HYDROGRAPHIC SURVEY DETAIL-SANDAKAN

16.1 INTRODUCTION

This chapter briefly describes the hydrographic details of the Sandakan Coast both the present status as well as data available and some of the major issues of concern if any. The hydrographic details of each of the following are briefly discussed:

1. Islands.
2. Rocks and Sand Bars.
3. Reefs.
4. Sea Bottom.
5. Depths.
6. Tides and Current.
7. Siltation.
8. Hydrographic survey

16.2 PRESENT STATUS

16.2.1 ISLANDS

Presently, there are 8 major islands in the area of Sandakan as listed below. There is not much development on the coast of these islands at the moment except for residential and tourist purposes. Updating the coastline is in progress using aerial video mapping technique by the Department of Hydrography, RMN.

Major islands in the Sandakan area are:

Pulau Silingan.
Pulau Libaran.
Pulau Nunuyon Laut.
Pulau Nunuyon Darat.
Pulau Berhala.
Pulau Duyong.
Pulau Bai.
Pulau Timbang.

16.2.2 ROCKS AND SAND BARS

It has been known that submerged rocks are present in the south and southwest of Pulau Bai, north of Tanjung Siagil, south of Pulau Timbang and the coast between Pulau Tikus and Sungai Gum-Gum. These submerged rocks, because of their submerged nature poses dangers to vessels that navigate in the area.

Apart from submerged rocks, there are also two prominent sand bars in the area (1958 survey) which lies on the northern side of Sungai Kinabatangan and Trusan Duyong. The shape and orientation of these sand bars (and/or others) are subject to change (over time) due to changes of underwater currents as well as effect from the nearby river. Hydrographic survey is being carried out to update the data.

16.2.3 REEFS

In Sandakan area, coral reefs extend from the coast of Tanjung Gisow in easterly direction up to Pulau Nunuyon Darat, and the vicinity of Pulau Silungan, Pulau Gulisan, Pulau Libaran, Pulau Bangkawan, Pulau Tikus, Pulau Nunuyon Laut, Pulau Berhala and Pulau Bai.

Presently, it is very hard to predict the present status of the coral reefs in this area as no available data on the growth rates, conditions and the abundance of the coral reefs. No marine habitat survey has been done specific to this area by the Navy. Nevertheless, hydrographic survey is being carried out at present for the purpose of comparison and updating the data from the 1958 survey that was conducted for charting purposes.


16.2.4 SEA BOTTOM

The main components of sea bottom texture in the area are mud, sand, coral, rock and their mixture. Sea bottom also consists of other marine habitats such as seaweeds, seagrasses and other benthic organisms. No study or survey has been carried out to determine the condition and status of the sea bottom habitats.

16.2.5 DEPTHS

The depth pattern of the marine waters in the area varies considerably. At the western side, shallow patches cover a wide area of the waters with depth below 18 feet. At the northern side however, although the depth of the water measures a maximum depth of more than 84 feet, the navigable waters is constrained by islands and coral reefs with maximum depth of only 24 feet. At the eastern side, deeper water is found that are navigable by bigger vessel. At the Sandakan Harbour approach, the channel narrows down and is also restricted by Pulau Berhala and Pulau Duyong (1 mile wide) with a minimum depth 60 feet. The depth also decreases at the approaches of Pulau Bai and furtheocks are found.

Bathymetric survey is in progress to update the present nautical chart.

16.2.6 TIDES AND CURRENT

The tidal streams are generally influenced by stream from Balabac Strait (flood direction to south-easterly with rate of 1 knot) and stream from Sibutu Passage (flood directing to north-westerly with rate of 1 knot).

The tidal at Sandakan is mainly diurnal with a range of 2.8 metres (during astronomical tides) and at the rate of 1.25 knots during spring flood and 2 knots during spring ebb.

Current observation continuously for 32 days is in progress near Pulau Berhala overseen by RMN and is expected to complete by end of this month.

16.2.7 SILTATION

A survey was jointly conducted by the Sandakan Ports Authority, Royal Malaysian Navy (RMN) and Marine Police on 12th May 98 to find out if siltation is a problem in this area. The results of the survey showed that silting in the port area is negligible. A survey was also conducted by RMN ship on 7th May 98 to check if there is silting outside Sandakan port. The result of the survey showed that siltation is not a problem and the depth remains the same as per the chart. Charts of the survey result are appended for reference.

It is suggested here that periodical survey every six months at specific sites should be conducted to observe the changes of the depth for future expansion of marine activities as well as to keep the siltation problem in check.

16.2.8 HYDROGRAPHIC SURVEY

Hydrographic survey by the Department of Hydrography in collaboration with the Royal Malaysian Navy is currently in progress for the Sandakan waters. Data collection is expected to be completed by end of this month, while thorough analysis and compilation of results is expected to be completed by end of the year. The hydrographic details will be updated accordingly when the survey result is finalised.

