CHAPTER 182 INTEGRATION AND COMPUTATION IN AN ENVIRONMENTAL STUDY

Transcription

1 CHAPTER 182 INTEGRATION AND COMPUTATION IN AN ENVIRONMENTAL STUDY J.B. Hinwood 1 by ABSTRACT A high level of integration of disciplines and se of a centralised compter data base and programming system were seen to offer advantages in a stdy of the marine and coastal environment of the Port Melborne Athority. These goals were only partially attained bt the effort was well worthwhile. 1. INTRODUCTION For an environmental stdy to achieve an overview of the wide range of variables, processes and interactions in a given region, the reslts of work in many disciplines mst be integrated. The integration of the different disciplines depends critically pon flows of information. These in trn depend pon the se of the compter to store, process and display information. This paper describes the integration of disciplines and the centralised compter data base and programming system sed in the Port.of Melborne Environmental Stdy. The prpose and reslts of the stdy are otlined first to provide the context. 2. THE PORT OP MELBOURNE ENVIRONMENTAL STUDY 2.1 Prpose The Port of Melborne Environmental Stdy was divided into firstly a stdy of the sociological implications of the possible expansion of Webb Dock with some emphasis on land transport serving the dock and secondly the Marine Stdy of 6 Webb Dock. The Marine Stdy was aimed at assessing the effects on the marine and coastal environment of reclamation and dredging activities associated with the constrction of Berth 6 Webb Dock. The site of the proposed constrction is in Hobsons Bay, close to the moth of the Yarra River. The stdy involved investigations of water movement, water qality, coastal processes and the ecology of the Bay. Environmental Stdies, University of Melborne. Marine Science and Ecology, Melborne. Centre for Environmental Stdies, University of Melborne. 327

2 328 COASTAL ENGINEERING-198 The Port of Melborne has been developed over the last 15 years along the lower Yarra River and arond its moth, in an indentation of Port Phillip Bay known as Hobsons Bay. The Webb Dock container terminal is in Hobsons Bay immediately to the east of the moth of the Yarra River (Fig. 1). Hobsons Bay forms the sothern bondary to Melborne, and hence is of importance to the city as a recreational area for boating, fishing, for swimming, and for the aesthetic enjoyment of water and its shoreline. The vale of Hobsons Bay wold be lowered if the water qality were to be redced, if the ecosystem of the bay were to be distrbed or if the beaches were severely eroded. Severe changes in the regime of the bay cold adversely affect commercial fishing within Port Phillip or cold conceivably interfere with port operations. Proper management can avoid these problems, bt management reqires reliable baseline information on the present state of the bay, an nderstanding of the processes which are important and, based pon both of these, strategies for predicting changes to the ecosystem of the bay following constrction or other activities. The stdy provided the baseline data on water circlation, water qality, beaches and sediments and marine ecology, an nderstanding of the important processes and specific predictions for the changes which wold reslt following constrction of Berth 6 Webb Dock. 2.2 Method The Port of Melborne Athority commissioned the Centre for Environmental Stdies, University of Melborne, to carry ot a stdy to provide baseline information and to assess the conseqences of constrction of a new berth No.6 in Webb Dock. This stdy was commenced in 1977 and the final report was presented in Agst Following a three months planning period, twelve months of measrement were carried ot within Hobsons Bay and the lower Yarra River. In addition to the data obtained specifically by the stdy, historical data and data collected on a contining basis by government athorities were sed. Water movement was determined by direct crrent metering, continos crrent metering, droge tracking and from temperatre and salinity data (Mills et al 1978, Dandy et al 198). Wave records, tidal data, long-term meteorological data for the Melborne Regional Station and wind data for periods of interest at Breakwater Pier were obtained from government departments. Water qality parameters measred were temperatre, salinity, dissolved oxygen, light transmission, trbidity, nitrogen, phosphors, E. coli and Salmonella bacteria and inflows from minor drains. For the stdy of the beaches and sediments, beach profiling and lead-lining were carried ot, sediment samples were collected and analysed, a sand tracer test was condcted and waves, winds and crrents were measred. Other data sed were air photos, records of constrction, dredging and shipping movements.

