Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Chaco Culture' has mentioned 'Drought' in the following places:
Occurrence Sentence Text Source
[6] Climate change is thought to have led to the emigration of Chacoans and the eventual abandonment of the canyon, beginning with a fifty-year drought commencing in 1130.
[8] The region averages fewer than 150xc2xa0frost-free days per year, and the local climate swings wildly from years of plentiful rainfall to prolonged drought.
The prevailing sparseness of plants and wildlife was echoed in ancient times, when overpopulation, expanding cultivation, overhunting, habitat destruction, and drought may have led the Chacoans to strip the canyon of wild plants and game.
The cohesive Chacoan system began unravelling around 1140, perhaps triggered by an extreme fifty-year drought that began in 1130;[27] chronic climatic instability, including a series of severe droughts, again struck the region between 1250 and 1450.