Milpa Alta - Geography and Environment

Geography and Environment

The borough of Milpa Alta is located in the southeast of the Federal District of Mexico City bordering the boroughs of Xochimilco, Tláhuac and Tlalpan, with the state of Morelos to the south and the State of Mexico to the west. It has the second largest territorial extension after Tlalpan, occupying 268.6km2. .

The terrain is rugged mostly consisting of volcanic peak along with some small flat areas mostly formed in the Cenozoic Era . City officials have classified the entire borough as a conservation zone, important for its role as an aquifer recharge area as well as its forests. Forest, farmland and grazing areas constitute 98.1% of the total surface area.

It has an average altitude of 2,420 meters above sea level with altitudes varying between 2,300 and 3,600. It is part of the Trans-Mexican Volcanic Belt and the Sierra Chichinautzin volcanic mountain chain, which separates the Federal District from the state of Morelos. The borough is divided into three zones: Ajusco-Teuhtli, the lowest elevations, Topilejo-Milpa Alta in the medium range and Cerro-Tlicuaya at the highest elevations. The main elevations are volcanic and include Cuautzin (3,510), Tulmiac, Ocusacayo (3,220), La Comalera (3,230), San Bartolo (3,200), Tláloc (3,510), Chichinautzin (3,470), Yecahuazac, Quimixtepec, El Oclayuca (3,140), El Pajonal (3,100), El Ocotécatl (3,480), Acopiaxco (3,320), Tetzacoatl (3,310), Tehutli (2,800) Cilcuayo (3,580), Nepanapa (3,460), Texalo (3,560), Oclayuca (3,390), San Miguel (2,988) .

The area belongs to the Amacuzac River basin but only small streams run on the surface. It has ample surface water but confined to small springs and streams which over time have formed a succession of narrow valleys or micro-basins, which are important for recharging the Valley of Mexico’s aquifers. These micro-basins include Cilcuayo, Río Milpa Alta and Cocpiaxco and contain the borough’s main towns.

Most of the area has a temperate climate, with cold climates found at the highest elevations. The average annual temperature is 15.6C with average lows at 13.7C and averages highs at 16.6C. Average annual precipitation is 731mm. Freezing temperatures occur occasionally from October to March especially in the higher elevations. The windiest months are February and March. On the Koppen scale, its climate is described as C (W2) (w) b (i’) which signified a relatively moist climate, with a rainy season in the summer especially in July and August. However, the climate varies substantially in the territory based mostly on altitude, with six sub-climates: C(E)(w2) which is relatively cold, C(E)(m) also relatively cold but wetter, C(w1) a temperate climate, C (w2) a températe and relatively wet climate, C ( w1) temperate and relatively dry and C ( w2) which is relatively cold with rains falling mostly in the highest areas.

The area has a number of species found nowhere else. The natural vegetation is mostly forest with a mix of pine, oyamel fir and holm oak, with some concentrations of Abies religiosa. The most intact forest is found in the small canyons of the Nepanapa volcano and the west side of the Tláloc volcano. Other vegetation include fruit trees such as tejocote (Crataegus pubescens), capulin (Prunus serotona ssp capulli) blackberry (Rubus adenotrichus) and well as various scrubs, grass and flowers. The rugged terrain presents a number of micro climates which favor certain species. Depending on conditions oak, cedar, strawberry trees (Arbutus sp), pirul (Schinus molle), tepozan (Buddleia cordata), nopal cactus and maguey can be found. Wildlife includes 59 species of mammals such as zacatuche rabbits (Romerolagus diazi), which in danger of extinction along with coyotes, deer, lynx and moles. However only sixteen of these species are still commonly seen because of habitat destruction. Species such as wild boar, bobcats and opossums are extinct in the area. There are about 200 bird species native to the area in 128 classes, 33 families and eleven orders. Eighty percent of the species live in the area year round. There are twenty four amphibian species from ten classes, seven families and two orders and fifty six species of reptiles from thirty one classes, ten families and two orders. A notable areas for these two classes of animal is the corridor between the Ajusco and Chichinautzin mountains.

While named after Villa Milpa Alta, the borough is not concentrated on a single community like Tlahuac or Xochimilco but rather is composed of twelve main towns all of which are rural. This limits the area’s connectivity with the urban zone of Mexico City. Main communities in the borough include San Pedro Atocpan, Villa Milpa Alta (formerly called Malacachtepec), San Bartolome Xicomulco, San Francisco Tecoxpa, Santa Ana Tlacotenco, San Lorenzo Tlacoyucan, San Juan Tepanahuac, San Agustin Ohtenco, San Antonio Tecómitl, San Pablo Oztotepec and San Jerónimo Miacantla. San Agustin Ohtenco is considered to be the smallest community in the Federal District of Mexico City. These main towns are subdivided into twenty nine neighborhoods called barrios and there are 225 communities in the borough total.. Villa Milpa Alta has seven barrios, San Mateo (the largest), La Concepción, Los Angeles, Santa Cruz, San Agustin, Santa Martha and La Luz.