3 ENVIRONMENTAL STUDY 329 Fig. Hobsons Bay, Melborne

4 33 COASTAL ENGINEERING-198 The ecological stdies concentrated on sampling the intertidal and sbtidal epibiota (algae and fana) on port strctres, and the benthic infana of the bed and intertidal margins of the bay. Pish poplations were sampled by seining in shallow water. A srvey of recreational fishing in Hobsons Bay was condcted. 2.3 Reslts The principal findings were: The water circlation in Hobsons Bay is primarily wind driven, bt the effects of Yarra River flow and stratification mst be taken into accont and tides may be important in some circmstances. Except in the srface plme of water from the Yarra River, the water of Hobsons Bay is predominantly derived from Port Phillip Bay. Within the Yarra River and river plme, bacterial and ntrient levels are high and dissolved oxygen concentrations are below desirable levels. Elsewhere the water qality meets EPA objectives. Sand is fond on and jst offshore of the beaches. Sediment movement on Sandridge Beach, to the east of Webb Dock, is highly variable bt is predominantly to the west. The silt bed of Hobsons Bay may be resspended by wave action bt is not ndergoing significant net movement. - Both the hard and soft sbstrates of Hobsons Bay and Webb Dock spport a diverse and prodctive biota, and there are significant poplations of fish. Prodctivity is lower in Webb Dock than in Hobsons Bay, bt it is still high by general standards. The biological commnities are well adapted to the existing environmental conditions and can withstand the distrbances imposed by shipping and the natral stresses of variable temperatre and salinity. All variables were related to water movement and water qality, hence predicted changes in flow patterns enabled the changes following constrction of Berth 6 to be predicted. 3. COMPUTATION 3.1 Prpose The extensive se of a compter data base and centralised programming system was anticipated to provide economical and fast data redction and presentation and ready access to all data by all participants in the stdy. The advantages of centralisation are that by examining the needs of all grops together, niformity of recording is obtained where possible, the nmber of data handling programs and the comptational effort are redced and ease of access and ease of inter-comparison of different types of variables are increased.

5 ENVIRONMENTAL STUDY Method The e.d.p. work was placed nder the control of one staff member possessing both a broad knowledge of disciplines involved in environmental stdies pls expert knowledge of compting, assisted by jnior programmers and data entry personnel. The se of a prely compter oriented specialist was not seen to provide the proper liaison which this position reqired, bt we recognise that we were very fortnate in obtaining the services of a man expert in both areas. The e.d.p. specialist developed a general strategy for data entry and error checking, data file strctre, freqently sed data maniplation and redction programs, and freqently sed tablar and graphical presentations of data. He collaborated with other senior staff in development of these and specialised analysis programs reqired, spervised jnior staff in preparing programs and sing them, and trained all staff in the se of the system as it was developed. Available fnds permitted minor improvements to be made to the existing compter hardware. The existing system, shown schematically in Fig. 2, consisted of a Hewlett Packard model 983 programmable calclator, with 8-K words memory, programmable in BASIC, with extended string and matrix handling capabilities. An internal cassette drive permitted storage of data with the capacity of 32-K words per cassette. The calclator was sable as stand-alone machine or as an intelligent terminal for data transmission to and from the University's Central Compter a CDC Cyber. A small plotter was connected to the 983 and other plotters were available at the University Compter Centre. This system serviced the Centre for Environmental Stdies, and cold not be wholly dedicated to this stdy, hence the decision was taken to provide an additional direct line to the University Compter and to provide an axiliary cassette drive for the 983. The software reqired may be divided into for grops. Data entry and error checking rotines were specially prepared for the stdy. Data maniplation, reformating and editing rotines were also specially written, to enable correction of data files, combination of files for se in calclations and to enable stranger tapes written in other compter installations to be read by the Cyber. Data preparation rotines, inclding those sed in smoothing raw data, for changing time base intervals, resolving vectors and so on, were again specially written althogh they tilised well known algorithms. Finally, the more sbstantial programs for tasks sch as time series analysis or statistical analysis were obtained from other installations wherever possible. Becase of its great convenience the SPSS package was tilised for all basic statistics operations, despite its inefficiency for some types of calclations. 3.3 Reslts Approximately 3, data vales were entered to form the main

