瓦背状浅沟分布特征分析

Distribution Features of Shallow Gully

利用航空影像分析黄土丘陵沟壑区周屯沟小流域（面积３３．６ｋｍ２）瓦背状浅沟分布规律。浅沟主要发育在坡耕地上。流域内，浅沟分布区占坡面面积的３１．３％，集中分布，平均频数７．２条／１００ｍ横坡面，密度为４～９条／１００ｍ的浅沟坡面占７８％。相关分析表明，浅沟频数与浅沟的长度、浅沟坡面的总坡度显著相关。浅沟的平均长度６４．７ｍ，３０～１１０ｍ长的浅沟占９１％，浅沟坡面总平均坡度数２３°，１３～３２°的占９５％。瓦背状浅沟实质上是坡耕地上一种产沙量较高的稳定地貌形态。

The distribution of shallow gully of Zhondunguo watershed in the loess hilly and gully regions were showed using the results from WB aerial photograph interpretation. The shallow gully covers 31.3% of total areas of hillslope in the watershed. It is average frequency(density) 7.2/100 m cross section of hillslope , the frequency range 49/100 m accounts for 78%. The total average degree of shallow gully hillside is 23;range 1232 is 95%. It is average length 67.4 m, range 30110 m is 91%. In fact, tileroofed shape shallow gully is a more stable geographical feature which can yield a higher silt. Interrelation analysis reveals a significant relationship between shallow gully density and total hillslope degree or shallow gully length.