地貌信息熵理论在冲沟沟头活跃度评价中的应用初探

Application of Geomorphologic Information Entropy Theory to Evaluation of Gulley Head Activity

冲沟沟头是整个冲沟活跃区中形态变化及侵蚀产沙最为剧烈的部位,其活跃程度决定着整个冲沟的发展方向。尝试运用地貌信息熵理论,基于RTK-GPS技术对冲沟沟头的实地监测数据,对干热河谷区36个冲沟沟头活跃度进行了评价研究。结果表明:研究区36个冲沟沟头在形态发育上均处于活跃期,但分别处于不同程度的侵蚀活跃状态;依据地貌信息熵值可将沟头发育状况划分为4个活跃程度等级,分别为稳定、较稳定、较活跃和活跃,被调查的36个沟头中约有44%处于较活跃或活跃状态,42%处于较稳定状态,仅有14%处于相对稳定状态;沟头发育监测数据验证表明,地貌信息熵理论评价结果与实际情况基本相符,可将其作为冲沟活跃程度评价的一种有效方法。

Gulley head is the most severe part of morphological changes and the process of erosion and sediment production in the active region of gulley. The activity depends on ihe development direction of the whole gulley. The paper tried to use the theory of geomorphologic information enlropy to evaluate and study the activity of 36 gulley heads in dry and hot valley region based on field monitoring data of gulley head by using RTK-GPS technique. The outcomes show that a) all 36 gulley heads in the studied area are in active stage of morphologic development, while the active erosion condition is in different degrees;b) according to the value of geomorphologic information entropy, the development status of gulley head can be divided into 4 grades of stable, relatively stable, relatively active and active. Among the investigated 36 gulley heads, there are about 44% in the statement of relatively active and active, 42% in the statement of relatively stable and only 14% in the statement of stable and; c) the monitoring data validation of gulley head development shows that the evaluation results of the theory of geomorphologic information entropy basically tallies with the actual situation, which can be used as an effective method to evaluate the active degree of gulley.