雨强和坡度对嵌套砾石工程边坡侵蚀特征的影响

为探究不同雨强和坡度对西南高山-亚高山地区急陡、高砾石含量工程边坡土壤侵蚀的影响.采用室内模拟降雨及人工配置土壤等方法,在5种雨强(25,40,45,65,85 mm/h), 5种坡度(35°,40°,45°,50°,60°)条件下进行模拟实验.研究结果表明:工程坡面产流率随着雨强的增加呈对数增加.不同雨强下坡面平均产流率变化过程随着坡度的变化差异性具有统计学意义.随着雨强的增加,同一坡面工程边坡侵蚀率明显增多.当雨强为40 mm/h时,工程坡面侵蚀率随坡度变化较小(<0.015 g/s);当雨强为65 mm/h时,同一坡面的侵蚀率随着坡度的增加而减少.工程坡面溅蚀率整体呈现出迅速增长至峰值后缓慢下降的趋势.同一边坡随着雨强的增加,坡面击溅侵蚀率在产流前和产流时都有明显的增加,不同粒径土壤增速具有明显差异,同一坡面随着坡度的增加,坡面泥沙溅蚀率存在临界值(40°～45°).降雨强度与土壤侵蚀相关性有统计学意义,不同雨强下坡度与径流过程和侵蚀过程的相关性具有明显差异性.结论:工程边坡中砾石具有增加下渗率和抗侵蚀作用,工程坡面土壤侵蚀率随降雨历时逐渐下降;坡度的增加在增大坡面流速的同...     

坡度对扰动黄棕壤土壤侵蚀的影响

通过人工模拟降雨试验,研究坡度对扰动黄棕壤的土壤侵蚀规律。结果表明:在坡度20°以内,随着坡度的增大,入渗量逐渐减少,径流量逐渐增大;坡度在20°~26.5°范围时,入渗量和径流量趋于平稳。土壤侵蚀量与径流量基本同步,在一定坡度内随着坡度的增大,侵蚀量增大;当降雨强度为40 mm/h和60 mm/h时,供试土壤侵蚀的临界坡度在20°~26.5°之间;当降雨强度增加至80 mm/h时,临界坡度大于26.5°。在试验坡度范围内,径流量、侵蚀量与降雨量均存在显著的线性关系。     

不同降雨条件对江苏高沙土地区水土流失的影响

采用人工模拟降雨法,针对江苏省局部高沙土地区,研究了在不同坡度、雨强及不同植被覆盖条件下扰动高沙土的侵蚀强度和侵蚀特点。结果表明:(1)径流量随坡度的增加而增加;土壤流失量与坡度存在一个临界值;雨强低于80 mm/h时的临界坡度为20°～26.5°;(2)降雨量相等时,径流量随着雨强的增加而增加,入渗量随着雨强的增加而减少;(3)植被覆盖能很大程度地减少径流量和土壤侵蚀量。     

高速公路边坡水土流失机理与养护管理研究

对重庆市梁忠高速公路填方路基边坡土壤开展室内模拟降雨试验,分析不同降雨强度和坡度条件下坡面产流和产沙的规律;结果表明:在0. 6 mm/min、0. 9 mm/min、1. 2 mm/min降雨强度条件下,起始产流时间随坡度呈减小趋势,当土体坡度一定时,起始产流时间不断减小,地表径流强度随着降雨强度的增大而增大;当降雨强度一定时,土体的起始产流时间随土体坡度增大逐渐减小,从而反映出地表径流强度不断增大;降雨强度对土壤侵蚀的临界坡度有一定影响,但两者具体变化关系需进一步研究。另外,通过高速公路边坡水土流失机理进行了研究,展开了高速公路边坡水土流失主要诱因分析,提出了科学的高边坡的养护管理措施。     

岩溶区钙与土壤有机碳关系的研究进展

土壤碳库在全球碳循环中占有重要的地位,土壤有机碳的稳定程度直接影响到其对大气CO2产生碳汇的潜力,土壤钙不仅是盐基离子,能影响土壤pH值,而且对土壤有机碳的稳定性和吸收大气CO2的能力产生影响。本文综述了土壤有机碳稳定机制研究方法,钙对土壤有机质稳定性影响研究进展,以及岩溶区富钙偏碱的地球化学背景下土壤大量钙存在对有机碳稳定性影响的研究进展。     

