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Mexico City Land Cover Change from 1985 to 2016 Hilda Rocha and Andrew Cardinal University of California, Santa Barbara Geography 115C, Spring 2017, Professor Vena Chu Contact Information: [email protected] & [email protected] Introduction Figures 1 • Mexico City is the capital and the most populous city of Mexico . In 2005 its whole 1985 Classification 2000 Classification 2016 Classification metropolitan zone registered 19.2 million inhabitants2. The city has expanded over three different entities: the Federal District where it was founded originally, the State of Mexico (which now contains over 50% of the city’s population), and a portion of the State of Hidalgo that recently has been incorporated into the metropolitan zone2. As of 2016, the population of Mexico City is estimated to be 8.9 million1, while the entire metropolitan area’s is estimated to be 21.1 million1, making it the most populous metropolitan area in the Western Hemisphere1. It is located in the Valley of Mexico, at Tlalnepantla-Izcalli Tlalnepantla-Izcalli Tlalnepantla-Izcalli an altitude of 2,240 meters (7,350 feet) 1. We analyzed land cover trends over the last three decades within certain areas of the metropolitan area. • For our primary analysis, we focus on two specific sections of the greater metropolitan area which have experienced drastic growth during our study period. We are expanding upon the spatial and temporal extents of similar research that observed urbanization rates in Mexico City between 1973 and 20003. That research concluded that the urbanized area surrounding the southwest part of Mexico City has expanded at the rate of 36.29% during the 1980s3. Toluca Toluca Toluca • The government in Mexico City has implemented measures to limit urban growth and maintain natural resources in certain areas designated as Preservation Zones (Suelo de Conservacion, SC)2. The existence of the SC categorization dates to the beginning of the 1980s, when the Urban Development Plan for the Federal District developed a zoning that divided the territory into two main zones: urban and non-urban area2. However, growth continues in the SC areas despite regulations, due to a lack of effective planning norms and an increase in the living standards of the poor2. This analysis can be used to evaluate the effectiveness of those policies. Data and Methods • Images used for analysis were acquired during the winter months in the years of Dense Urban Light Urban Healthy Vegetation Sparse Vegetation Grasslands Barren Soils Water 1985, 1994, 2000, 2010 (Landsat 5 TM), and 2016 (Landsat 8 OLI). • Band display combinations of RGB 7-4-2, 7-5-3, and 3-2-1 (true color) were primarily used to select training sites. Toluca - Land Coverage Area 900 Tlalnepantla-Izcalli - Land Coverage Area 700 • Training site regions were chosen simultaneously, with all of the images linked; then 800 600 they were adjusted as necessary for each image to ensure accuracy. The images pictured above show land coverages in the greater Mexico 700 500 • A supervised maximum likelihood classification was utilized, and accuracy City Metropolitan Area with three of the five classification images 600 assessments were performed using training and assessment sites collected by produced (1994 and 2010 omitted). Two study area subsets that 500 400 400 separate parties. Producer and user accuracies for all classifications were between experienced significant growth are outlined with black boxes (Toluca to 300 the South and Tlalnepantla-Izcalli to the North). Net land cover change 300 90% and 100%. 200 200 Area Area (Square Kilometers) • Seven classes were created during classification. These were later combined and over the full study area is quantified in figure 5 below, and the two Area (square kilometers) 100 simplified into four classes for change detection and display purposes: Two urban subset area’s land coverage amounts are shown in figures 2 and 3 to 100 0 0 classes and three vegetation classes were combined into one class each. the right. Similar land coverage classes (urban & vegetation) were 1985 1994 2000 2010 2016 1985 1994 2000 2010 2016 combined and totaled for display purposes. Vegetation Baren Soils Urban Vegetation Baren Soils Urban Figure 1: Land cover, Toluca, 5 study years with combined class Figure 2: Land cover, Tlalnepantla-Izcalli, 5 study years with totals. combined class totals Study Area Queretaro Conclusions & Results Mexico City Hidalgo Study Area Land Coverage • Mexico City has undergone vast land cover changes over time, and preservation laws MEXICO Percent Change have likely had a positive effect on development in protected areas. The most rapid 200 1985-2016 growth did not occur within the preservation zones, but instead in Toluca. Tlalnepantla-Izcalli • From 1985 – 2016, for the Tlalnepantla-Izcalli subset area, water bodies increased in 157.8% area by 13.5 km2, vegetation increased in area by 36.6 km2, barren soils decreased in 150 area by 583.2 km2, and urban area increased by 160.2 km2. 120% Tlaxcala • From 1985 – 2016, for the Toluca subset area, water bodies increased in area by 2.9 Toluca 100 84% km2, vegetation increased in area by 31.8 km2, barren soils decreased in area by Mexico 529.9 km2, and urban area increased by 495.3 km2. City 50 • From 1985 – 2016, for the greater Mexico City study area (pictured right), water increased in area by 45.0 km2, vegetation increased in area by 479.9 km2, barren 0 soils decreased in area by 2,253.6 km2, and urban area increased by 1,732.8 km2. State of Mexico References -50 Morelos -55% 1 www.populationreview.com 2 Adrian Guillermo Aguilar (2008). “Peri-urbanization, illegal settlements and environmental impact in Mexico City” Cities, Volume 25, Guerrero -100 Issue 3, 133-145 Urban Vegetation Barren Soils Water 3 M. A. Torres‐Vera , R. M. Prol‐Ledesma & D. Garcia‐Lopez (2009). “Three decades of land use variations in Mexico City” Preservation Zone Puebla International Journal of Remote Sensing, Volume 30, Issue 1, 117-138 Landsat Images, USGS Earth Explorer: LC08_L1TP_026046-47_20161222_20170218_01_T1, LT05_L1TP_026046- 47_20100205_20161016_01_T1, LT05_L1TP_026046-47_20000210_20161215_01_T1, LT05_L1TP_026046- Figure 3: Mexico, with Mexico City and contiguous states. Preservation Zones highlighted in green. Study area and Toluca and Figure 4: 2016 Landsat 8 OLI 753 = RGB False Color Composite with Mexico Figure 5: Net land cover change over the full study area. 47_19940225_20170115_01_T1, LT05_L1TP_026046-47_19850131_20170219_01_T1 Tlalnepantla-Izcalli subset areas overlay. City overlay. .