Singapore Island Research Articles

Uncertainties in modelling of tidal flows off Singapore Island

Abstract A hydrodynamic model has been constructed for predicting the tidal currents off the south west coast of Singapore Island and has been verified against survey data from the area. A study examining the sensitivity of the model to changes in the input parameters has been undertaken and a statistical experimental design technique has been employed to determine the minimum number of computer runs required to quantify the sensitivity of the model. The uncertainty in predicting the time of the turn of tide is estimated from the statistical results as is the uncertainty in the predicted movement of drogues in both simple and complex tidal flows. The method is extended to estimate the uncertainties in the spread and concentration of a dye patch using a particle tracking random walk model and allowing for the uncertainties in the wind and in horizontal and vertical mixing rates as determined from a series of experimental studies of dye patch spread.

P55 Designing a registration system for the clinical research database system

Excessive rainwater infiltration can be an important causal agent of both slope and whole tree uprooting failures. Early warnings or stabilization measures on high-risk slopes or trees are critically important. To identify the high-risk areas, it is necessary to conduct seepage, slope and tree stability analyses over a large region. Given the spatial variability of soil properties, a soil database is therefore required before performing distributed or Geographical Information System (GIS) -based water balance and stability analyses. Considering that the unsaturated soil properties could be very different from saturated soil properties, in this study, a soil database containing both saturated and unsaturated hydraulic and mechanical soil properties was developed for the first time. Machine learning methods were used to predict the unknown soil properties. Based on the predicted soil properties, spatial distributions of different saturated and unsaturated soil properties were generated using the ordinary kriging method. Then the soil database was developed with Singapore island being divided into 97 zones, with each zone having similar soil properties. In this study, the importance of different input variables in soil properties prediction was also investigated. In addition to soil plasticity (i.e., Liquid Limit (LL), Plastic Limit (PL) and Plasticity Index (PI)) and grain size distribution (i.e., gravel, sand, and fines fractions), location (i.e., longitude and latitude) was found to be of high importance as well and are recommended to be used as input variables to predict soil properties, especially when data volume is relatively limited. For those soil properties that cover a large range of values, model performance is better when logarithm values were used as the outputs. Moreover, given the possible correlation between some output parameters, the prediction of the Soil-water Characteristic Curve (SWCC) from a multi-output model is recommended after comparing its performance with a single output model. Furthermore, the performance of two commonly used machine learning methods (i.e., random forest regression and artificial neural network) in soil properties prediction were compared and the prediction error resulting from the random forest regression method was generally smaller. The developed database includes the mean values of saturated permeability, saturated and unsaturated shear strength parameters, and SWCC in each zone. The database can be applied in regional GIS-based water balance and slope stability analyses to account for the spatial heterogeneity instead of assuming constant soil properties.

The Ecological Transformation of Singapore, 1819-1990

In 1819 the island of Singapore was almost en- tirely covered in rain forest, with a flora similar to the adja- cent Malay Peninsula but a relatively depauperate vertebrate fauna. The cultivation of cash crops resulted in rapid deforestation which was largely completed by the end of the nineteenth century. The cultivated area reached a maximum in 1935 and declined thereafter. Today, more than half the island is urbanized and less than 100 ha of primary rain forest survives. A further 1600 ha is covered in tall secondary forest. Floristic extinctions are impossible to quantify reliably but at least 100 bird species, twenty fresh- water fish species and several species of mammal have been lost. Man-made, open habitats are dominated by exotics but few have penetrated the forest. The naturalized biota in- cludes at least 138 vascular plant species, eighteen bird species, five mammal species, twenty fish species, several species of reptiles and amphibia, and an unknown number of invertebrates. Over much of inland Singapore there are probably none of the plant or animal species that occurred there 170 years ago. Despite this, in all the major taxonomic groups for which I have information the majority of known native species can still be found in Singapore today.

