Flood Routing

EH406 Engineering Hydrology I Flow Routing through Reservoirs and Lakes This technique is utilize in Flood warning studies Reservoir spillway send off Hydropower production planning Water resources studies Techniques of flow routing, of this and other types, atomic number 18 also encountered as components in a wide diverseness of hydrological flow models.
Combined Inflow = I(t)

Control - Natural quiver Outcrop or Manmade (Weir) Lake or reservoir

Q(t)

The user must return four types of information Lake geometry this allows the storage volume elevation intercourse to be obtained The wet elevation outflow relation ( = natural spring rating curve). These two allow the important S-Q relation to be obtained see below. The inflow hydrograph(s) observed, synthetic or backrouted outflows The starting lake water take
Lecture Notes Flow Routing 2.doc 1 18th September 2003

 persistency Equation

I (t ) ? Q(t ) = Q(t ) + K (Q)

dQ dS dS dQ = = K (Q) dt dt dQ dt

(1a)

dQ = I (t ) dt

(1b)

where K(Q) is the slope of the S Q relation,

K (Q) = dS dQ

(1c)

In a linear reservoir K is a constant and accordingly S = KQ. In practice the S Q relation is gently concave downwards and K varies with Q and hence with water level, H.



Since S has to increase with water level and Q also increases with water level it follows that S increases with Q. Hence K = dS/dQ fucking neer be negative. However K usually decreases with Q. The value of K applicable when water levels and discharges are in truth low can be very large relative to K determine when water levels and discharges are high. K is reminiscent of a anteroom time in that when the reservoir is almost empty (large K) inflows forget remain, on average, a long time in the lake onward discharge and when the reservoir is full (smaller K) inflows pass through very quickly. [In the above do not confuse KQ, which is S cypher by Q, with K(Q) which indicates that K depends on i.e. is a function of Q].
natural S-Q relation...If you want to get a full essay, order it on our website: Orderessay



If you want to get a full essay, wisit our page: write my essay .