sr, W

Surface irrigation systems

Furrow

ndonvorhech ath tcien

2013 Elsevier B.V. All rights reserved.

ve becoing to t7 billiorlds fonder ir

leading to wastage of water, water logging, salinization and pollu-tion of surface and groundwater resources. However, surface irriga-tion systems, when properly designed and managed, can attainapplication efciencies similar to that of pressurized irrigationsystems (James, 1988). Thus, in order to improve performance ofsurface irrigation systems, there is a need for proper design and

r softwareloped in thof surface

tion include: BASCAD (Boonstra and Jurriens, 1988), B(Maheshwari and McMahon, 1991), FISDEV (Zerihun and1992), BASIN (Clemmens et al., 1995), BORDER (Strelkoff et al.,1998) and SURDEV (Jurriens, 2001). All the above software havebeen developed only to design any one of the three surfaceirrigation systems (furrow or border or basin). However, SIRMOD(Walker, 2003) and SRFR/WinSRFR (Bautista et al., 2009) are themost comprehensive software developed so far to design threetypes of surface irrigation systems (furrow, border and basin).These software are good for research and design but are still

Corresponding author. Tel.: +91 3222 283146.

Computers and Electronics in Agriculture 100 (2014) 100109

Contents lists availab

tr

elsE-mail address: nsr@agfe.iitkgp.ernet.in (N.S. Raghuwanshi).result in reduced crop yields. Merriam (1977) and Kay (1990) statedthat low efciencies in surface irrigation are not inherent to themethod but are due to poor design and management. Poor designsandmanagement are generally responsible for inefcient irrigation,

correct them.A number of surface irrigation based compute

mic the complexity in designing have been deveSome of the early developed software in the eld0168-1699/$ - see front matter 2013 Elsevier B.V. All rights reserved.http://dx.doi.org/10.1016/j.compag.2013.11.004to mi-e past.irriga-ICADMFeyen,other 40% of the food supplies (Dowgert, 2010). The majority of thisland is irrigated using surface methods, namely, basin, border andfurrows. Surface irrigation is thewidely usedmethodofwater appli-cation to agricultural lands in which water is distributed over theeld by overland ow. In spite of its wide use, themethod is charac-terized by low irrigation efciencies and uniformities that may

a large number of variables makes the design of surface irrigationquite complex. The main task in the design of surface irrigationsystems is the selection of inow ow rate (Q0) at which applica-tion efciency (Ea) is maximum. In addition, a surface irrigationsystem needs to be monitored or evaluated on a regular basis. Eval-uation helps to identify problems and the measures required toOpen channelPipeline

1. Introduction

Over the years, irrigated lands hatheworlds food requirement. Accordtal cultivated lands in the world (1.52fed agriculture, supply 60% of thewo20% of the worlds cultivated lands ume crucial for meetinghe FAO, about 80% of to-n hectares) under rain-od; while the remainingrigation, contribute the

management. Mathematical models of surface irrigation can helpin better design and management of these systems.

In the past three decades considerable research has been con-ducted to develop mathematical models for simulating surface irri-gation performance. These models depend on several interactingfactors such as eld dimensions, eld slope, ow rate, cutoff time,soil inltration characteristics and ow resistance. The presence ofBasinBorder

comprehensive Help menu is incorporated in the SIDES to facilitate a thorough understanding of the the-ory and methodology adopted for the design.Development of Surface Irrigation SystemSoftware (SIDES)

Sirisha Adamala, N.S. Raghuwanshi , Ashok MishraAgricultural and Food Engineering Department, Indian Institute of Technology, Kharagpu

a r t i c l e i n f o

Article history:Received 4 January 2013Received in revised form 5 November 2013Accepted 11 November 2013

Keywords:

a b s t r a c t

A software for the design awith the design of water cin educational and research6 programming language. Tthe volume balance approathe SIDES matched well wimaximum application ef

