Hydrometeorological Characteristics of Severe Rainstorms in Illinois - PDF document

Hydrometeorological Characteristics of Severe Rainstorms in Illinois a 6 . . . 1 1 1 2 2 4 5 6 6 Tabl 2 100-Yea Rainstor Estimate Storm duration Depth (inches) for given area (mi 1 ) (hours) 10 25 50 100 200 500 Northwest Section 6 5. 5. 5. 5. 5. 4. 1 6. 6. 6. 6. 6. 5. 2 8. 8. 8. 7. 7. 7. 4 9. 9. 8. 8. 8. 8. North Central Section 6 5. 4. 4. 4. 4. 4. 1 5. 5. 5. 5. 5. 5. 2 7. 7. 6. 6. 6. 6. 4 7. 7. 7. 7. 7. 7. South Central Section 6 5. 5. 5. 5. 5. 4. 1 6. 6. 6. 6. 6. 6. 2 8. 8. 8. 7. 7. 7. 4 9. 8. 8. 8. 8. 8. Southeast Section 6 6. 5. 5. 5. 5. 5. 1 7. 7. 6. 6. 6. 6. 2 8. 8. 8. 8. 8. 7. 4 9. 9. 9. 8. 8. 8. Tabl 3 Rati o 100-Yea Rainstort Probabl Maximu Stor i Illinoi Storm Average ratio for given duration (hours) area (mi 2 ) 6 12 24 48 Relatio betwee Maximu Observe an Probabl Maximu Storm A par o it researc program th Atmospheri Science Sectio o th Wate Survemad a comprehensiv stud o al heav rainstorm recorde i Illinoi durin th 75-yea period1887-1961 Befor 1887 record ar to spars t carr ou suc stor studies Beginnin i1948 extensiv fiel survey o sever rainstorm i Illinoi wer initiate b th Wate Surveyan thes hav provide muc informatio o th spatial temporal an synopti weathe characteristic o suc storms Fo storm prio t 1948 analysi wa base primaril o dat recordeb th climatologica networ o th Weathe Bureau Area-dept relation wer compute foeac storm Thes wer the adjuste fo gag densit difference (variation i samplin densityb us o empirica transformatio factor develope fro th field-surveye storm (Huf anSemonin 1960) Tabl 4 show th area-dept envelop value (mea rainfal maxima observe i Illinoistorm fo stor period o 6 t 4 hour an area o 1 t 100 squar miles base upo storstudie b th Wate Surve an Corp o Engineer (U S Army 1945) Compariso o table 4 a 6 ‘ true a 6 The values in table 6 represent envelope values for the state, not a specific location within the state. a a a a a a a 6 a 7 6 a 6 Thes studie hav yielde muc knowledg concernin th characteristic o sever rainstorm iIllinois A par o thi research depth-duration-are relation wer determine i thes stormsTh previou section hav deal wit generalize relationships However i sometime desirablfo th desig hydrologis t hav informatio relatin t specifi storm producin exceptionallheav rainfal amount ove area (basins o variou sizes Therefore tabl 8 wa compile t provid suc informatio o a grou o outstandinstorm occurrin betwee 194 an 1978 Tabl 8 show area-dept relation fo extremelheav storm whic encompasse area o 500 squar mile o more Dat hav bee presentefo stor period o 3 t 2 hours Th fewe numbe i th 3-hou categor wa dictate b ouinabilit t subdivid th storm int 3-hou increment i th majorit o th field-surveye stormsMos o th dat i tabl 8 ar fro fiel surveys sinc the ar relativel larg storm no containewithi an raingag network Th las colum i tabl 8 show th sectio (figur 1 i whic thstor wa centered Tabl 8 Depth-Duration-Are Relation i Selecte Storm Depth (inches) for given area (mi 2 ) and duration (hours) Date 25 50 100 200 500 WOO 2000 5000 10,000 Section 24 Hours 8/16-17/59 10. 10. 9. 9. 8. 8. 7. 5. 4. S 6/14-15/57 16. 16. 15. 14. 12. 11. 9. 6. 5. S 6/27-28/57 12. 12. 11. 11. 10. 9. 8. 7. 6. S 7/12-13/57 11. 11. 10. 10. 9. 8. 7. 5. 4. N 5/21-22/57* 7. 7. 7. 7. 6. 6. 5. 4. 3. S 10/9-10/54 11. 11. 11. 10. 10. 9. 8. 7. 5. N 12 Hours 7/2/62 5. 4. 4. 4. 3. 2. 2. 1. N 7/28-29/61 10. 9. 9. 8. 7. 6. 5. 4. 3. S 5/20/59 6. 6. 5. 5. 4. 3. 2. 1. N 8/16-17/59 9. 9. 8. 8. 7. 7. 6. 4. 3. S 7/14/58 8. 8. 8. 7. 7. 6. 5. 3. N 6/14-15/57 16. 15. 14. 13. 12. 10. 8. 6. 4. S 6/27-28/57 12. 11. 10. 10. 9. 8. 7. 5. 4. S 7/12-13/57 9. 9. 9. 8. 8. 7. 6. 