Geoscience Reference
In-Depth Information
would not have been sui cient to sustain human populations. Most likely,
a good harvest would have yielded enough food for the current year, plus
one year's reserve, but no more. Multiyear failed harvests would have been
devastating to the growing population.
h ere is evidence that human populations were feeling the impacts
of these droughts throughout the Southwest. h e archaeological record
shows that populations at Mesa Verde in southwestern Colorado began
building dams and canals, presumably to store and then transfer water
onto terraced i elds as a response to the decreased reliability of rainfall. h e
region was occupied between about AD 550 and 1275 before it was suddenly
abandoned.
In Utah and western Colorado, the Fremont people vanished abruptly at
the same time as the Ancestral Pueblo. In many cases, the populations l ed
to high clif dwellings. Some of the evidence shows that as crops, particularly
maize, began to fail, the people hid their limited food in storage chambers
carved into the clif s. h ese may have been last-ditch ef orts to stave of
collapse. h e Sinagua culture in central Arizona also abandoned sites
throughout the region following an occupation from AD 1125 to 1300.
the impact on native californians
h e unusually dry climate during the Medieval drought appeared to
have tested the endurance and coping strategies of even well-adapted native
populations in California. Skeletal remains—bones and teeth—are used as
indicators of the health and condition of these populations. h ey show that
life in the interior of California was particularly dii cult because the drought
severely reduced sources of food (nuts, acorns, plants, deer, and other game).
Settlements along rivers were abandoned, and trade between inland and
coastal groups broke down.
As water supplies dried up, conl icts—even battles—between groups arose
over territory and resources. Populations had grown in better times prior
to the drought, leading to more territorial disputes and competition over
oak groves. Along the Southern California coast and on the Santa Barbara
Channel Islands, the Chumash Indians were then too populous to move
during the drought as they had during earlier periods of dry climate. Skeletal
evidence shows dramatic increases in malnutrition and diseases as well as
projectile injuries and head wounds, interpreted as having been inl icted
