高密度聚乙烯(HDPE)蜂巢式沙障对土壤水分的影响

先以机械沙障固沙、再进行生物固沙,是常见的治沙模式。近年来传统材料沙障与新型材料沙障的固沙效果差异一直引人关注。用中子水分仪分别测定流沙、高密度聚乙烯（HDPE）蜂巢式沙障和半隐蔽草方格沙障内的土壤含水量,通过对比流沙和两种机械沙障铺设下的土壤含水量、土壤蓄水量对降雨的响应关系以及在植物不同生长时期下的不同土层土壤含水量变化,评价其固沙效果。结果表明：（1）两种机械沙障对土壤水分都有较好的蓄积效果,且HDPE蜂巢式沙障蓄水量高于草方格沙障（P < 0.001）;（2）在较长的干旱时间里,草方格沙障的土壤蓄水量变化比新型HDPE蜂巢式沙障滞后;（3） HDPE蜂巢式沙障和草方格沙障都有较好的保水效果,但HDPE蜂巢式沙障因高度持久的优势,保水效果更高;（4） HDPE蜂巢式沙障60~110 cm土层的土壤含水量明显高于草方格沙障土壤含水量且固沙时间越长效果越明显,从铺设中期开始HDPE蜂巢式沙障60~110 cm土层土壤含水量为7%的情况连续出现,有时部分土层会出现土壤含水量在8%以上的情况;（5） HDPE蜂巢式沙障对植物个体生长的间接作用比草方格沙障大。     

开封市不同功能区城市土壤有机碳含量与密度分析(英文)

Urban soil, forming along with the development of city, has unique properties of soil organic carbon. On the basis of field investigation and laboratory analysis, soil organic carbon (SOC) of Kaifeng city was studied, and the results showed that the characteristics of SOC were different not only among function districts in urban area, but also between urban area and suburbs. The order of SOC in topsoil was industrial district > recreational district > traffic district > cultural/educational district > residential/administrative district. The density of soil organic carbon (SOCD) in both topsoil and profile followed the orders of recreational district >industrial district > traffic district>cultural/educational district > residential/adminis- trative district, and cultural/educational district > traffic district>industrial district>recreational district > administrative/residential district, respectively. SOCD in both topsoil and profile decreased along the transection line from urban area to suburbs and urban area had 2.53-fold more SOCD in topsoil and 1.56-fold more SOCD in profile than suburbs, respectively. SOC decreased with the depth and was mainly distributed within the scope of 0-30 cm. The variances of SOC in urban area were more complicated than that in suburbs.     

Content and densities of soil organic carbon in urban soil in different function districts of Kaifeng

Urban soil, forming along with the development of city, has unique properties of soil organic carbon. On the basis of field investigation and laboratory analysis, soil organic carbon (SOC) of Kaifeng city was studied, and the results showed that the characteristics of SOC were different not only among function districts in urban area, but also between urban area and suburbs. The order of SOC in topsoil was industrial district > recreational district > traffic district > cultural/educational district > residential/administrative district. The density of soil organic carbon (SOCD) in both topsoil and profile followed the orders of recreational district > industrial district > traffic district>cultural/educational district > residential/administrative district, and cultural/educational district s>traffic district>industrial district>recreational district > administrative/residential district, respectively. SOCD in both topsoil and profile decreased along the transection line from urban area to suburbs and urban area had 2.53-fold more SOCD in topsoil and 1.56-fold more SOCD in profile than suburbs, respectively. SOC decreased with the depth and was mainly distributed within the scope of 0–30 cm. The variances of SOC in urban area were more complicated than that in suburbs.     

