Table 1 Channel connectivity index system
In the AHP model, channel connectivity is regarded as the objective layer. Boundary, flow and sediment are connected as the second layer, namely, the subsystem layer t. Among all kinds of indexes, the boundary connectivity indexes include the stability coefficient C1 and stream gradient C2. The flow connectivity indexes include discharge capacity C3, runoff C4, matching index of maximum flow C5, and matching index of minimum flow C6. The sediment connectivity indexes include sediment load C7 and sediment matching index C8, and all kinds of indexes are listed as the third layer, namely, indicator layers (Fig. 2a).