any three questions need to be answered
ENV511-A2-2018(v3) Assignment 2: Problems 1 ENV511 Statistical Methods for Impact Analysis Assignment 2: Problems Due Date: midnight, Sunday, Week 10 Value: 20% of final mark Format: 5 problems, each worth 4% of final mark Instructions: Read these (reasonably) carefully! • Read the problems carefully and make sure that you understand them properly before you try to answer them. If you have any questions about any of the problems, then please contact me for clarification. • You do not need to follow any particular format when submitting your answers. Simply address each problem in the way you think best. In particular, note that you do not need to answer each, or any, of the problems with an essay. Write short notes or dot points, and include diagrams or tables, as you find easiest. (If you want to address a problem with an essay then you can do this also.) • None of the problems require calculations or statistical analyses. One of them does, however, require you to interpret the results of analyses (Problem 1). • None of the problems requires a particularly lengthy answer; a couple of pages should be sufficient for most problems. (But you can write a longer answer if you think a particular problem requires it.) Assignment 2: Problems 2 Problem 1. The analysis of variance table (Table 1) and graph (Figure 2) below report some of the results of an Environmental Monitoring Program established to examine the effect of creating an artificial reef offshore from a beach (the reef was created by sinking old boats). Part of the study involved monitoring the diversity of the fish (i.e. number of species) in a bed of seagrass near the reef (Reef) and in two beds at some distance from it (Control site 1 and 2). In this part of the study, numbers of species were recorded from three replicate quadrats in each of the beds at the six times shown in Figure 2. Note that new, randomly selected, quadrats were sampled at each of the six times. Three of the sampling times – 1, 2 and 3 – were before the reef was created and three – 4, 5 and 6 – were after. Figure 1 illustrates the layout of this study. Describe what the analysis (Table 1) indicates about the effects of the reef. Be sure to refer to the table (mention all the source rows except “Within”) and the graph (Figure 2) in your answer. Figure 1: Design of study. The diagram below illustrates the physical arrangement of the system and the samples. Note that new, randomly selected, quadrats were sampled each sampling time. The white, black and grey objects represent the sunken ships (old boats). Assignment 2: Problems 3 Figure 2: Numbers of species over time. Each point is the mean number of species counted in the three replicate quadrats sampled in each bed at each time. On this graph, Time 4 is Time 1 after the impact, Time 5 is Time 2 after the impact, and Time 6 is Time 3 after the impact. Further explanation of Table 1. The “Site” source of variation compares the three locations/sites sampled. The “Impact status” source of variation compares before to after the start of the impact (creation of reef). Finally, the “Time” source of variation compares times 1, 2 and 3 (before and after). The terms with “×” are interactions between the factors (or “main effects”): see the study materials for information on how to interpret these. Source df MS F-ratio p-value Impact status [Before; After] 1 75.85 0.73 0.482 Time†(impact status) [1–3; 4–6] 4 44.57 1.17 0.392 Site [Reef; C1; C2] 2 289.13 169.71 0.000 * Site × Impact status 2 103.46 60.73 0.000 * Site × Time(impact status) 8 38.05 22.33 0.000 * Within 36 1.7 Table 1: Analysis of variance table. The df, MS and F-ratio for testing the significance of each factor are given, along with the p-value. Significant factors and interactions—where the p-level < 0.05—are labelled with an asterisk (*). † note that the source (factor) “time” is nested in the “impact status” factor and refers to the first, second or third sampling time before or after the impact. there are only three times listed because there were only three times sampled in each period (before and after). time 654321 