DOMINION'S RAINFALL

Poverty Bay Herald, Volume LV, Issue 17234, 14 April 1930, Page 7

DOMINION'S RAINFALL

INTERESTING FEATURES SURVEY OF 35 YEARS (Special to the Herald.) WELLINGTON, this day. A survey of New Zealand's rainfall covering a poriud of 35 years from 1801 has been completed by the Government .Meteorologist, Dr. E. Kidson, and ts being published by the direction of the Hon. tl. Atmore, Minister of Scientific ami Industrial Research. The outstanding result of this long survey is to show that the- rainfall of tiie Dominion is nut a fluctuating quality, but that the, variation from year to year is remarkably slight, and the average annual precipitation is high. The conclusion reached is that the Dominion is extremely fortunate in us rainfall, for in spite of the fact that in places it is very heavy, and the general average is high, the number ot rainy days is practically nowhere excessive. When in addition it is remembered that the average amount of cloud is only moderate, that the air is well washed by rain and little polluted by smoke, and that sunshine is abundant, the richness of New Zealand pastures can be readily understood. THE NORTH ISLAND. Well-planned .maps show at a- glance the average annual rainfall in all parts of the -Dominion. So far as the North Island is concerned, there is scarcely any part which has a. smaller rainfall than 60in. per annum. Quite a number of patches of high country get lOOin. The peninsula extending between the, Bay of Plenty and Hawke's Bay to the north east at East Cape is one with a generally heavy rainfall, a. considerable area' having over 100 in., including a patch north-east of Wairoa. The remaining areas of heavy precipitation are around Mount Egmont—SOOin. at the Mountain House is not an unusual annual fall — and in the Tararua. and Rimutaka ranges. High land masses have a great influence in causing precipitation, and this effect is called by the meteorologist "rain shadow." The most remarkable, according to this survey, is that extending inland from Gisborne, which is sheltered by ranges on all sides except the east and south-east. The country to the north-east of Lake Taupo is also a relatively sheltered and dry area. The large and important region extending inland from the Taranaki Bight, and including the Rangitikei and Mauawatu counties, is protected by the Egmont and Tongariro massifs to the north-west, the high country of the South Island to the southwest, and the Tararuas and Huahines to the east. Another important "rain shadow" lies in the eastern districts south from Napier. The North Island is, on the whole, in tiro opinion of the meteorologist, remarkably well watered. SOUTH ISLAND RAINFALL. In the South Island the rainfall distribution is more varied. The wettest region is that running down the western side of the range from northern to southern extremities. It is likely that a fall of 2Coin. is greatly exceeded at only few places in this zone, though the area receiving 200 in. is considerable. Regret is expressed at the lack of data from the west coast, and the report remarks that one is forced to the conclusion that the principal reason is the reluctance of some of the inhabitants to publish, figures showing a high rainfall, which they fear will give their district the reputation of having a bad climate. This attitude is very much to be deprecated. Nothing is gained by the suppression, of truth. On the contrary, the facts are probably more favorable than is believed by residents in other parts of the country. The heaviest precipitation occurs to the west of the main divide, while the decline to the eastward is described as astonishing. Over almost all the lowlying plains of Canterbury and Otago low rainfalls—between 25 and oOin.—are recorded, while the driest country in the Dominion is found in the inland basins, such as the Mackenzie country and Central Otago. In the latter there is a considerable area which receives less than 15in. per annum, and in parts of Alexandra and Galloway district 13in. or slightly less is all that is recorded. Surprisingly heavy rainfalls' are recorded in .Marlliorough Sounds, although the total falls away rapidly towards the straits at Stephens Island and the Brothers.

Southland has for the most part a moderate rainfall in the settled areas, but it becomes rather heavy near the coast. Stewart Island has a high average fall, probably in all parts.