Computers and Elec

journal homepage: www.Design and Evaluation

est Bengal 721 302, India

evaluation of surface irrigation systems (furrow, border and basin) alongeyance systems (open channel and pipe line) is developed to assist usersganizations. The software named as SIDES is developed using Visual Basicdeveloped software for the design of surface irrigation systems is based onnd is tested using the available published datasets. Results obtained usinghe published datasets for all the designs. Besides the design parameters atcy, SIDES also provides detailed tabular and step wise design results. A

le at ScienceDirect

onics in Agriculture

evier .com/locate /compag

roniNomenclature

a, k, f0 empirical parameters; (a = dimensionless),(k = m2/min/m), (f0 = m2/min/m)

A, P area of cross-section (m2) and wetted perimeter(m) of the channel

A0 wetted area at the upstream (m2)b, T, y bottom width, top width and depth of a channel

(m)C Chezys constantCh HazenWilliams constantD diameter of pipeline (m)DPR deep percolation ratio (%)DU distribution uniformitye roughness coefcient (m)Ea application efciency (%)g acceleration due to gravity (m/s2)Hf head loss due to friction (m)i loss of head per unit length (dimensionless)I inltration rate as f (x, t) (m/s)L, W eld length and width (m)Lp length of pipe (m)n Mannings roughness coefcientNf, Ns, Nb number of furrows, number of sets, number of

borders/basinsp, r empirical parameters of advance equationp1, p2 shape coefcientsQ discharge capacity of open channel/pipeline/sup-

ply system (m3/s)

S. Adamala et al. / Computers and Electlacking in the step wise design process which are very essential forstudent learning. Also, the above software do not have a module fordesign of water conveyance systems, which is a priori design as-pect before planning any surface irrigation system. Therefore, thepresent study was undertaken with the following objectives:

1. To develop a computer software for the design and evalua-tion of surface irrigation systems along with the design ofwater conveyance systems with an interface that is conve-nient for both developer and average user.

2. To verify the developed software with the available pub-lished data.

2. Theoretical background

2.1. Design of water conveyance systems

The water supply and rate of irrigation delivery for the areaserved by the conveyance system shall be sufcient to make irriga-tion practical and feasible, for the crops to be grown and the irriga-tion water application methods to be used. The water conveyancesystem consists of either open channel or pipeline. Different openchannel (rectangular, triangular, trapezoidal and parabolic) crosssections and pipeline are designed to convey the water from sourceto irrigation elds. Table 1 shows different methods considered fordesign of pipeline, in the present study.

2.2. Design of surface irrigation systems

The volume balance approach is selected for designing and eval-uating surface irrigation systems. The generic form of the volume

Q0, Qmax, Qmin inow, maximum, minimum ow rates (m3/min)S slope of the open channel/pipeline (%)S0 longitudinal slope (m/m)Sf slope of energy grade line (m/m)Sy relative water surface slope (%)t time from the start of inow (min)T = t ts opportunity time (min)t0.5L advance time to one-half of the eld length (min)tco, tr, td cutoff time, recession time, depletion time (min)tL advance time to end of the eld (min)Treq intake opportunity time (min)ts time required (min) for the water front to reach a

distance of s (m) from the head of the eldTWR tail water ratio (%)TWV volume of tail water (m3)v kinematic viscosity of water (m2/s)v velocity of ow as f (x, t) (m/s)V0.5L inltrated volume to one-half of the eld length

(m3)VL inltrated volume to end of the eld (m3)Vmax maximum non erosive ow velocity (m/s)Wb width of border/basin (m)x water front advance (m)xa length of adequate area (m)xd length of inadequate area (m)y0 inlet depth (m)z side slope of a channel (zH:1V)Z cumulative inltration per unit length (m3/m)Zreq required depth of water (m)

Greek symbols

cs in Agriculture 100 (2014) 100109 101balance model for the advance phase is based on the Lewis-Milneintegral, which computes the inltration integral as a function oftime and can be expressed as:

Q0t ryA0xZ x0

Zt tsds 1

For sloping elds, the upstream ow area (A0) can be accomplishedwith the Mannings equation:

