ABSTRACT
All too often as cities have expanded and man-made features have come to dominate local landscapes, it has been forgotten that natural processes still operate on any area of land. The river valleys are still there and ignoring their existence has led us to build in places subject to flooding, with catastrophic consequences for affected populations. The rains still come or fail, causing floods or droughts over which we have little real control, and with which the complex water management systems that we have devised to bring water to cities and farmland, or to hold back floodwater, cannot always cope. The winds still blow and the sun still shines, causing the atmospheric conditions which accentuate the air quality problems linked to our landuse patterns and transportation systems. While our cities have been devised to cope with a range of natural forces, we have tended to neglect the extremes, at great economic and social cost (Spirn, 1984; Hough, 1989; McHarg, 1995).
