Abstract

As the latest achievement of analysis and assessment of irrigation efficiency in recent years,this book attempts to systematically discuss the knowledge and theories on irrigation water utilization efficiency,to fully elaborate on the analytical method of the efficiency within irrigation districts and regions and its application,and to analyze and study the key contributory factors,the threshold value,and the water-saving potential,and in this way to form a theoretical foundation and a technical system for the measuring and analysis of the efficiency.The whole book is divided into seven chapters,including the connotation of irrigation water use efficiency indicators,the research on measuring and analytical methods,the construction of measuring and analytical network,the development of measuring and analytical software and information management system,the analysis of key contributory factors of irrigation water utilization efficiency,the preliminary analysis of the threshold of irrigation water utilization efficiency and so on.

The main progresses made by this book are summarized as follows.

(1)The theoretical framework for the measurement and evaluation of the irrigation water utilization efficiency on national,provincial and irrigation district scales is proposed.The framework is constructed through spatial scale expansion of points and faces and function transformation by applying the amount of irrigation water as the weight.Its establishment is to meet the demand for assessing the coefficient on different scales.

(2)A multi-factor head-end measurement and analysis method for the irrigation water utilization efficiency in irrigation districts is put forward.Aiming at solving the problems in the application of traditional measurement and analysis methods,the research proposes a measurement and analysis method that is systematic,scietific,and feasible.This method is based on the definition of the coefficient.Meanwhile,complex factors of various procedures including water supply from multiple sources,water consumption by multiuser,irrigation spanning more than one year,irrigation for dealkalization or interplanting,and sufficient or insufficient irrigation are also taken into account.

(3)The sample irrigated regions of the national,provincial,and irrigation district levels are determined through quota sampling of the non-probability sampling method.Moreover,the study establishes a national measurement,analysis,and evaluation network for irrigation water utilization efficiency that consists of sample irrigation regions of different scales and types.

(4)The information management system for irrigation water utilization efficiency at provincial and notional levels is developed based on the Internet.On this basis,dynamically evaluates the annual variations of the water utilization efficiency of sample irrigated regions,provincial regions,and the whole nation have been dynamically evaluated since 2006.The results provide scientific bases for the government’s decision-making,water utilization management,development planning,and the implementation of the strictest water resources management.

(5)It preliminarily discusses the analysis method of threshold value for the water utilization efficiency in typical irrigation districts based on comprehensive factors including engineering economy and ecological environment.Then,on this basis,it puts forward the threshold value of the efficiency on national and provincial levels and discusses increasing potential of water utilization efficiency.