共查询到18条相似文献，搜索用时 140 毫秒
1.
土地利用对溶丘洼地土壤容重、水分和有机质空间异质性的影响——以南洞流域驻马哨洼地为例 总被引：1，自引：1，他引：0
为了探究溶丘洼地土壤空间异质性及其影响因素,本文以驻马哨溶丘洼地为研究对象,利用经典统计学和地统计学的方法,从不同土地利用、坡度、坡向、土壤深度分析土壤容重、水分及有机质的空间异质性。结果表明:（1）土壤有机质为强变异,变异系数为0.71,容重和水分变异系数分别为0.15、0.11,属中等变异,土壤容重和水分呈极显著负相关,和有机质呈显著负相关,相关系数分别为-0.609、-0.581;（2）块基比介于0.78~0.97,随机部分引起的空间变异程度较大,空间自相关较小,且模型拟合较好。（3）耕地土壤有机质、水分含量最低,容重最大,而灌木土壤反之;（4）北坡土壤容重高于南坡,变异系数小于南坡;而土壤水分、有机质低于南坡,变异系数高于南坡。从不同坡位、坡向的比较中,皆体现了土地利用对土壤空间异质性的影响。在土地利用作为主要因素的影响下,驻马哨洼地土壤水分、容重、有机质由随机部分引起的空间变异增加,空间自相关减小。 相似文献
2.
典型岩溶峰丛洼地坡面土壤水分空间变异性 总被引：3，自引：1，他引：2
采用网格法测量典型坡面上旱季（12月）和雨季（5月）的表层(0~5 cm)土壤含水量,以地统计学方法分析其空间变异性,结果表明:（1）与单一土地利用坡面相比,人为扰动强、土地利用多样的岩溶峰丛坡地表层土壤含水量表现为坡上未被扰动的自然植被区明显高于坡下人为改造的区域;旱季时坡地林地表层土壤平均含水量（32.8%）明显高于位于坡下的梯田空闲地（24.2%）、梯田橘园（20.0%）、梯田菜园（22.0%）、坡地裸地（23.5%）;雨季时,坡地裸地（30.2%）和梯田橘园（32.1%）有明显增大,梯田空闲地（17.8%）剧烈减小,坡地林地（32.2%）土壤含水量依然最高;（2）旱、雨季整个坡面上空间结构比分别为21.0%、8.7%,表现为雨季的空间相关性更好;旱、雨季表层土壤含水量变异系数分别为20.1%和31.7%,属中等程度变异;雨季表层土壤含水量的变程（77.5 m）显著高于旱季（8.0 m）,雨季的土壤含水量具有较好的空间变异结构;（3）裸岩周围空间的土壤含水量随与裸岩的距离增大而减小,梯田石坎周围空间的土壤含水量随与梯田石坎的距离增大而递减。 相似文献
3.
土壤水分是黄土高原关键带水循环、地下水补给和植被恢复的关键因素。为揭示黄土高原关键带黄土整个剖面的土壤水分空间变化特征,通过土芯钻探的方式获取了黄土高原关键带5个典型样点（杨凌、长武、富县、安塞和神木）从地表到基岩的土壤水分样品,采用经典统计学和地统计学相结合的方法分析了剖面土壤水分的分布规律、变异特征及空间结构。结果表明:黄土高原关键带剖面土壤水分从南往北,土壤平均含水量由高变低;5个样点的土壤水分均为中等变异,随着深度由40 m增加到200 m,土壤水分变异性变弱,且样点之间的土壤含水量差异降低;地统计学分析表明样点的半方差函数能被理论模型较好地拟合（杨凌除外）,指数模型能够描述大部分样点深剖面的空间变异结构。相关结果有助于了解黄土高原深层土壤水分状况及分布规律,对于黄土高原土壤水资源估算和区域植被恢复具有重要价值。 相似文献
4.
