对郑国渠淤灌“四万余顷”的新认识昌森《史记·河渠书》与《汉书·沟洫志》都记有秦修郑国渠的灌溉面积，即“溉泽卤之地四万余顷”，把它折成市亩有两种观点，一是以秦汉时一大亩等于０．６９市亩计，折今２８０万市亩。二是以一小亩等于０．２８８市亩计，折今１１５万... Zheng Guqin silt irrigation, “40,000 ares,” a new understanding of Chang-sen “Historical Records River Gully” and “Han ditch Chi Chi” are recorded in Qin irrigation Zheng Gu Qu irrigation area, "It folded into the city of acres have two kinds of views, one is the Qin and Han dynasties equal to 0.69 mu, accounting for 2.8 million mu. The second is equivalent to 0.288 mu per mu, discount of 115 million ...