!$Author: fredfox $
!$Date: 2006-02-25 00:21:16 $
!$Revision: 1.2 $
!$Source: /weru/cvs/wepp/wepp.watbal/idat.for,v $

      SUBROUTINE IDAT(TR, R, RR, DT, DTC, NR, NF, TRF, RF, DUR)
C
C     + + + PURPOSE + + +
C     READS IN INITIAL PARAMETERS AND DOES SOME PRELIMINARY
C     CALCULATIONS.
C
C     CALLED FROM MAIN
C     AUTHOR(S): D. FLANAGAN, J. ASCOUGH
C     VERSION: THIS MODULE TAKEN FROM ASCOUGH STANDALONE IRS CODE
C     DATE CODED:  3-22-2005
C     CODED BY: D. FLANAGAN
C
C
C     + + + PARAMETER DECLARATIONS + + +
C      
      INTEGER MXTIME, MXPOND
      PARAMETER (MXTIME = 1000, MXPOND = 65)

C     + + + ARGUMENT DECLARATIONS + + +

      INTEGER NR, NF
      REAL TR(MXTIME), R(MXTIME), RR(MXTIME), DT, DTC, TRF(MXTIME),
     1     RF(MXTIME), DUR
     
C     + + + ARGUMENT DEFINITIONS + + +
C
C     NR      -
C     NF      -
C     TR      -
C     R       -
C     RR      -
C     DT      -
C     DTC     -
C     TRF     -
C     RF      -
C     DUR     -
C
C     + + + LOCAL VARIABLES + + +
C
      INTEGER I, J, NDT, IRAIN
      REAL X, Y, TEST
      REAL P, DURD, TPD, IP, DDT
      DOUBLE PRECISION XX
      REAL PMAX, DMAX
      PARAMETER (PMAX = 250.0, DMAX = 1440.0)

C     + + + LOCAL DEFINITIONS + + +
C     XX      - local temporary variable (double precision)

C     + + + END SPECIFICATIONS + + +
C
C     READ THE RAINFALL FLAG (1 = VARIABLE INTENSITY; 2 = 
C     CONSTANT INTENSITY; 3 = DISAGGREGATION MODEL)
C     
      READ (3,*) IRAIN      
C     
C     VARIABLE INTENSITY INPUT 
C     
C  10 WRITE (*,1300)
C     LB = 1
C     UB = 100
C     CALL GETI(NR,LB,UB,IEND)
C     
C      WRITE (*,1400)
C    I = 0
      IF(IRAIN.EQ.1) THEN
C
C        READ THE NUMBER OF PRECIPITATION INPUT VALUES
C     
         READ (3,*) NR
         DO I = 1, NR
C
C        READ THE PRECIPITATION TIME (MIN) AND AMOUNT (MM)         
C        FIRST TIME MUST EQUAL ZERO; FIRST RATE .NE. TO ZERO
C        LAST TIME MUST BE GT ZERO; LAST RATE MUST EQUAL ZERO
         READ (3,*) X,Y
C   20    WRITE (*,1500) I
C         CALL GETRV(XXX,2,IEND)
C         X = XXX(1)
C         Y = XXX(2)
C         IF (I.GT.1) THEN
C            IF (X.LT.TRF(I-1)) THEN
C               WRITE (*,1600)
C               GO TO 20
C            END IF
C            IF (I.EQ.NR.AND.Y.NE.0.) THEN
C               WRITE (*,2000)
C               GO TO 20
C            END IF
C         END IF
            IF (X.GE.0) THEN
C           CONVERT TIME FROM MINUTES TO HOURS
            TRF(I) = X / 60.
            RF(I) = Y
            END IF
         END DO 
      END IF
C     GO TO 90

C     CONSTANT INTENSITY INPUT

      IF (IRAIN.EQ.2) THEN
C  40 WRITE (*,2100)
C     CALL GETR(Y,0.,1000.,IEND)
C     WRITE (*,2200)
C     CALL GETR(X,1.,10000.,IEND)

C     READ THE TOTAL PRECIPITATION AMOUNT (MM) AND THE 
C     STORM DURATION (MIN)

      READ (3,*) Y,X
      TRF(1) = 0.
C     CONVERT TIME FROM MINUTES TO HOURS
      TRF(2) = X / 60.
      RF(1) = Y / TRF(2)
      RF(2) = 0.
      NR = 2
      END IF
C     GO TO 90

