Spectral analysis of forest model time series

The use of spectral analysis to elucidate the cyclic behavior in time series generated by a forest stand growth simulation model is discussed. A stand-level simulator, FORET, for an Appalachian deciduous forest is described. An estimate of the power spectral density of the total biomass time series is calculated. The power spectral density estimate indicates a dominant cyclic behavior with a period of about 200 years. In addition the spectral density is approximately bandlimited. This characteristic makes possible the application of the sampling theorem for analysis of sampling rates.     

ENHANCING EVACUATION WARNING COMPLIANCE: SUGGESTIONS FOREMERGENCY PLANNING*

This review of incentives to evacuate is meaningful largely in the context of planning for and managing the consequences of the impact of riverine floods. Of course, incentives do not constitute an emergency plan. At best, they should be seen as suggestions for structuring some elements of a plan. Furthermore, the enumeration of incentives presented here is meant to be suggestive rather than exhaustive. A primary objective of this paper has been to underscore the importance of advance planning in coping with hazards and to argue that, even though limited, existing research can be productively used in the planning process. The incentives described here are based upon or drawn from empirical research on people's performance under flood disaster conditions. This reflects the view that it is important to build emergency planning around people's known reaction patterns. Too often emergency plans which are administratively devised turn out to be based upon misconceptions of how people react (cf. Drabek and Stephenson, 1971, p. 202; Dynes et al., 1972, p. 31) and, therefore, potentially create more difficulties than they solve. One must be cautioned, however, that although our data indicate that people say they would support the idea of various evacuation incentives examined here, these are attitudinal data and not performance data. Thus, the real test of evacuation incentives lies in their implementation and in evaluation data on pilot programs which, unfortunately, do not presently exist. The outlook for the feasibility of developing and utilizing evacuation incentives appears to be positive, though, judging from responses to our interviews. In the final analysis, it would appear to be wise to develop emergency plans which guide and channel citizen actions into complementary and productive protection behavior patterns. The present discussion of incentives to evacuate is intended to encourage data-based emergency planning.