6 1 332 COASTAL ENGINEERING-198 w w O -H slogica Water ratre 3g r -rh -p QJ OJ a C to tpfn to ) p s n s to n * 13 C ro to -P P ro Ul Q 1 G O G * rh x* Is ^3 >1 ID rh -H a en w >i 1 G to n m -p D ) (1) SH 1 L p. o to a c a a c m Q) In < p p M rj } r-t Q U P "i OJ G JJ -H -P U O ft r-l ft Tl G 1 U 1J U JJ O G p -H JJ H O ft H ft O G 1 ffl H b io ^ )H 2» s5 a ft ) SH JJ = 8 1 JJ ro a) U ) O En DJ ( ) ft a ro EH ' o j3 >i a) r4 U 1 C H <_) > OJ tn to o Recorded Water Qality Data -p 115 CO JJ a! r-l ^ PJ <^> w 3 rd 1 w m M QJ U r-l ro rrj -rt JJ pq fc ro OJ JJ «J G 3 O. rt Of e rh P -rt 3 O CO JH G O rh >i [fl Jj H OJ - JJ ro -H G H H <D S CO H H OJ rh ro ) B G rj) O OJ r-t (/] ft Fig. 2 Compter configration sed for data entry archiving and processing

7 ENVIRONMENTAL STUDY 333 data base, while tapes obtained from government agencies contribted a frther 2, data vales, primarily meteorological data. The centralised programming facility provided approximately 8 programs, most of them in the area of data maniplation, reformating and editing. Approximately 8 additional programs or variations of programs were prepared otside the central system, mostly in the areas of data analysis and presentation. Averaged over the corse of the stdy, the compter specialist devoted between one and two days of each week to the job. Jnior programmers contribted approximately one man year of work and data entry personnel approximately three man years. Other project staff contribted approximately half a man year to the programming and abot the same to the data entry. The forms of data inpt, principal compter files created and the sorce of the principal compter programs sed are shown in Table 1 for the water qality and water movement data; the first six colmns represent over 98% of the data. The table shows that a wide variety of inpt forms were sed, most data were pt onto local cassette for limited local comptations and onto the central data base, and processed on the central compter programs. The similar tables for the sediment data again showed the same featres with nearly all comptation done centrally. The tables for the ecological and hman activity data showed that most data were keyed in and entered into local cassette files and the central data base, bt most comptation was done locally or on programmable calclators. The se of this system reslted in an excellent data base, achieved economically. The anticipated benefits of rapidly available data and rapid presentation of simple analyses were not realised for three reasons. Firstly, at the conclsion of the year of data collection a bottleneck developed becase of the excessive amont of data entry simltaneosly with development and tilisation of the analysis programs. Compter specialists and hardware were both overloaded for several months and remained nder pressre for a considerable time. Secoridly, some members of the team possessed programming skills and chose to exercise them rather than await the development of programs by the hard-pressed compter specialist. This practical bt necessary decision reslted in some dplication of efforts and redced the ftre tility of the sets of programs developed, throgh se of different formats and less complete docmentation. Finally, the proper development of the analysis programs had to await the development of an nderstanding of the Hobsons Bay systems. For example, the spatial and temporal variability of crrents in Hobsons Bay was greater than anticipated, so that the droge movements with their bilt in averaging provided a better pictre of water movements than did the crrent metering. The nexpectedly large poplations of sbtidal epibiota also lead to changes in methods of analysis.

