东北黑土区不同季节侵蚀沟形态发育比较分析

Comparative Analysis of the Development the Geometric Forms of Gully in Different Seasons in Black Soil Area of Northeast China

侵蚀沟形态特征是了解沟蚀发生、发育的关键性因素,探究不同季节侵蚀沟形态参数变化特征对深入理解侵蚀沟的侵蚀过程和侵蚀沟的治理工作具有重要意义。选取黑龙江省海伦市光荣小流域内的3条侵蚀沟为研究对象,探究季节变化下侵蚀沟长度、面积、体积等形态参数值的差异。结果表明:(1)不同季节侵蚀沟横断面形态由沟头到沟尾均呈现出由“V”形向“U”形转变;(2)侵蚀沟在降雨期由沟头前进和沟尾后退所引起的长度增加量大于融雪期由沟头前进所引起的长度增加量;(3)侵蚀沟面积在降雨期的增加量大于融雪期,但不同时期侵蚀沟面积变化位置不同,降雨期侵蚀沟面积增加主要是由长度变化和沟头周围发生大规模崩塌引起的,而融雪期则是由长度变化和沟岸扩张引起侵蚀沟面积增加;(4)侵蚀沟体积在降雨期变化量大于融雪期,这与侵蚀沟长度、面积和径流的剪切能力有关,降雨径流的下切侵蚀能力大于融雪径流。研究结果可为侵蚀沟防治提供理论依据。

The morphological characteristics of gully erosion are the key factors to understand the occurrence and development of gully erosion,which are regarded having the great significance to explore the variation characteristics of gully morphology parameters in different seasons for in-depth understanding of the erosion process of gully erosion and its governance.In this study,three erosion gullies in Guangrong small watershed of Hailun City,Heilongjiang Province were selected as the research objects to explore the differences in the length,area,volume and other morphological parameters of erosion gully under seasonal changes.The results showed that:(1)The cross-sectional morphology of erosion gullies changed from“V”shape to“U”shape from the head to the tail in different seasons;(2)The length increase of erosion gullies caused by the gully advance and the gully tail retreat during the rainfall period was greater than that caused by the gully advance during the snow melt period;(3)The increase of erosion gully area in the precipitation period was greater than that in the snow melt period,but the changes of erosion gully area in different periods were different.The increase of erosion gully area in the precipitation period was mainly caused by the change of gully length and the large-scale collapse around the gully head,while the increase of erosion gully area was caused by the change of gully length and the expansion of gully bank in the snow melt period;(4)The variation of gully volume in the precipitation period was greater than that in the snow melt period,which was related to the variation of gully length,area and the shearing capacity of runoff.The undercut gully erosion capacity of runoff generated by rainfall in the precipitation period was greater than that generated by snow melt runoff in the snow melt period.The results can provide theoretical bases for the prevention and control of gully erosion.