Fertility Decline and Pronatalist Policy in Singapore

In 1819 a few 100 Malays inhabited the island of present day Singapore and after the British East India Company began a trading post here the population increased quickly to >137000 by 1881. 3 migration droves occurred in the 1819-1930s period consisting mainly of Chinese and to a lesser extend Indians and Malays. Partially due to the efforts of the Singapore Family Planning and Population Board and to a government campaign to encourage small families in the 1960s the total fertility rate in Singapore declined from 5.5-1.6 (1967 and 1983 respectively). This trend and differentials between the average number of children of women with little or no formal education (3.5) and university educated women (1.6) concerned the Prime Minister. He initiated a change to a pronatalist policy without seeking public opinion. Many believe another reason for this switch in policy had to do with the fact that the below replacement fertility pattern was found only among Chinese women. Since the Chinese are dominant politically economically and socioculturally government leaders may not want to lose this dominance. Further the government does not consider immigration as a means of maintaining population size so the effort to promote higher fertility may continue for years even though some social scientists doubt that higher fertility can be achieved. Nevertheless the people of Singapore may not be willing to risk their higher standard of living by having large families despite any financial incentives the government offers. In addition women have become an essential and integral part of the labor force and higher rates of female participation in the labor market accompanies low fertility.

Dacus dorsalis . [Distribution map

Abstract A new distribution map is provided for Dacus dorsal is Hendel [Diptera: Tephritidae] Oriental fruit fly Polyphagous, attacks most fleshy fruits and vegetables. Information is given on the geographical distribution in ASIA, Bangladesh, Burma, China, Hongkong, India, Indonesia, Jammu and Kashmir, Kampuchea, Laos, Malaysia, Nepal, Ogasawara Islands, Pakistan, Ryukyu Islands, Sikkim, Singapore, Sri Lanka, Taiwan, Thailand, Vietnam, AUSTRALASIA, AND PACIFIC ISLANDS, Christmas Islands, Hawaii, Mariana Islands, NORTH AMERICA, USA, California.

Antonina graminis . [Distribution map

Abstract A new distribution map is provided for Antonina graminis (Maskell) [Hemiptera: Pseudococcidae] Rhodes grass scale. Attacks many Gramineae, notably Rhodes grass (Chloris gayana) Information is given on the geographical distribution in AFRICA, Kenya, Libya, Madagascar, Mauritius, Nigeria, Somalia, South Africa, Uganda, Zimbabwe, ASIA, Bangladesh, China, Hong Kong, India, Indonesia, Iran, Iraq, Israel, Kuwait, Malaysia, Pakistan, Philippines, Ryukyu Islands, Saudi Arabia, Singapore, Sri Lanka, Taiwan, Thailand, AUSTRALASIA, and PACIFIC ISLANDS, Australia, Caroline Islands, Cook Islands, Fiji, Hawaii, Kiribati, Mariana Islands, Marshall Islands, New Caledonia, Papua New Guinea, Solomon islands, Tonga, Tuvalu, Wake Island, Irian Jaya.

Suicide in the island of Singapore.

In a study of suicide in Singapore in 1980 there were 230 cases and the suicide rate for the general population was 9.5 per 100,000. The age-specific rates increased steeply after 50 years and there was a male preponderance especially in the age group 60 years and over. Comparing the three major ethnic groups in Singapore, the highest rate was seen in the Indians and Chinese, whereas the Malays had the lowest. Amongst the suicides there were 59 (25.7%) with mental illness, mainly schizophrenia, and they were of a younger age group, 20-39 years. The commonest method of suicide was jumping from high-rise flats.

Nilaparvata lugens . [Distribution map

Abstract A new distribution map is provided for Nilaparvata lugens (Stål) [Hemiptera: Delphacidae] Brown planthopper. Attacks rice, causing 'hopper-burn' and transmitting grassy and ragged stunt virus diseases, and may also develop on wild species of Oryza, Leersia and Zizania. Information is given on the geographical distribution in ASIA, Bangladesh, Brunei, Burma, China, Hong Kong, India, Indonesia, Japan, Kampuchea, Korea, Laos, Malaysia, Nepal, Pakistan, Philippines, Singapore, Sri Lanka, Taiwan, Thailand, Vietnam, AUSTRALASIA and PACIFIC ISLANDS, Australia, Caroline Islands, Fiji, Mariana Islands, Papua New Guinea, Solomon Islands.

