Factors influencing effective utilization coefficient of irrigation water as determined with Horton fractal

Canal system data from 20 typical irrigation districts in Heilongjiang Province were analyzed by Horton's law to calculate fractal dimension values of each irrigation district and comparison made with theoretical fractal dimension values. The fractal dimension values of three-level irrigation district were found to be within theoretical ranges from Horton's law. But the fractal dimension value of Wutonghe Irrigation District in four-level irrigation district was 3.037, about 1.23% higher than the upper limit of the theoretical range. Grey correlation degree analysis showed that correlation degree of effective irrigation area, water-saving irrigation area proportion, canal system structure complexity, canal density and effective utilization coefficient of irrigation water were 0.695, 0.556, 0.606, 0.700 respectively, with correlation degree of fractal dimension values of 0.575, 0.585, 0.711, 0.613 respectively. The correlation degree of each factor of four level irrigation area and effective utilization coefficient of irrigation water were 0.700, 0.730, 0.605, 0.675, correlation degree with fractal dimension values were 0.763, 0.602, 0.583, 0.546 respectively. The above factors were used to make regression analysis of effective utilization coefficient and fractal dimension value of irrigation water respectively. Transformation scheme of canal system structure to improve effective utilization coefficient of irrigation water was obtained, with certain reference value for optimization of canal system structure of typical irrigation areas in Heilongjiang Province.