A0 Q20n

2

3600p1S0

! 1p2

2

In a level-slope condition, such as basin, it is assumed that thefriction slope is equal to the inlet depth, y0, divided by the distancecovered by water, x. This leads to the following expression for y0(Walker and Skogerboe, 1987):

y0 Q20n

2x3600

!0:233

Cumulative inltrationZ canbe estimatedusing theKostiakovLewisequation as follows:

Z kTa f0T 4Assuming the power advance, x ptrs (i.e. ts x=p1=r) andsimplifying (Eq. (1)) after substituting ts and Z, results:

Q0t ryA0x rzkTaxf0Tx1 r 5

where rz = subsurface prole shape factor, which is a function ofthe exponent of the inltration function (Walker and Skogerboe,1987):

ry surface prole shape factor (varies from 0.77 to0.80)

rz subsurface prole shape factor

border and basin). Eq. (5) can be written for two points (half of the

(3)

(5)

ronield length, L/2, and eld length, L) to represent the advance trajec-tory as follows:

At the end of the eld:

Q0tL ryA0L rzktaLLf0tLL1 r 7

At the mid-length of the eld:

Q0t0:5L ryA0L2

rzkta0:5LL2

f0t0:5LL21 r 8

2.2.1. Estimation of inltration parametersFor determining parameters k and a of the inltration func-

tion, Eqs. (7) and (8) can be solved knowing the advance times cor-responding to two locations as follows (Walker and Skogerboe,1987):

a lnVLV0:5LlntLt0:5L 9rz a r1 a 11 a1 r 6

The above volume balance equation (Eq. (5)) can be solved for anytwo waterfront advance points, say (x1, t1) and (x2, t2), to obtaineither advance time at two locations with known inltration func-tion or inltration parameters with known advance time. Typically,these two advance points are considered as the water front advanceat the middle and tail end of the eld or irrigation system (furrow,

Table 1Commonly used equations for the pipeline design.

Source Equation

DarcyWeisbach andColebrookWhite Q 0:9641D

2:5gHfLp

r ln e3:7D 1:78m

D1:5gHfLp

q

HazenWilliams Q 0:2786 Ch S0:54 D2:63Mannings Q 0:3115 1n

S0:5 D2:667Chezys Q 0:3725 C i0:5 D2:5

where Q = discharge capacity of pipeline/open channel/ supply system (m3/s);D = diameter of pipeline (m); g = acceleration due to gravity (9.806 m/s2); Hf = headloss due to friction (m); Lp = length of pipe (m); e = roughness coefcient (m);v = kinematic viscosity of water (m2/s); Ch = HazenWilliams constant; S = bedslope (%); n = Mannings roughness coefcient; C = Chezys constant; i = loss of headper unit length (Hf/Lp).

102 S. Adamala et al. / Computers and Electk VLrztaL

10

where

VL Q0tLL ryA0 f0tL1 r 11

V0:5L 2Q0t0:5LL ryA0 f0t0:5L1 r 12

However, steady state inltration rate (f0) must be known beforehand. The technique used for determining f0 is the inow-outowmethod, in which the entire furrow is used essentially as an inl-trometer and can be found using the following equation (Walkerand Skogerboe, 1987):

f0 Q in QoutL 133. Development of software

The Visual Basic 6.0 programming language is used to developthe software, called SIDES. SIDES consists of three modules: (1) de-sign of water conveyance systems (open channel and pipeline), (2)design of surface irrigation systems (furrow, border and basin), and(3) evaluation of surface irrigation systems.

3.1. Design of water conveyance systems

3.1.1. Design of open channelsThe input and output data required for design of open channels

are shown in Table 2. Depending on input data, the output can beobtained for different channel sections. Design of open channels is

basedtion, vwith tTWR 100 Ea DPR 19Tail water volume (TWV): It indicates the surface water runoffat the end of a eld.

TWV Q0 tco TWR 20(4) Tail water ratio (TWR): It is the ratio of average depth of eldrunoff to the average depth applied.tcoQ0 100 for complete and overirrigation 17

DPR Vza ZreqxdtcoQ0

100 for underirrigation 18through drainage beyond the root zone. High deep percola-tion losses aggravate waterlogging and salinity problems,and leach valuable crop nutrients from the root zone.

