MarineInvestigationDraftReport

1、hydrographic survey, historical data collection and analysis data for the design of intake and outfall system at independent water and power plant in mirbat, sultanate of omandraft reportfebruary 2010alsafa environmental & technical services llcp.o. box: 3013cpo seebpostal code: 111sultanate of

2、omantel: (00968) 24499809fax: (00968) 24494750e-mail: .omweb site: alsafa environmental & technical services llchydrographic survey reportiifebruary 2010hydrographic survey, historical data collection and analysis data for the design of intake and outfall system at independent water and power pl

3、ant in mirbat, sultanate of omanproposal no: safa/100-2009 february 2010revisions:itemnamedatefield study and report prepared by:dr. sanak. senathipathi saravanan kalimuthurashid al barwani 13th february, 2010checked and approved by:masood ahmed15th february, 2010revision no.-document ref:safa/100-2

4、009copyright:this document has been prepared by alsafa environmental & technical services (alsafa ets) for the above titled project. alsafa ets accepts no responsibility or liability for this document to any party other than the client for whom it was commissioned.this document should not be rel

5、ied upon or used for any other project without the prior written authority of alsafa ets.alsafa environmental & technical services llchydrographic survey reportiiifebruary 2010table of contents1introduction .1-11.1background.1-12location and surrounding activities.2-12.1nearest tide station.2-12

6、.2navigational channel details.2-22.3hydraulic structure and harbour details.2-22.4sea water pollution.2-23methodology.3-43.1measurement of tidal elevations .3-43.2measurement of water quality .3-43.3measurement of waves and currents.3-53.4measurement of sediment concentration.3-54measurement result

7、s.4-74.1tidal elevations.4-74.2water quality measurements.4-14.2.1variation of seawater temperature.4-14.2.2variation of seawater salinity.4-34.2.3variation of sediment concentration.4-14.3measured waves and current .4-14.4wind speed and direction.4-64.5stability of coastal sediment .4-74.5.1stabili

8、ty of coastal sediment.4-74.6marine ecology.4-94.6.1overview.4-94.6.2coastal ecosystems.4-104.6.3habitats.4-134.6.4beach region.4-134.6.5intertidal zone.4-154.6.6subtidal zone- intake station.4-164.6.7outfall station.4-184.6.8control station.4-194.6.9plankton.4-204.6.10benthic infauna .4-224.6.11ben

9、thic infaunal biomass.4-234.6.12benthic infaunal density.4-244.6.13sediments infaunal relative abundance.4-254.6.14phytoplankton.4-264.6.15primary production (chlorophyll- a) .4-28alsafa environmental & technical services llchydrographic survey reportivfebruary 20104.6.16conservation status of t

10、he project site.4-294.6.17conclusion.4-305historical oceanographic data.5-15.1seawater temperature data (three hottest month).5-15.2seawater temperature over the years.5-25.3tide.5-35.3.1general tidal characteristics.5-35.3.2historical tide data .5-45.3.3historical waves and current data.5-75.4histo

11、rical storm surge and tsunami.5-85.4.1storm surge.5-85.4.2tsunami.5-13 list of figurefigure 2-1: iwpp salalah project site.2-1figure 2-2: tide gage station and distance.2-2figure 2-3: sea weeds at intake area.2-3figure 3-1 control panel for pressure sensor.3-4figure 3-2 pressure sensor.3-4figure 3-3

12、 idronaut-316 ctd probe for water quality measurements.3-5figure 3-4 adcp deployed at the project site.3-6figure 4-1 measured and predicted tidal elevations for taqa project site.4-7figure 4-2 measured and predicted tidal elevations for four days.4-8figure 4-3: variation of temperature in the water

13、column (spring tide).4-1figure 4-4: variation of temperature in the water column (mixed tide).4-2figure 4-5: variation of temperature in the water column (neap tide).4-2figure 4-6: variation of salinity in the water column (spring tide).4-3figure 4-7: variation of salinity in the water column (mixed

14、 tide) .4-4figure 4-8: variation of salinity in the water column (neap tide).4-4figure 4-9 measured wave height at taqa project site.4-1figure 4-10 measured peak wave period at taqa project site.4-2figure 4-11 peak wave period verus maximum wave height.4-3figure 4-12 mean wave direction at taqa proj