Thrips hawaiiensis . [Distribution map

Abstract A new distribution map is provided for Thrips hawaiiensis (Morg.) ( Euthrips hawaiiensis (Morg.), Thrips albipes [Thrips hawaiiensis] Bagn.) (including T. h. imitator Priesner) (Thysanoptera, Thripidae). Host Plants: Banana, citrus, crucifers, legumes, lucerne. Information is given on the geographical distribution in ASIA, Bangladesh, Burma, China, Hong Kong, India, Indonesia, Japan, Korea, Laos, Malaysia, Pakistan, Philippines, Ryukyu Islands, Singapore, Sri Lanka, Taiwan, Thailand, AFRICA, Angola, Mozambique, Nigeria, Sierra Leone, Uganda, AUSTRALASIA, and PACIFIC ISLANDS, Australia, Fiji, Hawaii, Norfolk Islands, Papua New Guinea, Western Samoa, Society Islands, NORTH AMERICA, USA.

Hypsipyla robusta . [Distribution map

Abstract A new distribution map is provided for Hypsipyla robusta (Moore) (Lep., -Pyrandae) (Toon shoot-and fruit-borer). Host Plants: Cedrella, Khaya, Toona . Information is given on the geographical distribution in ASIA, Andaman Is, Burma, India, Indonesia, Malaysia, Pakistan, Sikkim, Singapore, Sri Lanka, AFRICA, Ghana, Madagascar, Malawi, Mauritius, Nigeria, Sierra Leone, Tanzania, Uganda, AUSTRALASIA, and PACIFIC ISLANDS, Australia, Papua New Guinea, Solomon Islands.

Achaea janata . [Distribution map

Abstract A new distribution map is provided for Achaea janata (L.) (Lep., Noctuidae) (Castor Semi-looper). Host Plants: Castor, cacao, Citrus , rice, rubber. Information is given on the geographical distribution in ASIA, Andaman Islands, Burma, Cocos-Keeling Islands, India, Indonesia, Laos, Malaysia, Nicobar Islands, Pakistan, Philippines, Sikkim, Singapore, Sri Lanka, Taiwan, Thailand, Vietnam (North), AUSTRALASIA and PACIFIC ISLANDS, Austral Islands, Australia, Caroline Islands, Cook Islands, Easter Island, Fiji, Gilbert Islands, Hawaii, Johnston Island, Marquesas Islands, Marshall Islands, New Caledonia, New Hebrides, Norfolk Island, Papua New Guinea, Phoenix Islands, Pitcairn Island, Samoa, American, and Western Society Islands, Tokelau, Tonga, Wallis Islands, Irian Jaya.

Papilio demoleus . [Distribution map

Abstract A new distribution map is provided for Papilio demoleus L. (Lep., Papilionidae) (Citrus Swallow Tail, Lemon Butterfly). Host Plants: Citrus, Zizyphus , bael fruit. Information is given on the geographical distribution in ASIA, Bangladesh, Bhutan, Burma, Cambodia, China, Hong Kong, India, Indonesia, Iran, Iraq, Jammu & Kashmir, Laos, Malaysia, Nepal, Pakistan, Saudi Arabia, Sikkim, Singapore, Sri Lanka, Taiwan, Thailand, Vietnam, AUSTRALASIA and PACIFIC ISLANDS, Australia, Lord Howe Island, Papua New Guinea.

Nuclear Power to the Pacific

The nuclear power industry is increasingly being pressured to export reactors to the Third World. The experiences of the five ASEAN (Association of Southeast Asian Nations) are recounted. To date, only the Philippine Republic has formally committed itself to a nuclear generator. The Republic lacks oil and has only limited hydroelectric potential. Its geothermal energy program is being accelerated. It appears Indonesia will be the next ASEAN country ''to go nuclear'', hoping to have a nuclear plant on-line in 1985. The island of Singapore has been voicing a desire for a nuclear power plant, but the country does not have space for a plant. The possibility of a floating station has been mentioned, but the World Bank does not finance unproved projects. Singapore could obtain an island from Indonesia or share a plant with Malaysia if a plant were built on the mainland of the Malay peninsula. The Thai Energy Generating Authority (EGAT) is preparing ''to go nuclear'' with the emergence of a stable coalition rule in Bangkok; the financial restrictions are discussed. Thailand is diligently searching for its own oil and gas. The article closes by projecting the problem that could arise with IAEA having only 40 inspectors whomore » are charged with monitoring nuclear power plants all over the world. The authors point out that the industrial countries themselves have proved wholly incapable of monitoring their own systems. (MCW)« less

