FWSEx_ C?? Verdana 3w b (THE ISOHYETAL METHOD(lC&&π3̙5G{_: Z-F0+%kEŌqbE:kEy|qgj{ް|-&0n7(&ϰ'/3:֨9㢿ƵjO7ʴ d#f蠬U~s%*A?m/ 8'cT>#U@XP'TZWx 9p){u\|Z)@ *g< X (Land Area >>o &g6 h @(Begin >>㐿ls[U%5%KBURUP+U">,, c*Z$ @!Z$|e~@`Xz#,,KIRЁ$ UTT2 HO 9 h@*JjZZE~YڵrT IU%U BR-SH -"?R?]H@*djGYiXsIRЁ$ UTT2 HO#,,K>P9*Z$ @!Z$|e~@`[5!ARЁ$ UTT2 HO#,,KۧE~h@*JjZXhxrT IU%U BR-SH -"?Ry-9*Z$ @!Z$|e~@`ZRЁ$ UTT2 HO#,,KG !_C` (8cmG #__` (6.5cm ! _H` (7cm _P # __` (8.5cm 1b} ! _H` (8cm  ! _H` (7cm b  # _\` (6.5cm ! !_H` (5cm c !_@` (6cmȡh !_A` (4cmـ #_a` (4.5cmԃ !_C` (3cm !_F` (3cmIU R }WٕL'L f͆fpc(l*l'2I@pٔIU R PWٕL'L f͆fpc(l*l'2I@pٔIU R }H%l&g&28{@))Z'Y͙I͙Ttk-` ao (This method works best with a greater distribution of ppt gages...:@? %g6 h(Next >>,IU R /@!06'5)錩|ege6sfVsfQ2IU R /@!06'5)錩|ege6sfVsfQ2IU R /Kʛ'V|Phg6eg6e asY- o[r (Now draw lines delineating a particular measurement. Use intervals of 1cm between each line. For instance, if one line represents 3cm, then the next line should represent 4cm, and then 5cm and so on.... Click next to see the lines drawn... @KU R [$|6@!26'5 |egeyfRsfQ0K U R [$|6@!26'5 |egeyfRsfQ0K!U"+[$|6H-kg2@{?))'͙Y͙Dtl"" !!"8PI#mGCߑ<fff%։33.㨪6WͨBĨ)!Ҙ(DM#i@ !$_A` (3cm$~i@@ i@T i@T@ i@ i@@ i@ i@@ i@T i@T@ i@ i@@ i@ i@@ i@T i@T@ i@ i@@ i@ i@@ i@T i@T@ i@ i@@  D%mO`<fff%; NZ-^R(hyk֢Nk2pH(ҦhZstӿ33+f**`i@ !,_G?` (7cm,Ui@@ i@h i@h@ i@̉ i@@ i@4 i@4@ i@ i@@ i@ i@@ i@h i@h@ i@̉ i@@ i@4 i@4@ i@ i@@  L-m"՟<fff%L.ދRǯ1;g# -/!(ƲJѫK> -\J i@ !._A` (8cm!.i@@ i@h !i@h@ i@̉ !i@@ i@4 !i@4@ i@ !i@@ i@ !i@@ i@h !i@h@ i@̉ !i@@ i@4 !i@4@ i@ !i@@?-/ !!A/8P@  ! 0o (Note how each line goes through a gage with the same amount of rainfall. For example: notice how the 7cm line goes through two gages that recorded 7cm. The 8cm line goes through two gages that measured 8cm, and so on..."0b @"?K1U R < %H%l&g&2@{G))Z'Y͙I͙TtkK2U R < %@!066 |e'e@sfRsfU0-31222B38A f4w (In order to properly draw a line when no gages with the exact amount your looking for is present, you have to make an educated guess as to where to put the line. For example: I put the 8cm line a little closer to the gage reading 8.5cm than I put it from the 7cm line. This is because 8.5cm is closer to being 8cm than 7cm is!"4D5fœ<%ihmbGXѩ4zx 杠p.V* }#5j j Jp@"#? t6w` (Why do the lines appear so awkward? There can be many reasons, however the most likely would be topographical influences. The figure to the left could easily be a mountain slope with gages reading higher levels of ppt being higher up the slope. The 8.5cm gage may be at the top of a mountain while the 3cm gages are down in a small valley...76"7BI8U R r(WٔL'L ͆fpg(k(l'2IPpוI9U R r(WٔL'L ͆fpg(k(l'2IPpוI:U R r(@!06'6 |geysfVs^Q2-;89::C$;8PBq<n\udd%G-5xF̮Ѷ)F̽(9l ZhUvcqE`_ZA6(k=?P@ VtȅO&<6 $=_k?` (Uphill'= j@"$&'? 9>oe (Though not always the case, closely-spaced isohyets may also be areas of steeper slopes (yellow). Further- spaced isohyets may be areas of little or no slope. It is possible that closely- spaced isohyets above steep slopes are results of enhanced orographic influence on rainfall...">1 ]?ll(<<<%c@pKFQ 1GL?SfPYKJ+g3(@ 0@>4* '(IA_XĖޟvٔ3$K=&Ρ(@LL31GDT f0yJ#FRZ=*4 ΍ѳy8FNl-=My3rd8[lh'^ڥK:P#2*{!1 E|c<6İK& vKh3ryttthg(49Ԙ3S ŝ3=3(O(Y D Bf:fN&S$~;jj{7V7WDgDLi̵txtxʩʪ;m#z@z ÞPPG=Nb oѢ]:@_%1 P.