DPR Vz ZreqLEa ZreqLtcoQ0 100 for complete and overirrigation 15

Ea Zreqxd VzitcoQ0 100 for underirrigation 16

Deep percolation ratio (DPR): It indicates the loss of water(2) Application efciency (Ea): It indicates how well a system isbeing used. It is dened as:14Average depth of water accumulated in all elements

100DUlq Average low-quarter depthdlq2.3. Performance evaluation of surface irrigation systems

In this study, surface irrigation systems performance evalua-tion is based on the procedure outlined by Walker and Skogerboe(1987). The primary indicators that are used in evaluation of sur-face irrigation systems are distribution uniformity, application ef-ciency, deep percolation ratio, tail water ratio, and tail watervolume described below:

(1) Distribution uniformity (DU): It measures how uniformlywater is applied to the eld, and is expressed as a percent-age. The most common measure of DU is the Low QuarterDU (DUlq), which is a measure of average inltrated depthin the low quarter of the eld, divided by the average inl-trated depth over the whole eld.

cs in Agriculture 100 (2014) 100109on the Mannings equation. Therefore, for a given cross sec-elocity and discharge (capacity) are calculated and comparedhe required capacity. The design is carried out using a trial

and error process, which continued until calculated capacity be-come equal to required capacity. Fig. 1 shows the open channel de-sign window of SIDES. The input data required for open channeldesign depends on the chosen cross section. A drop down box isprovided for selecting Mannings roughness coefcient values fordifferent channel linings. For validating the open channel design,input datasets were taken from (Michael, 1999) and (Murty, 1985).

3.1.2. Design of pipelineFour empirical approaches have been adopted for the design of

coefcients, and Mannings roughness coefcient values, if theyare not known to user. For the design of pipeline the datasets weretaken from (Gilberto, 2005) and (Bansal, 2005).

3.1.3. Design of surface irrigation systems

Table 2Input and output data for the open channels design.

Cross section Input Output

Rectangular Q, n and S b, yTriangular Q, n, S and z yTrapezoidal Q, n, S and z b, yParabolic Q, n and S T, y

where b, T, y = bottom width, top width and depth of a channel, respectively (m).

Table 3Different cases considered for the three empirical approaches.

Empirical approach Cases

Input Output

HazenWilliams (1) Lp, Ch, Q and Hf D(2) Lp, Ch, D and Hf Q(3) Lp, Ch, D and Q Hf

Mannings (1) Lp, n, Q and Hf D(2) Lp, n, D and Hf Q(3) Lp, n, D and Q Hf

Chezys (1) Lp, C, Q and Hf D(2) Lp, C, D and Hf Q(3) Lp, C, D and Q Hf

S. Adamala et al. / Computers and Electronics in Agriculture 100 (2014) 100109 103pipeline systems (Table 1). Depending on input data different caseshave been considered for these four empirical approaches (Table3). The design procedure involves in DarcyWeisbach or Cole-brook-White equation for the following three cases is explained as:

Case (1) Given: Lp, e, Q and Hf; Find: D. This case is a typical ofrst step in designing a pipeline and solution is based on trialand error method.

Case (2) Given: Lp, e, D and Hf; Find: Q. The solution for this caseis simple because it has a direct solution.

Case (3) Given: Lp, e, D and Q; Find: Hf. The solution for this casealso based on trial and error method.

