Cyclone Namu

The FMS started to issue special weather bulletins for the Solomon Islands Meteorological Service (SIMS) during May 15, which advised that the system had gale-force winds associated with it and that it would affect Malaita and smaller islands.[1] As a result, the SIMS issued a gale warning before the bulletins were suspended during the next day, after the system weakened and it became doubtful that gales were associated with the depression.[1][6] After the depression was named Namu during May 17, the FMS resumed issuing the weather bulletins, which advised the SIMS of the threat posed by Namu to Malaita, Guadalcanal, San Cristobal and other smaller islands.[1] Over the next few days, these bulletins were revised accordingly and advised the SIMS which areas would be affected by gale, storm and hurricane-force winds and the threat of flooding from rain or storm surge.[1] These bulletins were subsequently used by the SIMS to prepare various gale and tropical cyclone warnings, which were subsequently broadcast in English and Pidgin around the clock by the Solomon Islands Broadcasting Corporation.[6][11] As the system approached and moved over the island nation on May 18, the Solomon Islands National Disaster Council was convened to oversee the relief effort.[12] Within the Solomon Islands, initial expectations were for a run of the mill tropical cyclone of a moderate intensity to impact the Solomon Islands.[12] However, many people were caught off guard by the cyclone's sudden increase in winds and the prolonged heavy rain, especially in remote areas where weather forecasts were difficult to disseminate because of communication problems.[1]

Namu impacted the Solomon Islands between May 17 - 20, with torrential and prolonged rainfall, high seas, gale to hurricane-force winds, wind gusts of over 150 km/h (93 mph), which caused flooding, landslides, mudslides, tidal and wind surges throughout the island nation.[1][12] In particular it was estimated that storm or hurricane-force winds had impacted Malaita, Small Malaita, Guadalcanal, Bellona, as well as other smaller islands, that the Namu's center had passed within 50 to 65 km (30 to 40 mi) off.[1][6] They also estimated that gale-force winds had impacted the area in between San Cristóbal, the Russell Islands, Santa Isabel and the northern tip of Malaita.[1] However, because of Namu's slow movement through the island nation, the majority of the deaths and damages, were caused by heavy rain, floods and mudslides, rather than as a direct effect of Namu's winds.[1] It was later estimated that parts of Guadalcanal had over 600 mm (24 in) of rainfall, while the weather station at Henderson Field recorded a rainfall total of 353 mm (13.9 in) between May 18 - 21.[6][13]

Namu is commonly thought to have caused 150 deaths when it impacted the Solomon Islands, however, this death toll is disputed with different totals listed in reliable sources.[nb 1][12][15] Within their final report, the Solomon Islands National Disaster Council reported that Namu had caused about 103 deaths, however, only 63 people were listed as dead or missing.[6] In particular they noted that 49 of these deaths occurred on Guadalcanal, 11 on Malaita, 2 in the Temotu province and 1 on Makaria.[6] During July 1991, Russell Blong and Deirdre Radford of Macquarie University published the results of an extensive survey into the natural disasters in the Solomon Islands, which "positively identified" 111 deaths in association with Cyclone Namu.[12][15]

During May 17, the newly named Tropical Cyclone Namu passed within 55 km (35 mi) of the isolated atoll: Sikaiana, which bore the brunt of the system as it approached the Solomon Islands.[6][12] Storm surge associated with the cyclone inundated the island with salt water, which contaminated water wells and exacerbated difficulties with fresh water supplies.[3][16] The storm surge also destroyed the majority of the traditional housing that had been made out of palm fronds and left the islanders without any food, water or shelter.[3][16] Over the next few weeks, the islanders relied on coconut milk, until HMAS Brunei was able to deliver relief supplies and over 200 drums of fresh water on June 4.[12]

After impacting Sikaiana, Namu moved south-westwards towards the southern part of Malaita, where it seemed to slow down and remain near-stationary for around five hours.[16] High winds associated with Namu, damaged roofs and defoliated the hills over central, southern and western Malaita, while waves damaged the coastline.[16]

Within the island nation meandering rivers changed their course and cut a straight path, which brought mud, silt and debris to rich farming areas.[1] The floods also exposed a site of an American and Japanese World War 2 ammunition dump on Guadalcanal from Henderson Field to Red Beach.[17][18]

