黑土耕作区侵蚀沟治理紧迫度空间分布特征

综合把握侵蚀沟发育状态及其治理紧迫程度可为有效判断区域侵蚀沟防控方向与治理重点提供重要参考。论文结合侵蚀沟形态数据,构建区域侵蚀沟治理紧迫度评价指标体系,从乡镇与网格尺度揭示区域侵蚀沟侵蚀程度及其空间分布规律。结果表明：① 从数量特征看,海伦黑土耕作区侵蚀沟分布呈非均衡状态,沟道长度以微/小型(≤500 m)为主,沟道面积以一/二级(≤0.8 hm²)为主。② 从空间规律看,网格尺度侵蚀沟密度等级呈现由西南向东北逐步增加趋势,而侵蚀沟密度等级以轻度侵蚀(≤2 km/km²)为主且在县域内无明显空间差异;乡镇尺度侵蚀沟密度以轻度侵蚀(≤2 km/km²)为主,主要分布在海伦西部,而侵蚀沟裂度以中/强度侵蚀(0.10%~0.35%)为主,主要分布在海伦西北与东南部。③ 从治理紧迫度看,2017年海伦黑土耕作区侵蚀沟以低紧迫治理(0.03~0.26)状态为主,主要分布在海伦低山低丘地区,位于海伦中西部乡镇;而紧迫/极紧迫治理紧迫度主要分布于低山/漫川漫岗区,位于海伦东北部。在未来区域侵蚀沟防治监测监管中,县级部门可依据乡镇侵蚀沟治理紧迫度优先防治侵蚀严重区域,而乡镇部门可依据网格尺度侵蚀沟治理紧迫度进行实地察看与重点监测。

Spatial pattern of gully erosion control urgency in black soil farming area

A comprehensive understanding of the development status of erosion gullies and the urgency of their erosion control can provide an important reference for effectively identifying the direction and key areas of regional gully erosion prevention and control. Combined with the spatial data of erosion gullies, this study constructed an evaluation index of regional gully erosion control urgency. The distribution characteristics of erosion gullies in the black soil farming area of Hailun City in 2017 were analyzed at the town and township level and the grid level, revealing the extent of gully erosion and its spatial distribution patterns. The results show that: 1) Quantitatively, the distribution of erosion gullies in Hailun black soil farming area is unbalanced. The length of gullies is mainly micro/small (≤ 500 m), and the area of gullies is of class I and II (≤ 0.8 hm²). Overall, the erosion gullies are of large number, short length, and small area. 2) Spatially, the density of erosion gullies at the grid level gradually increased from the southwest to the northeast, while their dissected degree was mainly light, and there was no significant spatial difference across the area. The density of erosion gullies at the town and township level was mainly low, and the gullies were mainly distributed in the west of Hailun, while their dissected degree was mainly moderate/intensive and they are mainly distributed in the northwest and southeast of Hailun City. 3) The erosion control urgency of erosion gullies in Hailun black soil farming area in 2017 was mainly in the low urgency state, accounting for 67.06% of the area, which was mainly distributed in the plain and hilly areas, located in the western townships of Hailun; and the urgent/extremely urgent states were mainly found in the low mountain and hilly areas, located in the northeast of Hailun. In the planning of regional gully erosion control, the city government should give priority to the prevention and control of serious erosion areas according to the urgency state of town and township gully erosion control, while the town and township governments can carry out field investigation and key area monitoring according to the urgency of gully erosion control identified at the grid scale.