FREQUENCY OF MOI$WRE SEFICIENCIES IN THE LOWER PENINSULA O? MICHIGAN Thests Ior I'Iw Degree of M. 5. MICHIGAN STATE UNIVERSITY Robert J. Moraniec 1959 'I—IESIS This is to certify that the thesis entitled FREQUENCY OF MOISTURE DEFICIENCIES IN THE LOWER PENINSULA OF MICHIGAN presented by Robert J. Moraniec has been accepted towards fulfillment of the requirements for M. S. degree in Agrl. Engineering Major professor Date January 1959 0-169 FREQUENCY OF MOISTURE DEFICIENCIES IN THE LOWER PENINSULA OF MICHIGAN by Robert J. Moraniec A THESIS Submitted to the College of Agriculture of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Agricultural Engineering 1959 Approved by W— ACKNOWLEDGEMFNTS The author expresses his sincere graditude to Professor Ernest H. Kidder of the Agricultural Eng- ineering Department, for his guidance and many help- ful suggestions during the course of this study. The author is very grateful to Mr. A. H. Eichmeier, director of the East Lansing, Office of the United States Weather Bureau and to Professor W. D. Eaten for the use of their IBM weather data cards. The author feels deeply indebted to Dr. A. W. Farrall, Head of the Agricultural Engineering Department, for making possible the research funds necessary for this study. The author also wishes to thank his wife Leo Denese, for her inspiration and typing. I. II. III. IV. VI. VII. VIII. IX. XI. XII. TABLE OF CONTENTS Page INTRODUCTIONOOOOOOOOOOO0.0.0.0000000000000.00.0.00001 REVIEW OF LITERATURE............................. 3 PROCEDURE........................................ 7 A. Calculating Evapotranspiration............... 7 B. Calculation of Moisture Deficient Days...... 10 DISCUSSION OF RESULTS........................... 32 A. Discussion of Moisture Deficient Days Occurring Once in Ten Years for Each Moisthre Reservoir.......................... 32 B. Discussion of Moisture Deficient Days Occurring Five Times in Ten Years for Each Moisture Reservoir..................... 35 APPLICATION OF RESULTS.......................... 37’ CONCLUSIONS..................................... 39 SUGGESIONS FOR FUTURE STUDIES................... #0 mmmmmms.n.g.u.u.n.. ...... ..u.n.n.u.71 APPENDIX I...................................... 73 APPENDIX 11..................................... 75 APPENDIX III.................................... 76 APPENDIX IV...OOOOOOOOOOOOOOOOOOOOOOOO0.0.0.0... 77 Table Table Table Table Table Table Table Table Table Table 10 LIST OF TABLES Page Actual dafly'evapotranspiration..............ll Example of computation for deter- mining number of moisture deficient days for varying soil moisture reserVOirSOOCOOOOOOOOO0.0...00......0.0.00.013 Moisture deficient days for South Haven, Michigan for 1, 2, 3, h, 5 and 7-inch soil moisture reservoirs.........16 Moisture deficient days for East Lansing, Michigan for l, 2, 3, h, 5 and 7—inch soil moisture reservoirs.........l8 Moisture deficient days for Ann Arbor, Michigan for 1, 2. 3. h. 5, and 7-inch soil moisture reservoirs.........2O Moisture deficient days for Big Rapids, Michigan for 1, 2, 3, A, 5 and 7-inch soil moisture reservoirs.........22 Moisture deficient days for Cold- water, Michigan for l, 2, 3, h, 5 . and 7-1n0h 8°11 m018ture reserv01raaooaoaaOQZA Moisture deficient days for Saginaw, Michigan for l, 2, 3. h. 5, and 7- inch soil moisture reservoirs...............26 Moisture deficient days for Traverse City, Michigan for l, 2, 3, A, 5 and 7-inch soil moisture reservoirs.........28 Moisture deficient days for Roscommon, Michigan for l, 2, 3, h, 5 and 7- inch soil moisture reservoirs...............30 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure N 10 11 12 13 14 15 16 17 18 LIST OF FIGURES Page Location of weather stations used to determine evapotranspiration............. 