15、ect site.4-3figure 4-13 rose diagram for maximum wave height at taqa project site.4-4figure 4-14 current magnitude at 1.6m above seabed.4-5figure 4-15 current direction at 1.6m above seabed.4-5figure 4-16 rose diagram for mean current at taqa project site.4-6figure 4-17: wind rose during 18th to 24t

16、hh december 2009 .4-7figure 4-18 particle size distribution of the seabed sample at taqa site.4-8figure 4-19 sediment stability parameter of coastal sediments at taqa project site.4-9figure 4-20: map of dhofar coast.4-10figure 4-21: habitat map and marine survey locations.4-12figure 4-22: vegetated

17、dune cordon.4-13figure 4-23: benthic infaunal biomass (g /m-2) .4-24figure 4-24: benthic infaunal density (individuals /m-2) .4-24figure 4-25: biodiversity indices of the identified taxa.4-25figure 4-26: relative abundance of phytoplankton group.4-28figure 4-26: coral distribution in oman.4-29figure

18、 5-1: seawater temperature variation of three hottest months in 1988.5-1figure 5-2: seawater temperature variation of three hottest months in 1995.5-1figure 5-3: variation of seawater temperature over the years.5-2alsafa environmental & technical services llchydrographic survey reportvfebruary 2

19、010figure 5-4: typical tidal elevation for port salalah.5-4figure 5-5: cumulative frequency of tidal elevations from 1990-2009 data.5-5figure 5-6: tide level variation during tsunami.5-13list of tables table 4-1: survey location.4-11table 4-2: zooplankton composition and density of occurrence.4-21ta

20、ble 4-3: list of infaunal species at the proposed site.4-23table 4-4: phytoplankton sampling location.4-27table 4-5: phytoplankton composition and density at intake and outfall location.4-27table 4-6: abundance (%) of phytoplankton group at intake and outfall location.4-28table 4-7: numbers of threa

21、tened species (sea turtles).4-30table 5-1: seawater temperature data over the years.5-2table 5-2: harmonic constants for tide at salalah.5-3table 5-3: main tidal elevations for port salalah.5-5table 5-4: tidal elevations based on cumulative frequency.5-6table 5-5: monthly average, maximum and minimu

22、m tidal elevations.5-6table 5-6: maximum wave height record for port salalah (all the wave heights are in meters).5-7table 5-7: maximum wave height versus return period.5-8table 5-8: 26th december 2004 tsunami in salalah.5-13table 5-9: summaries of tsunamis related to arabian peninsula.5-14 list of

23、platesplate 4-1: ghost crabs ocypode sp.4-14plate 4-2: reproductive mounts of ocypode sp.4-14plate 4-3: turtle nesting track.4-14plate 4-4: loggerhead turtle.4-14plate 4-5: plastic materials.4-14plate 4-6: abandoned fishing traps.4-14plate 4-7: hermit crab.4-15plate 4-8: ghost crabs.4-15plate 4-9: r

24、ocky intertidal region.4-15plate 4-10: rock oyster (saccostrea sp.) and green algae.4-15plate 4-11: sea urchin.4-16plate 4-12: wrasse fish thalassoma sp.4-16plate 4-13: scarus sp.4-16plate 4-14: cheilodipterus sp.4-16plate 4-15: pterois sp.4-17plate 4-16: moray eel.4-17plate 4-17: sponges ( porifera

25、) .4-17plate 4-18: school of fishes.4-17plate 4-19: sponges.4-17plate 4-20: hard coral favia sp.4-17plate 4-21: typical sandy bottom at the outfall.4-18plate 4-22: red algae and green algae.4-19plate 4-23: school of fishes.4-19plate 4-24: sponges.4-19plate 4-25: epaulet grouper epinephelus stoliczka

26、e.4-19plate 4-26: indo-pacific sergeant abudefduf vaigiensis.4-20plate 4-27: longfin bannerfish heniochus acuminatus.4-20plate 4-28: wrasse fish thalassoma sp.4-20plate 4-29: porcupine fish diodon hystrix.4-20plate 4-30: standard zooplankton net.4-21alsafa environmental & technical services llch

