Hard or Soft Environmental Systems?

1444 22 1495 3 2939 document 1495 WP-80-025.pdf application/pdf b1e22a039f85594b9bace66e8bced29d MD5 1104479 2016-01-15 01:48:34 https://pure.iiasa.ac.at/id/eprint/1444/1/WP-80-025.pdf 1444 1 1 text en public

WP-80-025.pdf

22 eb6aa4f8fb4aef7267805d54802d11b6ce4ebc33 25314 1 37046 document 25314 indexcodes.txt text/x-c++ bc9e1b2b75ec1fe5b12735d2ea72ada4 MD5 10354 2016-01-15 19:14:35 https://pure.iiasa.ac.at/id/eprint/1444/2/indexcodes.txt 1444 2 2 text/x-c++ other Generate index codes conversion from text to indexcodes en public

indexcodes.txt

lightbox.jpg

preview.jpg

medium.jpg

small.jpg

WP-80-025.pdf

http://eprints.org/relation/isVersionOf https://pure.iiasa.ac.at/id/document/1495 http://eprints.org/relation/isVolatileVersionOf https://pure.iiasa.ac.at/id/document/1495 http://eprints.org/relation/isCoversheetVersionOf https://pure.iiasa.ac.at/id/document/1495 archive 351 disk0/00/00/14/44 2016-01-15 01:48:34 2021-08-27 17:09:59 2016-01-15 01:48:34 monograph show 4 Beck M.B. 562 Hard or Soft Environmental Systems? pub iis_env prog_ren Recent trends in lake and stream water quality modeling indicate a conflict between the search for improved accuracy through increasing model size and complexity and the search for applicability through simplification of already existing models. Much of this conflict turns on the fact that that which can be simulated in principle is simply not matched by that which can be observed and verified in practice. This paper is concerned with that conflict. Its aim is to introduce and clarify some of the arguments surrounding two issues of key importance in resolving the conflict: uncertainty in the mathematical relationships hypothesized for a particular model (calibration and model structure identification); and uncertainty associated with the predictions obtained from the model (prediction error analysis). These are issues concerning the reliability of models and model-based forecasts. The paper discusses the general problem of model calibration. This discussion exposes limitations of the existing methodology; that is to say, limitations brought about by a previously inadequate perception of the relatively hard/soft nature of water quality-ecological systems. Many methods are available for parameter estimation but few are available for solving the prior, and less tractable problem of model structure identification. The conceptual problem of model structure identification is therefore examined in more detail. The paper argues that there is an intimate relationship between prediction and model calibration. This relationship is especially important in accounting for uncertainty in the development and use of models. And using this argument it is possible to state a dilemma; a dilemma, in fact, that captures some limiting features of both large and small models. 1980-02 published WP-80-025 WP-80-025 2986 public working_paper IIASA, Laxenburg, Austria 27 FALSE info:eu-repo/semantics/book