不同雨强和坡度条件海涂盐土边坡侵蚀细沟发育过程

采用室内人工模拟降雨试验,在不同坡度(11.3°、21.8°、35.0°)和降雨强度(85 mm/h、110 mm/h、125 mm/h)条件下,模拟海涂盐土边坡细沟发育过程。坡面侵蚀细沟发育动态采用数码摄像进行监测,通过Image-Pro Plus(IPP)6图像分析软件对图像和数据进行整理。结果表明:(a)不同坡度和降雨强度条件下,径流产生后,很快在坡面形成细沟且细沟沟网密度变化较快;细沟数量、细沟深度、细沟平均宽度和细沟密度均随降雨时间延长而增大。(b)缓坡度条件下,土壤跌坑发育慢,细沟侵蚀率低;随着坡度增大,坡面跌坑形成后水流聚集迅速,水流侵蚀冲刷力强,细沟发育快。(c)细沟发育越深,坡面细沟数量也越多;坡面侵蚀率与细沟平均深度及水流雷诺数分别在p0.05和p0.01水平上呈显著的正线性相关关系。     

三峡库区紫色土坡耕地土壤侵蚀研究：进展与方向

紫色土坡耕地是三峡库区粮食经济作物的主产载体,也是库区水土流失的主要源地和入库泥沙的主要来源。结合野外调查和相关报道,对三峡库区紫色土坡耕地土壤侵蚀研究方法、侵蚀强度、泥沙颗粒形态以及侵蚀引起的养分流失等方面进行综述。结果表明,坡耕地土壤侵蚀研究方法主要包括径流小区法、人工模拟降雨法和侵蚀针法等直接观测方法和核素示踪、模型模拟和遥感监测等间接观测方法;库区紫色土坡耕地土壤侵蚀速率达3464～9452t／km2,其中15°～25°坡度范围的土壤侵蚀最为严重,是今后坡耕地土壤流失防治的重点坡段;流失泥沙主要以〈0．02mm的团聚体和〈0．002mm的粘粒为主,其中粉粒（0．002~0．02mm）和粘粒（〈0．002mm）携带的养分流失较多;植物篱、垄作和坡改梯等措施理水效果明显,均对坡耕地侵蚀产沙具有较好的控制作用。今后应在模型方法、埂坎结构和功能、水土保持措施适宜性评价等方面拓展研究。     

Prediction of Soil Erosion on Different Underlaying Surface in Construction Period of Xichang to Panzhihua Expressway

In order to investigate the behavior of soil erosion on the slope of the different underlaying surface during construction, the experiment with natural rainfall on Xichang-Panzhihua highway was conducted, to quantify the runoff and soil loss. The results show that. （1） the main type of soil erosion is gully erosion, the amount of soil erosion caused by gully erosion is higher than that by surface erosion. （2） The principal factor causing soil erosion on the slope of the embankment is individual amount of precipitation, the width of the embankment and rain intensity. （3） The principal factor causing soil erosion on the cutting slope is individual amount of precipitation, the width of the cutting slope and rain intensity. （4） The principal factor causing soil erosion on the slope of the dumped soil area is individual amount of precipitation, the width of the flat roof and rain intensity. There are well linear relationships between the amount of soil erosion and the principal factor, and their correlation coefficient are 0.935 7-0.999 8.     

宁杭高铁不同乔木覆盖下侵蚀强度季节差异

高铁线路边坡具有跨度大、跨地貌多、治理耗时长的特点,以宁杭高铁江苏段为例,宁杭高铁已正式运营7年,自然恢复条件下土壤流失现状的调查和研究可以为水土流失的综合治理提供指导意见。对2018年3月—2019年2月典型样地土壤抗冲性、抗剪性、土壤理化性质、侵蚀强度进行了季度监测。选取4处扰动后的缓地样地,以及相邻处的原状样地,样地植被类型主要为刺槐(Robinia pseudoacacia L.)、马尾松(Pinus massoniana Lamb.)、榉树(Zelkova serrata(Thunb.)Makino)、女贞(Ligustrum lucidum),研究表明:①全量元素和有机质变化趋势呈现春夏渐增、秋冬渐衰的趋势。马尾松、刺槐养分水平较高,女贞、榉树养分水平偏低,但养分含量稳定性较优良;②抗冲刷指数与抗剪性指标全年变化趋势为春夏季下降,秋冬季上升,马尾松和刺槐林分抗冲抗剪性较为优良;③夏季土壤侵蚀强度高于春季、秋季、冬季,马尾松和刺槐林分土壤侵蚀强度较小;④土壤含水率、降雨量、降雨强度、全磷含量、抗冲刷系数、抗剪性、草本植被覆盖度和土壤侵蚀强度具有较强的相关性,降雨强度、含水率和日最大降雨量、有机质、覆盖度、抗剪性和抗冲刷系数对土壤侵蚀的贡献率较高。     