12 Location of weather stations used in calculation of moisture deficient days... 15 Moisture deficient days-in May for a 1-inch reservoir....................... 41 Moisture deficient days in May for a 2-inch reservoir....................... 42 Moisture deficient days in May for a 3-inch reservoir....................... 43 Moisture deficient days in May for a L'inCh reserVOir,.,..,.,,...,.......... A“ Moisture deficient days in May for a 6-inch reserVOir.OOOOOOOOCOCCOOOOOOO... [+5 Moisture deficient days in May for a 8-inCh reserVO1rOOO.OOOOOOCOOOOOOOO.0.. [+6 Moisture deficient days in June for a 1-inch reservoirOOOOOOOOOOOOOOOOOOOOOOO 1+7 Moisture deficient days in June for az-inch reservoiFOOOOOOOOOOOO0.0.0.0.... #8 Moisture deficient days in June for 83-inch reservoir.OOOOOOOOOOOOOOOOOOOOOO A9 Moisture deficient days in June for ah-inch reservoir.OOOOOOOOOOOOOOOOOOOOOO 50 Moisture deficient days in June for a6-inch reserVOirOOOOOOOOOOOOO0.00.00... 51 Moisture deficient days in June for 88-inch reserVO1r.OOOOOOOOOOOOOOOOOOOOOO 52 Moisture deficient days in July for a1-1nchreserVOirOOOOOOOOOOOOOOO0.00.0.0 53 Joisture deficient days in July for a2-1nCh reserVOirOOOOOOOOOO.0.0.0.000... 5h Moisture deficient days in July for 83-1n0hreserVO1r.OOOOOOOOOOOOOOCOOOOOOO 55 Moisture deficient days in July for a a-inch reservoir 56 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure 19 20 21 22 23 24 25 27 28 29 3O 31 32 Page Moisture deficient days in July for a 6-inCh reserVOinmaaaaoooaaaaoaooaaoa 57 Moisture deficient days in July for " 8-lnCh reserVOiranaeaaaaaaaooaaaaaoa 58 Moisture deficient days in August for a l‘inCh reserVOir.aoaoaaaaaaooooo 59 Moisture deficient days in August for a Z'inCh reserVOircacao-0000000000060 Moisture deficient days in August for a 3-inch reserVOir0000000000000... 61 Moisture deficient days in August for a h-inch reservoir................ 62 Moisture deficient days in August for a 6-inch reservoir................ 63 Moisture deficient days in August for a 8-inCh reservoiraaaaoaaoaaoooooo 64 Moisture deficient days in September for a 1-inch reservoir.................65 Moisture deficient days in September for a 2-inch reservoir................ 66 Moisture deficient days in September foraB-ionch reseWOirOOOOOOOOOOOOOOOO 67 Moisture deficient days in September for a 4-inch reservoir................ 68 Moisture deficient days in September for a 6-inch reservoir,,,,,,,,,,,,,,,, 69 Moisture deficient days in September for a 8-inch reservoir OOOOOOOOOOOOOOIO 7O INTRODUCTION Moisture deficiency in the root zone of the soil during the crop production season, is a major problem confronting Michigan farmers. With an erratic rainfall distribution pattern, the amount of moisture available for the plant may often be less than the amount required for maximum plant development and yield. The soil is like a large reservoir where water is added by rainfall, irrigation, or capillary action, and removed by evapo- transpiration, deep percolation, or surface runoff. With good agricultural practices through-out the growing season on non-irrigated soil the movement of water by capillary action, deep percolation, and surface runoff will be negligible. When the balance between rainfall and evapotranspiration indicates the reservoir is empty, plant growth is retarded. Evapotranspiration is computed by finding the amount of water that can be evaporated with the energy received from the sun. The energy received from the sun is assumed to be proportional to the energy used for the evapotranspiration of moisture from the soil. The use of supplemental irrigation has been increas- ing in recent years where rainfall through the growing season is inadequate. Farmers