35 30 25 20 15 n um be r of sp ec ie s c1 c2 reef site bars are one standard error from the mean plot of number of species re ef s cr ea te d assignment 2: problems 4 problem 2. read the following description of an environmental monitoring study carefully then answer the three questions (a to c) on the next page. a mine is due to release effluent into two streams in the wet-dry tropics (where there are very distinct wet and dry seasons, with little to no rain falling during the dry). a monitoring program will commence two years before the first release and continue for two years afterwards (it may continue after that but this question considers just those four years). monitoring will be done on the two impact streams and on two similar streams which will not receive effluent. one element of the program will involve using small nets to catch macro- invertebrates (water bugs) at selected sites on each creek. one site will be upstream, and the other downstream, of the spot where the effluent will be released (see diagram). each sampling time, 5 samples will be taken at each of the sites and the number of species of macro-invertebrates will be recorded (this will be done later in the lab). sampling is done three times during the wet season, at monthly intervals, each year. the sampling schedule is summarised in table 2 (on the next page). figure 3: design of study. the diagram below illustrates the physical arrangement of the system and the samples. the two creeks in the centre will receive effluent after two years. the red dotted circles indicate the sampling sites: 5 samples will be taken at each site on each sampling occasion. effluent flows downstream from the release point below the mine. assignment 2: problems 5 questions: a) list the factors in the design and give the number of levels in each factor. b) state, with reasons, which factors are fixed and which are random. c) state, with reasons, which factors (if any) are nested in other factors. year 13–14 2014 14–15 2015 sep 15 15–16 2016 16–17 2017 season wet dry wet dry start wet dry wet dry impact 1 15 0 15 0 n/a 15 0 15 0 impact 2 15 0 15 0 n/a 15 0 15 0 control 1 15 0 15 0 n/a 15 0 15 0 control 2 15 0 15 0 n/a 15 0 15 0 table 2: sampling schedule. this table illustrates the planned sampling program. in this table, “15” means that 15 samples will be collected at that time in that year in that area. the number of samples is 15 because 5 samples are every two months in the wet season. (“n/a” means “not applicable”: this column—sep 15—is included just to indicate when the release of effluent will start.) assignment 2: problems 6 problem 3. three different environmental studies are briefly described below. for each, indicate the type of study done (study guide: figure 1.4), the kind of impact which was studied (study guide: figure 1.5) and the aspect(s) of the system which were monitored (study guide: figure 1.6). a) in 2003, work started on building an lng plant at wickham point in darwin harbour. for the plant to proceed, some parts of the sea floor in darwin harbour, near wickham point, had to be dredged to be deeper. one effect of this is the disturbance of the mud and a consequent increase in turbidity. one part of the environmental monitoring program was done by surveying coral in the harbour for bleaching events: events where the functioning of the coral’s symbiotic algae is disrupted, due, in this case, to decreased light levels. the corals were surveyed: the critical information recorded was the percentage of the coral in an area showing bleaching. this information was collected while dredging was occurring. (once a certain level of bleaching occurs, dredging must stop.) b) a fish farm is releasing effluent with high levels of nutrients into streams feeding into mangrove forests. monitoring started some years before the first release and continues so long as the farm is operating. several things are measured and recorded on a number of plots in the forest: (i) the growth of mangrove seedlings, in height (cm); (ii) the number of mangrove seedlings (in the plot); and (iii) the percentage cover of algae (in the plot). c) inpex, as part