opposite bank side, this process is seen as a flow-through reaches (**Figure 7F**). This interaction occurs most frequently when the stream cuts perpendicular to the regional GW flow, which in the case of fluvial plains is along their axis.