Namu passed just to the west of the Rennell and Bellona Province, with both islands in the province feeling the effects of the cyclone.[16] On Rennell Island, 20 houses were destroyed while both the school and the airstrip were damaged by storm surge, high winds and heavy rain.[3] The damage to Bellona was considered more serious with 160 traditional houses destroyed by storm surge, high winds and heavy rain.[3][16]

Bridge damaged by Namu

Most of the damage caused by Cyclone Namu occurred due to river flooding.[13][19] The cyclone affected 48% of the Solomon's land area and 62% of its total population.[20] Along the eastern coast of the island, damage was massive; entire villages were destroyed. Gardens were devastated and walking pathways were blocked.[21][22][23] In Babanakira, 5 people died.[24]

On the island of Guadalcanal, a single mudslide was responsible for killing 38 villagers.[25] Of the 43 people that lived in the small town of Valebaibai, only 5 survived, all of whom narrowly escaped.[26] Moreover, 14 dead bodies were found in the central and southern areas of Guadalcanal on May 21 when flood waters began to recede.[27]

Deep flood water covered 75% of the island's (Guadalcanal) coastal plain;[28] these waters cut off channels and destroyed coastal villages. Furthermore, the Lungga, Ngalimbiu, Mberande, and Nggurambusu rivers sustained the worst flood damage;[13] water depth in some of the aforementioned rivers reached 8 m (26 ft).[29] Many trees were brought down due to high winds.[13] Also, numerous plantations were destroyed across the island. However, little beach erosion occurred on the island.[13] Moreover, 22% of homes on the island were either damaged or destroyed.[3] One bridge was also destroyed on the island.[30] Offshore Honiara, the capital of the nation, two ships [one was 60 ft (20 m) long and the other was 120 ft (35 m) long] each sank during the storm.[31] Throughout the capital, several schools were destroyed. The two bridges that connected the city with the island of Guadalcanal were destroyed, thus leaving Honiara isolated.[32] Furthermore, about 5,000 homeless were left homeless across the city,[33] 2,000 of whom sought refuge in a local college due to the storm. Although no people were to have confirmed to have died in the city, five children were reported missing in one of the capital's suburbs, Ngalimera.[32]

In both Guadalacal and Malatia, extensive areas of irrigated rice crops were submerged under floodwaters and mud.[1] In some areas, nearly all homes were destroyed. Mudslides and logs destroyed roads, bridges, water pipes and drainage systems. Crops such as cocoa, copra, coffee, and rice were destroyed, resulting in thousands of dollars in damage.[26] Additionally, communication between the outer and island of the Solomon group was completely destroyed.[34]

In all, approximately 90,000 people, one third of the country's population, were reportedly homeless.[19][35] The southern islands of the Solomon's chain were seriously affected by the passage of Namu, becoming the worst tropical cyclone to impact the area in five years.[19] Of the 25,000 "traditional" houses on the Solomon Island, 6,000 (26%) were destroyed. Most of the fatalities were due to landslides and flooding. Property damaged totaled $25 million (1986 USD)[26] and the storm also caused US $100 million in economic losses in the Solomon Islands.[36] On May 18, Honiara's Central Hospital authorities decided to evacuate several patients, as the hospital was located on a coastal strip that was vulnerable to river flooding and seawater inundation.[14]

On June 4, the Government of the Solomon Islands lifted the emergency period, four weeks after the system had impacted the islands.[14] After the emergency period was lifted, outside assistance that had been brought in to assist with relief efforts were gradually withdrawn, including armed services from Australia and New Zealand.[14] However, external assistance from Australia and New Zealand amongst others, was still needed due to the Solomon Islands reliance on overseas aid in general.[14] As a result, a two-day meeting took place in Honiara during July, at which the Solomon Islands Government requested and was promised about 13.5 million for 20 rehabilitation programs.[50] Pledges of assistance were made by Australia, Britain, New Zealand, the European Economic Community and agencies of the United Nations and the United States of America.[50] These programs included projects to replace rural primary schools flattened by the cyclone, bridges and water supply systems swept away by Namu.[50]

During December 1986, the then Solomon Islands Prime Minister Sir Peter Kenilorea resigned, after allegations surfaced that he had channelled aid from France for Cyclone Namu towards the rebuilding of his village. However, the allegation was never proven.[51]

During March 1987, volunteers from the Australian Rotarians, commenced an eighteen-month project to build 93 schools in the Solomon Islands.[52][53]

Questions were raised during the systems aftermath over whether or not excessive deforestation worsened the impact of the flood. The government denied reports that deforestation had any link to the catastrophe.[54]