16.3 AVAILABLE DATA

Apart from the siltation survey conducted in May 1998, most of the data used in this report are based on data from very old survey. These data are:

Hydrographic Details - British survey 1958 (Admiralty Chart 1649).
Meteorological Data - British Observation 1943 - 1970 (Pilots Book).
Tidal Information - RMN and National Mapping Department (1994 - 1996).

Other data for this section are shown in Figures 16.1-16.6

16.4 MAJOR ISSUES

The major issues of concern in the Sandakan waters that need to be addressed is the destruction of marine habitats particularly the coral reefs, seagrasses, seaweeds and to a large extend the fish population due to illegal activities such as fish bombing and other illegal fishing methods. Pollution by indiscriminate dumping of solid wastes from the ever increasing squatter population along the Sandakan coastal areas is also one of the major issues in the Sandakan waters. Measures on land reclamation along the coastal areas should also be taken to avoid siltation. Such measures will require concern, and the developers of coastal areas must comply with procedures of all relevant departments.

Figure 16.1: Average Observation of Meteorological Data 1942-1970

Figure 16.2: Tidal Range from 1994 – 1996

Figure 16.3: Islands within Sandakan District

Figure 16.4: Bathymetric Chart of Sandakan Waters

Figure 16.5: Sea Bottom Texture of Sandakan Waters

Figure 16.6: Tidal Stream Diagram for Sandakan Waters

CHS survey launch

NEW SEASON OF HYDROGRAPHIC SUREYS SURVEY LAUNCH

The Canadian Hydrographic Service (CHS) began its hydrographic survey season on Quebec’s navigable water bodies on April 19, 2010. The surveys focus particularly on the maintained channel in the St. Lawrence, the ports of Montreal, Trois-Rivières, Sorel, Sept-Îles and some harbours on the Gaspé Peninsula. Other surveys will also be conducted in the Lower North Shore, Gaspé Peninsula and Magdalen Islands areas as well as on the stretch of the St. Lawrence between Québec and Montréal.

The surveys are conducted using hydrographic launches equipped with highly precise echo sounders and electronic positioning systems; the information gathered – on the location of shoals, for instance – is used to update the official nautical publications and charts produced by CHS, the ultimate goal being to ensure the safe navigation of waterways. By the end of the season in December, the hydrographic teams will have covered over 10,000 km to monitor the condition of the St. Lawrence channel.

Report hazards

Mariners are invited to notify CHS when they discover a hazard (or an apparent hazard) to shipping or if they observe changes in the data recorded on nautical charts. To make it easier for CHS teams to spot reported hazards, it is important for the people making the reports to indicate the nature of the hazard, its position, the date and time it was observed, etc. Information can be reported by phone (418-775-0502) or by e-mail (chsinfo@dfo-mpo.gc.ca). Current nautical charts are essential to safe navigation.

The Canadian Hydrographic Service is responsible for mapping Canada’s navigable waters. It prepares, publishes and updates the nautical charts and official nautical publications that are essential to all mariners. Its Quebec catalogue features 60 nautical charts.

You need to know what is HYDROGRAPHIC SURVEY

Here's my thougths about HYDROGRAPHIC SURVEY

Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging, offshore oil exploration/drilling and related disciplines. Strong emphasis is placed on soundings, shorelines, tides, currents, sea floor and submerged obstructions that relate to the previously mentioned activities. The term Hydrography is sometimes used synonomously to describe Maritime Cartography, which in the final stages of the hydrographic process uses the raw data collected through hydrographic survey into information usable by the end user.

Hydrography is collected under rules which vary depending on the acceptance authority. Traditionally conducted by vessels and with Echo sounding, surveys are increasingly conducted with the aid of aircraft and sophisticated electronic sensor systems in shallow waters.

National and International Maritime Hydrography

Hydrographic offices evolved from naval heritage and are usually found within national naval structures, for example Spain's Instituto Hidrográfico de la Marina^[1]. Coordination of those organizations and product standardization is voluntarily joined with the goal of improving hydrography and safe navigation is conducted by the International Hydrographic Organization (IHO). The IHO publishes Standards and Specifications^[2] followed by member states as well as Memoranda of Understanding and Co-operative Agreements^[3] with hydrographic survey interests.

The product of such hydrography is most often seen on nautical charts published by the national agencies and required by the International Maritime Organization (IMO)^[4], the Safety of Life at Sea (SOLAS)^[5] and national regulations to be carried on vessels for safety purposes. Increasingly those charts are provided and used in electronic form unders IHO standards.

[edit] History and Responsibilities

The United Kingdom has a long hydrographic history officially begun with the 1683 appointment of Captain Grenville Collins as Hydrographer to the King^[6]. With the Royal Navy dominating the seas hydrography grew to a worldwide hydrographic activity. That tradition extended to the nations with a common legacy in the Empire, for example, the Australian Hydrographic Service^[7]. The British Admiralty Hydrographic Office became the United Kingdom Hydrographic Office which continues the legacy within the Ministry of Defence^[8] with responsibility for the Admiralty Charts^[9]. The Royal Navy maintains a number of hydrographic survey vessels^[10] to continue the work today.

