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Group Title: Computer series
Title: A Microcomputer program for potential evapotranspiration
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00095262/00002
 Material Information
Title: A Microcomputer program for potential evapotranspiration
Physical Description: 1 computer disk + : ;
Language: English
Creator: Fitzpatrick, George E.
Schicchi, Barbara
Ferguson, Francis Jr., 1959-
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville, Fla
Publication Date: 1984
Copyright Date: 1984
 Subjects
Subject: Evapotranspiration -- Computer programs   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
General Note: Cover title.
Statement of Responsibility: George Fitzpatrick, Barbara Schicchi, and Francis Ferguson, Jr.
 Record Information
Bibliographic ID: UF00095262
Volume ID: VID00002
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 10736484

Table of Contents
    Front Cover
        Page 1
        Page 2
    Main
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
    Appendix
        Page 20
        Page 21
        Page 22
    Back Cover
        Page 23
        Page 24
Full Text

Floppy disc included with this
item has been shelved separately.
Consult LUIS or ask circulation
staff for assistance.


Circular 590


A Microcomputer Program

For Potential

Evapotranspiration


[COMPUTER SERIES


George Fitzpatrick, Barbara Schicchi and Francis Ferguson, Jr.


101
F6 3 6c ve Extension Service / Institute of Food and Agricultural Sciences / University of Florida / John T. Woeste, Dean
590
rfn i ri


January 1984







FLORIDA COOPERATIVE EXTENSION SERVICE
UNIVERSITY OF FLORIDA
INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
COOPERATIVE EXTENSION SERVICE AGRICULTURAL EXPERIMENT STATION
SCHOOL OF FOREST RESOURCES AND CONSERVATION COLLEGE OF AGRICULTURE


il UNIVERSITY OF FLORIDA

(904) 392-7853


REPLY TO: IFAS Software Support
Building 120, Room 203
University of Florida
Gainesville, FL 32611


December 8, 1988


MEMORANDUM

TO: IFAS Software Customers

FR: Dennis G. Watson

RE: Running BASIC programs

The program you have just purchased was
Originally, we distributed only the BASIC
BASIC interpreter to run the program.


written in the BASIC programming language.
language source file and required that you use a


We now distribute BASIC programs in compiled form. This means that you do not have
to load BASIC prior to running the program. Until the documentation is updated to reflect
this change, please refer to the following instructions to start program 011, titled "Potential
Evapotranspiration".

First, make a duplicate copy of the distribution disk. Store the distribution disk in a safe
place and use the duplicate copy as your working disk. To run the program simply type:

PET

at the DOS prompt and press the Enter (or Return) key.

Once you have started the program, the instructions in the documentation should apply. In
some cases, the documentation or program may allow you the option of exiting to BASIC
or DOS. With a compiled program, regardless of which you choose, you will exit to
DOS.

If you need more space on your working disk, you can delete any files with the extension
".BAS". These are BASIC source files and you do not need them to run the program.

If you have any questions about this program, please contact the IFAS Software Support
office, Bldg 120 Room 203, Gainesville, FL 32611 or phone (904) 392-7853.





The Institute of Food and Agricultural Sciences is an Equal Employment Opportunity Affirmative Action Employer authorized to provide research,
educational information and other services c i ,- . ,- *- .. .r- . .; ,: ; Jt.. ...* ,. -" national origin.
COOPERATIVE EXTENSION WORK IN A-: IJ M,: UL r'.-Ei AF E L 1, H.:,- E ..I:. i..: :TaTE ;'iF L'.C r[ ; rii.i ERSITYOF
FLORIDA, U.S. DEPARTMENT OF AGRICULTURE. AND BOARDS OF COUNTY COMMISSIONERS COOPERATING












A MICROCOMPUTER PROGRAM FOR


POTENTIAL EVAPOTRANSPIRATION


George Fitzpatrick, Barbara Schicchi, and Francis Ferguson, Jr.*


Consumptive water use has always been an important aspect of plant cultivation,
and is becoming an increasingly vital concern in areas where water supplies are
falling short of demand. Periodic water shortages in many parts of Florida have had
significant effects on agricultural production and have added new emphasis to the *
importance of making sound water use predictions.

Consumptive water use in vegetation, often called evapotranspiration (ET), is
the amount of water transpired from the cuticle or stomata in the leaves plus the
amount of water evaporated from the adjacent soil in any specified time.
Evapotranspiration is usually expressed in terms of inches or centimeters rather than
in volumetric terms like gallons or liters, but conversions can easily be made. One
inch of water covering one acre, for instance, is equivalent to 27,200 gallons.

There are many factors that influence how much water crops require, such as
amount and rate of precipitation, temperature, length of growing season, stage of
plant growth, amount of sunlight, humidity, wind movement, advection, water quality,
and soil fertility. Moreover, these factors may interact with one another in ways
that can be very difficult to predict, so growers must exercise great care in
budgeting water resources.for optimum crop growth.

