This division lies closely hemmed in between
high mountains and the sea. The surface features
include small and isolated valley lowlands, bordered by hills and backed by high mountain
ranges. The heavy rains in the highlands feed
numerous torrential streams. The gravels and
sands which they bring down with them to the
lowlands are piled up in huge alluvial fans along
the piedmonts. Delta plains grow where the
rivers flow into the sea. Owing to the concentration of rain in the winter season, the regimen of
these streams shows a maximum in that season.
However, where the streams rise high enough in
the mountains to reach the snow fields, the maximum flow comes during the melting period in the
spring. The removal of forest from the mountains
has seriously changed this regimen in many
areas. The removal of the forest causes severe
floods during the winter and spring, and during
the summer these floods are followed by
droughts, when the streams dry up. The original
forest cover of most of the regions bordering the
Mediterranean Sea has largely been removed,
seriously affecting the habitability of the
lowlands.
References
Borchert JF (1950) The climate of the central North
American grassland. Ann Assoc Am Geogr 40:1–39
James PE (1959) A geography of man, 2nd edn. Ginn,
Boston, 656 pp
Jenny H (1941) Factors of soil formation. McGraw-Hill,
New York, 281 pp
Thornthwaite CW (1931) The climates of North America
according to a new classification. Geogr Rev
21:633–655, with separate map at 1:20,000,000
Trewartha GT (1968) An introduction to climate, 4th edn.
McGraw-Hill, New York, 408 pp
Walter H, Harnickell E, Mueller-Dombois D (1975)
Climate-diagram maps of the individual continents
and the ecological climatic regions of the earth.
Springer-Verlag, Berlin, 36 pp, with 9 maps
68
6 The Humid Temperate Ecoregions
high mountains and the sea. The surface features
include small and isolated valley lowlands, bordered by hills and backed by high mountain
ranges. The heavy rains in the highlands feed
numerous torrential streams. The gravels and
sands which they bring down with them to the
lowlands are piled up in huge alluvial fans along
the piedmonts. Delta plains grow where the
rivers flow into the sea. Owing to the concentration of rain in the winter season, the regimen of
these streams shows a maximum in that season.
However, where the streams rise high enough in
the mountains to reach the snow fields, the maximum flow comes during the melting period in the
spring. The removal of forest from the mountains
has seriously changed this regimen in many
areas. The removal of the forest causes severe
floods during the winter and spring, and during
the summer these floods are followed by
droughts, when the streams dry up. The original
forest cover of most of the regions bordering the
Mediterranean Sea has largely been removed,
seriously affecting the habitability of the
lowlands.
References
Borchert JF (1950) The climate of the central North
American grassland. Ann Assoc Am Geogr 40:1–39
James PE (1959) A geography of man, 2nd edn. Ginn,
Boston, 656 pp
Jenny H (1941) Factors of soil formation. McGraw-Hill,
New York, 281 pp
Thornthwaite CW (1931) The climates of North America
according to a new classification. Geogr Rev
21:633–655, with separate map at 1:20,000,000
Trewartha GT (1968) An introduction to climate, 4th edn.
McGraw-Hill, New York, 408 pp
Walter H, Harnickell E, Mueller-Dombois D (1975)
Climate-diagram maps of the individual continents
and the ecological climatic regions of the earth.
Springer-Verlag, Berlin, 36 pp, with 9 maps
68
6 The Humid Temperate Ecoregions