Studies on the Hydraulic Structure and Water Qualigy Purification in the Agricultural Channel

在农业渠道水工建筑物的研究中，采用双分量电磁流速仪测量紊流流速。对农业明渠水流中存在水生植物和不存在水生植物两种情况进行了测量。利用时间序列资料计算了谱密度函数和R/S曲线，在有水生植物存在的水流中，高频区的谱密度函数在流面的斜率为-2.2，流底的斜率为-1.7--1.9。而在无水生植物存在的水流中，所有测点的平均值为-1.66。通过R/S分析，计算曲线用两条直线表示。在水质净化的研究中，我们进行了两个实验。第一个实验是关于水质的自我净化。从该实验中，我们分析了一周或两周内的悬浮固体、溶解氧、生化需氧量、化学需氧量、总氮和总磷酸盐。通过对水质的分析，计算了生化需氧量的去除速率系数和有机氮从NH_4^+-N到NO_2^--N和从NO_2^--N到NO_3^--N的反应速率系数。该装置对农业渠道水流的水质净化非常有效。

In the study on the hydraulic structure at the agricultural channel, we measured the turbulent flow velocity by the use of the electro-magnetic current meter of the two components. The measurement were conducted over two cases which an aquatic plants are in existence in the agricultural open channel flow and not. By the use of the time series data we calcutated the spectral density function and the curves of R/S.The spectral density function in the region of the high frequency were decreased in the slope of -2.2 at the flow surface and -1.7--1.9 at the flow bottom in the flow shich the aqatic plants were in existence. On the other hand it was -1.66 in the all measurement points of the flow which an aquatic plants were not in existence. From the analysis of R/S, the calcutaion curve was represented by the two lines. Moreover we calculiated the turbulent diffusion coefficients from the auto-correlation coefficeints and the measure of despersion of turbulent velocity.In the study on the purification of the water quality, we conducted two experiments. The first experiment was concered to the self-purification of the water quality. From this experiment we analyzed a suspened solid, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total nitrogen and total phosphate over a one week or two weeks period. By the analysis of the water quality, we calculated the removal velocity coefficients of the biochemical oxygen demand and the costants of the reaction speed of the organic nitrogeneous matter from NH_4^+-N to NO_2^--N and from NO_2^--N to NO_3^--N.The second experiment was studied for the artificial purification of the water quality by the use of crushed stone. This apparatus was very effective for the purification of the water quality in the agricultural channel flow.