having irrigation systems could use an individual bookkeeping system, where the rainfall is added and evapotranspiration is subtracted to obtain their soil reserve for each day of the season. Other farmers contemplating buying irrigation equip- ment need information on how many times each year, and the number of years in ten they can expect to use the equipment. The objective of this study was to determine evapotranspiration rates and to compute the frequency of moisture deficient days through-out the growing season from the Michigan climatological data. REVIEW OF LITERATURE Cahow (3), studied the precipitation in Michigan and classified a drought as a "period constituting seven days or more in which leSs than 0.25 inches of precipi- tation has occurred in 2b hours." He then calculated the frequency of one, two, three, four, and five week droughts for the lower peninsula of Michigan. Van Bavel, (16), developed a method for using daily precipitation and daily moisture loss to estimate the supply of available moisture in the soil. This method assumes that crops have a moisture reservoir in the soil to the depth of the effective root zone. The capacity of this reservoir varies directly with the root depth of the crop and the water holding capacity of the soil. If the root depth is two feet and the water holding capacity is one inch per foot then the crop has a two inch moisture reservoir. In computing -his daily moisture loss Van Bavel takes into account the moisture removed by evaporation from the soil and transpiration from the leaves. This is commonly refered to as evapotranspiration. Empirical Formula Based 22,E§perimental Data Thornthwaite, (12), assumes that the relationship between temperature and evapotranspiration is exponential. A In other words, when temperature and evapotranspiration- are plotted on log-log paper they form a straight line. Thornthwaite's (12) assumption is based on exper— ience with watersheds in central and eastern United States and is therefore of limited value. Where temperature and radiation are strongly correlated this method works well. In southern latitudes or locations where the land is effected by large bodies of water as in Michigan, the air temperature lags behind radiation by three to four weeks giving evapotranspiration values which are questionable. Blaney and Griddle (2) developed an empirical for- mula in which uzt’x xf. ' .UJz monthly evapotranspiration in inches. t: average monthly temperature in °F. f a empirical consum tive use factor. p=. percent of annua daytime hours occuring that month. Values of f are obtained by growing various crepe in large vats or lysimeters that can be weighted with- out destroying the crop. The daily change in weight is then given the value of f which is similar for most crops. The value of f often varies from one location to another. The Blaney Criddle formula is based on temperature and length of day which implies the use of radiation energy. Good results are obtained where radiation is closely related to temperature. Estimates of seasonal requirements are generally better than the shorter monthly periods. Theoretical Vapgr Trggsfer Method Thornthwaite and Holzman (13), developed a vapor transfer formula in which E = K0 “‘1 ' "ZHW " 31 (Log 152/21)z E = rate of evaporation. K =universal constant. slzheightl. xl evapor density at height 1. ulawind speed at height 1. Formulas of this nature have not been thoroughly tested and the neccessary data is not available. Theoretical £22551 Balancg Methgg This method is based on the fact that the energy received by the earths surface through radiation must be equal to the energy used for evaporation plus that used t0~ heat both the soil and the air. The energy used for