Actual evapotranspiration in crops may be measured in a number of ways, but all.
known methods require large amounts of detailed climatological, meteorological, and
direct observational data .in order to make the most accurate determinations. Since
such detailed data do not exist for most locations, methods of estimating eva-
potranspiration using mathematical formulas have been developed. All of these
methods estimate potential evapotranspiration, which is defined as the condition
where a vegetated surface is releasing water to the atmosphere at a rate that is not
limited by deficiencies in water supply. In this sense, potential evapotranspiration
can be regarded as a general maximum amount of water that can be taken up by vegeta-
tion over a period of time. Since water is often in limited supply during some point
in a crop's production period, actual evapotranspiration may often be less than the
computed potential evapotranspiration. The conservative nature of using potential
evapotranspiration rates in irrigation planning is therefore a major advantage,
since, when errors -do occur, danger of overwatering is much greater than the danger
of uPderwatering ane the danger of overw&cering is much easier for an observant
grower to manage. Moreoever, it should be kept in mind that very short-term

Extension Water Quality Specialist, AREC Fort Lauderdale, former Research Technician,
AREC Fort Lauderdale; former Extension Computer Specialist, Lake County Cooperative
Extension Service, IFAS, University of Florida

IVRSITY Of FLORIDA LIBRARIES











very short-term expressions of potential evapotranspiration, such as daily or weekly
estimates, can sometimes contain a large error. This is because short-term extremes
in local weather conditions can have a tremendous impact on crop water use but are
not considered in most potential evapotranspiration estiration. procedures. For this
reason potential evapotranspiration methods are best for relatively long-term water
use estimates, periods of one month or more.

Overview of the Micro:omputer Programs


The basis of these programs is the Thornthwaite method of computing potential
evapotranspiration. This method uses air temperature as an index of the energy
available for evapotranspiration, and assumes that available energy is shared in
fixed proportion between heating the atmosphere and evapotranspiration. Unlike the
other major potential evapotranspiration estimation procedures, there are no correc-
tion factors for different vegetation types, making the empirical calculation relati-
vely simple. The program computes monthly potential evapotranspiration by the
following empirical formula




10 To
P.E.T. m 1.6 | -g








where: P.E.T. potential evapotranspiration in centimeters per month (the program
also converts this figure into inches per month)
Ta monthly average temperature in degrees Celsius (the program will convert
degrees Fahrenheit into degrees Celsius)

1.5
STal
I annual heat index "















a- 4.9 x 10-1 + 1.79 x 10-2 I 7.71 x 10-5 12 + 6.75 x 10-7 r3


The program asks for information about the monthly average air temperature of
the location for which potential evapotranspiration is to be calculated. This infor-
mation may be obtained from the National Weather Service, and, for many Florida loca-
tions, is summarized in Extension Circular 464, Florida Daily Temperature Normals.
The computer operator will first type in the location name and then the monthly
average temperature, in degrees Fahreheit, for each month in order from January to
December. The computer will display these temperatures on the CRT screen and ask the
operator if the data are entered correctly and instruct the operator how to correct
any incorrectly entered data. Then the computer will print out the monthly average
temperatures in both degrees Celsius and degrees Fahrenheit, and the potential evapo-
transpiration in 2 columns, one column expressed in centimeters per month and one
column expressed in inches per month.

A Sample Run Digital Equipment Co. (DEC) POP-11

With the system in monitor (.) mode, type in 'HELLO' or 'H'. You will then need
to type in a previously assigned user identification code and password. When the
screen prompts 'READY', type in:












where n is type in the number of the disk drive on which the program resides. (See
Appendix 8 for how to type in and store the Potential ET program on the Digital (DEC)
POP-11 system).











Here is what the display looks like on a sample run. In this example, 20-year
temperature averages for the city of Homestead, taken from Extension Circular 464,
are used. As each month is displayed, the computer operator types in tho monthly
average temperature:





Enter location name or END to exit Program? HOMESTEAD

Enter monthly mean temperatures in degrees F


JANUARY ? 65.3
FEBRUARY ? 66.1
MARCH ? 69.4
APRIL ? 73.1
MAY ? 75.9
JUNE ? 79.2
JULY ? 80.5
AUGUST ? 81.0
SEPTEMBER ? 80.2
OCTOBER ? 76.3
NOVEMBER ? 70.4
DECEMBER ? 66.4





Next the computer will type on the screen:




If no corrections, enter 0O else enter no. of month to be corrected?




So, if you made an error In typing the temperature for July, enter the number 7.
will then have an opportunity to reenter the temperature for July. The computer
continue to ask for corrections until you respond with a *. If a 4 is entered,
is, there are no errors in the temperature data, the computer will print out the
information:
















TEMPERATURE HEAT POTENTIAL ET
F DEG C DEG INDEX Cmi/MO zNn/hO

JANUARY 65.3 18.5 7.1 5.1 2.0
FEBRUARY 66.1 18.9 7.4 5.5 2.*
MARCH 69.4 20.8 6.5 7.0 2.0
APRIL 73.1 22.8 ;. 9.0 3.6
hAY 75.9 24.4 10.8 10.8 4.3
JUNE 79.2 26.2 12.0 13.1 ..2
JULY 80.5 26.9 12.5 14.i 5.6
AUGUST 81.0 27.2 12.7 14.5 5.7
:SEPTEMBER 80.2 26.8 12.4 13.9 5.5
OCTOBER 76.3 24.6 10.9 11.1i 4.
NOVEMBER 70.4 21.3 8.8 7.5 3.0
OECEMBER 66.4 19.1 7.5 5.6 2.2