A similar procedure was also been adopted for the design ofpipelines by using other three empirical approaches (Table 3).Fig. 2 shows the pipeline system design window of SIDES. The in-put data required for pipeline design depends on the chosen meth-od. The chosen methods can be used to determine pipe diameter(D), total head loss (Hf) or discharge (Q). These cases are summa-rized in Table 3. An option of Select from table is provided forselecting the values of loss coefcients for various ttings, avail-able pipe diameters, pipe roughness coefcients, HazenWilliamsFig. 1. Design of oFig. 3 shows the procedure adopted for design of surface irriga-tion systems. For designing of surface irrigation systems, the com-putation of required intake time (Treq) by NewtonRaphsonprocedure, advance time (tL) using two-point method and deple-tion time (td) are necessary which involves an iterative or trialand error procedure as suggested by Walker and Skogerboe(1987). Fig. 4 shows the furrow irrigation system design windowin SIDES. The input data includes data of eld topography/geome-try (eld length, eld width, furrow spacing, type of soil and eldslope), inltration characteristics (KostiakovLewis inltrationmodel parameters), supply system capacity, irrigation require-ment, Mannings roughness coefcient and shape coefcients. Acommand Select from table is provided for selecting Manningsroughness coefcient and inltration parameters for both the rstirrigation and subsequent irrigations. These two different irriga-tions are chosen to consider the change in inltration characteris-tics during the cropping season. In SIDES an option is provided forthe selection of inltration parameters as reported by Walker(2003) as a function of soil texture if information on inltrationis not known to user for furrow, border and basin irrigation sys-tems. These inltration characteristics should be used primarilyfor obtaining the rst estimate of design. Users are advised topen channels.

Fig. 2. Design of pipeline system.

Input data

Enter: L, W, Q, S 0, Vmax, Zreq Select: p1, p2, a, k, f0, n

Calculate: minimum, maximum flow rates (Qmin, Qmax) 0.50min

0.000157*L*SQ = n

22

pmax max

1 0

nQ = V * 3600*p *S

Select inflow rate (Q0), so that Qmax < Q0 < Qmin

Advance time (tL) Intake time (Treq) Calculate:

Furrow BasinBorder

Enter: Furrow spacing (Fs)

Time of cutoff (tco) = Treq+ tL

Ns = Nf *Q0/Q

Nf = W/Fs

Integer

Calculate: No. of furrows, sets (Nf, Ns)

YesNo

Q0 = Q0+0.001

No. of borders or basins (Nb) = W/Wb

Width (Wb) = Q/Q0

Integer

0.60

0 0.50

Q n Inflow depth (y )=60S

Yes No

Q0 = Q0+0.001 y0< dike height

BasinBorder

Recession time: tr = Treq + tL

Calculate: Depletion time (td)

0co d

0

y Lt = t -

2Q

Application efficiency,

req 0Loc

0

Z L - 0.77y Lt = + tQ

d reqt TYes

Irrigation is complete Under irrigation

0co req

0

y Lt = T -

2Q

No

reqa

co 0

Z LE = t Q

Assumptions: (i) The water i.e. remaining on the border at the instant the water is shut off is triangular in shape. (ii) The water infiltrates at an equal rate everywhere in the field.

Fig. 3. Flowchart for the design of surface irrigation systems (Walker and Skogerboe, 1987).

104 S. Adamala et al. / Computers and Electronics in Agriculture 100 (2014) 100109

desi

roniuse actual eld data to obtain eld representative designs. Furrowshape coefcients can be calculated from the measured elevationand depth data using the Calculate command. The data set shown

Fig. 4. Required inputs for the

S. Adamala et al. / Computers and Electin Fig. 4 for the design of furrow irrigation system was taken fromWalker and Skogerboe (1987).

Fig. 5 shows the detailed design results of the furrow irrigationsystem which includes the eld length and width utilized to coverthe total available water, ow per furrow, number of furrows,number of sets, intake time, advance time, cutoff time and applica-tion efciency for rst irrigation. The results are displayed in a tab-ular form to compare designs related to different inow rates.Here, a command Results at best efciency is provided for dis-playing results pertaining to the maximum application efciencyfor the rst irrigation. Due to the similarity in the design of all sur-face irrigation systems, the developed windows for border and ba-sin are not shown here. For the design of border and basinirrigation systems, the datasets were also taken from (Walkerand Skogerboe, 1987).