8 334 COASTAL ENGINEERING-198 TABLE 1 Use of-compter System for Water Qality Data id -H (Dm P id O -P id id «Q CD in 3,y tn o id H,* a n P -H ^ C!H H rh id (a W «r rd id P id o a ) > H ) < ni 4J +J a ra H Q."S < a) EH «p c CD n to M P 3 U U «X X X i 1 CM i 1 X 1 X i 1 CM i I M X X 1 X X EH «CM OS 1 X 1 1 X X X X 1 X 1 > 5 H ft M X X 1 X Breakwater Wind Me lb. Wind, Rain CD & EH CD *> Id Q M X X X 1 X EH P & * C H &, CM 1 X ) p P rh J cd ) CD HH Q Id -H I-H U PH id n id P < +> c H id -H O U Ix, -- CNJ 1 1 X G -H P id rh^ id ft o S S3 rh id M 3 ) d «O 6 id P -H id in 3 > U ft-rt ff G s -g o CD o e n O U H CL, M 1 > i- a> i E id 4-> id id 3 +) a, +J tn c e c o a> o CD ri CJ O O CM id to C H n (II C H P CD ell H P -H P O V4 3 (1) id P t", n >i xi 3 H H C p c.a >i o +J P H >i H >-i in & P C p a H H H o TS B r-h c H H CD 1 -rh +J 1 rh Ul rh i) 3 id id (li 1 (II n P s^ (1) ** ft to R * o ft (II ft id fci P ti c p (li Ill o id p P H a (II p m id 13 p In H in CD id H id H A! -P -P (II JJ O -H H fd SH i) (I r-t B TJ M ) id H 3 H U ^ U U w ft id +> 11) ft (1) id P ft P (II in C ro TI ft () ( III id id ( P o 3 fi <) a >1 <i) (I (1) +J P ) p H >i rl R fi n o () H ft rh 3 rh i-h a e () rh id Id H -rl () id TI ft e (i) -H n Tl TI n e p 1) 11) (1) ID III (1) rl C p >1 >1 ft +J R rl X (1) ) id c H th w w NS CM H l-l CM II II II II II II II En W

9 ENVIRONMENTAL STUDY 335 The appendix contains a description of one of the data entryprograms and illstrates the passage of data from inpt to analysis. 4. INTEGRATION OF DISCIPLINES 4.1 Prposes of Integration of Disciplines Direct collaboration between specialists in different disciplines is reqired for two principal reasons: firstly becase of the need to tilise information obtained by one discipline to explain and extend the reslts obtained within another. For example, biomass and poplations of the biota were fond to depend pon the physical and chemical variables of temperatre, salinity, trbidity, water velocity and location with respect to the river plme. Analysis and interpretation of these data reqired collaboration of sedimentologists, marine chemists, engineers and biologists. Secondly, nless all factors are favorable, the making of a recommendation on proposed works reqires that nlike qantities be compared or nlike measres be combined for example a loss of water sitable for swimming might be offset by an increase in waters available for fish nrsery areas. 4.2 Methods of Integration of Disciplines Integration of the different disciplines reqired that the individals perceive the benefits of close cooperation and that the facility for this cooperation be provided. As has been pointed ot by many others, it is necessary to pt effort into sch collaborative work for it to scceed. Even the gaining of working knowledge of the jargon of the other disciplines reqires effort, bt is an essential prereqisite to collaboration. In the planning of this environmental stdy, as with most others, the tasks were distribted according to the specialised backgronds of the different workers, so that one of the team was responsible for the ecological stdies, another for the sediment stdies, and so on. Sch a division of labor seems to be navoidable if high technical standards within each area of the stdy are to be achieved. The initial division then had to be overcome by conscios effort, by planning for the different parts of the stdy to interlock and by arranging for the offices of the different specialists to be in close proximity and for them to work together as mch as possible. Total integration was clearly not essential or even desirable. Determination of the hydrodynamic patterns reqired hor by hor measrements while determination of the typical poplations of barnacles at a site reqired seasonal measrements and even the actal days of measrement did not have to coincide for the one series to provide spport to the other. By not striving for needless synchronisation,

