基于分形理论的察尔森灌区渠系水利用效率分析

Analysis on water utilization efficiency of canal-system on fractal theory in Chaersen irrigation district based

为研究灌区渠系布置结构和渠系水利用效率之间关系,更合理指导灌区进行渠系节水改造和灌溉管理,应用分形理论对察尔森灌区各灌域渠系布置结构与渠系水分利用效率进行评价,根据察尔森灌区现状渠系资料,采用Horton河系定律计算了各灌域的分形维数(好田1.3,义勒力特3.6,乌兰哈达2.5,斯力很1.6,国光1.7,哈达那拉1.8),在此基础上,结合2013—3014年实际测算数据,分析了各灌域的分维数和渠系水利用效率的关系。结果表明:各灌域渠系水利用效率与分维数之间基本呈大开口抛物线,随分维数(D)增大,渠系水利用效率先减小后增大;察尔森灌区各灌域可通过适当降低分维值以提高渠系水利用效率;未来通过减少斗渠长度同时增加支渠数目与长度的措施是察尔森灌区提高渠系水利用效率的方向之一。

In order to provide a guidance for the canal water saving transformation and irrigation management,the relationship between the canal-system framework and the efficiency of water utilization in canal-system in Chaersen irrigation district were explored by using the fractal theory. The fractal dimension of the irrigation regions in Chaersen irrigation district(1. 3 for Haotian,3. 6 for Yilelite,2. 5 for Wulanhada,1. 6 for Silihen,1. 7 for Guoguang,1. 8 for Hadanala) was calculated by the Horton River's law with the observation data on the irrigation canal system. The fractal dimension,combined with the actual measured data in 2013—2014,was used in analyzing the relationship between the fractal dimension and the efficiency of water utilization in canal-system. The results indicated that the efficiency of water utilization in canal-system and the fractal dimension of the irrigation regions showed a large opening parabola,the efficiency of water utilization in canal-system decreasing first and then increasing with the increase of the fractal dimension(D). The efficiency of water utilization in canal-system could be improved by properly reducing the fractal dimension in Chaersen irrigation district. To decrease the lateral channel length and increase the branch number and length was one way to improve the efficiency of water utilization in canal-system in Chaersen irrigation district in the future.