黑河中游绿洲及绿洲-荒漠生态脆弱带土壤含水量空间分异研究

以黑河中游平川绿洲和六坝绿洲为例,对绿洲及绿洲-荒漠生态过渡带土壤含水量空间分异进行了分析研究。结果表明:在无灌溉条件下绿洲及绿洲-荒漠生态过渡带的土壤含水量水平分异明显,绿洲土壤含水量高于绿洲-荒漠生态过渡带和荒漠地区土壤含水量,并出现从绿洲到绿洲-荒漠过渡带和荒漠依次递减的趋势,主要受土壤性状、土壤水分水平运动和绿洲-荒漠局地大气环流影响;绿洲活动层土壤含水量垂直分异上表现为从表层向下逐渐增加,而过渡带和荒漠区活动层土壤含水量垂直分异则是表层和底层比20~30cm处低,可能与荒漠土壤凝结水的形成与运动有关。受绿洲地下水过度开采和绿洲边缘人类活动影响,在绿洲-荒漠过渡带形成了生态裂谷,对绿洲生态系统的安全构成威胁。     

塔克拉玛干沙漠腹地风沙土的力学性质

风沙土是形成于干旱、半干旱区的一种特殊性质的土,其力学性质不同于一般土体,结构松散性为其最主要的特点。通过对塔克拉玛干沙漠腹地14个风沙土样进行压缩试验和抗剪试验,获得了风沙土的基本力学参数:风沙土压缩模量值在50.00~142.86MPa之间,是一种低压缩性土;风沙土的内摩擦角值在31°55'~36°19'之间,低于河流冲积砂的内摩擦角值;风沙土存在结构力,其力学效应相当于粘聚力,可以在剪切试验中测出,其值在0.6~9.3kPa之间。并分析了影响这些力学参数的主要因素。     

TRIME-T3用于盐碱地土壤含水量测定的试验研究

以陕西省富平县卤泊滩盐碱地改良区为例,在其上游地段选取两块农田为研究对象,布置典型观测断面并埋设测管,运用TRIME-T3法和烘干法对观测断面土壤剖面含水量进行测定,并同步测定土壤含盐量。对两种方法测得的土壤含水量进行对比分析,研究土壤盐分对TRIME-T3法测定的土壤含水量影响以及该方法在盐碱地农田土壤剖面含水量测试中的应用。研究结果显示：（1）TRIME-T3法测量值较烘干法值偏大,但两者之间有较高的相关性,回归分析结果表明可以用y=0.866 3x+0.754 5的线性函数进行校正,校正后的TRIME-T3测量值中将有94.4%的值接近土壤含水量真实值。（2）通过对校正函数进行实例验证,结果表明TRIME-T3标定曲线值与烘干法测定值非常接近,绝对误差<1 cm³·cm^-3,相对误差在5%以下,表明TRIME-T3法通过一定的校正后可以很好地表达该盐碱地农田土壤剖面含水量信息。（3）通过对TRIME-T3测定的含水量与相应含盐量进行分析,发现两者之间的相关性并不显著,表明该方法可适用于盐碱地农田土壤剖面含水量测定。该研究结果可为类似地区盐碱地土壤剖面水分测定技术（TRIME-T3）的应用提供科学依据和理论参考。     

Content and densities of soil organic carbon in urban soil in different function districts of Kaifeng

Urban soil, forming along with the development of city, has unique properties of soil organic carbon. On the basis of field investigation and laboratory analysis, soil organic carbon (SOC) of Kaifeng city was studied, and the results showed that the characteristics of SOC were different not only among function districts in urban area, but also between urban area and suburbs. The order of SOC in topsoil was industrial district > recreational district > traffic district > cultural/educational district > residential/administrative district. The density of soil organic carbon (SOCD) in both topsoil and profile followed the orders of recreational district > industrial district > traffic district>cultural/educational district > residential/adminis- trative district, and cultural/educational district > traffic district>industrial district>recreational district > administrative/residential district, respectively. SOCD in both topsoil and profile decreased along the transection line from urban area to suburbs and urban area had 2.53-fold more SOCD in topsoil and 1.56-fold more SOCD in profile than suburbs, respectively. SOC decreased with the depth and was mainly distributed within the scope of 0–30 cm. The variances of SOC in urban area were more complicated than that in suburbs.     

