'Handbook of Mesopotamia. Vol. I. 1918' [‎18] (27/568)

1.8 BOUNDARIES AND PHYSICAL FEATURES
hood of the Tigris above Mosul is sharply undulating and broken by
deep ravines.
The southern plains are open steppes of clay and gravel, clothed
with grass in spring. On the borders of the plain and the hill-
country there is some cultivation by settled agriculturists grouped
at intervals in or round large villages or small towns. In the interior
of the southern plains there are only a few semi-nomads, who raise
small patches of crops along the rivers or from rain-water wells else
where. North of the Lesser Zab the villages of the semi-nomads
become more frequent, and the plain of Erbil, where the better-
watered country begins, is comparatively well cultivated by a settled
population. The same is true of the plains between the Great Zab
and Mosul and to the north of Mosul. The country in the region of
the Zabs has a fertile soil and a fair rainfall, and might, it is
believed, be made very productive by irrigation.
(c) The Highlands of Southern and the
Diyaleh valley up to the line Jeziret-ibn-'Omar—Bitlis, Mesopotamia
is bounded on the east and north by an arc of high limestone ranges
rising to 8,000-13,000 ft. above sea-level. Between these high
mountains and the Tigris plains is the lower hill-country, where the
altitudes vary from 1,000 to 7,000 ft. above the sea. I
(i) The lower hill-country in the southern part of this area, E.
of Kufri, Kirkuk, Altun Kdprii, and Erbil, consists either of rolling
downs or of lines of rocky heights, in which sandstone predominates.
The trend of the hills is generally about NW.-SE. In spring the
downs and valleys have much grass on them. The water-supply is
fair, but in parts is rather scarce during the summer, when many of
the streams dry up altogether. Between this region and the higher
ranges are the well-watered upland plains of Suleimaniyeh and
Raniyeh. Along the border of the hills from Kufri to north of
Kirkuk petroleum appears in places.
To the north of Erbil and Mosul the hills of the submontane belt
are in general loftier and more rugged than in the down-country
farther south. In the basin of the Great Zab, conglomerate and
sandstone are found ; more to the north the limestone comes down
to the edge of the plain in the Jebel Abyadh range S. of Zakho.
The ranges run generally NW.-SE. or E.-W. The valleys are well
watered, and some are well wooded. Many of them have a fertile
soil and contain cultivation, but the country is much under-popu
lated, owing to inter-tribal and inter-racial fighting and raiding.
(ii) Along the Persian frontier the high mountain-country of
southern Kurdistan, rising to about 11,000 ft. above the sea, is well
watered by numerous streams flowing through deep valleys or gorges