水保所知识产出(1956---)知识库

中性多聚糖（Jag S）是一种新型高聚物，研究该高聚物对黄土坡面降雨入渗的影响
可对采用土壤侵蚀化学调控技术措施防治黄土坡面土壤侵蚀提供新的理论基础。通过人工模拟降雨试
验，研究不同雨强（1.0、1.5、2.0 mm min-1），不同坡度（10°、15°、20°）条件下，坡面降雨入渗
及产流时间与喷施不同剂量（1、3、5 g m-2）Jag S之间的关系。结果表明：在不同坡度不同雨强下，
与裸露坡面相比，喷施3种剂量的高分子化学材料Jag S均减少了前期降雨入渗率，但1及3 g m-2剂量
Jag S处理能够明显提高黄土坡面入渗性能，减缓入渗在整个降雨过程的下降趋势，提高稳渗率，强化
入渗效应均值分别为21.53%及9.17%，大剂量（5 g m-2）Jag S反而降低了土壤入渗性能（小雨强下除
外）。喷施不同剂量Jag S的坡面其产流开始时间差异很小，但均早于裸露坡面，且表现为Jag S喷施剂
量越大，坡面越早产流，大坡度大剂量对降雨产流时间影响较大。三个剂量对应产流时间提前百分比
均值分别为47.26%、50.47%及66.28%。总之，Jag S在一定程度上能改善黄土坡面土壤结构，提高黄
土坡面降雨入渗性能，从而降低土壤侵蚀，为采用高聚物进行水土保持提供了科学依据。

【Objective】The technology of using chemicals to control soil erosion is mainly implemented
through spraying high molecular compounds over on the surface soil layer to improve its soil structure，
to enhance stability of its soil aggregates，to prevent dispersion of its clays and hence to increase rain
water infiltration rate and eventually to control surface runoff and soil erosion. Jag S is a kind of neutral
polysaccharide and a new type of high polymer. This study on effect of the use of this high polymer on rainwater
infiltration rate in loess slopes is intended to lay down a new theoretic basis for applying the technology of
using chemicals to control soil erosion to the Loess Plateau in arid and semi-arid regions for erosion control
and water conservation. Control of soil erosion with chemicals is a new method，which is developed on the
basis of the modern chemical industry and different from the traditional soil and water conservation methods.
【Method】An indoor experiment was conducted in the Rainfall Simulation Hall at the State Key Laboratory
of Soil Erosion and Dryland Farming on the Loess Plateau at the Institute of Soil and Water Conservation.
A rainfall simulator system with side-sprinklers was used to simulate rainfall events different in intensity
ranging from 0.5 to 3.5 mm min-1. The sprinklers were 16 m high above the experimental field，providing
simulated rainfall events over 80% in uniformity and raindrops 0.25 to 0.375 mm in diameter，when a rainfall
event was set at 1～2 mm min-1 in rainfall intensity. Kinetic energy of the raindrops striking at surface soil of
the field ranged from 365 to 847 J h-1 m -2. The indoor simulated rainfall experiment was designed to explorerelationships of rain water infiltration rate and initiation time of runoff with dosage（1，3 and 5 g m-2）of Jag
S used relative to slope gradient（10°，15° and 20°）and rainfall intensity（1.0，1.5 and 2.0 mm min-1）.
【Result】Results show that compared with the CK slope，all the slopes sprayed with Jag S regardless of
rate were lowered in infiltration rate during the initial period of all rainfall events. However，the spraying of
1 and 3 g m-2 Jag S significantly raised rain water infiltration rate on all loess soil slopes in the late stages of
the rainfall events，and reduced the buffering effect during the initial periods of the rainfalls. Consequently，
the rain water infiltration rate increased by 21.53% and the infiltration enhancement rate by 9.17%. On the
contrary，the spraying of 5 g m-2 Jag S weakened the rainfall water infiltration rate in all rainfall events except
for the one lowest in intens ity（1.0 mm min-1）and in all the loess slopes. The soil slopes s prayed with J ag S，
regardless of rate，differed very slightly in runoff initiation time，however，they had runoff initiated earlier
than the CK slope. The higher the Jag S spraying rat，the earlier the runoff initiated. Obviously the effects of
a high Jag S spraying rate and a high slope gradient on runoff initiation were significant. The runoff initiation
advancement rate on slopes sprayed with 1，3 and 5 g m-2 was 47.26%，50.47% and 66.28%，respectively，
under rainfalls the same in intensity. 【Conclusion】All the finding indicate that Jag S is to a certain extent，
effective to improve soil structure of the loess slopes and increase rainwater infiltration rate and hence reduce
soil erosion. Consequently，spraying of the neutral polymer Jag S on surface soil of a loess slope is a potential
alternative to control soil erosion on the Loess Plateau. The findings of this study may serve as a scientific
basis for soil and water conservation using polymers.