基于AHP与Rough Set的农业节水技术综合评价

Abstract

The agricultural water-saving technologies and their application conditions are different in different regions with different natural conditions,so it is difficult and uncertain to evaluate the existing agricultural water-saving technologies.It has great significance to select reasonable evaluation indexes and build a more scientific and comprehensive model that will help to evaluate the agricultural water-saving technologies.According to field surveys and the Delphi method,this paper selected nine indexes from twenty evaluation indexes of agricultural water-saving technology.Water-saving rate,accumulated temperature and soil fertility are ecological factors;output/input,labor input and economy input are belong to economic factors,while the reliable of technical,technical level and the acceptance from farmers are the social factors.Based on these nine indexes,a comprehensive and systematic evaluation index system of agricultural water-saving technology was constructed,allowing avoiding information overlap.This paper proposed a full evaluation model(ARM) based on Analytic Hierarchy Process(AHP) and Rough Set,which introduced the experience factor to revise the indexes weight by AHP and Rough Set.Using AHP,Rough Set and ARM,the existing major agricultural water-saving technologies,such as plastic mulch,straw mulch and furrow irrigation technologies were evaluated in Wuwei City,in the Gansu province.In the evaluation of plastic mulch technology,AHP emphasized a very high economic benefit(0.44),while Rough Set was most important in ecological benefit(0.33) and social benefit(0.32),failing the economic benefits(0.05).ARM revised the evaluation results of those two methods,and obtained the economic,ecological and social benefits of plastic mulch technology,was 0.36,0.20 and 0.13 respectively.However,in the evaluation of straw mulch technology,there was a significant difference in the results by Rough Set,where ARM obtained the economic,ecological and social benefits was 0.09,0.18 and 0.06 respectively.In the evaluation of furrow irrigation technology,Rough Set emphasized the ecological benefit about 0.28.After the revision of the evaluation results of those two methods,ARM obtained the economic,ecological and social benefits,was 0.24,0.01 and 0.13 respectively.Generally,evaluation results of ARM showed that plastic mulch technology gave the best economic benefit.Moreover the ecological benefit of plastic mulch and straw mulch technologies were higher by 0.19 and 0.17 than furrow irrigation technology,and this might be mainly due to the fact that straw mulch technology could keep moisture,increase soil organic matter and adjust the ground temperature in the late growth stages of maize.In addition,it emerged that plastic mulch technology could save more water as well as improve the ground temperature at seedling stage.Compared with straw mulch technology,the social benefit by plastic mulch technology and furrow irrigation technology was higher by 112.12% and 18.18% respectively,which shows that those two technologies present a strong social character,in the semi-arid areas of He Xi region.Therefore,plastic mulch technology is likely to result the best agricultural water-saving technology in maize cropping,whereas straw mulch technology demonstrated a high ecological benefit but low economic benefit,which does not fit the conditions of the Northwest of China.Based on Rough Set and AHP,ARM combined the subjective knowledge with the objective factors,could effectively overcome the problem that many of the evaluation models determined the weight subjectivity,thus the evaluation results become more realistic,which provided a scientific and simple evaluation method of agricultural water-saving technology.