荒漠-绿洲区土壤性质过渡特征

荒漠-绿洲区是干旱区地表景观格局变化最频繁的地区,深入研究荒漠-绿洲区不同景观格局土壤环境的差异对揭示干旱区生态系统过程至关重要。本研究通过采集石羊河流域荒漠、过渡带和绿洲土壤样品,综合运用多种分析方法,研究荒漠-绿洲区不同景观格局土壤理化属性的差异及其相互作用关系。结果表明：从荒漠、过渡带到绿洲景观,土壤质地和持水性能在不断好转,酸碱度和盐分状况变化不大,养分状况则表现为荒漠和过渡带具有近乎相同的有机碳和全氮含量,绿洲具有显著增加的有机碳、全氮和全磷含量。在不同深度上,荒漠景观土壤理化属性几乎没有变化;过渡带土壤质地由表层至深层不断改善,含水量逐层增大,全磷含量缓慢增加,C∶N和C∶P的值波动减小;绿洲景观土壤含水量由表层至深层显著增加,养分含量显著降低,C∶N和C∶P的值显著减小。总体而言,荒漠景观土壤理化属性的分异程度最小,绿洲景观分异程度最大,过渡带景观在土壤质地和含水量方面的分异程度较大,在土壤养分方面的分异程度较小。此外,过渡带景观土壤理化属性的自相关程度最高,且土壤质地是引起其他土壤理化属性分异的主要原因。     

FDR在高寒草地土壤水分测量中的标定及其应用

FDR(Frequency Domain Reflectometry)———频域反射仪是一种用于测量土壤水分的仪器,这是一种利用电磁脉冲方法,根据电磁波在介质中传播速度来测试介质的介电常数从而测定土壤水分的仪器。通过介绍FDR系统在高山草甸土上的校正结果,研究表明,野外校正比较符合实际情况,可以作为青藏高原地区高山草甸土进行FDR校正的参考。由于具有快速、准确等优点,能自动、连续地监测土壤含水量,FDR是一种值得推广的土壤水分测定仪器。     

干旱区土壤水分微波遥感反演算法综述

土壤水分是气候、水文、生态和农业系统的关键组成要素,同时也是监控土地退化和干旱的重要指标,土壤水分信息的及时获取对于规划和管理这些系统来说具有极其重要的意义.微波具有全天候、穿透性以及不受云层影响的独特物理机制使其在研究大尺度土壤水分反演时具有明显优势,已成为当前土壤水分遥感研究的主要大气窗口.在干旱区微波遥感土壤水分...     

古尔班通古特沙漠风沙土土壤蒸发特征

土壤表面蒸发是降水的无效损失,其大小直接决定着降水转化为有效土壤水的效率,从而间接决定了植物可利用水分的多寡。在降水稀少的沙漠区,定量认识土壤蒸发的大小和其所占降水的比例显得尤为重要。在2004年全生长期(5~9月)应用自制的微型蒸渗仪(Micro-Lysime-ter)测定了风沙土(有结皮覆盖的丘间低地和裸露沙丘顶部)和对照的荒漠盐碱土的土壤蒸发。结果表明:在相似的气象条件下,风沙土区的丘间低地和荒漠盐碱土的日平均蒸发量分别约是裸露沙丘(风沙土区)的2倍和3倍。整个生长期裸露沙丘的累积蒸发量为18.7mm,丘间低地为38.8mm,荒漠盐碱土为52.1mm。根据整个观测期的累积蒸发量和累积降雨量计算得出的蒸发降雨比分别为:裸露沙丘0.20,丘间低地0.42,荒漠盐碱土0.62,表明裸露沙丘由降水转化为土壤水而储存的比率最高。同时,从数据分析中可以看出:在风沙土区0~5cm土层的含水量对土壤蒸发起决定作用,而盐碱土区的土壤蒸发则受到更深层次土壤水分的影响。裸露沙丘低的土壤蒸发、高的降水转化效率,为植被恢复奠定了良好的基础。因此,裸露沙丘的低蒸发量可以视为植被状况对生态水文过程的一种良性反馈。     