^S!D? EVerdana !F_I` E(3cmF !G_G?` E(4cmGC- !H_I` E(5cmH #I_b` E(5.5cm IYP !J_J` E(6cm J !K_G?` E(6cm K7 #L_e` E(6.5cm L,w  !M_G?` E(7cm M! #N_h` E(7.5cmN:ZB` !O_G` E(7cmO62 !P_G?` E(8cmPq !Q_I` E(8cmQpDR]L4h<fff%PsJBˤBsRds޷PPbiXAvw\9󾢞$pRgrg@ !S_O` (8cmSY@gTd<fff%k9:*j(YI(YoQ^J Y;B u]hk76?8h6(4{+#{TcJq !U_O` (7cmUz6FVnFT<fff%sQ k"P. ^Zb8Z,V@Ap2Y,Vlb !W_L` (6cmWEt逿@Xm}"<fff%ZkMhc6` cIjWh60gXQE !Y_L` (5cmYL\@Zm|<fff%^`ULa hfCf .hP(hYŔbZӀ ![_L` (4cm['ҿ;\m<fff%:P%\hi׾6wqe{/x\x !]_W` (3cm]aO ^o (This isohyet chart shows a relatively flat basin. It also shows the center of the storm where ppt fell the most! Here, it is likely that there was little or no influence from topography.^J I_U R r,WהL'L ͆fpc(l(l'2I@pٕI`U R r,@!06'6 |'esfVs^Q2-a_```Ea0D@IbU R @@!26'5 |egeysfVsfQ0IcU R @@!26'5 |egeysfVsfQ0"dbcccd8@E eo (Once you have determined the locations of each isohyet, you then measure the area in between each isohyet. For instance, measure the area between the 3cm and 4cm isohyets, then between the 4cm and 5cm isohyets, and so on... eڹcfdK;W22%OG||I;4>@T˛HՀ6O˛6K緀!i@@@@@@jm0}_22%*O6ta7kamYu} ,%O8U`R+_'@W;^]cwU[U?uSts _sTxUs+qfYPX̴#Xgje̖?X?jҖ)k,qP-Vx4!g7yc#p~STӿr1YpheXv3.~9uF D!j^*@@@@@@kd4l`22%qO7 y eUdWٗ6dU"`Y8b 8Z ֆHil'skU Yhw#g, ,[`.j4ϟTIO x!kcJv@@@@@@El]DAX22%Bs.VGD eRW}b`Ubf \bj!led@@@@@!f @@@@!gp@@@@!h-@@@@@@!i@@@@@@!j^*@@@@@@!kcJv@@@@@@!led@@@@!?-mbcccm8@@      ?InU R L@!256 |e'@ys^RsfU2IoU R L@!256 |e'@ys^RsfU2-pnooop8@ qo( (Let's say we figured the size of each area as shown numerically to the left... we will take these numbers and plug them into a simple graph and compute the average ppt next!.... qz7` %rg% P (54sq km!r! &sg)G P (40 sq km"seZ &tg% P (6 sq. km#tX"P` 'ug? P (43 sq. km$uل 'vg? P (32 sq. km%v!` 'wg? P (38 sq. km&w` 'xg? P (20 sq. km'x`@ ?"yo.1WT%=Z(y  zw؍ ( Col.1 Col.2 Col.3 Avg. Area Col.1 x Col.2 Isohyet between (cm) isohyets ------------------------------------ <3 20 3x20= 60 3.5 38 3.5x38= 133 4.5 32 4.5x32= 144 5.5 43 5.5x43= 237 6.5 54 6.5x54= 351 7.5 40 7.5x40= 300 >8 6 8x6= 48)zL` %{g* (Next >>*{I|U R y,K' V|Pgg6eg6e asaI}U R y,K' V|Pgg6eg6e asa-~|}}}+~K@()*+ W{ȍ (60(~ W{ȍ (133)` W{ȍ (144* W{ȍ (237+ W{ȍ (351,ŀ W{ȍ (300- W{ȍ (48. W{ȍ (202l~ W{ȍ (383` W{ȍ (324 W{ȍ (435` W{ȍ (546ŀ W[{ȍ (67 W{ȍ (408@(\t`) * h+ , - ̈.L2th3456788̈@(i)l{x*l+l,l-l.Ә2i34{x4454x647Ә84@(_x)q*̂+̔,̦ -̷. 2_3q4 56 7P 8@(|U),f*,x+,0,,-,0.l2U3Lf4Lx5L6L7ܾ8L0@(J)\*m+,8-.̴82(J3\4n856ؑ87h88آ@(<@ )Q*c(+uH,Ȉ-H.,Ȉ2@(3`Q4`cȈ5`t6`Ȉ7Ȉ8`H@(5)LG0*LX+LjЈ,L|P-LЈ.P2<53G04YP5j06|P7|P8@(+8)<*N@+``,q-`.2+@3x<4xN5x_6xq78x`@(\ ) 2H* CȈ+ U, gh- x.Lh2T Ȉ32H4Dh5UH6gh7h8x@(P)l'؈*l9X+lKx,l\-lnx.2X3'؈495J؈6\7 8nx@( ؈)`*.+A,R-d. u\f<%sz/Ȟ@PA !_\`ր @(2330 w # (Divide the sum of column 3 by the total area of the basin. The result is the average you're looking for!1CL2l 3`4/5@`6R7u8dT|@<%QPu9$@ "_`ր @(1273:@@@@@@@@@@@@@@@@@0(@:hP@09:$@0J:X@0[:@0m :\`@0~`:@0ʏ:ԣh@0 :@?0ߺ:#]N܅<<%vv<1YT;l .o (5.5cm = average<{ +o (Close Window=@