heating the soil and air can be neglected for daily balances, and if an error of 5 percent is acceptable they can be neglected on the monthly balances. Penman (10) first published a method of estimating the amount of radiative energy gained by the surface and expressed this in mm of evaporated water. The method was slightly modified by Van Bavel (18) giving the following equation for evapotranspiration. AH+.27 EL ET A+.27 ET = evapotranspiration in mm/day. 23 a slope of t e saturated vapor pressure curve. at air temperature. (See appendix II, A.) H = net radiation. E‘s .35 (e - e )(l+ .0098 u20 min/day. ea:= saturagion apor pressure at mean air temperature in mm Hg. (See appendix II, B.) ed = saturation vapor pressure at mean dew int. or actual vapor pressure of air in mm g. also equal to e. 1 (percent relative humidity). wind speed at 2 meters in miles per day which is equal to “h x (W) 0% uhpa wind speed in miles per day at height h in feet. u2 Van Bavel (18), states that the experimental evidence so far lends the most support to the Penman formula for determining evapotranspiration values. PROCEDURE Temperature in Michigan lags behind radiation by approximately four weeks. Any method of calculating evapotranspiration without using radiation as one of the variables would give questionable results. Experi- mental evidence so far show more favorable results with the Penman formula as a universal method (18). Therefore the Penman(lO) method was used for calculating evapo- transpiration. This method indicated the potential evapotranspiration that can take place on vegetation. It was then modified by a factor of .75 to obtain actual evapotranspiration. Tests in the Netherlands indicate that .75 was the best correction factor for obtaining actual evapotranspiration from potential evapotranspiration. Calculating Evapgtranspiration Penman's formula is Et :3 A H + .27 E. Et = potential evapotranspiration in mm/day. A: a slope of saturated vapor pressure curve. (see appendix II, A.) Ht 2 net radiation. Ea :- auxiliary quantity. 8 := factor denoting influence of diffusion resistance. D == factor denoting influence of length of day. Net radiatidn values were calculated from: Ht: Ra (l-r)(0.18 +0.55 n/N) - KT,“ (0.56 - 0.092I‘_ed )(0.10 + 0.90 n/N) Ra.a mean monthly extraterrestrial radiation. r =: 0.20 radiation reflection coefficient for vegetation. . n/N= ratio actual to possible hours of sgnshine. ¢"= Stefan Boltzman constant 2.01 x 10' mm/day. Ta = absolute temperature of air 0R. ed =-saturation vapor pressure at mean dew point. Values of Ea were calculated from: Ea== 0.35 (e - e )(l-+ 0.0098 u ) mm/day. °a1= saturation v por pressure a% mean air temperature. u2:= windspeed at two meters. Values of S were calculated from: S = La/(La+ 0.16) La== effective diffusion lenght of air which is equal to .65 (1 0.0098 uz) Values of D were calculated from: 11/24 +- 1/r sin N1T/21. hours from sunrise to sunset. I'- The wind speed was given in miles per hour at a D N “ll height 60 feet in East Lansing, 6h feet in Detroit, 81 feet in Grand Rapids, and 89 feet in Alpena. The formula Penman (10) uses to convert this to a two meter 'elevation is: - log 6.6 u2.. uh x ( log h ) ’uhfl= wind speed at height h in miles per day. No further corrections were made to this value because it was felt that even though'the tower was located in town on top of a building, the figure obtained for 2 meters would still represent the rural wind speed. The average air temperatures in cities has been about 1 to 2% degrees °F higher in the summer time because of higher night time temperatures brought about by the slow cooling rate for buildings and roads (5). East Lansing Temperature June July Sept. City Temperature 68.9 72.8 68.8 Rural