27、ydrographic survey report1-1february 20101introduction1.1backgroundalsafa environment and technical services llc, oman, was contracted by sepco-iii, to carryout historical oceanographic data analysis and oceanographic measurement services in connection with the independent water and power plant (iwp

28、p), taqah, oman.in order to execute the assignment, alsafa ets mobilized their team to salalah on 17th december 2009 to undertake the following oceanographic survey. tidal measurement (30 days); wave and current measurement (7 days);salinity, temperature and sediment concentration measurement in dif

29、ferent layers (28 hrs for spring, mixed and neap tide level);wind speed and direction measurement (7 days); marine ecological survey;monitoring of floating particles; and coastal stability analysis. further the team has collected the following historical data from relevant public authorities and the

30、 analysis was carried out using ms-excel and matlab software. tide data for 20 years; wave and current data;seawater temperature data;historical storm surge and tsunami data;this document details the methods employed by alsafa and the results obtained for this study. alsafa environmental & techn

31、ical services llchydrographic survey report2-1february 20102location and surrounding activitiesthe iwpp project site is located in between taqah and mirbat, 42 km east of salalah close to scout camp on the coastal shoreline cliff. the site bounded by arabian sea to the south, scout camp to west, a n

32、arrow wadi (stream) to the north and east. the project location is presented in figure 2-1. figure 2-1: iwpp salalah project site 2.1nearest tide stationdescriptiondatanearest tide gauge stationsalalah geographic locationlattitute=16 56.1 n; longitute=054 00.4 edistance53 kmstide data availability19

33、89 to 2009nearest water intake or drainage sitethere were no intake sites or drainage near to proposed intake and outfall areaalsafa environmental & technical services llchydrographic survey report2-2february 2010figure 2-2: tide gage station and distance2.2navigational channel detailsthe propos

34、ed intake and outfall is not located in the navigational channel. the navigational channel located for away from intake point approximately 10 kms.2.3hydraulic structure and harbour detailsthere is no hydraulic structure around the intake and outfall area. there is no other program nearby the power

35、plant. in future, the phase ii of iwpp might be established adjacent to this power plant.there is no harbor near to the power plant. salalah port is located 53 km away from the project site. 2.4sea water pollution alsafa ets team has monitored the intake site from 18th december 2009 to 24th december

36、 2009 to assess the seawater pollution. since there is no source of seawater pollution in the area, we have not found floating particles during the monitoring period. however, we observed some small batches (maximum size 1m*0.5 m) of sea weeds in some occasion (especially morning time) at intake poi

37、nt as presented in below figure. 53 kmsproject sitealsafa environmental & technical services llchydrographic survey report3-3february 2010further, alsafa ets team found fishing activities at approximately 3 km east of intake site. some small floating plastic cans (capacity 2- 10l) found in that

38、area to indicate the fishing net.figure 2-3: sea weeds at intake areaalsafa environmental & technical services llchydrographic survey report3-4february 20103methodology 3.1measurement of tidal elevationsthe tidal elevations were measured using a pressure sensor (model kadec21-mizu) by north-one

39、co. japan (http:/www.north- the control panel and the pressure sensor are shown in figure 3-1 and figure 3-2, respectively. the data was stored at an interval of 5 minutes for a period of approximately one month. the data was downloaded and the analysis was done using ms-excel. figure 3-1 control pa

40、nel for pressure sensorfigure 3-2 pressure sensor3.2measurement of water qualityin the present project ctd was used for in-situ measurements of conductivity, temperature and dissolved oxygen. ctd stands for (measurement of) conductivity, temperature and depth. it measures the conductivity and temper

41、ature of the seawater column relative to depth. conductivity and temperature information is valuable because the salinity (the concentration of salt) of the seawater can be derived from these two variables. this is because electric current passes much more easily through water with a higher salt con

42、tent. so if we know the conductivity of the water, we know how much salt is in the water. density of water is calculated from in situ measurements of conductivity, temperature and pressure.in the present case idronaut ctd, model 316 (figure 3-3) used. in the beginning, the instrument is accessed thr

43、ough a computer to setup the measurement mode. here it was set to measure conductivity, temperature and do at 0.5m interval. since ctd has a pressure sensor, when it is lowered in water it measures the pressure, calculates the depth and at every 0.5m depth change, takes the readings. these readings

