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� . <br /> : �- . <br /> � _ _ <br /> ) ._ '(t c ' V m:;/ <br /> l.f <br /> Sfa�m Juict,on • .� �n��;. <br /> 9 � <br /> �/O min. <br /> a �� <br /> i � ' <br /> �� <br /> � C 2 �Ltuximum Sfcrogi �E'vquircd <br /> �20min. CriliGol :�torm <br /> � i du�ofion <br /> 90 min. �j0 min. <br /> i l7. - 4o min <br /> l - — — 6,o m.n. <br /> � � f -�--- � .. - <br /> , <br /> � , Qa7vF� lZof¢��. <br /> �� :(� .. _ ,. - � — ._� — <br /> l fi� :i <br /> r'i; <br /> �,�� .: <br /> O <br /> p /O ' li) 90I 4U 00 60 70 <br /> Timc �n Minuf¢s <br /> I�IGU[tE i l TYPICAL EXA�t!`LE nP GN-SITG DLTEN7'ION <br /> ItATIONAL h1ET'ciOD ANALYSIS <br /> detcntion ar�alyscs. 7he assumed relcase curve AllowaUlc release rate: Q = 2.5 cfs <br /> I a�prosincatcs a formal rescrauir routing i�e <br /> much thr. same way thc Rational Methud Required: <br /> Ilydrograph a�proxim,tes a truc stonn Uetcrmine the critical storage volumt <br /> , hydrop,raph. Tl�c curvc a!i'�wo f�r thc low <br /> reicx:.e �ate n� thc Ucginnirg oi ,: :�� r:n and an titnrm Srorm Rdcasc Rcquircd <br /> incrcasing re'.'asc rate as lhc .tut�3c eolumc Uur:ilion Runof( Flow Slorage <br /> incrcascs. in ncttnal 1'cod^tou;,in�;�_tf�c (�tinulcs) Volumc Volumc Vutume <br /> u fl?_ c � t <br /> maximura releasr rate �vil�alwys occur at the cu (t (£� ( � tl <br /> loint µficrc_hc o_itflow hy_ci�op.raph crosscs 8 3710 I400 2510 <br /> thc rctcAing lim�;tl111f,1on nv }lv �ro��i�ph. �� 4206 1500 270C <br /> Fcr ths rcason, thc dcsi�n rcleasc _itc ia � 5 S�gq 2250 2434 <br /> iorccd to eoincide witi� that.soint on lh� 2� 5820 3000 28Z� <br /> fallin� limb of lhc_hy_droPr�h resultina from �� G4R0 4500 1980 <br /> the storm of �uration =��al_t4_he lime o[ 4U 734q ` G000 1?4M1 <br /> concchtrati Lj'Qt11te_1�15u�.'ihc ecicase ratc is <br /> jie1A constant past this point. 'llie critical 'p�e crilical storage volume is tL•en 2,934 <br /> storage volumc is thcn found by detcnr,i��.ing cuUic feel occuiring for a IS-minute rainfa0 <br /> thc area betwccn lhe intlow nnd relrr�e �yuralion, or timc of conccntreti��n. <br /> � vc <br /> hydrographs. Cxantplc t�o. 2 cnntinua: tLc r�any_cilacS.Dlld�eS in thc Ucn--S <br /> wlculalions init�atcd in Ir.xam�i Nn. 1 to _i1r_ '.ji'..'�Iit.rLt�t.G,L `::•1"1.TS.. 't;:,�L-t�sc1C"« <br /> dcicmune the t�yuirrd storad�' '^'����T���• r:,te�_�(fl_ toJ;ie 11�si_r._�ic Icv�[o�u <br /> � E•xamplc No. 2 f:anicula� _._i_�fall 6�cqucncy. l:nder thesc <br /> Given: circumstan:cs Uie r:least rate is calculated <br /> Draina6c t•ltin and other fiydrologic utili:mg thc R:+tiona'. Fomwla with a C value <br /> infonnati�m presented in Eixampl. No. 1 , h:�r.sr.r�istic of U�c unricvcloped conditions <br /> � <br /> ��. <br />