Incremental adaptation strategies for agricultural water management under water scarcity condition in Northeast Iran

Population growth and climate changes as two synergistic phenomena have damaged water resources nationwide and worldwide.The water resources available for agriculture is one of the most critical limiting factors in food production enhancement in Iran.Agriculture must tackle the challenge of supplying the increasing demands for food due to population growth.For this purpose,we must get acquainted with how farmers make decisions and their adaptations to water scarcity conditions by studying their adaptation strategies.In this case,we can predict the farmers’behaviors by recognizing the optimal adaptation strategies under water scarcity crisis.This study aims to provide a model to examine and analyze the farmers’behaviors in the realm of water scarcity and the contributing factors to it,facilitating a better understanding of the potential implications of such scarcity,introducing the adaptation changeability procedures for agricultural water management and assistance to farmers to adapt,and developing the actions for mitigating the vulnerability of agriculture sector in Iran.In this study,175 farmers in Northeast Iran were interviewed to conduct an applied research by questionnaire survey.The research tool was a researcher-made questionnaire designed based on the theoretical literature and designed model.According to the research,the model of incremental adaptation strategies could determine the effects of a set of psychological and socioeconomic factors and the formation of adaptation decisions in water resources management under water scarcity conditions.The results indicated that the concern and attitude,farmers’knowledge and technical skill,self-efficiency and risk-taking level,social capital and information availability for farmers,and the internal norm are significantly and positively correlated in this model.The results provide a proper understanding of farmers’sustainable decision-making and a perspective on contributing factors to the strategy framework and improved policies in the form of incremental adaptation strategies when facing water scarcity in agricultural water resources management.Thus,this study will respond to deal with water scarcity by changing farmers’behaviors in dry lands and water scarce regions.

Nonlinear adaptive switching control for a class of non-affine nonlinear systems

An improved nonlinear adaptive switching control method is presented to relax the assumption on the higher order nonlinear terms of a class of discrete-time non-affine nonlinear systems. The proposed control strategy is composed of a linear adaptive controller, a neural network(NN) based nonlinear adaptive controller and a switching mechanism. An incremental model is derived to represent the considered system and an improved robust adaptive law is chosen to update the parameters of the linear adaptive controller. A new performance criterion of the switching mechanism is designed to select the proper controller. Using this control scheme, all the signals in the system are proved to be bounded. Numerical examples verify the effectiveness of the proposed algorithm.