Changes in overland flow and sediment during simulated rainfall events on cropland in hilly areas of the Sichuan Basin, China

Water and soil loss are the major causes of the land degradation in the hilly area of the Sichuan Basin, China, where purple soil (FAO, Calcaric Regosols) is widely distributed. Little research has been conducted on changes in overland flow and sediment during rain events on sloping cropland in this area. In this study, 45 artificial rainfall events were applied to five runoff plots with slopes of 9%, 18%, 27%, 36%, and 47%, respectively. Results showed that erosion processes on purple soil of sloping cropland are complex, because the sediment concentration changes with time under different situations. According to correlations between runoff discharge and sediment concentration, all erosion events were classified into three types: (1) positive correlation; (2) negative correlation; and (3) no correlation. Positive correlations were dominant, accounting for 60% of all events. Rainfall intensity, slope gradient, and tillage treatment were the main factors that influenced erosion events.     

皖西大别山区土壤侵蚀空间分布特征及与地形的关系

基于修正的通用土壤流失方程和GIS空间分析方法,定量分析了皖西大别山区土壤侵蚀空间分布特征,讨论了侵蚀强度与海拔、坡度、坡向等因子的关系.基于信息熵模型评价地形因子与土壤侵蚀强度的空间相关性结果表明:(1)皖西大别山区2010年土壤侵蚀总量为1844.30×10~4t,平均侵蚀模数为1415.05t/km~2·a.区域以微度和轻度侵蚀为主,分别占总面积的52.95%和31.99%,侵蚀强度由东南至西北逐渐加剧.(2)坡度和海拔主导着区域内土壤侵蚀强度的空间分布.随着坡度和海拔增加,侵蚀强度不断加剧,强度侵蚀的面积比例增加,微度侵蚀的面积减少;在坡度15-25°区域、海拔200-500m区域的土壤侵蚀总量最大.坡向对土壤侵蚀强度的影响较小,土壤侵蚀强度在东南坡向较其它坡向略强.(3)地形因子与土壤侵蚀强度的空间相关性强弱为:坡度海拔坡向.坡度是安徽省大别山区土壤侵蚀强度的主导因子.     

广西不同林龄马尾松人工林土壤碳储量动态变化

为了解不同林龄马尾松Pinus massoniana人工林土壤碳储量的动态变化,选取广西横县镇龙林场不同林龄（幼龄林、中龄林、成熟林、过熟林）的马尾松人工林为研究对象,对林地土壤有机碳含量及土壤碳储量的变化特征进行研究,并探讨其影响因素。研究表明,随着林龄递增,各土层土壤有机碳含量及土壤碳储量总体表现为增加趋势,且不同林龄的同一土层之间均差异显著。不同林龄0—60 cm土层土壤有机碳含量表现为过熟林（16.82±0.23）g/kg > 成熟林（13.47±0.14）g/kg > 中龄林（10.91±0.38）g/kg > 幼龄林（10.74±0.14）g/kg,且差异显著（P<0.05）。不同林龄0—60 cm土层土壤碳储量表现为过熟林（104.92±18.08）t/hm²>成熟林（100.52±1.18）t/hm² > 中龄林（80.25±5.34）t/hm² > 幼龄林（80.23±4.54）t/hm²,且差异显著（P<0.05）。各林龄土壤有机碳含量、土壤碳储量主要集中在0—20 cm土层,并随土层深度的增加而递减,表现为土壤碳表聚现象,表层（0—20 cm）土壤碳储量所占比例均明显高于其他土层,表明不同林龄主要影响马尾松人工林土壤表层的碳含量;不同林龄土壤有机碳含量、土壤碳储量与乔木、灌木层Shannon-Wiener指数、物种丰富度、凋落物层现存量、总孔隙度、土壤含水量、土壤pH值均无显著相关关系（P>0.05）,与根系生物量呈极显著正相关关系（P<0.01）,与土壤容重呈极显著负相关关系（P<0.01）;群落总生物量、地上部分生物量均与表层（0-20 cm）土壤有机碳含量和土壤碳储量呈极显著正相关关系（P<0.01）,与20-40,40-60 cm土层土壤有机碳含量呈显著正相关关系（P<0.05）,而与后两个土层的土壤碳储量均无显著相关。该结果为研究土壤碳储量动态变化提供科学依据,有利于实现尾松人工林多目标可持续经营。     

