黄土高原沟谷侵蚀速率研究──以洛川黄土源区为例

Study of the Gully Erosion Rates on the Loess Plateau──Taking Luo Chuan Yuan As an Example

据洛川塬区８条典型沟谷大量地质地貌实测资料，以恢复、量测各时段沟谷形体为主线，用黄土──古土壤层存在沟谷两侧的披覆关系、Ｃ１４测年及考古资料确定了沟谷发育年代，指出洛河及其主要支流诞生于５５．５万年前，后经历了５个演化阶段，并测算出３３～２５、２５～１４、１４～１和１万年以来及历史时期沟道的侵蚀量、侵蚀率及其递增率。在３３～２５万年前，侵蚀量为９４５．６２４ｔ／ａ，２５—１４万年前为６７２．５１ｔ／ａ，１４—１０万年前为５４１．７３ｔ／ａ，１万年前为２５３５．９８ｔ／ａ。

On the basis of intensive investigation data of gully features in morphology and stratum contacts and C14 datings,this paper get the follow results the Luo he river and its main tributaries were formed in 555 ha B. P.,i. e. mid-middle pleistocene,and after that 5 periods of intensive erosion have gone through.The eroded capacity and rates in each period are as follows: 330250ha B. P., 945. 624t/a.;250-140ha B.P.,672.51t/a.; 140-10ha B.P.,541.73 t/a.; 10kaB. P.,2 535. 98t/a.,headed erosion rates in 5 000 a B. P.,1.3 464m/a.as well as 0. 225m/a. in 40a B. P.