[edit] United States

In United States statutory authority for hydrographic surveys of territorial waters and the Exclusive Economic Zone (EEZ) lies with the National Oceanographic and Atmospheric Administration (NOAA)^[11][12]. NOAA hydrographic surveys are conducted by the National Ocean Service^[13][14], a uniformed corps^[15] within NOAA and a fleet of survey vessels based at two major centers^[16]. The organic survey assets are supplemented by other agencies^[17] and contract surveys in order to survey the large areas within its responsibility. Those were identified in the NOAA Hydrographic Survey Priorities (NHSP) - East Coast alone as being 3,603 square miles classified as critical.^[18] The 2009 status shows 29,412 out of 510,841 "Navigationally Significant" Square Nautical Miles were completed.^[11] The NOAA Office of Coast Survey, Hydrographic Surveys Division estimates it has awarded approximately $250 million in contracts for hydrographic surveying and related support since 1994.^[19]

For inland surface waters such as rivers, streams and inland lakes the U.S. Geological Survey (USGS) has national responsibility. USGS coordinates survey data collection and publishes a National Hydrography Dataset^[20][21] that is designed to be used with geographic information systems (GIS). Other federal agencies such as the Environmental Protection Agency^[22] and the U.S. Fish and Wildlife Service use^[23] these data and, along with state and local hydrographic collection organizations, contribute to the national hydrographic data base. The Environmental Protection Agency conducts or contracts for surveys on projects such as the GE/Hudson River Super Fund site.

The U.S. Coast Guard conducts hydrographic survey operations, particularly in the Polar regions^[24].

The National Geospatial Intelligence Agency^[25] (NGA) oversees charting of international waters for Department of Defense purposes. The Navy's Naval Oceanographic Office^[26] conducts many the oceanic surveys. The U.S. Army Corps of Engineers conducts hydrographic surveys supporting its responsibility for the major waterway projects that include navigation and flood control. Hydrographic data from those surveys is published by districts^[27]. Such data is incorporated into both NOAA and NGIA products and the Corps engages in efforts to improve hydrographic collection methods^[28]. Military combat organizations such as the Navy's SEAL and engineering units have specialized hydrographic reconnaissance survey capability.

The NOAA Office of Coast Survey, Coast Survey Partners web page offers a useful list and summary of major player activities, government and private, with links to those partner web sites.

[edit] Hydrograpic Survey Conducted by Non-national Agencies

Governmental entities below national level conduct or contract for hydrographic surveys for waters within their jurisdiction with both internal and contract assets. Such surveys are commonly conducted by or under the standards approved by or the supervision of national organizations, particularly when the use is for the purposes of chart making/distribution or dredging of state controlled waters.

In the United States there is coordination with the National Hydrography Dataset in survey collection and publication^[29]. State environmental organizations publish hydrographic data relating to their mission^[30].

[edit] Hydrograpic Survey Conducted by Private Organizations

Large scale hydrographic and geophysical survey is conducted by commercial entities, particularly in the dredging, marine construction, oil exploration & drilling industries. Industry installing submarine cable for communications^[31] or power^[32] require detailed surveys of cable routes prior to installation with increased use of acoustic imagery equipment previously found only in military applications^[33]. There are specialized companies with both the assets and expertise to contract for such surveys with both commercial and governmental entities. Companies, Universities and investment groups will often fund Hydrographic surveys of public waterways prior to developing areas adjacent those waterways. Survey firms are also contracted to survey in support of design and engineering firms that are under contract for large public projects.^[34] Private surveys are also conducted before dredging operations and after these operations are completed. Companies with large private slips, docks or other water front installations have their facilities and the open water near their facilities surveyed regularly.

[edit] Process

Modern surveying relies as much on software as hardware. In suitable shallow water areas Light Detection and Ranging (LIDAR) may be used^[11]. Equipment can be installed on inflatable craft, such as Zodiacs, small craft, AUVs (Autonomous Underwater Vehicles), UUVs (Unmanned Underwater Vehicles) or large ships, and can include sidescan, single beam and multibeam equipment. At one time different data collection methods and standards were used in collecting hydrographic data for maritime safety and for scientific or engineering bathymetric charts. Increasingly with aid of improved collection techniques and computer processing the data is collected under one standard and extracted for the specific use.

After data is collected, it has to undergo post-processing. A massive amount of data is collected during the typical Hydrographic survey, often several soundings per square foot. Depending on the final use (navigation charts, Digital Terrain Model, volume calculation for dredging, topography, Bathymetry) this data must be thinned out. It must also be error corrected (bad soundings,) and corrected for the effects of tides, waves/heave, water level and water temperature differences (thermoclines.) Usually the surveyor has additional data collection equipment on site to record the data required for correcting the soundings. Final output of charts can be created in a combination of specialty charting software or a CAD package, usually Autocad.