of its ichthys project, is building a lng processing plant at bladydin point in darwin harbour. inpex is required to do regular monitoring during the construction phase to check for environmental impacts. one of these monitoring programs involves measuring the number, survival and growth of mangrove seedlings in permanent study plots at various locations around the harbour. http://en.wikipedia.org/wiki/coral_bleaching http://www.inpex.com.au/projects/ichthys-project.aspx assignment 2: problems 7 problem 4. in a quest to lower petrol prices in darwin, the nt government proposes to subsidise the building of an oil refinery on channel island in darwin harbour. the so-clean oil & petroleum company has put in a bid for this project. under their plan, ships would anchor near the island and the oil would be pumped along a short submarine pipeline to the refinery. products would be exported by truck along the road. the construction of the refinery would, obviously, initially cause some disturbance to the terrestrial environment on the island. the only effect on the nearby marine ecosystems (much of the island is fringed by mangroves and there are extensive coral reefs between the island and the mainland) during the construction phase, which is planned for the dry season, would be from some sediment laden run-off. once the refinery is operating, ships will be entering the harbour and anchoring near the island to offload oil, then leaving. tanker trucks will travel to and fro along the road to the island collecting and distributing products. the access road already exists but would need to be upgraded for heavier vehicles and more frequent traffic. describe and discuss the following: a) the specific issues which should be considered in an environmental impact statement (the eis is the key document in the review process to decide whether the project proceeds). refer to figure 1.1 in the study guide for an outline of issues. b) the environmental monitoring programs which should be set up to monitor the operation of the refinery once it is operating normally. in your answer, consider both the marine and terrestrial ecosystems. figure 3: map of darwin harbour showing location of channel island and other relevant features. the location of significant 0.05—are="" labelled="" with="" an="" asterisk="" (*).="" †="" note="" that="" the="" source="" (factor)="" “time”="" is="" nested="" in="" the="" “impact="" status”="" factor="" and="" refers="" to="" the="" first,="" second="" or="" third="" sampling="" time="" before="" or="" after="" the="" impact.="" there="" are="" only="" three="" times="" listed="" because="" there="" were="" only="" three="" times="" sampled="" in="" each="" period="" (before="" and="" after).="" time="" 654321="" 35="" 30="" 25="" 20="" 15="" n="" um="" be="" r="" of="" sp="" ec="" ie="" s="" c1="" c2="" reef="" site="" bars="" are="" one="" standard="" error="" from="" the="" mean="" plot="" of="" number="" of="" species="" re="" ef="" s="" cr="" ea="" te="" d="" assignment="" 2:="" problems="" 4="" problem="" 2.="" read="" the="" following="" description="" of="" an="" environmental="" monitoring="" study="" carefully="" then="" answer="" the="" three="" questions="" (a="" to="" c)="" on="" the="" next="" page.="" a="" mine="" is="" due="" to="" release="" effluent="" into="" two="" streams="" in="" the="" wet-dry="" tropics="" (where="" there="" are="" very="" distinct="" wet="" and="" dry="" seasons,="" with="" little="" to="" no="" rain="" falling="" during="" the="" dry).="" a="" monitoring="" program="" will="" commence="" two="" years="" before="" the="" first="" release="" and="" continue="" for="" two="" years="" afterwards="" (it="" may="" continue="" after="" that="" but="" this="" question="" considers="" just="" those="" four="" years).="" monitoring="" will="" be="" done="" on="" the="" two="" impact="" streams="" and="" on="" two="" similar="" streams="" which="" will="" not="" receive="" effluent.="" one="" element="" of="" the="" program="" will="" involve="" using="" small="" nets="" to="" catch="" macro-="" invertebrates="" (water="" bugs)="" at="" selected="" sites="" on="" each="" creek.