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黄土 丘陵区 高效农业 多级梯田暴雨侵蚀规律初步研究
贾立志
Subtype硕士
Thesis Advisor高建恩
2014-05
Degree Grantor中国科学院研究生院
Place of Conferral北京
Keyword黄土丘陵区 高效农业多级梯田 侵蚀规律 Wepp 模型 防蚀措施
Abstract

梯田是防止黄土丘陵沟壑区坡耕地水土流失的一种有效的水土保持措施,也是保
障黄土丘陵区农业生产以及粮食安全的重要措施。本文针对安塞县马家沟流域高效农
业多级梯田在暴雨冲蚀条件下土壤侵蚀剧烈、水土流失严重、梯田容易被冲毁以及梯
田坡面防蚀措施不足以抵御暴雨冲刷等问题,在对该多级梯田在特大暴雨冲刷后的侵
蚀状况进行观测分析的基础上,运用 WEPP 模型对其进行模拟,提出了该区的多级
梯田防蚀措施,主要结论如下:
1、多级梯田土壤物理性质空间变化。对马家沟流域曹新庄多级梯田的各级梯田
土壤容重以及土壤含水量进行测定分析,结果表明:土地管理措施为裸地的梯田断面
土壤容重明显高于其他各级梯田,耕作措施可以降低土壤容重,对于改善土壤结构与
提高有机质含量具有重要的作用。采用适宜的土壤耕作方式不仅可以改善土壤特性,
还可提高田间水分利用效率,达到保水增产的目的。各级梯田断面的土壤含水量在
0-100 cm 土壤深度之间随着土壤深度的增加都会出现一个先增加再缓慢减小,再增加
的趋势,在 100-160 cm 土壤深度之间,土壤含水量基本保持不变或有极小的变化程
度,土壤含水量基本达到稳定。表层土壤含水量和 100 cm 土壤含水量从上到下随着
梯田级数的增加逐渐增加,并且 1-7 级梯田土壤含水量增加幅度小,第 8 级梯田表层
土壤含水量达到饱和含水量的 52.7%,100 cm 土层深度土壤含水量达到饱和含水量的
80.7%,土壤含水量已经接近饱和,说明第八级梯田有地下水出露。
2、多级梯田的暴雨侵蚀规律。安塞县马家沟流域曹新庄多级梯田在 2013 年 6-9
月暴雨冲刷下土壤侵蚀严重。平均侵蚀模数为 20659.7 t/hm 2 ,超过该区平均年侵蚀模
数的 47.6%,大于剧烈侵蚀(15000 t/(km 2 •a))的标准。按高程从上到下该多级梯田
最上级侵蚀轻微,依次往下梯田侵蚀面积所占百分比逐渐增大并且增加明显,上部梯
田主要以面蚀为主,仅发生轻微沟蚀。下部梯田面蚀、沟蚀都比较严重。尤其是第 7、
8 级梯田,面蚀和沟蚀总面积达到 75%以上,大部分农作物被淤积的泥沙覆盖,大面
积田地的土壤侵蚀对当地正常的农业生产造成严重的影响。梯田侵蚀量与梯田汇水面
积、地表径流量等条件有关,由于地表径流量的增加,下级梯田侵蚀比上级梯田严重,影响梯田侵蚀灾害发生的主要因素是地表径流量。
3、WEPP 模型对暴雨冲刷下多级梯田侵蚀模拟初步研究。针对不同级梯田的不
同坡长、坡度、管理措施条件下,WEPP 模型对土壤侵蚀量与径流量的模拟精度也表
现出不同。总的来说,WEPP 模型能够较好地模拟黄土丘陵区多级梯田在暴雨条件下
的产流量与土壤侵蚀量,从上到下随着梯田级数的增加 WEPP 模型的模拟精度有降
低趋势,并且对产流量的模拟精度要高于土壤侵蚀量的精度。WEPP 模型对多级梯田
暴雨冲刷的径流量模拟效果较好,由于该区地下水丰富的原因,径流系数法计算得值
总体高于模拟值。WEPP 模型对下级梯田的模拟精度低于上级梯田。由于 WEPP 模型
缺少拦挡措施模块,没有充分考虑梯田田埂在拦蓄泥沙方面的作用,在模拟土壤侵蚀
量时,模拟值总体上要大于实测值。随着梯田级数增加,模拟值与实测值之间的相对
误差值增加显著,第8级梯田模拟侵蚀量与实测侵蚀量之间的相对误差达到169.01%,
梯田田埂在应对暴雨冲刷时对多级梯田的防蚀起到了重要的作用。
4、发展高效农业多级梯田设计标准需要适当提高。对马家沟流域曹新庄多级梯
田的坡面植被以及梯田田埂的冲蚀与冲毁情况进行统计分析,结果表明:多级梯田在
暴雨冲刷下 1-4 级梯田的坡面植被和梯田田埂基本未被冲蚀,5、6 级梯田大部分被冲
毁,仅保存少部分,而第 7、8 级梯田的坡面植被覆盖率在暴雨后覆盖率变为 0,并
且梯田田埂被完全冲毁。控制梯田侵蚀的关键是控制地表径流量,采用生物措施与工
程措施结合的手段可以有效地对多级梯田进行水沙调控来防蚀水土流失以达到提高
水土资源利用效率的目的,对应不同级数梯田应采取不同的措施进行梯田防蚀。基于
发展高效农业的要求,给出黄土丘陵沟壑区多级梯田的修建标准。
关键词:黄土丘陵区;高效农业多级梯田;侵蚀规律;WEPP 模型;防蚀措施

