## Abstract

To study the relationship between the effective utilization coefficient of irrigation water and canal system structure including the influences of various factors in irrigation districts, the fractal dimensions of each irrigation district by Horton's law were calculated by using canal data from 20 typical irrigation districts in Heilongjiang Province. The results showed that the fractal dimensions of the three-level irrigation districts were within the general range of the Horton water law. Of the four-level irrigation districts, only the fractal dimension of the Wutong River irrigation district was 3.037, which was beyond the upper limit of approximately 1.23%. Using gray relational analysis, the correlation degrees of four factors such as the effective irrigated area, the water-saving area ratio, the complexity of the canal structure, the channel density with the effective utilization coefficient of irrigation water and the fractal dimensions were all above 0.5 in the three- and four-level irrigation districts.