="" one="" site="" will="" be="" upstream,="" and="" the="" other="" downstream,="" of="" the="" spot="" where="" the="" effluent="" will="" be="" released="" (see="" diagram).="" each="" sampling="" time,="" 5="" samples="" will="" be="" taken="" at="" each="" of="" the="" sites="" and="" the="" number="" of="" species="" of="" macro-invertebrates="" will="" be="" recorded="" (this="" will="" be="" done="" later="" in="" the="" lab).="" sampling="" is="" done="" three="" times="" during="" the="" wet="" season,="" at="" monthly="" intervals,="" each="" year.="" the="" sampling="" schedule="" is="" summarised="" in="" table="" 2="" (on="" the="" next="" page).="" figure="" 3:="" design="" of="" study.="" the="" diagram="" below="" illustrates="" the="" physical="" arrangement="" of="" the="" system="" and="" the="" samples.="" the="" two="" creeks="" in="" the="" centre="" will="" receive="" effluent="" after="" two="" years.="" the="" red="" dotted="" circles="" indicate="" the="" sampling="" sites:="" 5="" samples="" will="" be="" taken="" at="" each="" site="" on="" each="" sampling="" occasion.="" effluent="" flows="" downstream="" from="" the="" release="" point="" below="" the="" mine.="" assignment="" 2:="" problems="" 5="" questions:="" a)="" list="" the="" factors="" in="" the="" design="" and="" give="" the="" number="" of="" levels="" in="" each="" factor.="" b)="" state,="" with="" reasons,="" which="" factors="" are="" fixed="" and="" which="" are="" random.="" c)="" state,="" with="" reasons,="" which="" factors="" (if="" any)="" are="" nested="" in="" other="" factors.="" year="" 13–14="" 2014="" 14–15="" 2015="" sep="" 15="" 15–16="" 2016="" 16–17="" 2017="" season="" wet="" dry="" wet="" dry="" start="" wet="" dry="" wet="" dry="" impact="" 1="" 15="" 0="" 15="" 0="" n/a="" 15="" 0="" 15="" 0="" impact="" 2="" 15="" 0="" 15="" 0="" n/a="" 15="" 0="" 15="" 0="" control="" 1="" 15="" 0="" 15="" 0="" n/a="" 15="" 0="" 15="" 0="" control="" 2="" 15="" 0="" 15="" 0="" n/a="" 15="" 0="" 15="" 0="" table="" 2:="" sampling="" schedule.="" this="" table="" illustrates="" the="" planned="" sampling="" program.="" in="" this="" table,="" “15”="" means="" that="" 15="" samples="" will="" be="" collected="" at="" that="" time="" in="" that="" year="" in="" that="" area.="" the="" number="" of="" samples="" is="" 15="" because="" 5="" samples="" are="" every="" two="" months="" in="" the="" wet="" season.="" (“n/a”="" means="" “not="" applicable”:="" this="" column—sep="" 15—is="" included="" just="" to="" indicate="" when="" the="" release="" of="" effluent="" will="" start.)="" assignment="" 2:="" problems="" 6="" problem="" 3.="" three="" different="" environmental="" studies="" are="" briefly="" described="" below.="" for="" each,="" indicate="" the="" type="" of="" study="" done="" (study="" guide:="" figure="" 1.4),="" the="" kind="" of="" impact="" which="" was="" studied="" (study="" guide:="" figure="" 1.5)="" and="" the="" aspect(s)="" of="" the="" system="" which="" were="" monitored="" (study="" guide:="" figure="" 1.6).="" a)="" in="" 2003,="" work="" started="" on="" building="" an="" lng="" plant="" at="" wickham="" point="" in="" darwin="" harbour.="" for="" the="" plant="" to="" proceed,="" some="" parts="" of="" the="" sea="" floor="" in="" darwin="" harbour,="" near="" wickham="" point,="" had="" to="" be="" dredged="" to="" be="" deeper.="" one="" effect="" of="" this="" is="" the="" disturbance="" of="" the="" mud="" and="" a="" consequent="" increase="" in="" turbidity.="" one="" part="" of="" the="" environmental="" monitoring="" program="" was="" done="" by="" surveying="" coral="" in="" the="" harbour="" for="" bleaching="" events:="" events="" where="" the="" functioning="" of="" the="" coral’s="" symbiotic="" algae="" is="" disrupted,="" due,="" in="" this="" case,="" to="" decreased="" light="" levels.="" the="" corals="" were="" surveyed:="" the="" critical="" information="" recorded="" was="" the="" percentage="" of="" the="" coral="" in="" an="" area="" showing="" bleaching.="" this="" information="" was="" collected="" while="" dredging="" was="" occurring.