Other Abstract

Building terraces is an effective way to prevent soil and water loss of slope land and an important
measure to guarantee agricultural production and food security in the loess plateau. In view of the
problems of efficient agriculture multi-level terraces under rainstorm erosion in the Majiagou river
basin, such as fierce soil erosion, severe soil and water loss, terraces easy to be washed out and
insufficient corrosion prevention measures of terrace slope, this paper monitors the scour situation of the
multi-level terraces under the rainstorm, uses a new generation of water erosion prediction
model-WEPP model-to simulate the section erosion situation of the multi-level terraces, and get the
following main conclusions:
1. Spatial distribution rule of soil physical properties of the multi-level terraces. Analyze the soil
bulk density and soil moisture content of the multi-level terraces at different levels in Cao xinzhuang in
the Majiagou river basin, the results show that: the soil bulk density of the terraces of which the land
management measure is bare land is obviously higher than that of other terraces at different levels and
cultivation measures can reduce soil bulk density, playing an important role for improving the soil
structure and soil organic matter content. Suitable way of soil cultivation can not only improve the soil
properties, but also improve the efficiency of water use in the field, achieve the goal of water production.
Soil moisture content of the terrace section at different levels presents a trend of first increase, then
slowly decrease, and then increase with the increase of soil depth between 0-100cm soil depth; between
100-160cm soil depth, soil moisture content remains unchanged or a tiny change, soil moisture content
achieves the stability. Surface soil moisture content and 100cm soil moisture content gradually increase
with the increase of terrace levels from top to bottom, and soil moisture content of level 1-7 terraces
does not show an obvious increase, surface soil moisture content of the 8th level terrace reaches 52.7%
of saturated moisture content, soil moisture content of the 100cm soil depth reaches 80.7% of saturated
moisture content, close to saturation.  2. Rainstorm erosion rule of the multi-level terraces. Soil erosion of the multi-level terraces under
rainstorm scour in Cao xinzhuang in the Majiagou river basin is serious. Average erosion modulus is
20659.7 t/hm 2 , more than 47.6% of the average annual erosion modulus, is greater than the severe
erosion standard (15000 t/(km 2 •a)). The top level of the multi-level terraces is eroded slightly, and the
terraces erosion area percentage increases gradually and significantly from top to bottom according to
the elevation. The upper terraces mainly show surface erosion and only a slight gully erosion; the lower
terraces show both serious surface erosion and gully erosion. In particular, surface erosion and gully
erosion of the 7th, 8th level terraces reach a total area of more than 75%, most of the crops are covered
by the deposited sediment. Terraces erosion amount is related to such conditions as the terrace
catchment area and the surface runoff, the main factor influencing the terraces erosion disaster is the
surface runoff. Due to the increase of surface runoff, the lower terraces are eroded more severely than
the upper terraces.
3. Preliminary study on the simlation of multilevel terrace erosion under rainstorm scour using
WEPP model. For different length of slope, slope, management measures of terraces at different levels,
the simulation accuracy of the WEPP model to the amount of soil erosion and runoff is also different. In
general, WEPP model can well simulate the amount of soil erosion and runoff of multi-level terraces
under rainstorm in the Loess Plateau, the simulation accuracy of WEPP model has a tendency to reduce
with the increase of terrace levels from top to bottom, and simulation accuracy is higher to the amount
of runoff than to the amount of soil erosion. WEPP model well simulates the runoff of the multi-level
terraces under rainstorm, and because the groundwater is rich, the value calculated using the runoff
coefficient method is higher than that of simulation in general. The simulation accuracy of WEPP model
is lower to the lower terraces than to the upper terraces. So, when using WEPP model to simulate the
runoff in the region, we should be fully considered about the influence of recharge of groundwater to
surface runoff and the influence of soil moisture content. Because WEPP model is lack of blocking
measures module, without fully considering the role of terrace ridge in the sediment retention, when
simulating the amount of soil erosion, the simulation value is greater than the measured value on the
whole. As terrace levels increase, the relative error between the simulation value and the measured
value increase significantly, and in particular the relative error of the 8th level terrace reaches 169.01%.
Facing rainstorm scour, terrace ridge plays an important role in the corrosion prevention of multi-level
terraces.
4. Preliminary study on the water and sediment regulation measures of multi-level terraces. By
controlling the runoff coefficient in the region and catchment area or changing the micro top  controlling the runoff coefficient in the region and catchment area or changing the micro topography
conditions, we can reduce surface runoff, thus achieve the goal of reducing the scour of runoff to terrace
slope, but only the forest-grass measures are not enough to withstand the scour of the worst torrential
rain, so we need to take engineering measures for water and sediment regulation design to layer upon
layer retain the slope runoff, in order to prevent the erosion of terraces. According to the actual situation
in the Loess Plateau, the main engineering measures are to build the back-slope terrace and terrace ridge
to regulate the water and sediment, the advisable slope of back-slope terrace is commonly 3°~5°,
construction of terrace ridge can refer to the terrace design specification and the erosion rule in the
region, according to the different terrace levels.
Key words: The Loess Plateau; Efficient Agriculture Multi-level Terraces; Erosion rule; WEPP model;
Corrosion prevention measures

Language中文
Document Type学位论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/8999
Collection水保所知识产出(1956---)
Recommended Citation
GB/T 7714
贾立志. 黄土 丘陵区 高效农业 多级梯田暴雨侵蚀规律初步研究[D]. 北京. 中国科学院研究生院,2014.
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