A Sample Run APPLE II


Begin by placing the program diskette in the disk drive. Now turn on the com-
puter, the monitor (screen), and the printer (if available.). The disk drive will
whirr for a moment, and the following program identification information will appear
on the screen;


** POTENTIAL EVAPOTRANSPIRATION *
VERSION 2.10


COOPERATIVE EXTENSION SERVICE
INSTITUTE OF FOOD AND
AGRICULTURAL SCIENCES (IFAS)
UNIVERSITY OF FLORIDA (UF)
FOR FURTHER INFORMATION CONTACT
FARM COMPUTER SUPPORT GROUP
CIO DEAN JOHN T. WOESTE
FLORIDA COOPERATIVE EXTENSION SERVICE
1038 MCCARTY HALL
UNIVERSITY OF FLORIDA
GAINESVILLE, FL 32611
COPYRIGHT 1983 SY IFAS, UF
PRESS RETURN TO CONTINUE


i'OTENTIAL i,'vPFOTkSPiRSRTIONr FOR miunt mi'EML











When the RETURN key is pressed, the screen will display;


,: --WORKING--




after which, the computer will ask you to enter the location name for this run of
data.


POTENTIAL EVAPOTRANSPIRATION

SNTER LOCATION NAME ________.......


key.


You should enter the location name, such as 'Homestead', and press the RETURN


POTENTIAL EVAPOTRANSPIRATION

ENTER LOCATION NAME HOMESTEAD


*o MONTH
1 JAN


The computer will now ask
for the location of Homestead.
perature averages for the city
used.


MEAN TEMPEiATURE


for the average temperature for the month of January
For the purpose of this example, twenty year tem-
of Homestead, taken from Extension Circular 464, are










Enter the temperature of '65.3' for the month of January, and press the RETURN
key.



POTENTIAL EVAPOTRANSPIRATION

ENTER LOCATION NAME HOMESTEAD

## MONTH MEAN TEMPERATURE
1 JAN 65.3
2 FEB --



As each month is displayed, enter the requested average temperature. If you
attempt to enter 4 mean temperature less than 32 or greater than 95 the computer will
display the following warning prompt on the bottom of the screen. Press the RETURN
key to re-enter the average temperature.




INVALID MEAN TEMPERATURE ENTRY
PRESS (RETURN) TO CONTINUE




If yoq make an incorrect average temperature entry, while entering the initial
twelve months, you will be allowed to correct the value after all twelve months of
Average temperatures are entered.

After all twelve months of average temperatures are entered the screen will
display:

POTENTIAL EVAPOTRANSP IRATION

ENTER LOCATION NAME HOMESTEAD

H# MONTH MEAN TEMPERATURE
1 JAN 65.3
2 FP3 66.1
3 MAR 69.4
4 APR 73.1
5 MAY 75.9
6 JUN 79.2
7 JUL 80.5
8 AUG 81.0
9 SEP 80.2
10 OCT 76.3
11 NOV 70.4
12 DEC 66.4

(0) COMPUTE POTENTIAL ST
(1) CORRECT A MONTHLY ENTRY











You now have the option to continue with the program and compute the monthly
evapotranspiration amounts or correct an invalid monthly average temperature.

Fcr example, you have incorrectly entered the average temperature for the month
of November, the value of 87 should be 70.4. To correct this mean temperature, enter
'1' and press the RETURN key.

The bottom of the screen will display the following prompt line:



**,* SENTER 'O' TO EXIT **
ENTER NUMBER TO CORRECT 1<->I _Z





Enter '11' (the eleventh month, as shown in the left column of the screen, is
November) and press the RETURN key. The bottom of the screen will now show the
following prompt line:



u*** ENTER '0' TO EXIT ''*'
ENTER NUMBER TO CORRECT 1(-)12 11
S1 NOV



Enter the correct average temperature of '70.4' and press the RETURN key. The
screen will now show the corrected value for the month of November.


POTENTIAL EVAPOTRANSPIRATION

ENTER LOCATION NAME HOMESTEAD

S MONTH MEAN TEMPERATURE
1 JAN 65.3
2 "MB 66.1
3 MAR 69.4
4 APR 73.1
5 MA 75.9
6 JUN 79.2
7 JUL 80.5
8 AUG 81.0
9 SEP 80.2
10 OCT 76.3
11 NOV 70.4
12 DEC 66.4

<"**** ENTER o0' TO EXIT **
ENTER NUMBER TO CORRECT 1<-> 12










From this point you may continue to correct invalid average temperatures or
enter a '0' and press the RETURN key to exit from the correction routine. When you
have completed the corrections, and the following prompt line is displayed at the
bottom of the screen, enter a '0' and press the RETURN key to continue \ith 'the com-
putation of the monthly potential evapotranspiration.


(0) COMPUTE POTENTIAL
(1) CORRECT A MONTHLY
--> 0


ET
ENTRY


The screen will display;



(--WORKJNC-->




while the values are being computed.

