The characteristics of gully erosion over rolling hilly black soil areas of Northeast China

In this study, short-term gully retreat was monitored from the active gullies selected in representative black soil area, using differential global positioning system (GPS). With the support of geographic information system (GIS), multi-temporal digital elevation models (DEM) were constructed from the data collected by GPS and used for further analysis. Based on the analysis of multi-temporal DEM, we discussed the erosion–deposition characteristics within gully and a developing model for black soil gully area of Northeast China was proposed. The results are: (1) The analysis of the monitored gully data in 2004 indicated that the retreat of gully head reached more than 10 m, gully area extended 170–400 m2, net gully eroded volume 220–320 m3,and gully erosion modulus 2200–4800 t?km?2?a?1. (2) Compared with the mature gully the initial gully grows rapidly, and its erosion parameters are relatively large. The erosion parameters have not only to do with flow energy, but also with the growth phase. (3) There are significant seasonal differences in gully erosion parameters. The extension of gully area and width dominates in winter and spring without marked net erosion while changes mainly occur in gully head and net erosion in rainy season. (4) It is remarkable for freeze-thaw erosion in the black soil area of NE China. The gully wall of SG2 extended 0.45 m under freeze-thaw effect in 2004, and the distance of gully head retreated maximally 6.4 m. (5) Due to freeze-thaw action and snowmelt, gully is primarily in the interior adjustment process in winter and early spring. There are much more depositions compared with that during rainy season, which can almost happen throughout the gully, while erosion mostly occurs near head, esp. for gullies having a relatively long history of development. On the other hand, the process of energy exchange with exterior dominates in rainy season. It is considered that this cyclic process is an important mechanism for gully growth in high latitude or/and high attitude regions.     

贡嘎山海螺沟土壤环境背景值特征

贡嘎山海螺沟土壤环境背景复杂,土壤元素背影值中,Cu,Zn,Pb,Cr,Ni,Mn和F都高于全国土壤的背景水平,而元素Cd,As,Se则相反;各土类间同一元素含量的变化不大;成土母质对土壤元素含量的影响深刻;土壤元素含量的垂直分异规律不明显。     

基于土壤侵蚀控制度的黄土高原水土流失治理潜力研究

以整个黄土高原为研究对象,首先将水土保持措施容量定义为某一区域能容纳的最大适宜水土保持措施量。根据梯田、林地和草地的适宜布设区域,在地理信息系统（GIS）软件的支持下,确定了黄土高原的水土保持措施容量。使用修正通用土壤流失方程（RUSLE）,计算了最小可能土壤侵蚀模数和2010年现状土壤侵蚀模数,并将水土保持措施容量下的最小可能土壤侵蚀模数与现状土壤侵蚀模数之比定义为土壤侵蚀控制度。随后使用土壤侵蚀控制度,对黄土高原水土流失治理潜力进行了研究。结果显示：黄土高原2010年现状土壤侵蚀模数为3355 t·km^-2·a^-1,最小可能土壤侵蚀模数为1921 t·km^-2·a^-1,土壤侵蚀控制度为0.57,属于中等水平。相比于现状条件,在水土保持措施容量条件下,微度侵蚀区比例从50.48%提高至57.71%,林草覆盖率从56.74%增加至69.15%,梯田所占比例由4.36%增加到19.03%,人均粮食产量可从418 kg·a^-1提高至459 kg·a^-1。研究成果对于黄土高原生态文明建设具有一定的指导意义。     

东北漫岗黑土区切沟侵蚀发育特征

随着人们对土壤侵蚀空间尺度认识的加深, 发育在更大空间尺度上的切沟愈来愈受到重视。切沟是土壤侵蚀的重要组成部分, 但现有的土壤侵蚀模型尚未包括切沟侵蚀部分。本研究利用高精度差分GPS, 在对东北典型漫岗黑土区切沟监测的基础上, 借助GIS 平台生成DEM, 通过DEM 的叠加分析, 探讨了沟内蚀积变化特征。并在此基础上, 提出了东北切沟侵蚀的概念模型, 认为冬春季冻融侵蚀产生沟内堆积-雨季径流产生侵蚀的过程可能是该区切沟发育的一种重要模式。     