Distribution characteristics of soil organic carbon of alpine meadow in the Eastern Qinghai-Tibet Plateau

A study on the distribution characteristics of soil organic carbon (SOC) in the alpine meadow in the Eastern Qinghai-Tibet Plateau has been carried out. The results indicate that the content of soil organic carbon (C _SOC) in the topsoil of terrace meadow (TM) ((67.16 ± 1.02) g·kg⁻¹) is more than that in the soil of upland meadow (UM) ((63.42 ± 0.65) g·kg⁻¹), while the C _SOC in upland shrubland (US) ((67.49 ± 0.83) g·kg⁻¹) is the most abundant in the scoreh stage (September). From May to September, the C _SOC in the topsoil of UM and US tends to descend, but that of TM tends to ascend. As for the distribution of the C _SOC and the density of SOC in the soil in the three sample areas, the data show that the deeper the soil, the lesser the content and density of SOC. The C _SOC in US is higher than that in TM and UM; the C _SOC in UM is the lowest at 0–10 cm soil depth. The density of SOC in US is always the lowest among UM, TM, and US at 0–40 cm depth, which shows that the storage of carbon in UM is more than that in US in the same range; the carbon pool capacity in UM is higher than that in US in the same range. Biography: ZHANG Wei (1979–), male, Lecturer, research direction: ecology of environment.     

Soil crevice formation and erosion in Yuanmou dry-hot valley, Yunnan Province, China

The basic characteristics, X-ray analysis and micromorphology of soil developed from the parent ruified soil had been probed, results showed that there were similarities among different types of the rubified soils. The soil clay (D<0.002 mm) contents (C _c ) were relative higher as between 29.16% and 80.03%. In addition, organic matter contents were lower as between 2.2–6.6 g/kg. The clay minerals in the rubified soils had high content of 2:1 type swelling minerals, e.g., smectite and vermiculite, which were the basic causes of formation of soil cracks and crevices. Soil micromorphology characteristics showed that microcosmic crevices universally distributed within the tight and compact soil microstructure were the microcosmic characteristics of crevices formation. The soil cracks and crevices changed the erosion process. Obviously, well developed soil crevice carries a significant connection with strong soil erosion in Yuanmou, Yunnan province, China. The term “soil crevice erosion” was coincided with the viewpoint put forward that soil crevice erosion played a dominant role in regional and violent soil erosion in this area. Foundation item: Supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-409) and the National Key Technology R&D Program of China (2006BAC01A11)     

Variation of δ13C in karst soil in Yaji Karst Experiment Site, Guilin

This study deals with δ₁₃ C variation in karst soil system of Yaji Karst Experiment Site, Guilin, a typical region of humid subtropical karst formations. Samples of near ground air, plant tissue, soil and water (soil solution and karst spring) were respectively collected on site in different seasons during 1996–1999. Considerable variation of δ₁₃ C values are not only found with different carbon pools of soil organic carbon, soil air CO₂ and soil water HCO₃⁻, but also with the soil depths and with different seasons during a year. The °₁₃ C values of CO₂ both of near ground air and soil air are lower in July than those in April by 1‰–4‰ PDB. Our results indicate that the δ₁₃ C values of carbon in the water and air are essentially dependent on interface carbon interaction of air-plant—soil-rock—water governed by soil organic carbon and soil CO₂ in the system.     

大兴安岭北端地形因子对针叶林土壤黑碳储量的影响

[目的]气候变化对人类社会发展产生的影响受到了世界各国的广泛关注,提高森林生态系统的固碳潜力被认为是经济可行且有效减缓大气二氧化碳(CO2)浓度的重要途径之一,大兴安岭地区森林生态系统的黑碳储量在全球碳循环和碳汇方面具有重要的作用.研究大兴安岭不同地形因子条件下土壤黑碳的储藏分布特征,为区域森林土壤黑碳储量准确估算和森...     

