The Second National Assessment on Natural and Related Technological Hazards calls landuse planning the single most promising approach for bringing about sustainable hazard mitigation. This article describes the essential elements of land-use planning for hazard mitigation. It highlights important choices involved in formulating planning processes, undertaking hazard assessments, and crafting programs to manage urban development so that it is more resilient to natural hazards. Research conducted over the past two decades suggests that if local governments make the right choices in crafting land-use-planning programs, communities will be less likely to suffer severe losses of lives and property in natural disasters.

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the magnitude 6.7 Northridge Earthquake struck the Los Angeles region in southern California, costing over $48 billion in direct losses and leaving 25,000 housing units uninhabitable. Exactly one year later, a magnitude 6.9 earthquake struck the Kobe region of Japan, causing approximately $150 billion in losses, the loss of over 6,400 lives, and severe damage to nearly 450,000 housing units. This paper reports on a study that sought to understand the local and individual planning and reconstruction decisions following these two earthquakes, set within the larger context of regional and national policies. It summarizes reconstruction progress and planning decisions for seven urban districts in the two affected areas. The next catastrophic urban disaster to strike a developed nation will be extraordinarily expensive, and prudence demands preparedness for both post-disaster financing and planning processes; provision of temporary and permanent housing requires external funding and local flexibility; local governments need to combine firm safety regulations with citizen participation in reconstruction planning; and post-disaster planning -to be fast, effective, equitable, and provide some improvements over previous conditions -requires well-funded planning processes, rich in information and communication.

Mode coupling theory is applied to the study of multimode optical fibers with graded-index cores. For coupling caused by random bends in the waveguide axis, the results predict the dependence of the induced losses on the fiber's characteristics. The impulse response is determined for fibers with random bends having several different power spectra. The results are used to predict the transmitted power, the delay time, and the rms pulse width in fibers with graded-index cores.

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