Conservation and the Tropical Marine Aquarium Trade

Although mainly developed in the last ten years, the international trade in tropical marine aquarium fishes has now reached remarkable proportions; in the U. S. A. the annual sales of aquaria, aquarium supplies, and aquarium fishes, probably approach US$ 600 millions, while estimates of the numbers of marine aquarium fishes exported each year from the Philippines alone range from about 3 to over 30 millions, valued at approximately US$ 1.25 million to over 6 millions. The exporting areas include the Philippines, Taiwan, Hong Kong, Thailand, Singapore, Indonesia, Australia, Sri Lanka, Ethiopia, Saudi Arabia, Kenya, Mauritius, the U.S.A. (Hawaii and Florida), and several Caribbean islands. The main importing countries are the U.S.A., Hong Kong, West Germany, Japan, U.K., Italy, Belgium, Canada, Australia, France, Holland, and Switzerland.Species extermination through this trade alone is scarcely conceivable, but local extinctions may occur, and indirect effects of collection of these fishes include accompanying destruction of the coral-reef habitat, changes in natural ecosystems, and the possibility of successful introduction of exotic species into areas where they did not occur previously (notably, Indo-Pacific species into the Caribbean). Clearly the trade will continue; but the current exploitation is inefficient, and controls must be applied both towards rational utilization of the resource and, as the most accessible and richest reefs are the most heavily exploited, towards a reduction of conflict between different uses of the resource.

Lee Kuan Yew and Singapore

SOME 15 short years ago, the sultry, green-clad island of Singapore, tightly wedged between the Malay Peninsula jutting south from Asia and the great island chain of Indonesia, was a complacent, unprogressive white man's colony with a polyglot population of Chinese, Malays, and Indians held-but not welded--together by the accident of geography and British imperial rule. Today, it is a remarkably and increasingly affluent Asian city-state with a growing sense of pride and identity, considerable racial integration, a per capita income closely approaching that of the West, and the cleanest streets, the best social services, and the most corruption-free government in the great sweep of non-Communist nations stretching from Afghanistan to Japan. This striking Asian success story owes nothing to abundant natural resources, esoteric Taoist charms, Malay magic or, indeed, to the fairy-godmother aid of affluent Western countries. Rather, it was achieved through the intelligent leadership of a small, cohesive group of competent technicians headed, firmly and unmistakably, by a sharpwitted, intellectually arrogant young man (only just 50) of Chinese ancestry, an upper-class British education and accent, and complete dedication, not to personal profit but to the creation of a prosperous and equitable society through the combination-rare in underdeveloped nations-of sound, realistic planning, efficient administration, hard work, and the cooperation of little, everyday people because they clearly benefit from it. To the writer's remark that Singapore was easily the most effectively administered metropolis in Asia, a widely-traveled and experienced diplomat said recently, Not just in Asia. It's the best-run city in the world. It is true, as Indonesians and Malaysians tired of hearing of their small neighbor's accomplishments unfailingly and resentfully point out, this island of 225 square miles and just over two million people is manageably-sized, a state in miniature. But the many problems that

Tiracola plagiata . [Distribution map

Abstract A new distribution map is provided for Tiracola plagiata (Wlk.) (Lep., Noctuidae) (Cacao Armyworm, Banana Fruit-eating Caterpillar). Host Plants: Banana, cacao, cassava, castor, Citrus , coffee, rubber, tea, tobacco. Information is given on the geographical distribution in ASIA, Cambodia, China, India, Indonesia, Laos, Malaysia, Philippines, Sikkim, Singapore, Sri Lanka, Taiwan, Thailand, Vietnam (North), AUSTRALASIA and PACIFIC ISLANDS, Australia, Cook Islands, Marquesas Islands, Papua and New Guinea, Samoa, Society Islands, Tonga, Irian Jaya.

USE OP CRENULATE SHAPED BAYS TO STABILIZE COASTS

Crenulate shaped bays are the rule rather than the exception on coastal margins of oceans, inland seas or lakes where sedimentary beaches exist between headlands. They have a particular orientation to the swell or resultant wave energy vector, such that the straight tangent section is downcoast and the curved portion upcoast. The latter is a logarithmic spiral at all stages of development of the bay. When fully stable, that is no littoral drift taking place, the constant of the log-spiral equation has a specific relationship to the approach angle of the waves to the headland alignment. In this condition it is shown that diffraction and refraction are involved when waves sculpture the curved beach in the lee of the upcoast headland. A further ratio to identify stable bays appears to be the ratio of indentation length to clearance between headlands. The application of crenulate shaped bays to stabilization of a reclaimed shoreline suffering strong littoral drift on Singapore Island is described.