以封丘地区典型的4种土地利用类型(传统耕作地、免耕地、金银花地和杨树林地)为例,系统研究了不同土地利用方式下土壤入渗特性的空间变异强度、空间变异结构及其主要变异源。结果表明,频繁的耕作会降低土壤异质性,弱化土壤特性空间变异结构,扰动较小的免耕地和金银花地的土壤入渗特性则具有相对明显的空间变异结构,扰动最小的杨树林地土壤的入渗特性具有最为明显的空间变异结构和最小的变程。容重、有机质含量和初始含水量是耕作地入渗的最主要变异源,初始含水量则是金银花地入渗的唯一显著性变异源;杨树林地入渗变异的主要变异源是有机质和初始含水量;影响免耕地入渗特性变异的变异源并不显著。在有些情况下,水温也可能成为入渗特性空间变异研究的重要干扰因素。 相似文献
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6.
通过对一块面积为1hm2麦田内的98个观测点取样分析,测定了两个时期的土壤水分和盐分含量。结果表明两个时期的土壤含水量均服从正态分布,底层盐分均服从对数正态分布,而表层的盐分分布具有不确定性。两个时期土壤水分和盐分的变异系数分别属于弱变异和中等变异强度。通过结构分析,发现两个时期的水分和盐分均在一定范围内存在空间相关性。对两个时期土壤水分和盐分空间分布的动态变化进行了比较,同时采用CoKriging方法进行估值,与Kriging法相比,其估计方差减少百分数最大达到了136.3%。 相似文献
7.
为掌握黄土高原区域尺度土壤水分的时空分异特征及其影响因素,在黄土高原布设一条南北方向样带（N=86）,动态监测0~5 m剖面土壤含水率。采用经典统计学方法分析了土壤蓄水量的分布规律、变异特征及影响因素。结果表明:不同土层土壤水分均呈中等程度变异,并由南向北递减,样带0~5 m剖面平均土壤蓄水量为735 mm;随着土层深度的增加,土壤水分在空间上的变异增强,而在时间上的变异减弱,表明深层土壤水分具有较强的时间稳定性特征。干燥度、黏粒、归一化植被指数和坡度是影响区域土壤水分空间分布的主要因素,可作为一定置信水平上预测区域土壤水分空间分布状况的预测变量。 相似文献
8.
分别在火山灰土和砂壤土两种土壤上进行了不同喷灌均匀系数和灌水量的土壤水分空间分布试验。对土壤干容重空间分布规律的研究表明,干容重在空间的随机分布可用正态分布来表示。为了确定喷灌洒水量和土壤含水率的空间结构,分别计算了它们的半方差和自相关函数。结果指出,喷灌洒水量的相关距离为h～6m,该距离随风速呈增大趋势;灌水停止4h后的土壤含水率的相关距离为5～6m,喷灌均匀系数对该距离无明显影响。田间试验还表明,喷灌洒水在土壤中的分布要比其在地表的分布均匀得多,土壤水分空间分布的均匀性主要取决于土壤初始含水率的均匀程度和灌水量。 相似文献
9.
为探明黄土高原北部坡面土壤饱和导水率(Ks)空间分布特征,为土壤水文过程模拟与预测提供理论依据,采用经典统计学和地统计学的空间变异分析方法,分析了坡面尺度土壤Ks的空间变异特征,并用一阶自回归状态空间模型对Ks的空间分布进行了模拟.研究区坡面尺度Ks的变异为中等程度变异,具有中等程度空间依赖性,变程为42 m.Ks与容重、砂粒、粉粒和黏粒含量在不同滞后距离下均具有自相关关系和交互相关关系.容重和土壤颗粒是影响坡面Ks空间分布的主要因素.状态空间模拟结果表明,基于容重和土壤颗粒的状态空间方程可以很好地解释坡面Ks的变异状况(R2>0.9).一阶自回归状态空间模型可用于田间条件下坡面尺度Ks分布特征的预测. 相似文献
10.
选取桂林丫吉试验场岩溶石山坡面上典型覆盖土壤的两个单元体为对象,对其土壤剖面层含水量的分布变化、土壤蒸发速率大小及其相关影响因素进行分析研究,结果表明:(1)土壤剖面最大含水率层位于土壤底部与基岩的交界处,中间过渡层土壤含水量最少,表层土壤水分受外界因素影响而变化显著;(2)在夏季岩溶石山区地表蒸发强烈,直径10cm的土壤柱日蒸发量为5~12mL之间,夜蒸发量在0~3mL之间;(3)几天内决定地表土壤日蒸发量(y)大小的因素主要是太阳辐射(x2)和土壤温度(x4),其关系式可表示为:y=18.018+0.001x2-0.691x4。 相似文献
11.