中国东北漫岗黑土区切沟侵蚀发育特征

In this study, short-term gully retreat was monitored from the active gullies selected in representative black soil area, using differential global positioning system (GPS). With the support of geographic information system (GIS), multi-temporal digital elevation models (DEM) were constructed from the data collected by GPS and used for further analysis. Based on the analysis of multi-temporal DEM, we discussed the erosion-deposition characteristics within gully and a developing model for black soil gully area of Northeast China was proposed. The results are: (1) The analysis of the monitored gully data in 2004 indicated that the retreat of gully head reached more than 10 m, gully area extended 170–400 m², net gully eroded volume 220–320 m³, and gully erosion modulus 2200–4800 t·km⁻²·a⁻¹. (2) Compared with the mature gully the initial gully grows rapidly, and its erosion parameters are relatively large. The erosion parameters have not only to do with flow energy, but also with the growth phase. (3) There are significant seasonal differences in gully erosion parameters. The extension of gully area and width dominates in winter and spring without marked net erosion while changes mainly occur in gully head and net erosion in rainy season. (4) It is remarkable for freeze-thaw erosion in the black soil area of NE China. The gully wall of SG2 extended 0.45 m under freeze-thaw effect in 2004, and the distance of gully head retreated maximally 6.4 m. (5) Due to freeze-thaw action and snowmelt, gully is primarily in the interior adjustment process in winter and early spring. There are much more depositions compared with that during rainy season, which can almost happen throughout the gully, while erosion mostly occurs near head, esp. for gullies having a relatively long history of development. On the other hand, the process of energy exchange with exterior dominates in rainy season. It is considered that this cyclic process is an important mechanism for gully growth in high latitude or/and high attitude regions. Foundation: Key Project for National Natural Science Foundation of China, No.40235056; The Ph.D. Programs Foundation of Ministry of Education of China, No.20030027015; China Postdoctoral Science Foundation, No.20070410482; Doctoral Foundation of University of Jinan, No.B0620; National Natural Science Foundation of China, No.40672158; Key Subject Foundation Supported by Shandong Province Author: Hu Gang (1976–), Ph.D and Associate Professor, specialized in soil erosion, environmental evolution and regional planning.     

陕北洛川塬黄土崩滑及谷坡扩展模式

陕北洛川黄土塬是水土流失严重的地区。通过野外调查发现黄土崩滑作用是造成该区水土流失的主要之一，发育于黄土塬-沟谷过渡地带。该区黄土崩滑首次被划分为单面崩滑及栅格崩滑两种基本类型。黄土单面崩滑主要分布于冲沟、切沟地貌环境，而栅格崩滑主要分布于级别较高的沟道之中，活跃于区域Ⅲ、Ⅳ级沟道，显示出黄土崩滑与区域水文网之间的对应关系。根据地貌景观和沟谷几何特征第一次提出洛川黄土塬河道谷坡以陡倾加宽和鱼鳞状后退扩展为模式。黄土崩滑是蚕塬的重要方式，在水土保持过程中，就加强不同类型崩滑的针对性研究、预报和防护治理，促进水保效益的提高。     

The contribution of gully erosion to total sediment production in a small watershed in Southwest China

Determining the contribution of gully erosion to the total sediment yield is important for enhancing decision-making regarding sediment abatement and soil conservation measures. The dry-hot valley region of the Jinsha River is one of the most intensive areas of gully erosion in China. However, the contribution of gully erosion to total sediment production in this region is unclear. Instead of using the source tracing technique commonly employed in other studies, this study provides a method of rapidly reconstructing historical sediment yields based on the properties of sediment that accumulated in an undrained pond at a small gully watershed outlet. We produced a three-dimensional model in geographical information system software to calculate the volume of each layer of accumulated pond deposits from 2006 to 2011. Moreover, we estimated sheet erosion amounts using the Universal Soil Loss Equation. The results showed that sheet erosion accounted for between 14.28 and 23.39% of the total sediment yield in the watershed in the case that the sediment delivery ratio was 100%. Therefore, gully erosion is the major source of total soil loss in this area, and effective soil measures of gully erosion mitigation are crucial for managing the sediment yield.     

Cu- and Zn-Soil Anomalies in the NE Border of the South Portuguese Zone (Iberian Variscides,Portugal) Identified by Multifractal and Geostatistical Analyses

