Over the territory extending from the Jor dan to the Persian Gulf there is slight rainfall and much of it is a desert uninhabited.
In Siberia there is much snow and little rainfall. The latter ranges from 8 inches from Persia to Tobolsk and increases to 12 inches over Amur watersheds. Snow falls over vast areas in great quantities and in the mountains remains most of the year, feeding its lengthy rivers and its numberless lakes. Some of these, such as Baikal 400 miles long by 20 to 50 miles wide and Lake Kossogol 120 miles long by 50 miles, cover great areas in a basin that was once a much longer lake. In eastern Siberia rain fall averages from 15 to 20 inches. In Man churia and northern China between the Volga and the Lena the rainfall ranges from 19 to 29 inches.
In China it ranges from 23 inches at Peking to 78 inches at Canton, which is swept by monsoons, It is only 5 to 7 inches in the north of Mongolia. In some coastal regions it amounts to 100 inches. Over the coastal re gions of the Malay Peninsula the rainfall ranges from 75 to 200 inches and over places in Java it is 78 inches, at Singapore it is 97 inches. Siam is occasionally swept by monsoons and the rainfall ranges from 180 inches at Mergni to 240 inches at Monlmein. At some other places it averages from 42 to 54 inches.
In India there is the greatest variation in precipitation in Asia. In its western coastal and Himalaya regions rainfall ranges from 75 to 100 inches on the west to 250 inches at ele vated localities, also in the west up to 610 inches in the Khasi Hills. where for a decade it aver aged 550 inches. If entirely caught and con served it would form a column of water 45 feet high. At Cherrapunji for 40 years it aver aged 426 inches. At Calcutta it averaged 65 inches. At Ceylon from 60 to 80 inches. At Madras 55 inches. At Bombay 75 inches and in the valley of the Ganges it falls to 25 inches and in that of the Indus to 6 inches. At Poovah it is 24 inches. North of Punjab, it ranges from 70 to 80 inches and also that amount on some of the lateral spurs of the Himalayas.
There are no available records, of precipita tion in countries to the north of India, but they are light, cold and covered with snows, which are their principal source of water supply. In Burma on the west coast it averages from 157 to 196 inches. Over the Irrawadi Valley in Burma it is only 39.27 inches, but in the delta it averages 98.42 inches, In Japan the average rainfall over the whole country is 61.8 inches.
Australasia and Oceanica.— In Australia rainfall varies greatly in different sections. At Brisbane it averages 50 inches, at other places 70 inches. At Melbourne it averages. 25.6 inches, at Port Phillip from 20 to 30 inches, at Adelaide 20 inches and in some parts of the Eyre Peninsula only 10 inches and this average extends to more than M of the continent. In South Australia it averages from 8 to 10 inches. In 1889 the Department of Mines at
Sydney collated rainfall data and estimated the amount at 50 or more watering places in Aus tralia. Those showed the weekly rainfall to range from of an inch in some localities to an inch in others and still others it ranged from 225 to 3.10 inches. In most of the inhabited regions of New Zealand, rainfall ranges from 30 to 50 inches per annum. In New South Wales it ranges from 12 to 46 inches. At Hay it ranges from 10.94 to 25.84 inches.
In the Philippines there is great variation in rainfall. At Manila it averages 76 inches and ranges from 162 to 152 inches over different islands. At Kauai, one of the Hawaiian islands, it averaged for 4 years 518 inches. On the island of Mauritius rainfall on the east coast has been as high as 141 inches and on the west coast at the same lime it averaged only 27.95 In Java a rainfall ranges from 70 inches at Batavia to 174 inches at Buitenzorg.
Except as otherwise stated, the foregoing are approximately the mean annual precipitation over the localities mentioned, as nearly as the measurements extending in most cases over a period of years disclosed. They furnish some data that may be considered in estimating such sources of their water supply.
Robert Lauterberg, meteorologist of Switzer land, once suggested that most measurements fail to give all the rainfall and that ordinary measurements must be increased 25 per cent to arrive at the actual precipitation.
There are, however, many instances of well known departures from the amounts heretofore given, when in wet years or cycles of years; or localities of excessive precipitation, the maxi mum precipitation is greater than the mean an nual precipitation. There are also dry years or cycles of years and dry localities, when the minimum precipitation is less than the mean annual precipitation. Such extremes are not constant, but may be considered in determining the hydrology of a given locality.
The foregoing records and measurements of rainfall are the mean annual precipitation over periods of years. Excessive precipitation, how ever, occurs in storms, when the hourly and daily rates in the localities affected may be ex traordinary. Such storms are usually of short durafion and are confined to small areas. Records of some of such excessive precipitations and of monthly tabulations in localities, where meteorological stations are maintained, are ob tabu* from the reports of the weather bureaus of this and other countries. Most of such measurements are included in the general aver ages of mean annual rainfall iiereiribefore stated.
Disposition of Precipitation.— The dispo sition of rainfall or precipitation is quite fully considered in the article on *Water Supply,* which is to follow under that title in a succeed ing volume of this encyclopedia.