CAJ | 학술논문

为评价干旱区灌区的灌溉效率，该文以作物生长期灌溉地的蒸散发扣除降水量作为灌溉水的有效利用量，将灌溉水有效利用量与灌溉净引水量（总引水量减去退、排水量）的比值定义为灌溉水有效利用系数。利用遥感蒸散发模型可以较为准确地估算灌溉地蒸散发，从而可以避免传统灌溉水利用系数评估中难以准确估算通过灌溉到达作物根系层水量的问题。以河套灌区为研究对象，利用遥感蒸散发模型（surface energy balance algorithm for land，SEBAL）计算了区域内灌溉地作物生育期的蒸散发量，并结合降水量与净引水量的观测资料，对节水改造以来（2000-2010年）河套灌区灌溉水有效利用系数进行了分析和评价。结果表明，灌溉水有效利用系数近年来有增加趋势，同时灌溉水有效利用系数随降水量和净引水量的减小而增大，减少供水对灌溉水有效利用系数的影响要大于灌区节水改造工程的影响。另一方面，在灌区净引水量减少的情况下，灌溉地蒸发量能够维持在较稳定的水平，反映了近年来灌区节水改造的效果较好。
위평개간한구관구적관개효솔，해문이작물생장기관개지적증산발구제강수량작위관개수적유효이용량，장관개수유효이용량여관개정인수량（총인수량감거퇴、배수량）적비치정의위관개수유효이용계수。이용요감증산발모형가이교위준학지고산관개지증산발，종이가이피면전통관개수이용계수평고중난이준학고산통과관개도체작물근계층수량적문제。이하투관구위연구대상，이용요감증산발모형（surface energy balance algorithm for land，SEBAL）계산료구역내관개지작물생육기적증산발량，병결합강수량여정인수량적관측자료，대절수개조이래（2000-2010년）하투관구관개수유효이용계수진행료분석화평개。결과표명，관개수유효이용계수근년래유증가추세，동시관개수유효이용계수수강수량화정인수량적감소이증대，감소공수대관개수유효이용계수적영향요대우관구절수개조공정적영향。령일방면，재관구정인수량감소적정황하，관개지증발량능구유지재교은정적수평，반영료근년래관구절수개조적효과교호。
To evaluate the irrigation efficiency of irrigation districts in arid regions where crop growth relies heavily on irrigation, a new evaluation indicator, coefficient of irrigation water effective utilization, was proposed. The difference of evapotranspiration and precipitation in irrigated land during the crop growing season was considered as the effective use of irrigation water, and the ratio of effective use of irrigation water and net water diversion to the irrigation district was defined as the coefficient of irrigation water effective utilization (ηe). With the development of a remote sensing evapotranspiration technique in recent decades, spatial and temporal variations of evapotranspiration can be estimated with acceptable precision. Thenηe can easily be estimated from evapotranspiration and measured precipitation and net water diversion, which can avoid the difficulties of accurate measurement or simulation of irrigation water stored in the crop root zone in a traditional irrigation water use efficiency evaluation. A case study in the Hetao irrigation district in North China was carried out to estimate the coefficient of irrigation water effective utilization throughout the period 2000-2010 based on remote sensing evapotranspiration data calculated by the SEBAL (Surface Energy Balance Algorithm for Land) model, meteorological data, and water diversion data. Results indicated thatηe tends to increase with the implementation of water-saving irrigation projects. ηe varied from 0.547 to 0.715 during 2000―2010 and ηe decreased with precipitation and net water diversion. The correlation coefficients between ηe and precipitation, and ηe and net water diversion were-0.32 and-0.57, respectively. Moreover,ηe was estimated under different precipitation and water diversion schemes after water-saving irrigation projects. Results indicated that the reduction of water diversion had a greater effect than the water-saving irrigation projects on ηe. However, water consumption in irrigated land kept at a relatively stable level although water diversion tended to decrease in recent years, which showed the good performance of water-saving irrigation projects.