Extensive Cu- and Zn-soil geochemical data in the Albernoa/Entradas–S. Domingos region (NE border of the Iberian Pyrite Belt, South Portuguese Zone) were examined to separate anomalies from background using the concentration–area fractal model. Distribution patterns of Cu and Zn concentrations in soil are primarily influenced by bedrock. The regional threshold values of Cu- and Zn-soil contents over metasedimentary sequences are 20–25 and 20–60 ppm, respectively, becoming 30–50 and 20–90 ppm, respectively, when metavolcanic rocks are present. The first-order threshold values for Cu are 80–90 ppm in soils over metasediments and 70–80 ppm in soils over sequences bearing metavolcanics. For Zn, the first-order threshold values are 40–80 and 90–100 ppm in soils over metasediments and metavolcanic rocks, respectively. Metasediments and metavolcanics comprising significant sulphide disseminations are outlined by Cu- and Zn-soil values above 100 and 300 ppm in soil, respectively. On the basis of these results, Alvares and Albernoa/Entradas areas emerge as the first priority targets for exploration. The observed non-coincidence of Cu- and Zn-soil anomalies in soil in the area could reflect difference in element dispersion during weathering, they mostly indicate distinct metal sources related to the original composition of different rock types or to chemical changes developed during Variscan deformation/re-crystallization path. The established regional baseline data can be used as reference for environmental studies.     

克拜东部黑土区侵蚀沟遥感分类与空间格局分析

近百年来,东北黑土区侵蚀沟的大量发育带来了一系列严重的社会经济问题,弄清侵蚀沟的类型、数量及分布情况是进行水土流失治理和生态环境建设的前提条件。以黑龙江省克拜东部黑土区作为典型研究区,采用2005年SPOT-5高分辨率卫星影象,结合野外调查,根据侵蚀沟的活跃程度,将黑土区的侵蚀沟分为活跃性、半活跃性和稳定性三种类型,阐述了不同类型侵蚀沟的影象特征和遥感分类方法,为利用遥感手段在区域尺度上对侵蚀沟进行快速调查提供了一种新途径。在对侵蚀沟进行信息提取和空间插值后,形成研究区不同类型侵蚀沟密度图,探讨了克拜东部黑土区侵蚀沟分布的空间格局特征及其影响因素,认为地貌发育过程中的“分水岭迁移”现象是造成该地区侵蚀沟密度东西差异的重要原因。     

东北漫川漫岗黑土区浅沟和切沟发生的地貌临界模型探讨

对东北漫川漫岗黑土区进行实地测量及地形图量算,推求出临界模型,校验了Moore的沟蚀发生公式。研究发现,该区浅沟发生的临界阈值和指数参数分别为0.0631和-0.4643,切沟发生的两参数分别为0.1161和-0.4457。同时发现Moore的沟蚀预测公式在该研究区并不适用。通过与野外实测浅沟和切沟发生位置对比,临界模型预测的沟蚀位置较好地反映了野外实际状况。     

泥石流沟谷坊坝群治理效应——以地震极重灾区北川县化石板沟为例

谷坊坝是泥石流治理的重要工程措施之一。化石板沟泥石流治理工程共设13座谷坊坝,组成梯级谷坊坝群;坝体主要分布在泥石流形成区和流通区,混凝土结构,轴向两端嵌入沟道两侧基岩0.5～1 m。通过对比化石板沟谷坊工程修建前后沟床纵坡比降、沟道两侧斜坡稳定性及泥石流侵蚀速率等方面的差异,证明谷坊工程能够有效拦蓄松散固体物质、稳固沟床和岸坡、降低沟道纵坡比降、降低泥石流流速和耗散流体能量、抬高沟道上游泥石流侵蚀基准面。研究发现,化石板沟谷坊坝群共拦截固体物质2.76×104 m3,仅占流域物源总量574.9×104 m3的0.5%,占近期可供给泥石流活动的物源量85×104 m3的3.3%;稳固沟床松散物质4.37×104 m3,仅占流域物源总量的0.76%,占近期可供给泥石流活动的物源量的5.2%;稳固沟道两侧坡体松散物质134.07×104 m3,占流域物源总量的23.3%,泥石流物源减少;回淤的沟道比降为原比降的60%～75%,相同频率下泥石流流速、峰值流量降低,沟道侵蚀速率下降,泥石流输沙量减少35%～57%;上游泥石流支沟侵蚀基准面抬升0.3～0.5 m。泥石流呈现从粘性到稀性,再到含沙水流的趋势发展。     

基于GIS的侵蚀冲沟与地貌因子的关系

冲沟是多种外力作用的结果,展示为多种地貌现象。选择胶东半岛北岩子口小流域作为研究对象,以正射影像（DOM）和数字高程模型（DEM）为数据源,选择土地利用、地形湿度指数、坡度坡长因子、水流动力指数、坡向、平面曲率和地表粗糙度等7个地貌因子,计算小流域土壤侵蚀敏感性,研究侵蚀冲沟与地貌因子的关系。结果表明:冲沟多发生在坡度坡长较大、水流动力强、地表湿度较低的林草地区域,多分布在阳坡的凹面;冲沟大多分布在土壤侵蚀中等敏感性及以上的区域,约占总冲沟的96.4%;在土壤侵蚀中等敏感性及以上区域,实验权重值对验证区冲沟分布的响应精度为87.9%,与实际值93.3%相差较小,精度较高。研究结果可为区域内冲沟侵蚀的评价提供一定科学依据。     

