The effectiveness of urban master plans in limiting development in a disaster-prone area of China was empirically investigated by measuring cities' land-cover changes against their master plans. If a master plan serves as guidance for urban polices that reduce property loss from earthquakes, floods, landslides, land subsidence, and rises in sea level, it will substantially limit urban development in areas at risk from environmental hazards. An environmental risk map weighted toward valuable forms of land cover was generated using geospatial databases of China's Yangtze River Delta region. Based on this data, the effects of five master plan measures ring-road patterns, block size, the area of urban built-up lands, the locations of industrial sites, and preservation zoning were tested using the multiple regression method. Cities showing a high degree of compliance, in particular with preservation zoning, had a smaller amount of urban land located in high-risk zones, on average, by 14 km(2). Among the top ten cities exposed to disproportionately high risks, eight were towns and only two were cities like Huzhou and Kunshan. (C) 2012 Elsevier B.V. All rights reserved.