The computer will next display the following screen;

DATA DESTINATION



(0) SCREEN
(1) PRINTER


*** If you want to see the information on the screen, enter a '0' and press the
RETURN. key. The screen will display the following information;



POTENTIAL ET FOR: HOMESTEAD


MONTH TEMPERATURE


JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC


(F)
65.3
66. 1
69.4
73. 1
75.9
79.2
80.5
11. 0
90.2
76. 3
70.4
66.4


(C)
18.5
18.9
20.8
22.8
24.4
26.2
26.9
27.2
26.8
24.6
21.3
19. 1


HEAT
INDEX
7.1
7.4
8.5
9.8
10.8
12.0
12.5
12.7
12.4
10.9
8.8
7.5


POTENTIAL ET
CM/MON IN/MON
5.1 2.0
5.5 2.1
7.0 2.8
9.0 3.6
10.8 4.3
13.1 5.2
14.1 5.6
14.5 5.7
13.9 5.5
11.1 '4.4
7.5 3.0
5.6 2.2











The pressing of the RETURN key will display the next option available to you.


*** If you
RETURf key.


want to see the information on the printer, enter a '1' and press the
Tht screen will display the following prompt:


IS THE PRINTER ON ?
EXIT 'ESC'







PRESS TO CONTINUE






The pressing of the key marked "ESC" will return you to the DATA DESTINATION
Menu. The pressing of the RETURN key will print the information on the printer con-
nected to your computer. Please note Appendix A for further information on printer
requirements with the APPLE system.



:POTENTIAL EVAPOTRANSPIRATION COPYRIGHT UNIVERSITY OF FLORIDA; IFAS 1983
THIS PROGRAM HAS BEEN DEVELOPED FOR IFAS BY F.FERGUSON AND B.SCHICCHI


POTENTIAL ET FOR: HOMESTEAD


--- TEMPERATURE ---
(F) (C)


U5. 3
66. 1
69.4
73. 1
75.9
79.2
80.5
81.0(
80.2
7/ 6.
70.4
66. 4


18.5
18.9
20.8
22.8
24.4
26.2
26.9
27.2 ""
26. 8
24.6
21. 3
19.1


HEAT INDEX


7. 1
7.4
8.5
9.8
10.8
12. 0
12.5
12.7
12.4
10.9
8.8
7.5


POTENTIAL ET RATE
CM/MONTH IN/MONTH


5. 1

7..1
9.0
10.8
13. 1
14. 1
14.5
13.9
11. 1
7.5
5.6


2.0
2. 1
2.8
3. 6
4.
5.12
5.6
5. 7
5.5
4.4
2. ,.
-C -


MONTH


JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC









After you have displayed the information, to either the screen or the printer,
the screen will display the following;






(---- SELECTIONS ----
(0) RERUN PROGRAM
(1) END PROGRAM EXIT









You may either enter '0' and press the RETURN key to rerun the pro-ran with dif-
ferent data, or enter '1' and press the RETUR,. key to terminate the program.




<---- SELECTIONS ---->
(0) RERUN PROGRAM
(1) END PROGRAM EXIT
-->1I

PROGRAM TERMINATED....


Program Listings


The programs as they appear in this publication will work without modification
on Digital Equipment Corporation (DEC) POP-11 computers, and APPLE II computers.
Minor modifications in BASIC commands and changes in screen format may be necessary
to run the programs on other brands or types of microcomputers.










PROGRAM LISTING DIGITAL EQUIPMENT CO. (DEC) POP-11


10 REM ***************************************
20 REM *a**********(**************************
30 REM *
40 REM ** POTENTIAL EVAPOTRANSPIRATION (PET) *K
50 REM *' (C) COPYRIGHT, 1983 **
60 REM ** UNIVERSITY OF FLORIDA; IFAS **
70 REM ** **
80 REM ** THIS PROGRAM HAS BEEN DEVELOPED BY *E
90 REM .* SPECIALIST; G. FITZPATRICK *
100 REM ** PROGRAMMER; B. SCHICCHI; PDP-11 **
110 REM ** PROGRAMMER; F. FERGUSON; APPLE II lc
120 REM ** #*
130 REM ** ORIGINAL VERSION: 09/12/81 **
140 REM CURRENT VERSION: 08/30/83 **
150 REM K* VERSION NUMBER: 1.3 **
160 REM *
170 REM Essas******s*as****s**t**a************
180 REM XXtXtiKX
190 REM .
200 REM Monthly mean temperatures are entered
210 REM in degrees Farenheit. The Program
220 REM converts the temperatures to Celsius,
230 REM tmen applies the Thornthwaite ET
240 REM equation.
250 REM *
260 DIM T1(12) \ REM Monthlw moan temp in F
270 DIM T2(12) \ REM Monthly mean temp in C
280 DIM 1(12) \ REM (T2(J)/5)%1.5
290 DIM E(12) \ REM Monthlw ET in cm/mo. 1.6((10*T2(J)/I)"A)
300 DIM M$(12) \ REM Months of wear
310 DIM EI(12) \ REM Monthlw ET in inches/mo
320 REM **
330 MS(1)-=JANUARY \ M$(2)=*FEBRUARY *
340 M$(3)='MARCH \ M$(4)='APRIL
350 M$(5)='MAY \ M$('6)='JUNE *
360 M$(7)s=JULY \ M$(8)="AUGUST *
370 M$(9) =SEPTEMBER' \ M$(10)=OCTOBER '
380 M$(11)=*NOVEMBER I \ MS(12)='DECEMBER *
390 REM **
400 OPEN "LP:" FOR OUTPUT AS FILE *3