Nephotettix nigropictus . [Distribution map

Abstract A new distribution map is provided for Nephotettix nigropictus (Stål) ( N. apicalis (Motsch.) including N. n. yapicola Linnavuori) (Hemipt., Cicadellidae) (Rice Leafhopper). Host Plants: Rice, Panicum, Cyperus, Poa . (A vector of rice dwarf virus, rice slunt, and other virus diseases) Information is given on the geographical distribution in ASIA, Andaman Islands, Burma, Cambodia, Ceylon, China, Hong Kong, India, Indonesia, Laos, Malaysia, Nepal, Nicobar Islands, Pakistan, Philippines, Singapore, Taiwan, Thailand, Vietnam, AUSTRALASIA AND PACIFIC ISLANDS, Caroline Islands, Mariana Islands, Papua and New Guinea, Irian Jaya.

Artificial injection of electrons into the geomagnetic field by teak and orange, low-altitude bursts of 1958

Recent analysis of Explorer 4 data establishes that a shell of trapped electrons at L = 1.2 approximately 115 km wide at the half-maximum intensity points resulted from the Teak burst 77 km above Johnston Island, August 1, 1958. Maximum unidirectional flux (Ee>0.58 Mev) above background was 1.4 × 105 electrons cm−2 ster−1 sec−1. The shell was observed for about three days from the Johannesburg, Lima, Singapore, and Johnston Island tracking stations. Buildup at the L = 1.2 shell was not immediate, reaching a maximum about 24 hours after the event. Initial observations (Singapore 18 min and Johnston Island 7 hours after the burst) showed maximum trapping at L =. 1.14. It is estimated that between 1019 and 1020 electrons were trapped one hour after the burst. Artificial injection from Orange (43 km) was found to be located principally above Johnston Island and was of short term (less than 1 day) and small magnitude.

Sand Waves in the Malacca Strait

The existence of sand waves in the region as shown in Fig. 2 was confirmed by the Joint Survey Team from Indonesia, Japan, Malaysia and Singapore during the preliminary hydrographic survey in the Malacca and Singapore Straits conducted from January to March 1969.The sand waves as appeared on echograms can be classified into the following categories : A. Round top type group I : a. Round top type (Fig. 3) b. Conical type (Fig. 4) C. Compound round top type (Fig. 5) B. Round top type group II : a. Asymmetric round top type (Fig. 6) b. Asymmetric compound round top type (Fig. 7) C. Pinnacle type group : a. Pinnacle type (Fig. 8) b. Asymmetric pinnacle type (Fig. 9) c. Asymmetric compound pinnacle type (Fig. 10) The distribution of sand waves according to their types is as follows : (a) Pinnacle types sand waves are developed in the area extending from the SE extremity of Malay Peninsula to Singapore offing, and their wave-heights are 8 to 15 metres.(b) In the area between SW tip of Singapore island and Benut offing, mixed existence of round top type group I and pinnacle type group is found.(c) Various types are found between Tg. Tohor and One Fathom Bank, but pinnacle type waves are prevailing in the offing between Tg. Tohor and Muar, where the largest sand wave (of a pinnacle type with a height of 20.6 metres and a length of 267 metres) was found. Sand waves of pinnacle type and round top type group II were seen off the coast from Muar to Cape Rachado, and their heights were 5 to 10 metres.(d) Between Cape Rachado and One Fathom Bank, those of pinnacle type and round top type group II with heights of more than 10 metres were found, among which where included those with heights reaching 15 to 18 metres.Of sand waves surveyed in the detailed survey area off Cape Rachado, 1, 144 waves were calculated as to their various factors for classification, and the following data were obtained : (1) Average wave-height and average wave-length.(2) Correlation between the height and length of waves (Fig. 14 and 15).(3) Relation between the water depth and existence ratio of each type of wave (Fig. 16).(4) Relation between the wave height and the existence ratio of each type of wave (Fig. 17).Causes for creation of sand waves and their movements were not studied in this paper, since this was the first time of study and, besides, detailed observations were not conducted for currents and tidal currents in the area in question.