漏水率在日本趋于逐年减少,1979年度末日本全国平均为16.5％。从水量上看,约为一个人口20万的城市用水量的一百倍左右。如设管道漏水量为(Q),则漏水孔的断面积(a)与水压(P)的函数以式(1)表示。 Q=caP~η (1)式中:c——漏水孔形状等的系数; η——系数。系数η有两种说法:一种说法为0.5;另一种说法为1.15。前者认为是小孔漏水,后者认为是地下渗流漏水。这种关系近于达 The leakage rate in Japan tends to decrease year by year. At the end of 1979, the national average was 16.5%. In terms of water quantity, it is about one hundred times that of a city with a population of 200,000. If the leakage of the pipe is (Q), the function of the area (a) of the leakage hole and the water pressure (P) is expressed by Equation (1). Q=caP~η (1) In the formula: c—coefficient of the leakage hole shape, etc.; η—coefficient. There are two arguments for the coefficient η: one is 0.5; the other is 1.15. The former believes that the small hole is leaking, and the latter thinks that it is a leakage of underground seepage. This relationship is close to reaching