930
50
960
970
975
980
985
990
1000
1010
1020
1030
1040
1050
1060
1070
1080
1090
1100
1110
1115
1120
1130
1140
1150
1160
1170
1180
1190
1200
1210
1220
1230
1240
1250
1260
1270
1280
1290
1300
1310
1320


REM ** PR INT T A B L E
PRINT 3, 'POTENTIAL EVAPOTRANSP RATION FOR *'C$;TAB(54)
PRINT #3,TAB(49);'REN ON ';DAT$
PRINT *3 \ PRINT *3rTAB(12);'temperature';TAB(29);'Heat';
PRINT *3,TAB(40);'POTENTIAL ET'
PRINT *3,TAB(10);"F Deg';TAB<19);'C De4;?TAB(29);'Inde;x';
PRINT #3,TAB(40);'cm/mo in/mo'
PRINT *3
FOR J=1 TO 12
PRINT #3,USING "'LLLLLLLLL*;M$(J);
) PRINT #3,USING ***'.*',T1(J); \ PRINT *3,TAB(19);
PRINT #3,USING #**.#*',T2(J); \ PRINT 3,rTAB(27';
'PRINT #3,USING *"**.*',I(J); \ PRINT *3,TAB(40);
I PRINT #3,USING *****.#,E(J) \ PRINT #3,TAB(48);
PRINT #*3USING *#**.**'E1(J)
NEXT J
) PRINT #3
SPRINT #3p*- - - - - - - - 3 - - ,
) PRINT #3"* - - - -*
'PRINT *3 \ PRINT *3
PRINT *3,CHRS(12)
GOSUB 1140
GO TO 620
REM *t Clear arrass for next ET calc
I=0 \ A=O \ Y$-* \ Cs$* a
FOR Jul TO 12
T1(J)=0 \ T2(J)=0 \ I(J)=O \ E(J)0-
NEXT J
RETURN
PRINT \ PRINT
PRINT :::::::::::::::::::::::::::::::::::::::::::::::::
PRINT ":::::::::::::8:::::::::"*
PRINT ": POTENTIAL EVAPOTRANSPIRATION COPYRIGHT UNIVERSE
PRINT "OF FLORIDA, IFAS 1983 :-
PRINT *: THIS PROGRAM HAS BEEN DEVELOPED FOR IFAS BY ';
PRINT 'B. SCHICCHI AND F. FERGUSON :*
PRINT ::::*:::::::::::::::::::::::::::::::::::::::::::::
PRINT '::::::::::::::::::::: :*
PRINT
CLOSE
STOP
END


- .6I


T:::;

TY ';



: :*4S








410 REM ** Print copyright inrfo
420 PRINT TAB 19) ;'* POTENTIAL EVAPOTRANSIPRATION ;*'
430 PRINT TAB30);'"VERSION 1.3'
440 PRINT \ PRINT
450 PRINT TAB(22)?"COOPERATIV'E EXTENSION SERVICE'
460 PRINT TAB(26);4INSTITUTE OF FJOD AND'
470 PRINT TAB(22);"AGRICULTURAL SCIENCES (IFAS)q
480 PRINT TAB<23);"UNIVERSITY OF FLORIDA (UF)"
490 PRINT
500 PRINT TAB(21);'FOR FURTHER INFORMATION CONTACT'
510 PRINT TAB(23);'FARM COMPUTER SUPPORT GROUP"
520 PRINT TAB(25);'C/O DEAN JOHN T. WOESTE'
530 PRINT TAB(18);'FLORIDA COOPERATIVE EXTENSION SERVICE'
540 PRINT TAB(28);'1038 MCCARTY HALL'
550 PRINT TAB(26);'UNIVERSITY OF FLORIDA'
560 PRINT TAB(26);'GAINESVILLE, FL 32611'
570 PRINT
580 PRINT TAB(25);'COPYRIGHT 1983 BY IFAS, UF'
590 PRINT \ PRINT TAB(26);'PRESS RETURN TO CONTINUE*
600 LINPUT R$
610 PRINT CHR$(12)
620 PRINT 'Enter location name OR enter END to exit program ';
630 LINPUT C$
640 IF C$s=END* GO TO 12v0
650 PRINT \ PRINT "Enter monthly mean temperatures in degrees F'
660 PRINT
670 FOR Jul TO 12
680 PRINT TAB(21);M$(J);
690 INPUT T1(J)
700 T2(J)=((T1(J)-32)$5)/9 \ REM Convert F to C
710 I(J)=(T2(J)/5)'1.5 \ REM Calculate I by month
720 NEXT J
730 PRINT \ PRINT "If no corrections, enter 09 *;
740 PRINT 'else enter no. of' month to be corrected '*
750 INPUT C9
760 IF C9=0 GO TO 820
770 PRINT \ PRINT 'Enter correction for *;M$(C9);
780 INPUT T1(C9)
790 T2(C9)=((Tl(C9)-32)*5)/9
300 I(C9)-(T2(C9)/5)^1.5
810 GO TO 730
820 REM s* Calculate annual heat index and exponent 'a'
830 C9=0
840 FOR J-1 TO 12
850 I"I+I(J)
860 NEXT J
870 A=.49+(.0179*I)-(7.710OOE-05*I'2)+(6.75000E-07*I-3)
880 REM ** Calculate monthly ET
890 FOR J=1 TO 12
900 E(J)=1.6*((10*T2(J)/I)"A)
910 E1(J)=E(J)/2.54
920 NEXT J