44、are stored in the instrument while it is alsafa environmental & technical services llchydrographic survey report3-5february 2010lowered (down cast) in water by a rope to the maximum depth and then brought back (up cast) to the surface. the instrument is instructed to measure only when it is lowe

45、red and not when it is brought back. later the data was uploaded from the instrument using idronaut-316 software and analyzed using ms-excel.figure 3-3 idronaut-316 ctd probe for water quality measurements3.3measurement of waves and currentsin the present project the acoustic doppler current profile

46、r (adcp) from nortek which is named as aquadopp profiler is used. it is designed for stationary applications and can be deployed on the bottom, on a mooring rig, on a buoy or on any other fixed structure. it is a complete instrument and includes all the parts required for a self contained deployment

47、 with data stored to an internal data logger. the aquadopp profiler uses three acoustic beams slanted at 25 to accurately measure the current profile in a user selectable number of cells. the internal tilt and compass sensors tell the current direction and the high-resolution pressure sensor gives t

48、he depthand the tidal elevation if the system is fixed mounted. the cell depth was set to be 1m, therefore the current is measured at every 1m of the water column. the instrument was deployed at the location specified by the client. here water depth was approximately 10m. figure 3-4 shows an underwa

49、ter picture of the adcp facing upwards.3.4measurement of sediment concentrationseawater samples were collected in the vertical column of the sea at 0.5m below the sea surface, 0.5h and 0.5m above the seabed by using integrated depth sampler. the samples were analysed at onsite using hand held digita

50、l analyzer. alsafa environmental & technical services llchydrographic survey report4-6february 2010figure 3-4 adcp deployed at the project sitethe collected data was screened offline and the values pertaining to low signal to noise ratio were removed. no other processing like smoothing or averag

51、ing was done.alsafa environmental & technical services llchydrographic survey report4-7february 20104measurement results4.1tidal elevationsthe tidal elevation data was collected for a period of approximately one month. the measured data along-with predicted tidal elevations using admiralty tidal

52、 charts are plotted in figure 4-1. the predicted data shows very good agreement with the measured tidal elevations, which means for the project site, predicted tidal elevations can be used for any specified time. some fluctuations especially at peak levels are observed, which are due to the waves su

53、perimposed on the tidal elevations. in order to further investigate the fluctuations in tidal elevations, the measured and predicted values are plotted for a shorter duration of four days close to spring tide in figure 4-2. it can be noted that the agreement between the measured and predicted data i

54、s excellent. the typical characteristic of the tide at salalah, showing two highs and one low, is very well described by the prediction. the average duration of tidal rise is found to be 8.5 hours whereas average duration of tidal fall is 8 hours. figure 4-1 measured and predicted tidal elevations f

55、or taqa project sitealsafa environmental & technical services llchydrographic survey report4-8february 2010figure 4-2 measured and predicted tidal elevations for four daysalsafa environmental & technical services llchydrographic survey report4-1february 20104.2water quality measurementsthe w

56、ater quality parameters like temperature and salinity were measured using a conductivity-temperature-depth (ctd) probe from a locally chartered fishing boat. the sediment concentration was measured at the onsite using potable total suspended particulate matter analyzer. the sediment samples were col

57、lected at three different depth integrating sampler. 4.2.1variation of seawater temperaturethe variation of seawater temperature for the spring, mixed and neap tides are provided in figure 4-3,figure 4-4 and figure 4-5. the detailed measurement data are provided in the attachment-2.figure 4-3: varia

58、tion of temperature in the water column (spring tide)alsafa environmental & technical services llchydrographic survey report4-2february 2010figure 4-4: variation of temperature in the water column (mixed tide)figure 4-5: variation of temperature in the water column (neap tide)alsafa environmenta

59、l & technical services llchydrographic survey report4-3february 20104.2.2variation of seawater salinitythe variation of seawater salinity for the spring, mixed and neap tides are provided in figure 4-6, figure 4-7 and figure 4-8. the detailed measurement data are provided in the attachment-2.fig

60、ure 4-6: variation of salinity in the water column (spring tide)alsafa environmental & technical services llchydrographic survey report4-4february 2010figure 4-7: variation of salinity in the water column (mixed tide)figure 4-8: variation of salinity in the water column (neap tide)alsafa environmental & technical services llchydrographic survey report4-1february 20104.2