Maps, Aerial Photos and Satellite Images on Environment Change - A Case Study of the Chenyoulan River Watershed, Taiwan Maps, Aerial Photos and Satellite Images on Environment Change - A Case Study of the Chenyoulan River Watershed, Taiwan I-Chun Fan Research Fellow, Institute of History and Philology, Executive Officer, Center for Geographic Information Science, Research Center for Humanities and Social Sciences, Academia Sinica

Overview 2 Archiving Maps, Remote Sensing Imagery Archiving Maps, Remote Sensing Imagery at GIS Center, Academia Sinica at GIS Center, Academia Sinica What the Maps and Remote Sensing Imagery can Help on the Studies of Enviroment Changes What the Maps and Remote Sensing Imagery can Help on the Studies of Enviroment Changes Case study of Landscape Changes in the Chenyoulan River Watershed, Taiwan Case study of Landscape Changes in the Chenyoulan River Watershed, Taiwan

3 Digital Archives of Maps and Remote Sensing Imagery at GIS Center URL: URL: 3 Topographic Map of Taiwan (1882) Formoza Island(1845)Aerial Photo (1946)

WebGIS-based Remote Sensing Imagery Management System Query System Digitizing Process Remote Sensing Aerial Photos 33,892 aerial photos of Taiwan during the 1940s. 25,788 aerial photos of China during the 1950s. More tahn15,000 rolls of aerial photo negatives total, (c. 2,000,000 sheets) Historical Maps Around 100,000 maps of China. Around 30,000 maps of Taiwan. Remote Sensing Aerial Photos 33,892 aerial photos of Taiwan during the 1940s. 25,788 aerial photos of China during the 1950s. More tahn15,000 rolls of aerial photo negatives total, (c. 2,000,000 sheets) Historical Maps Around 100,000 maps of China. Around 30,000 maps of Taiwan. Content Management Systems

Issues Clarified through Maps, Aerial Photos and Satellite Images in Historical Perspective Issues of Land Use and Socio-economic Developments (Deforestation, Cultivation, Roads) Hillside Disasters (Landslides, Deris Flows) Long Time Scale Settlement Distribution Geomorphological Change and River Rehabilitation Environmental Conservation Issues Historical transition Short Time Scale Spatio-temporal GIS Platform

6 Study Area - The Chenyoulan River Watershed Area: 448 km2 Area: 448 km2 Length: 42.4 km Length: 42.4 km With Steep Slope With Steep Slope Many River Terraces Many River Terraces High Turbidity Stream Flow High Turbidity Stream Flow Many Landslides & Debris Flows occurred Many Landslides & Debris Flows occurred National Forest Area & Aboriginal Reserved lands National Forest Area & Aboriginal Reserved lands

Rectification & Georeferencing of Maps, Aerial Photos and Satellite Images Using Watershed boundaries as Ground Control Points

Application of the High Resolution DTMs to Generate Precise Watershed Boundaries 5m 10m 20m 30m 40m

2D Images of the Chenyoulan River Watershed 9

10 3D-Platform of the Chenyoulan River Watershed

Geomorphological Changes of the River Terrace and Landslides (3D) 11

The Spatio-temporal Framework of the Chenyoulan River Watershed, 1946~2010- Extended Issues Spatial correlation between deforestation, cultivation, roads and landslides Spatial correlation between deforestation, cultivation, roads and landslides 12

Land Use of the Chenyoulan River Watershed from

Reserved Area of the Indigenous People in the Chenyoulan River Watershed -Restricted Stages (1946) -Green: Deforestation area; Red: Cultivation ; Pink: Landslides

Reserved Area of the Indigenous Peoples in the Chenyoulan River Watershed - Interim between Restricted and Developed Stages (1971) -Green: Deforestation area; Red: Cultivation; Pink: Landslides

Reserved Area of the Indigenous People in the Chenyoulan River Watershed - Contemporary Situation(2011) -Green: Deforestation area; Red: Cultivation; Pink: Landslides

Spatial Correlation between Deforestation, Cultivation, Roads and Landslides by 1946 Large deforestation areas Large deforestation areas Few landsilde occurred in deforestation area Few landsilde occurred in deforestation area 17

Spatial Correlation between Deforestation, Cultivation, Roads and Landslides by1971 Deforestation area reduced and fragmented Deforestation area reduced and fragmented Increase of cultivation and roads Increase of cultivation and roads Small landslides increased Small landslides increased 18

Spatial Correlation between Deforestation, Cultivation, Roads and Landslides by 2002 Deforestation area was fully recovered Deforestation area was fully recovered Land cultivation grew with road development Land cultivation grew with road development Many new landsildes occurred along roads Many new landsildes occurred along roads 19

Conclusion  Visualization of Landscape Changes.  Spatial Qualitative to Quantitative Analysis.  Building A Spatio-temporal Platform Serves for Interdisciplinary Approach to the Environmental Issues

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