590
a50
oOo
410

30
o40
850
670

690
700
710
720
730
740
750
760
770
780

800
810
810
930
840
850
8.0
870
880
390
900
920
930
940
950
960
9 1"0"
.80
990

1000
1010
1020
1030
1040
1050
1060
1070
1080
1090
1100
11120
1130
1140
1150
1170
1180
1190


IF Ni% = 0 -THEN 170
IF N1% a I THEN PRINT : PRINT : PRINT : PRINT "PROGRAM TER
MINATED ."; CHRS (7)
END
PRINT TAB( 10)"**" TAB( 15)"MONTH" TAB( 23)"MEAN TEMPERATU
RE"
FOR I XI TO X2
IF I ( 10 THEN IS a " STRS (I)
IF I > a 10 THEN IS a STRIP (I)
VTAS (6 I): HTAB (10): PRINT IS TA8( 16)P?$(I) TAB( 29);:
OKS a "..09":LN% a 4: GOSUS 1010:TI(1,t) a VAL (RES)
IF Tit(1,) ( a 32 OR T a 95 THEN COSUB 910: GOTO
660
NEXT I
RETURN
GOSUB 1100: REM CLEAR LOVER SCR'SEN
VTAB (21): HTAS (1): INVERSE : PRINT "**** ENTER '0'
TO EXIT *****:. NORMAL
PRINT "ENTER NUMBER TO CORRECTI<-)12 ";:OKS a "09":LN% a 2
: GOSUB 1010:C% a VAL (RES): IF C% ) 12 THEN 700
IF C% ) 12 THEN 700
It C% a 0 THEN 800
LET TEMP T1(1,C%): REM SAVE VALUE
PRINT PRINT : PRINT TAB( 10)C% TAB( 16)MMS(C%) TAB( 29);
OKI .09":LN% a 4: GOSUI 1010:TI(1,C%) a VAL (RE$)
IF T1(I.C%) (< 32 OR TI(1.C%) > a 95 THEN GOSUB 910:TI(
1,C%) a TEMP: COTO 700
VTAS (6 + C%): HTAI (29): PRINT ": VTAS (6 C%): HTAB
(29): PRINT TI(l,C%)
GOTO 700
RETURN
TEXT : HOME : VTAB (12): HTAR (14): INVERSE : PRINT "(--WOR
KING-->": NORMAL : RETURN
PRINT : PRINT Ds;"PR*1": PRINT CilR$ (9);"80N": RETURN
PRINT : PRINT DS;"PRS0": RETURN
HOME
INVERSE : PRINT D" ATA DESTINATION ": NORMAL
VTAS (6)
PRINT TAB( IS)"(0) SCREEN"
PRINT TAB( 13)"(1) PRINTER"
PRINT TAB( 12)"--> ";:OKI a "01":LN% a 1: GOSUB 1010:DP%
VAL (RES)
RETURN
GOSUB 1100: REM CLEAR LOWER SCRE::N
VTAB (22): HTAB (1): INVERSE : PRINT "INVALID MEAN TEMPERATE
URE ENTRY": NORMAL
COSUB 990: REM PRESS RETURN
GOSUB 1100: REM CLEAR LOVER SCREEN
RETURN
HOME : VTAI (12): HTAB (10)
PRINT "IS THE PRINTER ON ?"
VTAS (14): HTAB (14): INVERSE : PRINT "EXIT 'ESC'*": NORMAL
VTAB (24): HTAB (1): PRINT "PRESS (RETURN) TO CONTINUE ";: GET
YS: I? Y ( > CHMRS (27) AND YS ( > CHRS (13) THEN 990
RETURN
LET RES a "":At a PEEK (36): FOR A I TO LN%: PRINT CHRS
(95),: NEXT : POKE 36,Al
GET AS
FOR A a I TO LEN (ORS) I STEP 2
IF LEN (REC) ( LN% AND At > a MID$ (OKI,A,.) AND As < a
MID$ (OKS,A 1.1) THEN RES* RES AS: PRINT AS;
NEXT A
IF AS a CHRS (8) AND LEN (RE) > 0 THEN RE$ a MKID (RES
.1. LEN (RE$) 1): PRINT At; CHRS (9S);AS;
IF AS ( > CHRS (13) THEN COTO 1020
IF LEN (RtE) < LM% THEN FOR A LEN (R9E) TO LN%: PRINT
" ";: NEXT
RETURN
FOR II a 21 TO 24
VTAB (II): HTAB (1): PRINT SPC( 39)
NEXT II
RETURN
TEXT : HOME
PRINT "POTENTIAL IT FOR: ";LNS
PRINT : PRINT "MONTH TEMPERATURE HEAT POTENTIAL ET"
PRINT (F) (C) INDEX CM/MON IN/MON"
FOR I I TO 12
PRINT MM1t(1) TAB( 7)T1SCI,I) TAB( 18 LEN (TIS(Z,I)))TI$
(2,1) TAB( 23 LEN (TlsI3.I)))TIS(3.I) TABS 32 LEN (TI