干旱区盐碱土剖面无机碳组分分布特征

通过分离土壤动态性无机碳,结合14C同位素技术,有效量化了盐碱土剖面无机碳组分的存储数量和年龄特征。结果表明：整个土壤剖面,盐土难溶性无机碳含量和可溶性无机碳含量明显高于碱土。无论是土壤难溶性无机碳储量还是可溶性无机碳储量,盐土和碱土中有近80%碳是存储在1 m以下,50%存储于3 m以下。相同土层,土壤可溶性无机碳储量约占土壤难溶性无机碳储量的30%。无论是盐土还是碱土,无机碳的年龄超过万年,而土壤可溶性无机碳的年龄明显低于土壤无机碳的年龄。研究结果证实尽管土壤可溶性无机碳储量较低,但其周转时间短,速率高,因此在参与现代碳循环的程度上明显要高于土壤无机碳。     

古尔班通古特沙漠春季土壤含水量空间格局

春季积雪融水是古尔班通古特沙漠土壤水分的重要补给源之一,为早春植物的萌发和生长创造了有利的条件。为掌握该地区春季沙丘的土壤水分分布状况,采用探地雷达测量技术,于2010年4月进行了多次野外测量,并通过对地面直达波信号的提取和分析,初步获得了一致的测量结果。结果表明：（1）探地雷达地面直达波测量的土壤平均含水量与20 cm深同步TDR的测量结果非常接近,两者总体相差在0.02 cm3/cm3以内,充分反映了GPR地面直达波测量结果的有效性和精确性;（2）春季积雪完全融化后,沙丘/沙垄顶部土壤水分明显低于垄间低地,这与前人的研究一致,反映了积雪和冻土层在消融过程中,沙丘表面融水在坡面重力作用下,沿难以透水的冻土层上界自坡上向坡下迁移,形成了垄间最高、坡部次之和垄顶最少的分布格局;（3）垄间低地的土壤水分明显受到低矮灌草丛的影响进行再分布,这是由于积雪最初沿植丛基部开始消融,并以植丛为中心形成漏斗状融洞,从而形成以植丛为中心汇集较多融雪水的格局,而垄间低地中较为高大的梭梭乔木对融雪水的再分布影响明显不如低矮的灌草丛,这与其地表茎基过少有关。此外,探地雷达测量实验提供了详实可靠的表层土壤含水量分布信息,可为荒漠生态系统的空间尺度研究提供真实可靠的数据基础。     

沙棘(Hippophae rhamnoides)对经客土改良石漠化土壤的适应性

石漠化地区基岩裸露、砾石堆积,水土流失严重,土壤与植被覆盖率低,因此引发一系列的生态恶化问题,而客土恢复植被是一项快速有效的治理途径.本试验在贵州毕节地区实施,以当地黄壤客土(T1,黄壤与砾石比为1∶1;T2,黄壤与砾石比为2∶1;T3,黄壤与砾石比为3∶1;T4,黄壤与砾石比为1∶0)改良石漠化,从耐瘠薄的灌木——沙...     

Quantitative retrieval of soil salt content based on measured spectral data

Choosing the Minqin Oasis, located downstream of the Shiyang River in Northwest China, as the study area, we used field-measured hyperspectral data and laboratory-measured soil salt content data to analyze the characteristics of saline soil spectral reflectance and its transformation in the area, and elucidated the relations between the soil spectral reflectance, reflectance transformation, and soil salt content. In addition, we screened sensitive wavebands. Then, a multiple linear regression model was established to predict the soil salt content based on the measured spectral data, and the accuracy of the model was verified using field-measured salinity data. The results showed that the overall shapes of the spectral curves of soils with different degrees of salinity were consistent, and the reflectance in visible and near-infrared bands for salinized soil was higher than that for non-salinized soil. After differential transformation, the correlation coefficient between the spectral reflectance and soil salt content was obviously improved. The first-order differential transformation model based on the logarithm of the reciprocal of saline soil spectral reflectance produced the highest accuracy and stability in the bands at 462 and 636 nm; the determination coefficient was 0.603, and the root mean square error was 5.407. Thus, the proposed model provides a good reference for the quantitative extraction and monitoring of regional soil salinization.     