Systematic variation of bedrock channel gradients in the central Oregon Coast Range: implications for rock uplift and shallow landsliding

In tectonically active regions, bedrock channels play a critical role in dictating the pace of landscape evolution. Models of fluvial incision into bedrock provide a means of investigating relationships between gradients of bedrock channels and patterns of active deformation. Variations in lithology, orographic precipitation, sediment supply, and erosional processes serve to complicate tectonic inferences derived from morphologic data, yet most tectonically active landscapes are characterized by these complexities. In contrast, the central Oregon Coast Range (OCR), which is situated above the Cascadia subduction zone, has experienced rock uplift for several million years, did not experience Pleistocene glaciation, boasts a relatively uniform lithology, and exhibits minor variations in precipitation. Although numerous process-based geomorphic studies suggest that rates of erosion across the OCR are relatively constant, it has not been demonstrated that bedrock channel gradients in the region exhibit spatially consistent values. Analysis of broadly distributed, small drainage basins (5–20 km) in the central OCR enables us to explore regional variability in bedrock channel gradients resulting from differential rock uplift or other sources. Consistent with previous studies that have documented local structural control of deformed fluvial terraces in the western portion of our study area, our data reveal a roughly 20-km-wide band of systematically elevated channel slopes (roughly twice the background value), roughly coincident with the strike of N–S-trending mapped folds. Although many factors could feasibly generate this pattern, including variable rock strength, precipitation gradients, or temporal or spatial variations in forearc deformation, the elevated bedrock channel slopes likely reflect differential rock uplift related to activity of local structures. Importantly, our analysis suggests that rock uplift and erosion rates may vary systematically across the OCR. Although our calculations were focused on the fluvial-dominated portion of study basins, our results have implications for upstream areas, including unchanneled valleys that often serve as source areas for long-runout debris flows. Zero-order basins (or topographic hollows) within the N–S-trending band of elevated channel slopes tend to be steeper than adjacent areas and may experience more frequent evacuation by shallow landsliding. Thus, this region of the OCR may be highly sensitive to land use practices and high-intensity rainstorms.     

顾及地貌结构特征的黄土沟头提取及分析

沟头是黄土地貌中发育最活跃的地貌部位,沟头的个体与群体对黄土沟间地的蚕食,成为监测黄土高原地面侵蚀演化的重要标识。有效获取并分析沟头的空间分布特征,对于系统、深入地研究黄土地貌的空间形态结构具有重要的意义。以陕北黄土高原典型地貌类型区为实验样区,设计并实现了基于5 m分辨率DEM的沟头提取算法,获取了各实验样区的沟头空间信息;运用点格局分析方法,分析了沟头的空间分布特征。实验结果显示,所提出顾及沟沿线的沟头自动提取方法,具有较好的合理性与精确性;同时,从黄土塬区、黄土残塬区到黄土丘陵沟壑区,随着沟壑发育程度的增强,沟头逐步逼近分水线,其空间分布呈现“远分水线聚集—随机—近分水线聚集”的变化格局。     

应用线性光谱分离技术研究喀斯特地区土地覆被变化——以贵州省关岭县为例

喀斯特地区土地覆被主要类型除了和非喀斯特地区一样的植被和裸露土壤外,还存在一个广泛分布的裸露基岩,一般遥感处理方法不具备直接定量提取这三类土地覆被参数的能力。基于地物光谱线性混合模型的线性光谱分离技术,可以在亚象元的尺度上直接获取植被覆盖、裸露土壤和裸露基岩等在各象元区域内的比例,非常适合用于喀斯特地区的土地覆被变化的研究。本文利用1987年2月17日和1999年12月27日LandsatTM各6波段遥感影像,使用ENVI软件,分离出植被、裸露土壤、裸露岩石和阴影等土地覆被丰度和RMS的空间分布。对比结果表明,研究区1987～1999年,植被覆盖率上升593%,裸露土壤面积下降1215%,裸露基岩面积上升408%。表明研究区尽管植被在恢复、水土流失总量在减少,但石漠化面积在明显上升,生态形势依旧严峻。     