PROGRAM LISTING APPLE II


10
14
18
22
26
30
34
38
42
46
48
49
50
54
56
58
62
66
70
74
78
82
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
320
330
340
350
360
370
380
390
400
410
420
430
440
450
460
470
480
490
500
510
320
530
540
550
560
570
580


REM **** **** ******************** *f**i
REM jn* ** i n i m m < i
REM ** **
REM *t POTENTIAL EVAPOTRANSPIRATION (PET) **
REM (C) COPYRIGHT, 1983 "
REM ** UNIVERSITY OF FLORIDA; IFAS **
REIM ** *
REM ** THIS PROGRAM HAS BEEN DEVELOPED BY **
REM ** SPECIALIST; G.FITZPATRICK X*
REM t* PROGRAMMER; I.SCHICCHI; POP-11 **
REM t* PROGRAMMER; F.FERGUSON; APPLE II **
REM t* **
REM *t ORIGINAL VERSION: 06/11/82 *
REM ** CURRENT VERSION: 07/29/83 **
REM ** VERSION NUMBER: Z.1 .
REM ** *t
REM ** FOR FURTHER INFORMATION CALL *t
REM ** THE LAKE COUNTY EXTENSION SERVICE **
REM ** TAVARES, FLORIDA (904) 343-4101 **
REM ** **
REM **************il*** l iil** ***
REM TI(1,X) a MONTHLY MEAN TEMP IN F
REM TI(2,X) MONTHLY MEAN TEMP IN C
REM TI(3,X) a (TI(2,)IS)A.5S
RED. TI(4,X) a MONTHLY ET RATE CMIMONTH
REM TI(S.X) a MONTHLY ET RATE INCHES/MONTH
REM SUM a ANNUAL HEAT INDEX
REM mUM a ANNUAL HEAT EXPONENT
CLEAR
DIM M<12),TiS1,2) ,TtsS,12)
LET 0S a CHRS (4)
FOR I a 1 TO 12: READ MMS(I): NEXT I
TEXT : HOME
INVERSE : PRINT POTENTIAL EVAPOTRANSPIRATION ". NORMAL
VTAS (4): HTAS (1)
PRINT "ENTER LOCATION NAME ";
LET OKS a ,-Z":LN% 1I: GOSUU 1010:LNS a RES: IF LEN CL
NS) a 0 THEN 230
PRINT : PRINT
LET XI 1:X2 12: GOSUB 620: REM ENTER MEAN TEMPS
VTAS (21): HTAB (1)
PRINT TAB( 10)"<(0) COMPUTE POTENTIAL IT"
PRINT TAB( 10)"(1) CORRECT A MONTHLY ENTRY"
PRINT TAB( 7)"--) ";:OKI "01*:LN% 1: GOSUB 1010:N% VAL
(RES)
IF Nm 1I THEN GOSU8 700: GOSUB 1100: GOTO 280
GOSUS 810: REM WORKING
FOR I a 1 TO 12
LET Ti(2,I) <<(TI(I,1) -.33) 5) / 9: REM CONVERT F TO C
LET TI(3,I) (TI(2,t) I 5) A 1.5
LET SUM a SUM + TI(3,I)
NEXT I
LET NUM a .49 + (.0179 SUM) (7.71E OS SUM A Z) (6
.7SE 07 SUM A 3)
FOR I t 1 TO 12
LET T144.1) = 1.6 ((10 TIt2,I) / SUM) A NUM)
LET TI(5,I) Ti(4.I) / 2.54
NEXT I
FOR I = I TO 5
FOR J a I T` 12
LET TEMP CIdI,J): GOSUB 1220:TIS(I.J) a TEMPS
NEXT J
NEXT I
GOSUB 840: REM DATA PATH
IF OP% a 0 THEN GOSUB 1140: GOSUl 990
IF DP% a I THEN GOSUS 960: IF YT a CHRI (27) THEN 490
IF OP% a 1 THEN GOSUB 810: GOSU0 820: GOSUB 1380: GOSUS 1Z
80: GOSUB 830
TEXT : HOME : VTAI (8)
PRINT TAB( 9)'"*--- SELECTIONS ---- >"
PRINT
PRINT TAB( 10)"(0) RERUN PROGRAM"
PRINT TAB( 10)"<(1) END PROGRAM ";: INVERSE : PRINT "EXIT":
NORMAL
PRINT TAB( 7)"--) ";:OKS a "Ot":LN% 1: GOSUS 1010:NI%
VAL (RES)













