Journal of Water Resource and Protection, 2014, 6, 1228-1237 Published Online September 2014 in SciRes. http://www.scirp.org/journal/jwarp http://dx.doi.org/10.4236/jwarp.2014.613112 How to cite this paper: Cohen, I.S., Arriaga, G.E., Valle, M.A.V., Ibarra, M.A.I., Villalobos, A.M. and Hurtado, P.B. (2014) Cli- mate Based Risk Assessment for Maize Producing Areas in Rainfed Agriculture in Mexico. Journal of Water Resource and Protection, 6, 1228-1237. http://dx.doi.org/10.4236/jwarp.2014.613112 Climate Based Risk Assessment for Maize Producing Areas in Rainfed Agriculture in Mexico I. Sanchez Cohen * , G. Esquivel Arriaga, M. A. Velasquez Valle, Marco A. Inzunza Ibarra, Arcadio Muñoz Villalobos, P. Bueno Hurtado Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias, Centro Nacional de Investigación Disciplinaria en Relación Agua Suelo Planta Atmósfera (INIFAP-CENID RASPA), Km. 6.5 Canal Sacramento, Zona Industrial Gómez Palacio, Durango, México Email: * sanchez.ignacio@inifap.gob.mx , esquivel.gerardo@inifap.gob.mx , velasquez.agustin@inifap.gob.mx , inzunza.marco@inifap.gob.mx , villalobos.arcadio@inifap.gob.mx , bueno.palmira@inifap.gob.mx Received 29 July 2014; revised 27 August 2014; accepted 21 September 2014 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Rainfed areas in Mexico accounts for 14 million hectares where around 23 million people live and are located in places where there is a little climatic information. The severe drought that has im- pacted northern Mexico in the past several years as well as other parts of the country, has forced decision takers to look for improved tools and procedures to prevent and to cope with this natural hazard. For this paper, the methodology of the Food and Agricultural Organization of the United Nations (FAO) for estimating water balance variables was modified to provide crop yield estima- tions under rainfed agriculture in maize producer states of Mexico. The water balance accounts for the daily variation of soil water content having main input rainfall (Pp) and main output crop evapotranspiration (Eta). The algorithm computes crop yield using two distinctive approaches: 1) one based on surplus/deficit functions for each crop considered and 2) yield estimations based on soil water balance and water function productions of the crop being analyzed. For computing wa- ter balance and crop yields, a computer model is built that incorporates the FAO method for water balance (MODEL SICTOD: Computational System for Decision Taking, acronym in Spanish) which stochastically generate precipitation based on wet/dry transition probabilities using a first order Markov chain scheme. Maps of average crop yields were obtained after interpolating model out- comes for the main maize producer states of Mexico: Jalisco, Michoacan, Guerrero, Puebla Oaxaca and Chiapas. Different planting dates were analyzed, early (90 days of length period), interme- diate (120 days of length period) and late (150 days of length period). Crop yield variability cor- relates to the transition probability on having a wet day following a dry day. Results have shown * Corresponding author.