C     DISSAGREGATION MODEL

      IF (IRAIN.EQ.3) THEN
          NR = 11
     
C         READ AMOUNT OF PRECIPITATION (MM), STORM DURATION (MIN), RATIO 
C         OF TIME TO PEAK TO DURATION (0-1), AND RATIO OF PEAK TO AVERAGE 
C         INTENSITY (0-1)

          READ (3,*) P, DURD, TPD, IP

        IF((P.LE.0.0.OR.P.GT.PMAX).OR.(DURD.LE.0.0.OR.DURD.GT.DMAX))THEN
             WRITE (*,1400)
             WRITE (*,1500) P, DURD
             STOP
          END IF

          IF (TPD.LE.0.0.OR.IP.LT.1.0) THEN
             WRITE (*,1600)
             STOP
          END IF

          IF (TPD.GT.1.0) THEN
             WRITE (*,1600)
             STOP
          END IF

 1400 FORMAT (//,10X,'PRECIPITATION AMOUNT AND DEPTH MUST BE POSITIVE',
     1    //)
 1500 FORMAT (//,10X,'PRECIPITATION AMOUNT (MM) = ',F5.2,10X,
     1    'DURATION (MIN) = ',F5.0,//)
 1600 FORMAT (/,' NOTE: TP MUST BE 0<TP<1 AND IP MUST BE >= 1.0 ')

C         CONVERT FROM MINUTES TO HOURS (CONVERSION REMOVED FROM DISAG)
          DURD = DURD / 60.
          CALL DISAG(NR, TRF, RF, P, DURD, TPD, IP)
       END IF
C      GO TO 90

C     FILE INPUT
C   60 WRITE (*,1700)
C      CALL OPEN(1,2,15,'RAINFALL FILE: ')

C      NR = 0
C   70 READ (1,*,END=80) X, Y
C      NR = NR + 1
C      TRF(NR) = X / 60.D0
C      RF(NR) = Y
C      GO TO 70
C   80 REWIND 1
C     
C     
C-----------------------------------------------------------------------
C     
C     GET TIME STEP FOR INFILTRATION
C     
      DUR = TRF(NR)
C  100 WRITE (*,2300)
C     CALL GETR(DDT,.01,1000.,IEND)
C
C     READ THE TIME STEP FOR RAINFALL EXCESS CALCULATIONS 
C     (TYPICALLY BETWEEN 1 AND 5 MINUTES)
C
      READ (3,*) DDT 
      NDT = DUR * 60. / DDT
C     
C     CHECK FOR POSSIBLE HYDROGRAPH ARRAY OVERFLOW
C     
      IF (NDT.GT.120) WRITE (*,1800) DDT, NDT
C        
C        READ (*,1900) ANS
C         IF (ANS.EQ.'Y'.OR.ANS.EQ.'Y') GO TO 100
C      END IF
C     
      DT = DDT
      DT = DT / 60.D0
      DTC = DT
      I = 0
C     
C     INSERT USER TIME STEP INTO RAINFALL DATA
C     
      XX = 0.D0
      I = 2
      TR(1) = TRF(1)
      R(1) = RF(1)
C     
      DO 120 J = 2, NR
  110    TEST = ABS(DTC-TRF(J))
         IF (I.GT.2) THEN
            XX = XX + R(I-2) * (TR(I-1)-TR(I-2))
            RR(I-1) = XX
         END IF
         IF (TEST.GT..015D0) THEN
C           
            IF (DTC.LT.TRF(J)) THEN
               R(I) = RF(J-1)
               TR(I) = DTC
               DTC = DTC + DT
               I = I + 1
               GO TO 110
            ELSE
               TR(I) = TRF(J)
               R(I) = RF(J)
               I = I + 1
            END IF
C        
         ELSE
            TR(I) = TRF(J)
            R(I) = RF(J)
            I = I + 1
            DTC = DTC + DT
         END IF
C     
  120 CONTINUE
C     
      NF = I - 1
      RR(NF) = RR(NF-1) + R(NF-1) * (TR(NF)-TR(NF-1))
C     
      RETURN
 1800 FORMAT (//' *** A TIME STEP OF ',I3,' MINUTES EQUALS ',I3,
     1    ' TIME STEPS.'/
     1    'THIS MAY CAUSE A TRUNCATION OF THE RECESSION HYDROGRAPH.'/)
      END