1(4,I)))TIs(4,I) TAB( 39 LEN (Ti (S, t ) )), S(5,I
12C3 NEXT I
12:0 RETURN
120 LET TEMP a INT ((TEMP .05) 10) / 10:TEMPS u STRs :TE
MP)
1230 LET TEMP a LEN (TEMPS)
1240 IF (TEMP > x I AND TEMP < a 3) AND INT ( VAL (TEMPS)) x
VAL (TEMPS) THEN TEMPs a TEMPs ".0". GOTO 1270
12350 IF TEMP a 2 AND LEFTS (TEMPIS,I a CHRS (46) THEN GOTO I
270
1260 IF MTD$ (TEMPS.TEMP 2.1) CHRS (46) THEN GOTO 1270
1270 RETURN
1230 POKE 36,20: PRINT "POTENTIAL ET FOR: ";LNS
1290 PRINT
1300 PRINT "MONTH";: POKE 36.11: PRINT "--- TEMPERATURE ---", POKE
36.39: PRINT "HEAT INDEX";: POKE 36,36: PRINT "POTENTIAL ET
RATE"
1310 POKE 36,11: PRINT "(F) (C)",: POKE 36.54 PRINT
"CMIMONTH INIMONTH"
1320 PRINT
L330 FOR I a I TO 12
1340 PRINT NM<(I);: POKE 36,15 LEN (TIS(lI,)): PRINT T1s(1,I
);: POKE 36.,30 LEN (TIt(2,I)): PRINT TIS(2.I);: POKE 36.
45 LEN (TIs(3,I)): PRINT T1S(3.I);
1350 POKE 36,60 LEN (Tl(4,I)): PRINT TI$(4,I),: POKE 36,73 -
LEN (TIS(S,I)): PRINT TIS(S,I)
1360 NEXT I
1370 RETURN
1380 PRINT
1390 PR INT: : : :: : : : : :::::::: : : : : :
1400 PRINT ": POTENTIAL' VAPOTRANSPIRATION COPYRIGHT UNIVER
SITY OF FLORIDA; IFAS 1983 :*
1410 PRINT ": THIS PROGRAM HAS SEEN DEVELOPED FOR IFAS BY F F
ERGUSON AND S.SCHICCI :-
1420 PRINT :::::::::::::::::::::::::
1430 PRINT
1440 RETURN
1450 DATA JAN,FEE,MAR,APR,MAY.JUN.JUL,AUG,SEP,OCT,NOV,DEC











Appendix A


(1) System and Language Requirements of the Program
The program is written in Applesoft BASIC and will run under DOS 3.1, 3.2, or
3.3. In addition, the program should operate unchanged on a Apple III using the
"emulation" mode, and any other micro-computer that will support Applesoft, and an
Apple DOS operating system.

(2) PRINTER REQUIREMENTS
The Applesoft program, as written, expects to find a printer located in slot #1
of the Apple. This assignment statement may be altered by changing line #820 of the
PET program. Line #830 issues the command to turn off the printer.
(3) NOTES FOR CONVERSIONS TO OTHER FORMS OF BASIC

The conversion of the Applesoft program to another form of BASIC should be a
relatively minor problem. The referencing of any Applesoft programming manual will
aid in the conversion process. Attention will need to be paid to the following
commands; CLEAR, HOME, TEXT, VTAB, HTAB, 6ET"'PEEK(XX), and POKE 36,XX.












APPENDIX B


ENTRY AND STORAGE OF THE POTENfIAL ET PROGRAM ON DIGITAL (DEC) PDP-11


1. With the swstei in monitor (.) mode, twpe in @BASIC.

2. The sianon request to operate BASIC will appear; wou twpe in *HELLO' or H

3. Twpe in a valid user identification code and password.

4. When the screen Prompts 'READY', twpe in: NEW RKn:POTET.BBS
where n is, you twpe the number of the disk drive on which you wish to
store the program.

5. When the screen PromPts 'READY'P besin twpins in the prorarep
line bw line, exactly as shown on the pass entitled
PROGRAM LISTING DIGITAL EQUIPMENT CO. (DEC) PDP-11.

6. After the last line has been entered, twpe in: SAVE
The prosrat will be stored on the disk drive wou specified in step 4.

7. If wou wish to have a printed comw of the program you Just entered,
twpe in: SAVE LP
BASIC maw make minor adJustments in the appearance of the listings
compared with what you twepd in. It will not, however, change the order
or content of the prosraer so check the listings carefully.

a. When the screen prompts 'READY' twpe in 'BYE' to exit from BASIC or
type in: RUN RKn:POTET.BBS to run the Potential ET program.


NOTE: Once the proerae has been saved, it is recalled in subsequent
sessions bw twpins in: OLD RKn:POTET.BBS after sisnon steps 1-4.
Anw changes made to the proarae after it has been saved maw be
retained bw twpina in: REPLACE RKn:POTET.BBS
Consult a BASIC lansuase reference suide for information about
chansinas addinar or deleting BASIC prosrae statements.











































































This public document was promulgated at a cost of $429.97, or 86 cents per copy, to inform the public of a computer
program for potential evapotranspiration. 1-500-84



COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL -
SCIENCES, K. R. Tefertiller, director, In cooperation with the United States Department of Agriculture, publishes this Infor-
mation to further the purpose of the May and June 30, 1914 Acts of Congress; and Is authorized to provide research, educa- IPASB
tional Information and other services only to Individuals and Institutions that function without regard to race, color, sex or
national origin. Single copies of Extension publications (excluding 4-H and Youth publIcations) are available free to Florida
residents from County Extension Offices. Information on bulk rates or copies for out-of-state purchasers Is available from r
C. M. Hinton, Publications Distribution Center, IFAS Building 664, University of Florida, Gainesville, Florida 32611. Before publicizing this
publication, editors should contact this address to determine availability.




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