Environments and People - Dragons and Tigers: A Geography of South, East and Southeast Asia - page 47

described as tropical wet and dry regimes because they ex-
perience distinct wet and dry seasons. T Tropical savannas
have an average yearly rainfall of 30 to 50 inches
(76-127 cm), most of which falls in summer. A mere 2 to
4 inches (5.08-19.16 cm) falls in the four, dry months of
winter. Savanna lands do not get particularly cold or hot.
Monthly temperatures average around 64ºF (18ºC).
Vegetation is typically xerophytic, or drought-
resistant. Savannas reveal trees, shrubs, and grasses in
various combinations depending on moisture and tem-
perature. When it is very dry , grasses become brittle and
shrivel up, and trees drop their leaves. In some places,
there are intermittent streams that only appear on the
surface in the wet season. As these evaporate in the dry
months, fish burrow into the remaining mud to survive
the drought.
Spontaneous or set fires function to maintain the
savanna. Early in the dry season (winter), “cool” fires
stimulate new growth. Late-occurring “hot” fires rage
out of control, killing trees, seeds, and every living
thing. However, in the fire aftermath, soils are more fer-
tile and better drained, and savanna lands are widely
used for grazing and crops such as grains and ground-
nuts (peanuts). However, crops rarely survive without
irrigation in dry periods. Consequently , governments
such as those of India, Pakistan, and Thailand, are de-
veloping large-scale irrigation schemes in their savanna
regions.

The Gobi , which means “waterless plain” in
Mongolian, is situated in Mongolia and northern
China. Covering an area of 500,000 square miles
(1,300,000 km 2 ), it is one of the largest deserts on
Earth and is the least populated region outside of the
polar ice caps. Winters can be extremely cold and sum-
mers unbearably hot. Because of sparse vegetation and
openness, heat loss is rapid and nights are relatively
cooler. When I spent a couple of weeks camping in
Mongolia, I wore a T T-shirt during the day and a heavy ,
wool jacket at night.
Wild, two-humped, Bactrian camels, that can sur-
vive on the limited supplies of salt water in the sesert, are
critically endangered. Only about 950 remain in the
Gobi. Also, the desert is encroaching on surrounding
grasslands. Overgrazing and the increasing use of trucks
are destroying the delicate grasses, which are soon sub-
sumed by blowing sand.
The Taklimakan covers most of the Tarim Basin in
northwestern China. With an area of 100,000 square
miles (270,000 km 2 ), it is China' is largest and most arid
desert. It is also one of the world' is biggest shifting-sand
deserts. Sand dunes cam rise as high as 1,000 feet (300 m).
Sandy areas are called shamo . There are also vast,
windswept expanses of nothing but stones and pebbles
(Figure 2-16). Diurnal temperatures (day to night) can
vary by as much as 300s. When I travelled across the
Taklimakan one summer, in a very rickety car with an
inebriated driver and no air-conditioning, the daytime
temperatures were above 120ºF (49ºC). Winter tempera-
tures can dive below minus 15ºF (-26ºC). Local wisdom
describes this desert as “the one you go into but never
come out!”

DESERTS
Xerophytic and often thorny shrubs and succulents are
found in deserts,which are defined as regions receiving
less than 10 inches (254 mm) of precipitation a year.
Some plants bloom only sporadically , waiting perhaps
years for rain. These are called ephemerals. Great
swathes of sandy or stony desert are devoid of vegetation.

Hot Desert
The Great Indian or Thar Desert of northwestern India
and southeastern Pakistan is the size of Louisiana and
North Carolina combined--that is, 92,000 square
miles (238,700 km 2 ). Most of the Thar is in the Indian
State of Rajasthan. It was here that India detonated its
first nuclear device in 1974. This arid environment
gets less than 1 inch (2.5 cm) of rain a year. In a partic-
ularly wet year, it might get almost 2 inches (5 cm).
Most (90%) of the precipitation arrives from July to
September from the wet Monsoon, which delivers tor-
rential rains elsewhere. However, rainfall here is erratic
and unpredictable. Average annual temperatures range
from 75

Cold Deserts
Montane deserts occur at very high elevations (above
10,000 feet; 3,000 m) and are exceedingly dry . These can
be found on the Tibetan Plateau and in the region north
of the Himalayas. (Refer to Figures 2-2 and 2-3). These
areas are deep in the continental interior and behind for-
midable mountains, out of reach of most moisture. They
are normally cold all year and often experience snow in
winter. The Tibetan Plateau is the largest and highest
plateau in the world and covers an area three times the
size of T Texas (950,000 mi 2 ; 2.5 million km 2 ).

to 79 Farenheit (24 -26 C) but it can get

much cooler in the winter.