CORONA High-Resolution Satellite and Aerial Imagery for Change Detection Assessment of Natural Hazard Risk and Urban Growth in El Alto/La Paz in Bolivia, Santiago de Chile, Yungay in Peru, Qazvin in Iran, and Mount St. Helens in the USA

Alexander Fekete

doi:10.3390/rs12193246

Abstract

Urban growth and natural hazard events are continuous trends and reliable monitoring is demanded by organisations such as the Intergovernmental Panel on Climate Change, the United Nations Office for Disaster Risk Reduction, or the United Nations Human Settlements Programme. CORONA is the program name of photoreconnaissance satellite imagery available from 1960 to 1984 provides an extension of monitoring ranges in comparison to later satellite data such as Landsat that are more widely used. Providing visual comparisons with aerial or high-resolution OrbView satellite imagery, this article demonstrates applications of CORONA images for change detection of urban growth and sprawl and natural hazard exposure. Cases from El Alto/ La Paz in Bolivia, Santiago de Chile, Yungay in Peru, Qazvin in Iran, and Mount St. Helens in the USA are analysed. After a preassessment of over 20 disaster events, the 1970 Yungay earthquake-triggered debris avalanche and the natural hazard processes of the 1980 Mt St. Helens volcanic eruption are further analysed. Usability and limitations of CORONA data are analysed, including the availability of data depending on flight missions, cloud cover, spatial and temporal resolution, but also rather scarce documentation of natural hazards in the 1960s and 70s. Results include the identification of urban borders expanding into hazard-prone areas such as mountains, riverbeds or erosion channels. These are important areas for future research, making more usage of this valuable but little-used data source. The article addresses geographers, spatial planners, political decision makers and other scientific areas dealing with remote sensing.

Highlights

Despite knowing more and more about disaster risk, losses keep mounting, researchers have observed since at least the year 1945 [1,2]
Results are presented based on the selection process indicated above concerning urban sprawl, natural hazards and in some cases, disaster sites
The high resolution allows to visually compare gullies formed by erosion (Figure 2a, indicated by the arrows) that have been modified by construction works of the expanding city (Figure 2b) and buildings and roads exposed on both the plateau rim as well as on the steep flanks

Summary

Introduction

Despite knowing more and more about disaster risk, losses keep mounting, researchers have observed since at least the year 1945 [1,2]. Population density and exposure of settlement areas to natural hazards such as earthquakes, floods or landslides are one of the most commonly used explanatory variables for disaster risk and resulting losses, often using remote sensing data for measuring this [5,6,7]. This is reflected in the range of actions and activities fostering research and disaster risk reduction for urban areas, especially large cities within campaigns of the United Nations or private institutions, recently for example, within ‘resilient cities’ campaigns [8,9,10,11]. Monitoring on urban sprawl or land cover change considering natural hazards is demanded in the context of Climate Change by the IPCC, especially for extreme events [14], and in the context of urbanisation by UN HABITAT [15]

Objectives

Methods

Results

Discussion

Conclusion