17 

 Cenote at Chichen Itza, State of Yucatan; Wilson, 1980), but diameters of 10 m are more common. 

 Many species of small fish occur in the caves, lakes, and sinkholes (Barrera, 1964; Lipske, 1990). 

 Shallow depressions (including natural collapse features called aguadas and small pothole features 

 called sartenejas commonly occur on the surface. These depressions fill with water during Uie rainy 

 season and retain water through much of the dry season, thus providing natural sources of water for 

 wildlife, plants, and humans. 



In response to the difficulties with obtaining drinking water from natural sources, the Maya of 

 X-Hazil Sur now obtain their drinking water from personal wells near their homes as well as from 

 underground pipes connected to the village water tank and supplied by a community well. These two 

 sources are highly reliable, and water availability no longer is a problem, except during power outages 

 or due to mechanical problems with the pumps. Water potability, however, is a separate issue as 

 chemicals used to purify the water may not always be available or added as necessary to ensure water 

 purity. As a results, village residents often suffered from diarrhea. 



Climate 



The climate of Quintana Roo is warm and humid. According to the Koppen terminology, the 

 main climate category is Aw (Tropical Savanna; Garda, 1973). There are two, well-developed 

 seasons; rainy and dry. The rainy season typically lasts from May through October (Sanchez Crispin, 

 1980; not seen, cited by Careaga Viliesid, 1990). The driest two or three months typically have less 

 than 60 nun precipitation each (Wilson, 1980). Annual precipitation in the state is 900-1,600 mm and 

 mean temperature is 20-25 °C. At the Sian Ka'an Biosphere Reserve (unmediately to die east of the 

 study site), annual precipitation is 1,000-1,200 mm, while about 70 percent of the rain occurs during 

 May-October (Ohnsted and Duran, 1991). The maximum temperatures occur during May-September, 

 while die minimum temperatures occur during December-January. During the dry season, cold fronts 

 (nortes) commonly move soudiward from the United States, causing diunderstorms, overcast skies, and 

 substantially lower (ca. 10-20° change) temperatures (Wilson, 1980). These fluctuauons, however, 



