'Mesopotamia' [‎6v] (12/152)

2
GEOGRAPHY
[No. 92
drop of 20-50 ft., marking a former coast line, and
the great alluvial plain of Irak begins. This district,
lying between the Euphrates and Tigris, is exceedingly
fertile: its area is about 35,000 square miles. In
general the surface of the upper plain country de
creases in fertility from north to south.
Lower Mesopotamia. —Tn Irak the only noticeable
eminences are the mounds that mark the sites of dead
cities, the high banks of old canal-beds, and here and
there knolls or slight ridges of gravel or sand. The
slope of the Irak plains from the neighbourhood of
Baghdad to the Persian Gulf The historical term used to describe the body of water between the Arabian Peninsula and Iran. is very slight. Baghdad
is 105 ft. above sea-level, Kut el-Amara on the Tigris
55 ft., Nasrie on the Euphrates 15 ft., Basra 8 ft.
There are also very gradual transverse inclines away
from the rivers (due to the heightening of the river
beds by the deposit of silt), and a slope from the foot
of the Persian hills to the neighbourhood of the Tigris;
these, in so far as they determine the present flood-
areas and marshes, have great importance for the culti
vation of the country as it is to-day, and also for pro
jects of irrigation.
The soil is mainly an argillaceous, calcareous loam of
great fertility; but by far the greater part of the
country is either marshland or arid waste. In the
southern part of Irak there are extensive permanent
swamps, the water of which rises and falls with the
season. Tn addition, the winter and spring floods of
the rivers overflow into wide inundations, which gener
ally dry up in the latter part of the summer, but some
times, when they have no adequate outlets, may remain
standing for some years. The position and extent of
these temporary flood areas vary, within certain limits,
from year to year. Where and.when the country is not
swamp, it is for the most part open plain. Cultivation
is almost entirely limited to the neighbourhood-of the
rivers and canals.
The Arabian desert, where it borders on south
western Irak, is a fairly hard gravelly plain, broken
in places by belts and patches of sand. Tt is inter