内蒙古典型草原区土壤硬度与土壤水分的空间变化分析——以锡林浩特为例

近些年来,内蒙古草原及其变化已经受到有关方面的关注,通过研究调查内蒙古草原区的几个典型植被类型,共49个样地的土壤硬度与土壤水分。土壤硬度测量深度为0~20 cm,土壤水分测量深度为0~40 cm(10 cm取一个土样),并分析了两者的空间分布规律。分析结果显示,典型草原三种植被类型的土壤硬度随其深度增加而增加,而就全部样地来说,土壤水分随其土壤深度增加没有明显的变化。土壤硬度与土壤水分的相关性不强。通过49个样地的四层硬度进行PCA分析,显示出四层硬度对测量点第一主成分的作用差不多,这样,可以求取四层硬度的平均值作为该测量点的硬度,利用Arcinfo软件形成硬度分布图,看出本研究区的土壤硬度大致可以分成3区域:北部硬度较大,中部其次,南部沙地硬度较小。     

Experimental research on physical properties of saline soil subgrade filler in Chaerhan region

In order to improve the engineering stability of saline soil of high chloride content in the Chaerhan salt lake region, six typical characteristics saline soil samples were selected, and tests on their...     

基于高光谱遥感的新疆北疆地区土壤砂粒含量反演研究

 土壤砂粒含量是表征土壤质量的重要指标,探索建立基于高光谱遥感的区域土壤砂粒含量反演方法对区域土壤质量监测具有重要意义。通过野外采集的高光谱数据与MODIS影像相结合,遴选出土壤砂粒含量的敏感波段与反演方程,进行干旱区裸地土壤砂粒含量遥感反演研究。结果表明：430 nm为土壤砂粒含量的敏感波段,原始光谱经变换后的数值与土壤砂粒含量的相关系数在430 nm处达到最大值0.76;基于MODIS第3波段中心波长460 nm处的土壤原始光谱的反演精度最高,达到89.30%,与实际情况吻合较好,表明MODIS第3波段可以应用于干旱区裸地土壤砂粒含量的遥感反演。     

中国耕地土壤相对湿度时空分异

以全国653个农业气象站1993-2013年耕地的土壤相对湿度数据为基础,运用地统计方法,分析中国耕地土壤相对湿度时空分异特征与规律。结果表明:自1993年以来全国耕地的土壤相对湿度呈现波动上升趋势。全国耕地的土壤相对湿度普遍大于60%,分布区域自4月中旬开始随夏季风推移不断向北向西扩大,自10月下旬开始向东、南方向缩小。耕地土壤相对湿度值随土壤深度的增加而增加。年际尺度上,耕地的土壤相对湿度在夏秋季上升速度最快,变化幅度随土层深度增加而变小。土壤相对湿度与降水量存在较强的正相关关系,与潜在蒸发量、气温普遍存在较强的负相关关系。土壤相对湿度与各气象要素的相关性随深度加深而减弱。春、夏、秋季气象因素对旱地土壤相对湿度影响较大,冬季气象因素对水田影响更大。     

Short and long term effects of bioturbation on soil erosion, water resources and soil development in an arid environment

The importance of vegetal cover on soil erosion processes has been recognized for a long time. However, the short and long term effects of faunal activity on soil erosion and soil development had been largely overlooked by geomorphologists. The study of runoff and erosion processes in the Negev desert indicated pronounced systematic differences in sediment concentration and soil erosion rates between rocky and colluvial surfaces. Erosion rates were always higher on the former than on the latter. Field observations drew attention to an intense burrowing and digging activity conducted mainly by Isopods and Porcupines. The monitoring of this activity, based on a grid system, which consists of rows 5 m wide, lasted ten consecutive years. Data obtained suggest the existence of a strong link between the spatial pattern of bioturbation and that of soil erosion. The study also examines, through feedback processes, the regulatory role of bioturbation on the spatial distribution of water availability; soil moisture and soil forming processes. Due to bioturbation two distinct environments were recognised. The rocky environment which is characterized by a positive feedback with a high water availability and low soil salinity; and the soil covered areas where a negative feedback results in low water availability and a high soil salinity.