Temperature 67.0 70.4 67.1 Difference 1.9 °F 2.h °F 1.7 OF A correction was made on average air temperature by subtracting 2 oF so that the values would represent aver— age rural air temperatures. Average values for relative humidity were about 5 percent lower in cities because the soil is covered with roads and buildings causing less evapotranspiration (5). East Lansing Relative Humidity Jmm JMJ Set. Rural RH‘ 6h 54 6E City RH 5h 49 50 Difference 10% 5% 11% To prevent overcorrecting the relative humdity, 5 percent was added to the average city value to give a representative rural value. Appendix 1 shows an example of the calculation pro- cedure for finding evapotranspiration rates. Monthly calculatings were made for Grand Rapids, Detroit, East - Lansing, and Alpena with the data listed in Appendix IV. 10 Results of these calculations when modified by multi- plying by .75 are shown in table 1. Because of the small difference between the values table 1)for the various locations through out the state, (figure 1) the value for Lower Michigan (table I) assumed to represent daily evapotranspiration for the Lower Peninsula of Michigan. Calculation of Moisture Deficient Days In calculating moisture deficient days only the crop production months, May through September, were used. The moisture reservoir of the soil was assumed to be full on the let. of May each year. The reservoir amounts used were 1, 2, 3, h. 5, and 7-inches, from which the Lower Michigan daily evapotranspiration values were subtracted and daily rainfall added, never allowing the total to go over the individual reservoir amounts or to go below zero. (See table 2.) By not allowing the total to go above the reservoir amount, water could be removed by runoff or deep_percolation. This happened when heavy rainfall was received in May or June. Later in the season under good agricultural practices very little runoff occurs and the soil reservoir will normally hold all the rainfall. A moisture deficient day occured each time the calculated soil moisture was zero as shown in table 2. The number of moisture deficient days occuring each month were counted and recorded for the six moisture reservoirs. This was accomplished by using the IBM equipment in the tabulating department of Michigan State University. 11 TABLE 1 -ACTUAL AVERAGE DAILY EVAPOTRANSPIRATION Grand Rapids .09 .12 .13 .10 .07 East Lansing .08 .12 .12 .10 .07 ‘ Detroit _ .09 .12 .13 .10 .07 Alpena .08 .11 .12 .10 .06 Lower Michigan .09 .12 .13 .10 .07 12 Alpena I e G and Rapids‘ 0' Eas:.Lansing Detroiv Figure 1. Location of weather stations used to determine evapotranspiration. 13 TABLE 2 EXAMPLE OF COMPUTATION FOR DETERMINING ,NUMBER OF MOISTURE DEFICIENT DAYS FOR VARYING SOIL MOISTURE RESERVOIRS ._- -9. .-_ — - - .___ _ Evapotrans- Precipi- -.m...- _ .___. Moisture Reservoir piration tation 1 inch 3 inch 5 inch Date inches inches inches inches_ inches Amount from previous months ‘0.33'“fi 0.55 2.75 l. 0.25 0.08 0.30 {2.50 2' 0.25 0.00 0.05 2.25 3 0.25 .0.00 0.00 2.00 .h 0.25 0.75 0.50 0.50 2.50 5 0.25 1.25 1.00 1.50 3.50 6 0.25 .75 1.25 ' 3.25 Total number of moisture deficient days ,2 l 0 1h Weather information for the stations shown in figure 2 were used for the calculation of moisture deficient days. This eliminated punching daily rain- fall on cards. The values calculated for Iowa-Michigan evapotranspiration given in table 1 were punched in columns 75 and 76 for all stations except East Lansing, where columns 73 and 7A were used. The No. 60A calculating punch did the computing and a trailer card inserted at the end of each month was punched with the actual number of moisture deficient days for the given month. After running the cards through three times for six moisture