Soil degradation resulted from unreasonable land use and erosion has been a serious problem in the black soil region of northeastern
China. This paper seeks to understand the relationships between topsoil properties and topography and land use for land management
targeting at improving soil quality in this region. A total of 292 soil samples and 81 volumetric rings were taken from a
typical small watershed of the region in June 2005 for examining total carbon (TC), total nitrogen (TN), soil texture (classified
into gravel, sand, silt, and clay), and bulk density (ρ
b), respectively. Spatial variability of these soil properties was evaluated with classical statistics and geostatistics methods.
The results of classical statistics indicated that TC, TN, sand, silt, clay content, and ρ
b were moderate variables while gravel had great variability. Soil properties were mainly correlated to slope position, elevation
and land types. Geostatistical analyses showed that the spatial autocorrelation for TC, TN, and silt was weak, strong for
clay and moderate for and ρ
b sand, respectively. The spatial variations of soil properties are affected comprehensively by topographic factors, land use,
erosion, and erosion control in this watershed. Past erosion, however, is the most important component to induce change of
soil properties. In this small watershed, current soil and water conservation measures play an important role in controlling
soil loss. But the restoration of soil properties was unsatisfactory. Comparing with untilled soil of this region, TC, TN,
silt content are excessively low; whereas ρ
b, sand and clay content are excessively high; gravel appears at most sampling locations. It is necessary for improving soil
properties to protect forest and grassland and change cultivation system of farmlands. 相似文献
12.
土地利用结构与生态过程 总被引：56，自引：0，他引：56
本文从土地利用与土壤水分、土地利用与土壤养分、土地利用与水土流失3个方面系统讨论了土地利用结构与生态过程研究的现状和特征,指出:1)土地利用结构对土壤水分的影响涉及生态系统、坡面、小流域和区域等系列尺度,土地利用的分布及景观特点影响土壤水分的时空变异;2)土地利用对土壤养分的影响表现在土地利用的镶嵌格局影响土壤养分的分布和迁移,土地利用的变化可以引起土壤养分的变化;3)土地利用与水土流失关系密切,土地利用的改变能够减少或增加径流和土壤侵蚀.尺度不同,土地利用与水土流失的机制也不尽相同.土地利用结构与生态过程的研究,还需要注重大尺度和多尺度上的综合研究. 相似文献
13.
Xue Zhang Zhongwu Li Guangming Zeng Xiaolan Xia Lin Yang Jiajie Wu 《Environmental Earth Sciences》2012,67(6):1725-1734
Erosion can have a significant impact on soil properties in areas characterized by undulating topography. The spatial trends of soil properties and the availability of soil nutrients change with land use conversion. Most studies on these changes in China, however, focus on the natural or agricultural ecosystems. Little attention has been paid to unique changes, such as the conversion of natural or agricultural land to economic development zones. To this end, it has been determined that the properties of the surface soil in an economic development zone with unique topography characterized by large mounds of earth and stones in the red soil hilly region in China. The aim of this study is to characterize the overall level and spatial patterns of the concentrations of topsoil selected soil properties, including pH, cation exchange capacity (CEC), bulk density, soil moisture, soil organic carbon (SOC), soil nitrogen (N), soil phosphorus (P), and soil potassium (K). Results show that the mean pH and CEC of soils is as low as 5.35 and 6.47?cmol?kg?1, and the mean value of soil moisture is 0.30?g?g?1, and the mean level of bulk density is 1.45?g?cm?3. SOC and total P are as low as 5.89 and 0.35?g?kg?1, while total N and total K have a high level of 8.44 and 25.2?g?kg?1. The mean level of alkali-hydrolyzable N, Olsen P, and available K is 54.33, 6.35, and 120.33?mg?kg?1, respectively, all at intermediate or low levels according to the Second National Soil Survey. All selected soil properties and nutrients have overall similar spatial patterns with the highest value on the lower slope positions except for alkali-hydrolyzable N. The results are most likely governed by the native properties of red soil, zonal climate, agricultural history for all the soils, and different degrees of soil erosion, and the probable impact of human activity like construction among different slope positions. Results indicate that (1) topography influences soil properties, as evidenced by the different spatial trends of the soil nutrients, and (2) human activity, especially construction, affects the soil properties of economic development zones. This study aims to provide valuable insights for the evaluation of soil quality as a prerequisite for land use planning in economic development zones. 相似文献
14.