不同降雨强度下滑坡表面冲蚀体积试验

在山区,降雨导致的土壤冲蚀是产生堆积物、改变地貌地形的主要因素。其过程复杂并且受如降雨强度、地表粗糙度等多种因素影响。为研究不同降雨强度条件下降雨对滑坡表面冲蚀的体积指标特性,采用实验室模拟降雨试验平台进行实验,Golden Surfer软件直接读取堆积体体积、3D模拟模型研究降雨与输出数量关系等方法,再现了以体积量直接输出的堆积物与降雨之间的关系。结果表明:降雨过程中,坡体深部土壤体积含水率变化较小,浅层土壤孔隙水压与含水率变化较大;降雨初期,降雨入渗有效提高表层孔隙水压力,地表径流小,带沙能力弱;随降雨时间增加,地表径流强度增加是提高水流冲刷力的主要因素,累计冲蚀堆积体体积随降雨强度增加而增大,但是增速减小,其主要原因是降雨后期,地表形成冲刷沟壑,累计冲蚀堆积体体积受地表粗糙程度限制;通过对降雨时间、降雨强度以及冲蚀堆积体体积进行三维拟合,发现三者幂函数曲线的拟合较好。     

Quantitative Remote Sensing Study on Regional Soil Erosion —— Bin County of Heilongjiang as an Example

Based on Chinese soil loss equation （CSLE） model, this paper utilized technical advantages of RS and geographic information system （GIS） on data access and erosion factors database building to study prediction methods of regional soil erosion. The spatial analysis module of ARCGIS platform was applied to study the spatial distribution of erosion and the inter-relations of the factors influencing regional soil erosion in the research area. As a result, the mean soil erosion modulus of Bin County is 3 555.42 t/（km^2.a）, which suggests moderate degree erosion. The mean soil erosion modulus of clayey meadow soil is higher than those of dark brown soil and black soil. Vegetation factor values are between 0.1-0.2. The mean slope gradient and slope length values are respectively 1.335 and 6.061 which shows slope length is a dominant factor. And soil type, vegetation coverage and topographic factors have remarkable relevance to each other. Therefore, RS, GIS and CSLE are applicable in regional scale to disclose spatial distribution characteristics of soil erosion and to analyze the characteristics of dominant soil erosion factor quantitatively.     

不同坡度和前期土壤含水率下裸地和草地的降雨产流试验分析

坡度和前期土壤含水率是降雨产流过程的重要影响因素。为探讨其对降雨产流过程的影响,采用人工降雨模拟试验,对太行山前平原区不同坡度和前期土壤含水率下草地和裸地降雨产流过程进行了研究。结果表明:(1)草地和裸地的径流量均随坡度和前期土壤含水率的增加而增大,且裸地在稳定阶段的产流量以及累积产流量均高于草地;同时,前期土壤含水率较高时,累积产流量与降雨历时呈现出分段函数的关系;(2)径流系数、产流滞时以及入渗率随坡度和前期土壤含水率的增加分别呈现出增大、减小和减小的趋势,且两影响因素对草地径流系数、产流滞时及入渗率的影响程度均强于裸地;(3)裸地和草地的入渗率均随坡度和前期土壤含水率的增加,其变化速率逐渐增大,且较其他入渗模型,Horton入渗模型可以很好地估算土壤入渗率以及入渗量。通过试验研究,以期为进一步探索太行山前平原区降雨产流规律提供参考。     

潞安矿区煤矸石山水土流失特征及植被恢复关键技术

为了有效解决煤矸石山的生态恢复治理,采用径流小区观测法研究了风化煤矸石山水土流失变化特征及植被恢复,结果表明:裸露或植被稀少的矸石山边坡、林地边坡径流量分别与30 min雨强、45 min雨强最相关;沿坡长方向从上到下土壤抗冲指数呈现出先减小后增大的趋势;植物根系丰富,边坡比裸露边坡土壤抗冲性强;煤矸石山植被恢复成功的关键技术措施是细致整地、改良土壤,选择抗旱耐瘠薄植物种,确定适宜的栽植密度。研究成果为矿区废弃地有效治理提供了科学依据。