黄河中游流域地貌形态对流域产沙量的影响

在黄河中游地区 ,选择了 5 0多个面积约 5 0 0～ 2 5 0 0平方公里的水文测站流域 ,分别代表 6种不同自然地理类型 ,在流域沟壑密度、沟间地坡度小于 15°面积百分比等地貌形态指标量计的基础上 ,进行了流域产沙量与地貌形态指标相关分析。结果表明 ,对于不同类型流域 ,流域产沙量随流域地貌的变化遵循不同的响应规律 ,而且视流域其它下垫面环境条件的均一程度 ,其相关程度和响应速率各不相同。受地面物质、植被、地貌发育阶段等流域其它下垫面环境条件的制约 ,除沟壑密度外 ,流域产沙量与流域地貌形态的关系都没有人们以前所预期的好。     

基于DEM的黄土沟谷横剖面形态特征研究——以宜君、延安、绥德为例

选用1:10 000高精度5.0 m分辨率的DEM数据,在陕北地区,按黄土地貌演化序列次序,遴选分别代表黄土残塬沟壑、梁状丘陵沟壑、峁状丘陵沟壑地貌的宜君、延安、绥德3个流域,研究其中1 831个沟谷横剖面19个因子的形态特征,利用主成分分析法确立核心因子,分析结果表明:①沟谷深度、宽度、横剖面面积、宽深比、侵蚀度与不对称性指标的主成分累积贡献率为95.02%,为黄土沟谷横剖面核心指标;②随级别的增加,3个流域沟谷宽度、横剖面积、宽深比、侵蚀度均呈现总体增加的态势,与黄土地貌发育阶段具有明显的空间耦合性,尤其是宽深比与侵蚀度指标,反映出低级别黄土沟谷溯源侵蚀现象明显,以下切侵蚀为主,而高级别沟谷沟沿线后移,以侧向侵蚀拓宽为主的规律;③随级别增加沟谷深度呈现先增后降的态势,并在中级别沟谷出现拐点,与实地调研发现沟谷在中级别下切侵蚀遇到基岩的现象相吻合。     

沟道流域坡面与沟谷侵蚀演化关系——以晋西王家沟小流域为例

以往坡、沟侵蚀关系研究主要限于水沙关系的探讨 ,有关原型尺度小流域坡、沟地貌侵蚀演化关系的定量研究甚少 ,尤其是坡、沟地貌特征对流域切割程度的综合影响与交互作用的定量研究尚属空白。本文在 3S技术支持下 ,根据晋西王家沟小流域 196 7年 1∶5 0 0 0正摄影像图 (DOM )、高程数字化模型 (DEM )和同期、同比例尺地形图 ,利用正交多项式回归分析方法 ,定量分析了坡、沟地貌特征对流域切割程度的影响与交互作用。研究表明 ,沟谷地在流域地貌演化及地表切割程度中起主导作用 ,在沟间地面积相同时 ,沟谷地面积约为0 1km2 是影响流域切割裂度侵蚀演化强度最大的区域 ,流域面积愈小影响流域地表破碎的程度最大。其沟道流域坡、沟地貌演化机制可用坡、沟水流动能的地貌指标的综合影响与交互作用来解释     

区域泥石流孕灾环境危险性评价——以北京军都山区为例

以北京军都山区实测泥石流沟谷数为基准,基于因子叠加、信息量模型和FCM-粗糙集三种方法,分别获得了泥石流灾害发生的危险性等级分布,结果表明:①各分区单位面积内泥石流沟谷数都随着危险性评价等级的提高而增多;②因子叠加法和信息量模型法可得出五级泥石流灾害危险性分级,而粗糙集法只得出三级分级;③以实际泥石流沟谷落在评价区数目为标准,信息量模型法有90%以上的泥石流沟谷在危险性高和极高区域;粗糙集法得到危险区域覆盖了63.72%的泥石流沟谷分布;④从单位面积泥石流沟谷数与泥石流沟谷分布比率可得,信息量模型法评价精度较高,因子叠加法没有形成良好的梯度,而粗糙集法计算等级结果与其他方法存在差异,故须在其他区域进行进一步研究。     

黑土耕作区侵蚀沟治理紧迫度空间分布特征

综合把握侵蚀沟发育状态及其治理紧迫程度可为有效判断区域侵蚀沟防控方向与治理重点提供重要参考.论文结合侵蚀沟形态数据,构建区域侵蚀沟治理紧迫度评价指标体系,从乡镇与网格尺度揭示区域侵蚀沟侵蚀程度及其空间分布规律.结果表明:①从数量特征看,海伦黑土耕作区侵蚀沟分布呈非均衡状态,沟道长度以微/小型(≤500 m)为主,沟道面...