="" (once="" a="" certain="" level="" of="" bleaching="" occurs,="" dredging="" must="" stop.)="" b)="" a="" fish="" farm="" is="" releasing="" effluent="" with="" high="" levels="" of="" nutrients="" into="" streams="" feeding="" into="" mangrove="" forests.="" monitoring="" started="" some="" years="" before="" the="" first="" release="" and="" continues="" so="" long="" as="" the="" farm="" is="" operating.="" several="" things="" are="" measured="" and="" recorded="" on="" a="" number="" of="" plots="" in="" the="" forest:="" (i)="" the="" growth="" of="" mangrove="" seedlings,="" in="" height="" (cm);="" (ii)="" the="" number="" of="" mangrove="" seedlings="" (in="" the="" plot);="" and="" (iii)="" the="" percentage="" cover="" of="" algae="" (in="" the="" plot).="" c)="" inpex,="" as="" part="" of="" its="" ichthys="" project,="" is="" building="" a="" lng="" processing="" plant="" at="" bladydin="" point="" in="" darwin="" harbour.="" inpex="" is="" required="" to="" do="" regular="" monitoring="" during="" the="" construction="" phase="" to="" check="" for="" environmental="" impacts.="" one="" of="" these="" monitoring="" programs="" involves="" measuring="" the="" number,="" survival="" and="" growth="" of="" mangrove="" seedlings="" in="" permanent="" study="" plots="" at="" various="" locations="" around="" the="" harbour.="" http://en.wikipedia.org/wiki/coral_bleaching="" http://www.inpex.com.au/projects/ichthys-project.aspx="" assignment="" 2:="" problems="" 7="" problem="" 4.="" in="" a="" quest="" to="" lower="" petrol="" prices="" in="" darwin,="" the="" nt="" government="" proposes="" to="" subsidise="" the="" building="" of="" an="" oil="" refinery="" on="" channel="" island="" in="" darwin="" harbour.="" the="" so-clean="" oil="" &="" petroleum="" company="" has="" put="" in="" a="" bid="" for="" this="" project.="" under="" their="" plan,="" ships="" would="" anchor="" near="" the="" island="" and="" the="" oil="" would="" be="" pumped="" along="" a="" short="" submarine="" pipeline="" to="" the="" refinery.="" products="" would="" be="" exported="" by="" truck="" along="" the="" road.="" the="" construction="" of="" the="" refinery="" would,="" obviously,="" initially="" cause="" some="" disturbance="" to="" the="" terrestrial="" environment="" on="" the="" island.="" the="" only="" effect="" on="" the="" nearby="" marine="" ecosystems="" (much="" of="" the="" island="" is="" fringed="" by="" mangroves="" and="" there="" are="" extensive="" coral="" reefs="" between="" the="" island="" and="" the="" mainland)="" during="" the="" construction="" phase,="" which="" is="" planned="" for="" the="" dry="" season,="" would="" be="" from="" some="" sediment="" laden="" run-off.="" once="" the="" refinery="" is="" operating,="" ships="" will="" be="" entering="" the="" harbour="" and="" anchoring="" near="" the="" island="" to="" offload="" oil,="" then="" leaving.="" tanker="" trucks="" will="" travel="" to="" and="" fro="" along="" the="" road="" to="" the="" island="" collecting="" and="" distributing="" products.="" the="" access="" road="" already="" exists="" but="" would="" need="" to="" be="" upgraded="" for="" heavier="" vehicles="" and="" more="" frequent="" traffic.="" describe="" and="" discuss="" the="" following:="" a)="" the="" specific="" issues="" which="" should="" be="" considered="" in="" an="" environmental="" impact="" statement="" (the="" eis="" is="" the="" key="" document="" in="" the="" review="" process="" to="" decide="" whether="" the="" project="" proceeds).="" refer="" to="" figure="" 1.1="" in="" the="" study="" guide="" for="" an="" outline="" of="" issues.="" b)="" the="" environmental="" monitoring="" programs="" which="" should="" be="" set="" up="" to="" monitor="" the="" operation="" of="" the="" refinery="" once="" it="" is="" operating="" normally.="" in="" your="" answer,="" consider="" both="" the="" marine="" and="" terrestrial="" ecosystems.="" figure="" 3:="" map="" of="" darwin="" harbour="" showing="" location="" of="" channel="" island="" and="" other="" relevant="" features.="" the="" location="" of="">