3.2. Evaluation of surface irrigation systems

3.2.1. Evaluation of inltration parametersSIDES uses two point method (Elliott and Walker, 1982) for

evaluation of KostiakovLewis inltration parameters (k and a).In SIDES, windows for the evaluation of the KostiakovLewis inl-tration model parameters for furrow, border and basin irrigationsystems were developed. The input data for the evaluation of in-take parameters was taken from Walker (1989).

3.2.2. Performance of surface irrigation systemsPerformance of surface irrigation event is measured using a

number of performance measures such as DU, Ea, DPR, TWR, andTWV. In SIDES, windows for the evaluation of furrow, border andbasin irrigation systems performance in terms of above mentionedmeasures were developed. The input data was taken from Walkerand Skogerboe (1987).4. Verication of the software

The developed software was veried using several published

gn of furrow irrigation system.

cs in Agriculture 100 (2014) 100109 105datasets (standard design procedures only) for testing purposes.For example, conveyance system designs for open channel was ver-ied using different examples from Michael (1999) and Murty(1985) whereas the pipeline design was veried using variousexamples from Gilberto (2005) and Bansal (2005). The design re-sults obtained by the software exactly matched with the variouspublished source values for both open channel and pipelinesystems.

Table 4 shows comparison of published and developed softwareobtained surface irrigation systems design results. The values con-sidered for comparison are inow (Q0) (although input but de-pends on number of furrows/border/basin in a given set),required intake time (Treq), advance time (tL), cutoff time (tco),number of sets (Ns), number of furrows/border/basin per set (Nf/Nb) and application efciency (Ea). From Table 4, it is clear thatthe results obtained by SIDES for the design of all surface irrigationsystems matched well with the published data, with a negligibledifference in case of advance time (tL), cut off time (tco) and appli-cation efciency (Ea) except for advance time computation in basindesign. The small discrepancy in these values may be due to thetruncation or round off error. In case of basin advance time, thisdifference is mainly caused by different value of exponent in ad-vance formula used in source and SIDES.

Table 5 shows comparison of furrow irrigation performancemeasures obtained with developed software, for a sample problemgiven in Walker and Skogerboe (1987). For all performance mea-sures (DU, Ea, DPR, TWR and TWV), the results obtained by SIDESmatched exactly with respective published values. The softwareobtained performance measures also matched with their respec-tive values for basin and border irrigation systems. The comparisonresults in Tables 4 and 5 gave same values with the published val-ues as they both are based on the same set of equations. Hencethese tables serve as a check against errors in the code. The results

ronics in Agriculture 100 (2014) 100109106 S. Adamala et al. / Computers and Electobtained using the SIDES for above mentioned verication exam-ples clearly demonstrate that the software results in accurate de-sign of conveyance and surface irrigation systems, and alsoaccurate evaluation of performance measures.

5. Key features of the SIDES over existing other software

In SIDES for all designs, an option is provided for saving detailedstep wise design results. For example these step wise design resultsfor furrow irrigation include calculation of inow rates, no. of sets,intake, advance, and cutoff times and application efciencies withno. of iterations. The developed software allows users to save all

Fig. 5. Design results of furrow irrigation system.

Table 4Comparison of output for the design of surface irrigation systems (initial irrigations).

Parameters Furrow Border Basin

SIDES Walker andSkogerboe (1987)

Difference(%)

SIDES Walker andSkogerboe (1987)

Difference(%)

SIDES Walker andSkogerboe (1987)

Difference(%)

Inow, Q0 (m3/min/m) 0.075 0.075 0 0.14 0.14 0 0.14 0.14 0Required intake time, Treq (min) 378.73 378.73 0 146.39 146.4 0.068 382.97 383.00 0.008Advance time, tL (min) 198.68 198.60 0.04 158.46 158.00 0.29 71.99 77.00 6.95Cutoff time, tco (min) 577.41 577.33 0.014 205.58 205.00 0.282 158.96 158.00 0.604No. of sets, Ns (No.) 6 6 0 2 2 0 8 8 0Furrows/Borders/Basins per set (No.) 80 80 0 185 185 0 90 90 0Application efciency, Ea (%) 69.28 69.30 0.028 65.67 66.00 0.502 80.88 81.20 0.395

Table 5Comparison of output for the performance evaluation of furrow irrigation system.

