A
General Description of Siam
37
po and Chainat, some low hills crop out of the alluvial upper stratum. But below this scarcely any spot of greater elevation than
its
surroundings inter-
rupts the flatness of the plain and the regularity of
the slope.
The less
Lower Siam is clayey, with more or The substratum is a marine sand quartz sand. soil of
formation.
The
where not cultivated, is chiefly covered with jungle grass, where herds of elephants live on brushwood and bamboo. Extensive forests do not plain,
Except in the high tracts along the rivers, even clumps of trees are scarce in the greatest part exist.
of the plain, apparently in
consequence of occasional and want of drainage. The coast of Lower Siam is flat, with a broad,
floods
shore, and is covered with mangrove trees, and further inland with nipa groves. Lagoons and dunes do not exist.
muddy
The ground
at the coast
above ordinary high-tide
is
only slightly elevated
level, so that
extraordinary
high tides overflow a strip of the adjacent land.
The
difference
between ebb- and
three to four metres in the gulf and
water to run
when the
far
up the
flood-level
is
causes the sea-
rivers in the
dry season,
discharge of water by the rivers
is
small.