Using GIS to Measure Land Use Threats to Archaeological Sites

Using GIS to Measure Using GIS to Measure Land Use Threats to Land Use Threats to Archaeological SitesArchaeological Sites

A Study of Teotihuacan, A Study of Teotihuacan, MexicoMexico

William Dietze GEOG 596A Peer Review Spring 2011William Dietze GEOG 596A Peer Review Spring 2011

Presentation OverviewPresentation Overview ProblemProblem

• Location of StudyLocation of Study• Background – PreHispanicBackground – PreHispanic• Background – ModernBackground – Modern• Municipios StatisticsMunicipios Statistics• ConservationConservation• ControversyControversy

Goals and ObjectivesGoals and Objectives Proposed MethodologyProposed Methodology

• Land Use CategoriesLand Use Categories Proposed TimeLineProposed TimeLine Preliminary ResultsPreliminary Results Further WorkFurther Work

AcknowledgementsAcknowledgements

Dr. L.J. GorenfloDr. L.J. Gorenflo

Department of Landscape Department of Landscape ArchitectureArchitecture

Pennsylvania State UniversityPennsylvania State University

Dr. Ian G. RobertsonDr. Ian G. Robertson

Department of Anthropology Department of Anthropology

Stanford University Stanford University

ProblemProblem

Continuing population increases Continuing population increases often results in the geographic often results in the geographic expansion of urban and developed expansion of urban and developed land. Archaeological sites in and near land. Archaeological sites in and near these cities are a cultural and these cities are a cultural and historical resource which must be historical resource which must be balanced against the needs of the balanced against the needs of the communities and preserved for future communities and preserved for future generations. generations.

Location of StudyLocation of Study

Teotihuacan is Teotihuacan is approximately approximately 45 km 45 km northeast of northeast of modern modern Mexico City.Mexico City.

Background – Pre-HispanicBackground – Pre-Hispanic

Teotihuacan is believed to have been Teotihuacan is believed to have been built in 100 BCE and reached the built in 100 BCE and reached the height of its population around 550 height of its population around 550 CE. At its peak it is estimated to CE. At its peak it is estimated to have had a population of over have had a population of over 100,000, spanned approximately 20 100,000, spanned approximately 20 square kilometerssquare kilometers

René Millon’sRené Millon’s Teotihuacan Mapping Project (TMP)Teotihuacan Mapping Project (TMP)

Background – ModernBackground – Modern

Two Two municipios municipios (or municipalities, similar (or municipalities, similar to counties in the US) overlay the extent of to counties in the US) overlay the extent of Teotihuacan – San Juan Teotihuacan and Teotihuacan – San Juan Teotihuacan and San Martín de las Pirámides .San Martín de las Pirámides .

Approximately 80% land use in these Approximately 80% land use in these municipiosmunicipios is agriculture with only 7% is agriculture with only 7% urbanurban

Both have shown a marked population Both have shown a marked population increase of 15% - 20% between 2000 and increase of 15% - 20% between 2000 and 2010.2010.

San Juan Teotihuacan

San Martín de lasPirámides

Environment (2005)

Square Km

Percent SquareKm

Percent

Total Area 83.16 67.22

Agriculture 72.18 86.80% 49.46 73.58%

Grassland 2.54 3.05% 6.16 9.16%

Forest 0 0 .24 0.36%

Xeric Bush 2.87 3.45% 7.18 10.68%

SecondaryVegetation

0 0 2.35 3.50%

Urban 5.56 6.69% 1.83 2.72%

MunicipiosMunicipios

Population Growth

24,851

46,77944,556

53,010

6,667

10,477

3,717 5,425

21,511

19,689

0

10,000

20,000

30,000

40,000

50,000

60,000

19

30

19

40

19

50

19

60

19

70

19

80

19

90

20

00

20

10

Year

Po

pu

lati

on

San Juan Teotihuacan

San Martín de las Pirámides

ConservationConservationTeotihuacan was entered into the UNESCO

World Heritage List in 1987. In 1988, the Monuments Archaeological Zones Decree expanded the original zone set in 1965 and established three defined areas surrounding the central monuments:

•Zone A – Central Area of Archaeological Monuments.

•Zone B – Extended Area of Archaeological Monuments.