Parameters SIDES Walker and Skogerboe(1987)

Distribution uniformity, DU (%) 77.17 77.17Application efciency, Ea (%) 80 80Deep percolation losses, DPR (%) 20 20Tail water ratio, TWR (%) 14.2 14.2Tail water volume, TWV (m3 per

furrow)3.2 3.2

Fig. 6. Help window.

the design steps such that they can be easily understood in thefuture. This key feature of SIDES makes users to get betterunderstanding and possibly greater trust in the used approach byrepeating the same calculations by hand. The designs are savedwithdefault extension .txt. The sample detail design procedures for theopen channels and pipelines are provided in Appendix A and B,respectively. The sample output for furrow irrigation design exam-ple (Figs. 4 and 5) as described in Fig. 3 is shown in Appendix C. Theresulting design procedure for furrow irrigation consists of 12 steps.

In addition to the above, a detailed and systematic Help at var-ious steps of design procedures is also provided in SIDES. Fig. 6shows the developed Help window in SIDES. This Help moduleprovides the complete description about the theory involved,methodology, sample datasets, and example validation results forthe effective and wise use of the developed software package.Besides this extensive Help Menu, several pop-up menus are alsoprovided in each module of the SIDES to facilitate quick decision-making by the users.

6. Conclusions

A computer based software package using Visual Basic 6 pro-gramming language was developed for the design and evaluation

of different surface irrigation systems including design of waterconveyance systems. The developed software package is calledSIDES, which is based on the volume balance approach andconsists of three modules. The three modules of the softwarewere rigorously tested at developers level using the severalavailable published datasets. The software was found to be ef-cient and reliable for the design and evaluation of surface irriga-tion systems and for the design of water conveyance systemsalso. Besides the design parameters at maximum application ef-ciency, the SIDES provides detailed outputs in tabular form fordifferent design alternatives at different levels of application ef-ciency. SIDES also has a provision to save the detailed design re-sults for later use and post-processing. Here it is worth tomention that the problems solved by the traditional methodare very cumbersome and time consuming. However, this prob-lem can be overcome using SIDES. In SIDES a Help module isprovided to facilitate a thorough understanding of the theoryand methodology adopted for the design. Besides this extensiveHelp Menu, several pop-up menus are also provided in eachmodule of the software to facilitate alert messages and quickdecision-making by the users. It is concluded that SIDES can beused as a teaching and design tool. It may be also useful for prac-ticing irrigation engineers.

Appendix A

Sample software output for the design of open channel:Here selected channel is: Trapezoidal cross sectionInput data:Bottom width, b = 0.4 mSide slope, z = 1.5H:1VMannings roughness coefcient, n = 0.025Flow discharge, Q = 0.182 m3/sBed slope, S = 0.1%Detailed design results:Step 1: Assume initial value for ow depth, y = 10 mStep 2: Substitute this value in following equations:Area of cross section, A = (b + z y) y = (0.4 + 0.4 10) 10 = 154 m2

Wetted perimeter, P = (b + (2 y sqrt(1 + z 2))) = = (0.4 + (2 10 (1 + 1.52)0.5)) = 36.46 mHydraulic radius, R = A/P = 154/36.46 = 4.22 mCalculated ow discharge, Q1 = (1/n) A R(2/3) sqrt(S) = (1/0.025) 154 36.46(2/3) 0.0010.5 = 509.0406 m3/s

509ste

.84 m

Hf3.13step

S. Adamala et al. / Computers and Electronics in Agriculture 100 (2014) 100109 107Step 3: Compare the values of actual and calculated discharge, i.e. = (Q1 Q) = =Since the computed value >0.0001, decrease the value of ow depth and repeat the

nal estimated value of ow depth y = 0.4 mDetailed design results at nal ow depth:Area of cross section, A = (b + z y) y = (0.4 + 1.5 0.4) 0.4 = 0.4 m2