4. N 5/21-22/57* 7. 7. 6. 6. 5. 5. 4. 3. S 10/9-10/54 7. 7. 7. 6. 6. 5. 5. 4. 3. N 7/8-9/51 12. 11. 10. 9. 8. 7. 6. 5. 4. N 6 Hours 8/16-17/59 5. 5. 4. 4. 4. 4. 3. 2. 2. S 6/14-15/57 12. 11. 10. 9. 8. 6. 5. 3. S 6/27-28/57 8. 8. 8. 7. 6. 6. 5. 4. 3. S 7/12-13/57 6. 6. 6. 6. 5. 5. 4. 3. N 5/21-22/57* 7. 6. 6. 6. 5. 4. 4. 3. S 10/9-10/54 5. 5. 5. 4. 4. 4. 3. 2. 2. N 7/8-9/5 + 11. 10. 10. 9. 8. 7. 6. 5. 4. N 3 Hours 8/16-17/59 4. 3. 3. 3. 3. 2. 2. 1. 1. S 6/14-15/57 8. 8. 7. 6. 5. 4. 3. 2. S 6/27-28/57 4. 4. 4. 4. 3. 3. 3. 2. 2. S 7/12-13/57 5. 5. 4. 4. 4. 3. 3. 2. N 7/8-9/51 7. 7. 6. 6. 5. 4. 3. 2. N *Fiel survey was primary data source **Network supplied most of isobyetal information tBoth field surveys and SWS networks provided key information 9 33 4 a a a A a 5 Tabl 13 Probabilit Distribution o Anteceden Rainfal fo 1 t 1 Day o Selecte Areai Storm Producin Rainfal o 1 Inc o Mor Average rainfall (inches) exceeded for given antecedent period and area (mi 2 ) Probability 1 Day 2 Days 3 Days 5 Days 10 Days (percent) 10 100 400 10 100 400 10 100 400 10 100 400 10 100 400 5 1.0 1.4 1.8 1.5 1.7 2.0 1.6 1.9 2.1 2.0 2.3 2.5 3.1 3.4 3.5 1 0.6 0.8 1.1 0.9 1.2 1.4 1.1 1.3 1.6 1.4 1.7 2.0 2.4 2.6 2.8 2 0.2 0.3 0.5 0.4 0.6 0.8 0.5 0.8 0.9 0.9 1.1 1.4 1.7 1.9 2.2 3 0.0 0.1 0.2 0.1 0.3 0.5 0.2 0.4 0.6 0.6 0.8 1.0 1.3 1.4 1.7 4 0.1 0.1 0.3 0.1 0.2 0.3 0.4 0.5 0.7 1.0 1.0 1.3 5 0.1 0.1 0.2 0.2 0.3 0.4 0.7 0.8 1.1 Result ar show i tabl 1 whic present probabilitie fo selecte area o 10 100an 40 squar mile durin anteceden period o 1 t 1 days Amount i th tabl wer abstracte fro probabilit curve derive fo eac specifie situation Tabl 1 show tha th anteceden rainfal tend t b greate a th samplin are increasesThi i relate t a stron tren fo heav convectiv storm o th large area t b associate witorganize convectiv activit o a macroscal natur an t occu durin period o relativel heavrainfal i th genera region Wherea a singl ai mas showe o stron intensit coul produca 1-inc mea o 1 squar miles i woul requir a stor syste o considerabl area exten tproduc a mea o thi magnitud ove 40 squar miles Intense isolate ai mas shower frequentl develo i summe durin period whe rainfal i no widespread SHAPE ORIENTATION AN MOVEMEN O HEAV RAINSTORM Basi runof characteristic i heav storm ar influence b th shape orientation anmovemen o th storms Severa Wate Surve studie utilizin networ an historica stor dathav yielde considerabl informatio o thi subject Finding ar summarize briefl i thfollowin paragraphs Stor Shap Tw studie hav bee mad t determin th shap characteristic o heav rainstormi Illinois I on study dat fro 26 storm o a dens raingag networ i eas centra Illinoiwer use t investigat shape o area o 5 40 squar mile (Huff 1967) Storm weruse i whic area mea rainfal exceede 0.5 inch I th othe study historica dat fo 35heav storm havin duration u t 7 hour wer use i a shap stud o large-scale flood-producin rai events Thes wer Illinoi storm i whic maximu 1-da amount exceede 4 inche o i whic 2-da an 3-da amount exceede 5 inche (Stou an Huff 1962) Stormencompasse area rangin fro a fe hundre mile t 10,00 squar miles Th stud o historica storm indicate tha th rai intensit center mos frequentlha a elliptica shape Th rati o majo t mino axi tende t increas wit increasin areenclose withi a give isohyet tha is th ellips become mor elongated Withi limit employei th study n significan differenc i th shap facto occurre wit increasin stor magnitudo wit duration rangin fro a fe hour t 7 hours 1 I th networ study elliptica pattern wer foun als t b th mos prevalen typebu th heavies storm tende t mad u o a serie o rainfal bands However intensitcenter withi thes band wer mos frequentl elliptical Fro thes tw studies a