Available online at www.sciencedirect.com Mathematics and Computers in Simulation 80 (2010) 887–893 A fuzzy soft flood alarm model Sunny Joseph Kalayathankal a,∗ , G. Suresh Singh b a Department of Mathematics, K.E. College, Mannanam, Kottayam, 686561, India b Department of Mathematics, University of Kerala, Trivandrum, 695581, India Received 4 February 2006; received in revised form 14 October 2009; accepted 16 October 2009 Available online 12 November 2009 Abstract A wide range of hydrological analyses for flood, water resources, water quality, ecological studies, etc., require reliable quantification of rainfall inputs. This work illustrates a fuzzy analysis that has the capability to simulate the unknown relations between a set of meteorological and hydrological parameters. A fuzzy approach to flood alarm prediction based on the fuzzy soft set theory is applied to five selected sites of Kerala, India to predict potential flood. © 2009 IMACS. Published by Elsevier B.V. All rights reserved. AMS Classification: 03B52; 94D05; 68T37 Keywords: Rainfall; Fuzzy soft set; Flood; Simulation 1. Introduction Rainfall being the dominant component in most hydrological systems, reliable quantification of rainfall is absolutely essential for various ecological, meteorological, geo-morphological and disaster management studies. Since the occurrence and distribution of rainfall over a region is controlled by many independent factors, reliable forecasting becomes a complex exercise. A challenging task for catchment management and flood management in particular is the creation of a reliable quantitative rainfall forecast. Accurate forecasts of the spatial and temporal distribution of rainfall are useful for flood warning. A flood warning system for fast responding catchments may require a rainfall forecast to provide sufficient lead time for early warning. A flood warning system is a non-structural measure for flood mitigation. Several parameters are responsible for flood related disasters and a quick-responding flood warning system is required for effective flood mitigation measures. Major atmospheric parameters affecting floods are rainfall, wind speed, wind direction, relative humidity and surface pressure. River and topography are two geographical parameters that directly impact rainfall and water dissipation. This paper investigates the potential of fuzzy soft set theory in real-time flood warning. Molodtsov [6] initiated the concept of soft set theory as a new mathematical tool for dealing with uncertainties. Soft set theory has rich potential for applications in several directions, a few of which had been shown by Molodtsov [6] in his pioneer work. In the present paper we use fuzzy soft sets, establish some results on them and develop an algorithm followed by simulation for flood warning in five important locations in the state of Kerala, India. ∗ Corresponding author. Tel.: +91 4812596606; fax: +91 4812590915. E-mail address: sunnyjose2000@yahoo.com (S.J. Kalayathankal). 0378-4754/$36.00 © 2009 IMACS. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.matcom.2009.10.003