黑土小流域沟道分布遥感监测及主控因素研究

为了对典型黑土区小流域沟道分布进行遥感监测，并解析影响其发育的主控因素，选择黑龙江省海伦市光荣村为研究区，通过对遥感影像和地形图的目视解译判读和空间分析，量化汇水区面积、坡长等12个变量，结合对264条切沟与等高线分布关系的地貌学分析、统计分析和野外详查，解译地表径流和机耕道作用等6种情形，对典型黑土区小流域切沟发育主控因素进行探讨。结果表明，研究区林地面积大小不能直接控制切沟发育，林地内活跃沟长占活跃切沟总长的46.2%。小流域汇聚坡是切沟发育的典型地形，沟长占总长的68.1%，汇聚坡导致地表集中径流，沟长占总长的63.0%。汇水区面积和坡长是影响沟长的最主要因素，而小流域坡度是影响沟密度的显著因素。同时，切沟侵蚀多伴生于农田机耕道路一侧，机耕道旁沟长约占其总长的23.3%。研究表明，黑土区切沟侵蚀主要与机耕道促进地表径流的作用密切相关，侵蚀沟综合治理必须考虑小流域景观布局和山水林田湖草综合治理，应将农田机耕道路周边大型活跃切沟防控作为黑土区保护的重中之重。

Gully distribution monitoring based remote sensing and key driving factors in the catchment scale of Mollisol region

To understand the key driving factors of the gully distribution and development in typical catchment of Mollisol region, visual interpretation, spatial analysis, detailed geomorphological field survey and statistical analysis were used to quantify the catchment properties(12 variables) and influencing factors(6 variables) of gully erosion in typical catchment of Mollisol region based on the satellite image and topographic map. The results showed that the forest area in catchment scale could not effectively control the gully development, and the active gully length in the forestland accounted for 46.2% of the total active gully length. The convergent slope of sub-catchment was a typical landform for gully development, and the gully length accounted for 68.1% of the total gully length. The gully length caused by concentrated surface runoff in convergent slope accounted for 63.0% of the total gully length. The catchment area and slope length were the most important factors affecting the gully length, while catchment slope was a significant factor to gully density. Meanwhile, gully erosion was highly associated with the field tractor road in this study region, and the gully length related tractor road accounted for about 23.3% of the total gully length. Our study highlights that the gully development is closely related to enhanced surface runoff caused by the field tractor road. Therfore, comprehensive soil and water management considering landscapes and agricultural tractor roads in the catchment scale should be the priority issue in gully prevention in Mollisol region of northeast China.