•Zone C – General Protection Area.

Archaeological Archaeological ZonesZones

ControversyControversy

In 2004, a Wal-Mart was built in Zone In 2004, a Wal-Mart was built in Zone C. Although outside of the restricted C. Although outside of the restricted monuments zones A and B, many felt monuments zones A and B, many felt this commercialized the site and this commercialized the site and there were allegations that artifacts there were allegations that artifacts were destroyed.were destroyed.

ControversyControversy

In 2009, INAH granted permission for a In 2009, INAH granted permission for a sound and light show “Teotihuacan sound and light show “Teotihuacan Resplendence”. Resplendence”.

The installation involved metal structures, The installation involved metal structures, 2,500 lights, and over 3 kilometers of 2,500 lights, and over 3 kilometers of electrical cable. Workers drilled over electrical cable. Workers drilled over 8,000 holes into the pyramids to secure 8,000 holes into the pyramids to secure the lights and framework.the lights and framework.

Following national and international Following national and international outcry, the show was cancelled.outcry, the show was cancelled.

Goals and ObjectivesGoals and Objectives

Examine the loss of the Teotihuacan Examine the loss of the Teotihuacan site due to changing modern land site due to changing modern land use patterns in the Mexico Valleyuse patterns in the Mexico Valley• Special regard to impact on Zones A, B, Special regard to impact on Zones A, B,

and C.and C.• Determine what impact expanding Determine what impact expanding

settlement and agriculture have had on settlement and agriculture have had on the site.the site.

Proposed MethodologyProposed Methodology

Define the study area rendered as a GIS Define the study area rendered as a GIS polygon.polygon.

Identify extent of ancient Teotihuacan and Identify extent of ancient Teotihuacan and render as a GIS polygon.render as a GIS polygon.

Identify land use patterns from aerial Identify land use patterns from aerial imagery and other geospatial data.imagery and other geospatial data.

Calculate percentage of the prehistoric Calculate percentage of the prehistoric site that is impacted by modern land use site that is impacted by modern land use practices.practices.

Land Use CategoriesLand Use Categories

Undeveloped – denoted by a Undeveloped – denoted by a minimal presence of structures minimal presence of structures and no apparent foliage and no apparent foliage patterns.patterns.

Agricultural – denoted by a Agricultural – denoted by a minimal presence of structures minimal presence of structures but regular patterns of plant but regular patterns of plant life.life.

Urban – denoted by a moderate Urban – denoted by a moderate to high density of structures.to high density of structures.

Proposed TimeLineProposed TimeLine

This project is dependent principally This project is dependent principally on the acquisition of historical on the acquisition of historical imagery and/or historical topographic imagery and/or historical topographic and street maps in digital form.and street maps in digital form.

Current imagery is immediately Current imagery is immediately available through Google Earth and available through Google Earth and ArcGIS Online.ArcGIS Online.

Preliminary ResultsPreliminary Results

Zone B has the same protections as Zone Zone B has the same protections as Zone A, but approximately 11% has been A, but approximately 11% has been developed.developed.

Zone A shows a very small percentage of Zone A shows a very small percentage of urbanization which are the result of later urbanization which are the result of later archaeological finds in urban areas that archaeological finds in urban areas that were afforded Zone A protection.were afforded Zone A protection.

Zone C has less restrictions, and nearly Zone C has less restrictions, and nearly 47% has been developed.47% has been developed.

Land Use of Archaeological Zones

0

500

1,000

1,500

2,000

Archaeological Zone

He

cta

res

Total Zone 295.52 1,419.23 1,559.46

Within TMP 295.52 1,366.00 1,159.14

Urbanized 7.33 159.48 729.25

Zone A Zone B Zone C

Preliminary ResultsPreliminary Results Areas identified as Areas identified as

most critical are most critical are those regions those regions within the extents within the extents determined by the determined by the TMP but fall outside TMP but fall outside the protected the protected archaeological archaeological zones.zones.

Further WorkFurther Work

1.1. Measure the expansion of urban Measure the expansion of urban areas within the study zone over areas within the study zone over time that impact the site.time that impact the site.

2.2. Determine the expansion of farming Determine the expansion of farming areas with the shift to mechanized areas with the shift to mechanized agriculture. agriculture.