reservoirs, the No. 120 sorter removed the trailer cards. The account- ing machine printed the information from the trailer cards and it was compiled in tables 3 through 10. For easier reading of the tables 3 through 10, all sero's were omitted. The bottom two lines of tables 3 through 10 give the actual number of moisture deficient days occuring once in ten years and five times in ten years. In this paper the probability of .l is refered to as 1 year in 10 and the probability of .5 is refered to as 5 years in 10. This is based on the actual number occuring over a thirty year period and may change slightly with a longer period of time. 15 . . Traverse‘City O Roscommon 0 Big Rapids . Saginaw 0 East Lansing ,South Haven ' 0 Ann Arbor Coldnater I Figure 2. (Location of weather stations used ' in calculation of moisture deficient days. 16 4 t._ HH OH H HH H OH id ouhh M o S 3 mm 3 NH S a. .3 53.3 a N HH 4H 4H MH b 0H MN H on 4 NH ON MN MN M HH 0 MM . , m MH 5 m 4m 5 h MH 0 mm H 0 NM 0 N HH Hm OH H H H #H OM HH M HH 4 04 m 4H mH 0H NH 0H 0 m¢ ¢ MH HN NN OH 54 NH ON wN OM OM h 0H 04 M HH ON md J MH ON m #4 4 w HH Ms M MH N M N4 H m 0H MN MN 4 MH H4 M MH HN h 04 m MH 5 0M H OH MH 5 mm H HH mH 4 NM 0 5H 0N 5N 5N 5 0H w on M MH m N MM H MN MN MN mN mN H m NH mH HN h #M 0 4H s MH MM H 0 HH MH m 5H N NM 0 dH ON 5 HM M HH MH NH 0 NH CM 5 MH 4N dN M HH N mN m h m wN M JH MN MN OH EN :5 :M cé =M :N :H :5 :m :# =M cN =H :b :m :4 :M :N :H OMINNOH Amado any ease mean an inane an an: ((Ail‘i" ((1).); .11) mmHoemmmmm mmpamHoz uHom mozeim.az< .me.e .m‘.~ .H mom zeeH20Hz .zmnem meson mom mean ezmeoeumo mmeemeos m memes muse» l7 H m N e 0H NH .9. each m N «H 3 4H 4H 3 .4 mm «N am am am 3,3- 5: 4H 4H 4H 4H 4H HH HH HH HH HH on . 0H 3 0H 0H 0H NH mm 0H 0H 0H H m m 4m N N N NH mm o m Nm . o m Hm 4H 4H 4H 4H N 4H 4N Hm 0m m NH 04 m m m m HH HH NH ON ON ON oN m4 4 4N mN mN 0N oN N4 pH pH pH 0H 0H 0H 0N 4N 4N 4N 4N 4N 04 m m m m4 N NH wH mH NH 44 m m m4 4 N4 N N N N N o m m o a H4 m H H H 04 N N 0H m m on H H m m m m mm m H NH NH mH Nm N NH NH NH NH NH on o m H 4 mm m m m m m m 4m 4 0H 0H 0H 0 HH 0H mm 4H 4H . 4H 4H m m m 4 Nm N 0 NH HN HN HN Hm NH NH NH NH NH NH 0H 0H 0H NN cm H H H H NH NN NN NN NN NN mN . 0H 0H mN N m m. m o 0 NH HN HN HN HN NN :5 am :4 :M :N :H :N :m :4 :M :N :H OmthmH rum .eNso 0m. sensoonm Ashen Hmv unsws< muse» z<: masom "QMDZHBZOQ M MHmmmmmm mmsequz gHom moszs nz< .m .4 .m .N .H .. mom zmmmmm NNMMMHoz HHom mozHuM az< .M .4 .M .N .H mom zqme NON MHmMmzwa 0 vs; 0 '31 mwcabmtswzme 75 APPENDIX II 104 , 86 68 so // 32 02 oh .6 .8 100 . 102 A 10‘} 1.6 438 , mm Hg/oF A. Temperature vs. slope of saturated vapor pressure curve. (From reference A.) 122 .r””l”””fl id. . // .86 , ,/ / 68 .x / 10 20', ‘ 30 #0 50 x 60 70 80 0a) ang 50 . B. Temperature vs. saturation vapor pressure. (From reference A.) 76 APPENDIX III 100 18.80 Heat of vaporization was assumed to be constant at 590 cal/gm of H20 (reference A) 77 APPENDIX IV CLIMATOLOGICAL DATA USED TO SOMPUTE EVAPOTRANSPIRATION Month m, n/N N r. RH uh Et mm/ day 73 hr. 0F 76 in/chy GRAND RAPIDS flay 15.7 60 14.9 58.2 64 .12 June 16.9 65 15.4 68.5 66 .16 July 15.9 72 15.1 73.6 67 .17 August 14.1 69 14.1 71.6 66 .14 September 11.9 58 12.2 64.1 70 .09 EAST LANSING May 15.7 62 14.9 ' 56.5 65 .11 June 16.9 67 15.4 67.4 68 .16 July 15.9 73 15.1 71.1 66 .16 August 14.1 69 14.1 69.0 68 .14 September 11.9 58 12.2 61.8 72 .09 DETROIT May 15.7 58 14.9 57.8 63 .12 June 16.9 65 15.4 68.1 64 .16 July 15.9 69 15.1' 73.1 62 .18 August 14.1 66 14.1 71.3 65 .14 September 11.9 61 12.2- 64.3 68 .10 ALPENA May 15.7 58 14.9 50.9 68 .11 June 16.9 64 15.4 61.5 70 .15 July 15.9 70 15.1 67.4 68 .16 August 14.0 63 14.1 65.8 7 .14 September 11.6 51 12.2 58.4 75 .08 1.:- A ask... 6 n... 3