Wetted perimeter, P = (b + (2 y sqrt(1 + z2))) = (0.4 + (2 0.4 (1 + 1.52)0.5)) = 1Top width, T = (b + (2 z y)) = (0.4 + (2 1.5 0.4)) = 1.6 mHydraulic radius, R = A/P = 0.4 /1.84 = 0.22 mHydraulic depth, HD = (A/T1) = (0.4/1.6) = 0.25 m

Appendix B

Sample software output for design of pipeline system.Computation of pipe diameter using DarcyWeisbach equation:Input data:Length of the pipe, Lp = 2000 mPipe roughness coefcient, e = 0.0001 mFlow discharge, Q = 2.2 m3/sHead loss due to friction, Hf = 1 mViscosity, v = 0.000001 m2/sAcceleration due to gravity, g = 9.81 m/s2

Detailed design results:Step 1: Assume initial value for diameter, D = 10 mStep 2: Substitute this value in DarcyWeisbach modelQ1= 0.9641 D^(2.5) sqrt(g Hf/ Lp) ln((e/3.7 D) + ((1.78 v)/(D^(1.5) sqrt(gStep 3: Compare the values of actual and estimated discharge, i.e. = (Q1 Q) = 27Since the computed value >0.0001, decrease the value of diameter and repeat thenal estimated value of diameter D = 1.64 m.0406-0.182 = = 508.8586ps 1 to 3 until they are equal to each other or

Appendix C

Design of a furrow irrigation systemInput data:Parameters of Modied KostiakovLewis inltration equation, for rst irrigation:Inltration exponent, a = 0.534Inltration parameter, k = 0.0028 m3/min/mBasic inltration rate, f0= 0.00022 m3/min/m

Mannings roughness coefcient, n = 0.04Field slope, S0 = 0.008 fractionShape coefcients: p1 = 0.325 and p2 = 2.734Stream size, Q = 6 m3/minLength, L = 200 m and Width, W = 720 mFurrow spacing, Fs = 1.5 mRequired depth of water, Zreq= 0.1 mSoil type = ClayStep 1: Compute Treq to satisfy irrigation requirement:(a) Zreq = irrigation requirement Fs = 0.1 1.5 = 0.15 m3/m length(b) Calculate Treq using Newton Raphson procedure: The basic mathematical model used is modied KostiakovLewis equation i.e.Zreq kTareq f0Treq

(i) Assume rst estimate of (Treq)i = 15.00 min(ii) Compute a revised estimate of Treqi1 based on following

formula,Treqi1 Treq

i ZreqkTreqai f0Treqi

ak=Treq1ai f0 15 0:10:0028150:5340:00022150:5340:0028=1510:5340:00022 224:56min

(iii) Compare the values of rst and revised estimates = Treqi1 Treqi 224:56 15 209:56minSince the computed value > 1 s, replace the rst value of Treq with revised value, i.e. (Treq)i = (Treq)i+1 Repeat the steps (ii) and (iii), until

they are equal or 1 s, replace the rst value of advance with revised value, i.e. T2 = T1. Repeat the steps 7(a) and 7(b), untilthey are equal or 1 s, replace the rst value of advance with revised value, i.e. T2 = T1. Repeat the steps 8(a) and 8(b), until

they are equal or

References

Bansal, R.K., 2005. Fluid Mechanics and Hydraulic Machines. Laxmi Publications,New Delhi, p. 1093.

Bautista, E., Clemmens, A.J., Strelkoff, T.S., Schlegel, J., 2009. Modern analysis ofsurface irrigation systems with WinSRFR. Agricultural Water Management 96,

Kay, M., 1990. Recent developments for improving water management in surfaceirrigation and overhead irrigation. Agricultural Water Management 17, 723.

Maheshwari, B.L., McMahon, T.A., 1991. BICADM: A Software Package for BorderIrrigation Computer Aided Design and Management. Dept. of Civil andAgricultural Engineering, University of Melbourne, Australia, p. 32.

Appendix C (continued)

Since the computed value not