10 336 COASTAL ENGINEERING-198 better se was made of boats, instrments and spport personnel. The flows of information are illstrated in Figs. 3, 4 and 5. Each figre shows the flows from left to right of raw data, redced data and basic statistics, combined and correlated reslts of several types of data, clminating in the predicted change in a selected variable following constrction. The flows of all levels of data to the data base have not been shown for clarity. Similar figres cold be presented for other variables sch as trbidity, epibiota, bacteria, algae, etc. Both the correlated reslts, which describe the present regime of the bay, and the predictions are sefl otpts from the stdy as are the raw data and basic statistics which provide a baseline against which ftre states may be compared. 4.3 Reslts of Integration of Disciplines Despite an appreciation of the need for integration, the different specialist tasks diverged very early and some of the field measrements were carried ot with inadeqate regard to integration of the disciplines. However, at the stage of analysis and reporting of reslts, a high degree of integration was achieved, in large measre by the channelling of all data throgh the e.d.p. specialist and by one of the senior staff making some contribtion to the writing of all of the component parts of the report. The pressres of meeting deadlines within the specific tasks discoraged the other members of the team to become involved otside their own speciality except pon direct reqest. This is a very common experience with inter-grop cooperation, where the willingness of the varios individals is not a sfficient stimls in the face of the more clearly perceived pressres within their own specialist task, and since the collaboration between grops freqently depends on one or two individals it may break down completely nder sch stress. 5. CONCLUSIONS The interdependence of all parts of the stdy, at the level of interpretation and prediction has been shown. The water movement investigation and the water qality investigation proved so interdependent that they were completely merged early in the stdy. All parts of the stdy depended on the reslts of the water qality and water movement investigations with the latter playing the major role in the prediction of changes following constrction. In this stdy, the predicted changes in all variables were very small and so application of mlti-objective planning techniqes was not necessary. Integration was encoraged by joint planning, by working in close proximity, and by joint writing of each major section of the report.

11 ENVIRONMENTAL STUDY 337 Fig. Flows of information sed to analyse crrents and water temperatres

12 338 COASTAL ENGINEERING-198 Tl ) Cw ll) ) U >-H Ui a R «w n) w z -tl CD M r-l H a) o) > S m 3=3 «* fl! Q OJ P EH Bi W H a w O EH o o «CM ) o -rh C o o P W ) H +J O (1) 1 H!> 4J to a «U3 ) s H o CD S Fig. Flows of information sed to analyse beach dynamics

13 ENVIRONMENTAL STUDY 339 Fig. Flows of information sed to analyse benthic biota

14 34 COASTAL ENGINEERING-198 However, fll integration was not obtained becase of the need to meet deadlines and the need to tilise specialists in each area to ensre high technical standards The objective of a centralised compting service for the stdy was not wholly sccessfl bt was worthwhile by making available docmented programs and data files, with common formats. The sccess achieved was largely de to having a person skilled in both compting and the disciplines involved in the stdy. Periods of high demand lead to delays, and to individally written programs which met the stdy objectives bt are not of general se. 6. ACKNOWLEDGEMENT The stdy was fnded by the Port of Melborne Athority, whose staff were of great assistance. 7. APPENDIX: DATA ENTRY, EDITING AND STORAGE A site of programs for se on the Hewlett Packard Model 983 calclator was developed to facilitate data entry, error checking and transfer for the prposes of the stdy. Data collected dring the intensive field exercise were recorded on special field sheets. These were hand edited in the office to correct for calibration and instrment errors prior to entry on the compter. Data were entered from the edited field sheets, or from printed paper tapes prodced by the crrent meters, by specially trained operators, throgh the keyboard of the 983, were stored on cassettes and were later transferred to the Cyber compter. Once stored in the Cyber, the data files cold be corrected, data cold be transformed, files cold be joined or merged and listings or plots of data prepared. As an example the seqence of steps for the continosly recording crrent meters will be described. These instrments printed the speed and direction on a paper tape at pre-determined intervals, normally five or fifteen mintes. For data entry the tapes were monted in a specially constrcted transport, monted on the 983. The operator, after monting the tape and cassette, generated a header file on the cassette, specifying the maximm record length, nmber of data fields per record and the nmber of characters in each field. He then entered specifications of the parameters, comprising parameter name, measring nit, alphanmeric or nmeric, scalar or vector, precision, maximm and minimm expected vales, time or position seqence of data, coordinate location of data point and time index. The operator then commenced the actal entry of data entering a nmber for crrent speed and one for crrent direction. The following tests were atomatically performed and if any scceeded, an error condition was signalled:

15 ENVIRONMENTAL STUDY 341 Incorrect field length (nmber of characters). Illegal alpha characters. Nmber of decimal places does not correspond to specified precision. Decimal place omission. Presence of more than one decimal point. Presence of decimal point in integer field. Data ot of range specified. These errors had to be corrected by the operators before the data were stored on cassette. They cold arise de to discrepancy between the raw data and the vale entered or as a reslt of an anomalos vale appearing in the data field reslting from instrmental or recording errors. Other errors were sally detected sing basic statistical and time series fnctions, following data entry. The simplest check was to prepare a time series plot of the velocity magnitde and direction, or of the orthogonal components and to examine this plot for anomalos vales. Basic statistics were obtained at the same time and gave an indication if the natre of the record differed from previos records. The cassette prepared on the 983 was then batched with varios others to the Cyber as a raw data file. Errors detected throgh the time series plot and other means were then corrected sing the file editing capability of the Cyber. Missing data were indicated by an asterisk or a seqence of 9s, bt were not replaced. The raw data files ths prepared form part of the data base. Before the continosly recorded velocities cold be sed for analysis, files of 3 days of data had to be prepared. First the data were maniplated, to obtain vales at constant time intervals throghot the files to be combined. This step was necessary as the starting time of one file might not be at an integral nmber of time steps after the end of the previos file, the time steps might not be eqal in the two files, or the time step might be shorter than that needed for the analysis so that alternate data only might be reqired in the combined file. The two files were then combined, with the gap between them treated as any other missing data. If the seqences of missing data were short, they were filled by interpolation bt if long they were filled manally tilising the best estimates after considering all of the available data. The resltant 3 day files were then stored as part of the data base and were tilised in data analysis. Analyses performed sing the 3 day files of crrent data inclded the preparation of velocity scattergrams, analysis of tidal harmonics, correlation of velocity data with wind and with atmospheric pressre, and correlation with velocity data obtained at other sites. From these analyses the physical factors responsible for the crrents were ascertained, the likely velocities nder particlar sets of physical circmstances were predicted for periods of interest, and annal averages were estimated. In addition to time series plots and scattergrams, hodographs, cmlative vector plots and other pictorial representations were sed to display the information^on the velocity field. This work is presented by Dandy, Mills and Hinwood (198). Tapes from

16 342 COASTAL ENGINEERING-198 the instrments which were recorded in a compter compatible form were handled in the same fashion as 983 raw data cassettes. 8. REFERENCES DANDY, G.C., MILLS, D.A. and HINWOOD, J.B. (198), Water movement stdies reqired for port planning, 17 ICCE, Sydney, March 198. MILLS, D.A,, COLMAN, R.S. and DANDY, G.C. (1978), Water movement in a complex estarine embayment a methodology for data collection and analysis-, Proc. 4th Ast. Conf. on Coastal and Ocean Eng., Adelaide, Nov. 1978, Instittion of Engineers, Ast., Canberra.