基于无人机遥感的元阳梯田典型灌区渠系结构特征
张兆豪, 宋维峰

(西南林业大学 生态与环境学院, 昆明 650224)

元阳梯田; 无人机; Horton河系定律; 灌溉渠系

Canal System Structure Characteristics of Typical Irrigation Areas in Yuanyang Terraces Based on UAV Remote Sensing
ZHANG Zhaohao, SONG Weifeng

(College of Ecology and Environment, Southwest Forestry University, Kunming 650224, China)

Yuanyang terrace; UAV; Horton river system law; irrigation canal system

备注

为研究元阳梯田灌溉渠系的空间结构特征,针对目前传统遥感影像对梯田沟渠分辨率不足,提取精度低的特点,提出了无人机遥感技术获取元阳梯田全福庄灌区遥感影像,利用ArcGIS 10.1软件提取灌溉渠系,把研究区分为3个亚灌区,运用Horton定律分别计算出其渠系结构参数特征。结果 表明:(1)研究区内渠系级别为5级,其中1级渠系平均长度最长,2级渠系数量最多,2级渠系在水量分配中起着控制性作用:随着灌溉面积的增大,渠频数和渠网密度表现为逐渐增大。(2)研究区的分形维数为全福庄总灌区(4.72)、小寨(1.93)、大寨(2.39)、大鱼塘(2.12),小寨灌区分形维数值偏低。(3)渠系级别越多,渠系总量越多。随着渠系级别的增加,渠系平均长度表现为逐级递减。(4)对灌溉面积与分形维数关系进行分析发现灌溉面积越大,其分形维数也越大,渠系结构越复杂,梯田蓄水也越深。无人机遥感技术为元阳梯田灌区渠系识别提供了新的技术途径,研究结果为灌区后期渠系改造和灌溉管理提供参考。

To study the spatial structure characteristics of irrigation canal system in Yuanyang terrace, in view of the lack of resolution of traditional remote sensing image on terrace ditch, and characteristics of low extraction precision, the remote sensing image of Quanfuzhuang irrigation area in Yuanyang terrace was obtained by using UAV remote sensing technology, ArcGIS 10.1 software was used to extract irrigation canal system. The study area was divided into three sub-irrigated areas and the characteristics of canal structure parameters were calculated by using Horton's law. The results show that:(1)the grade of canal system in the study area is 5, in which the average length of the first canal system is the longest, and the number of the second canal system is the largest; the second canal system plays a controlling role in water distribution, canal frequency and canal network density increase gradually with the increase of irrigation area;(2)the fractal dimension of the total irrigation area of Quanfuzhuang is 4.72, 1.93 for Xiaozhai, 2.39 for Dazhai and 2.12 for Dayutang, the fractal dimension value of Xiaozhai irrigation area is low;(3)the more canal levels, the more total canal volume; the average canal length decreases step by step with the increase of canal level;(4)by analyzing the relationship between irrigation area and fractal dimension, it is found that the larger the irrigation area is, the larger the fractal dimension is, the more complex the canal structure is, and the deeper the water storage is. UAV remote sensing technology can provide a new technical approach for canal system identification in the irrigation area of Yuanyang terrace. The results can be used as reference for canal system reconstruction and irrigation management.