mea shapfacto ha bee determine tha ca b use a guidanc i hydrologi problem i whic storshap i a significan desig factor Th shap relatio i show i figur 6 fo stor area o 10 t 10,00 squar miles Thisohyeta shap facto ha bee expresse a a functio o th are enclose b th isohyet Thordinat represent th media rati o majo t mino axi o th elliptica isohye enclosin thare give o th abscissa Figur 6 i applicabl fo al Illinoi storm wit duration u 7hours an shoul b usefu wher i pertinen t incorporat a stor shap facto int hydrologimodels Stor Orientatio A importan consideratio i an regio i th orientatio o th majo axi o heavrainstorms Fo example i th axe o heav rainstorm ten t b paralle t a rive basi oothe are o concern the th tota runof i thi regio wil b greater o th average tha ia regio perpendicula t mos stor axes Th orientatio o th stor axi als provide aindicatio o th movemen o th majo precipitation-producin entitie embedde i an largescal weathe system Sinc mos individua stor element hav a componen o motio froth west a azimut angl rangin fro 18 t 360 wa ascribe t eac storm Thus i a storha a orientatio o 230° th orientatio wa alon a lin fro 23 t 050 (SW-NE) Networstudie sho i i the ver likel tha th majo rain-producin cell withi a stor wit thiorientatio move fro th southwes t th northeast N significan differenc wa foun betwee th orientatio o storm whe the werstratifie accordin t mea rainfal an area extent Tabl 1 show th distributio i 26heav storm havin mea rainfal exceedin 1 inc ove a contiguou are o 10,00 squar mile 1 ARE O ELLIPTICA STORM mi 2 Figur 6 Shap facto fo heav rainstorm Azimuth Percent Azimuth Percent (degrees) of storms (degrees) of storms 4 6 6 1 8 9 3 a a a a a W a Azimuth Percent Azimuth Percent (degrees) of storms (degrees) of storms 6 4 2 2 2 2 7 4 REFERENCE Ackermann W C 1970 Rainfall frequencies. Illinoi Stat Wate Surve Technica Lette 13 6 p Hershfield Davi M 1961 Rainfall frequency atlas o the United States. U S Departmen o CommerceWeathe Bureau Washington DC Technica Pape 40 11 p Huff F A 1967 Time distribution o rainfall i heavy storms. Wate Resource Research v 3:1007-1019 Huff F A 1975 Urban effects o the distribution o heavy convective rainfall. Wate Resource Researchv 11:889-896 Huff F A. an S Changnon Jr 1965 Development and utilization o Illinois precipitation networks. Internationa Associatio o Scientifi Hydrolog Publicatio No 67 pp 97-125 Huff F A. an J C Neill 1959 Frequency relations for storm rainfall i Illinois. Illinoi Stat Wate SurveBulleti 46 6 p Huff F A. an R Semonin 1960 A investigation o flood-producing storms i Illinois. America Meteorologica Societ Meteorologica Monographs v 4(22):50-55 Huff F A. an J L Vogel 1976 Hydrometeorology o heavy rainstorms i Chicago and northeastern Illinois. Illinoi Stat Wate Surve o Investigation.82 6 p Huff F A. R G Semonin S A Changnon Jr. an D M A Jones 1958 Hydrometeorological analysis osevere rainstorms i Illinois, 1956-1957. Illinoi Stat Wate Survey Repor o Investigatio 35 7 Riedel J T. J F Appleby an R W Schloemer 1956 Variation o the probable maximum precipitation east of the 105th meridian for areas from 10 to 1000 square miles and durations of 6, 12, 24, and 48 hours. U S Departmen o Commerce Weathe Bureau Washington DC Hydrometeorolog Repor 33 Stout G E. an F Huff 1962 Studies o severe rainstorms i Illinois. ASC Journa o Hydraulic Divisionv 88(HY4):129-146 U S Army 1945 Storm rainfall i the United States, depth-area-duration data. (Plu supplementar dat sinc1945) Corp o Engineers Washington DC Vogel J L. an F A Huff 1977 Relation between surface winds, storm movement, and rainfall. I Summaro METROMEX Volum 1 Weathe Anomalie an Impacts Illinoi Stat Wate Surve Bulleti 62pp 61-66 1