Key Curves for River Water Flow

Hello! I need to make me 8 Key Curves for River Water Flow. Here is the recommendations: Every river has about 12-15 measurements (one or two per month). Every measurement has the folloing data: H - water high, V - water Velocity; F - river bed Area; Q - water quantity (Q = V*F) H is constant for every measurement. Q (cm3/sec); V (meter/sec) F (m2) ; H (cm) According to the dada we have to make key curves for Q; V; F. In most of the cases there will be more than 1 curve for Q;V;F, because the river bed may has changed trough the year, which mean we will have different Area (F) for the same H. The maximum diversion from each point to the curve is 6%. I am attaching an Excel data for 8 rivers. So you can see the real data. Each tab is different river. Thank you!