Improper cultivation practices are seriously degrading native forest ecosystems in northern Iran. Hence, the objectives of this study are to compare selected soil properties, runoff amount, erosion and also introducing equations to predict the runoff and soil erosion in three types of land use (forest, garden and cultivated). A simple portable rainfall simulator has been set in 90 random points to create experimental rainfall. Result showed that changes in natural forest led to a significant clay, organic carbon of soil, total N and antecedent soil moisture decrease and sand, pH and bulk density increasing. The rainfall runoff experiments indicate that runoff content of the natural forest soils was 35 % and respectively 38.45 % higher than the garden and cultivated land soils .This result could be related to the higher antecedent soil moisture in natural forest compared with the other land uses. According to the obtained results, garden soil erosion and cultivated land was 1.351 and respectively 1.587 times higher than the forest. The correlation matrix revealed that runoff content was positively correlated with antecedent soil moisture, bulk density and silt, and negatively with soil organic carbon, total N and sand. Also, soil organic carbon, total N, clay and sand showed negative correlation with soil erosion, while there is a positive correlation between erosion and silt, bulk density, pH and antecedent soil moisture. The results of multiple linear regression showed that runoff in forest, garden and cultivated land can be predicted with correlation coefficient of 0.637, 0.547 and 0.624, respectively. The correlation coefficients of 0.798, 0.628 and 0.560 in equations indicate their moderate potential in simulating soil erosion. 相似文献
15.
Estimation of surface soil water content from surface temperatures in dust source regions of Mongolia and China 总被引：2，自引：2，他引：0
Surface conditions, such as surface roughness and soil moisture, control wind erosion and dust emission in northeast Asia.
Data on spatial and temporal changes of surface soil water content are needed for dust-modeling systems used to predict dust
events with the aim of preventing damage from them. A modified temperature-vegetation dryness index (MTVDI) was tested to
see if it could reproduce surface soil water contents measured during the dust event season in Bayan Unjuul, Mongolia, and
Shenmu, China. MTVDI was calculated from land surface temperature and aerodynamic minimum and maximum surface temperatures
estimated from meteorological data. The standard deviation of the error of estimations of soil water content from MTVDI was
±1.5% in Bayan Unjuul when soil water content was lower than 4%. This compares favorably with the observational error of ±1%
of the soil moisture sensors used. 相似文献
16.
Priyabrata Santra Bhabani Sankar Das Debashish Chakravarty 《Environmental Earth Sciences》2012,65(7):2051-2061
Surface map of soil properties plays an important role in various applications in a watershed. Ordinary kriging (OK) and regression
kriging (RK) are conventionally used to prepare these surface maps but generally need large number of regularly girded soil
samples. In this context, REML-EBLUP (REsidual Maximum Likelihood estimation of semivariogram parameters followed by Empirical
Best Linear Unbiased Prediction) shown capable but not fully tested in a watershed scale. In this study, REML-EBLUP approach
was applied to prepare surface maps of several soil properties in a hilly watershed of Eastern India and the performance was
compared with conventionally used spatial interpolation methods: OK and RK. Evaluation of these three spatial interpolation
methods through root-mean-squared residuals (RMSR) and mean squared deviation ratio (MSDR) showed better performance of REML-EBLUP
over the other methods. Reduction in sample size through random selection of sampling points from full dataset also resulted
in better performance of REML-EBLUP over OK and RK approach. The detailed investigation on effect of sample number on performance
of spatial interpolation methods concluded that a minimum sampling density of 4/km2 may successfully be adopted for spatial prediction of soil properties in a watershed scale using the REML-EBLUP approach. 相似文献
17.
祁连山退化高寒草甸土壤水分空间变异特征分析 总被引：12，自引：0，他引：12
利用传统统计学方法和地统计学方法,对祁连山地区受到过度放牧影响而退化为以狼毒为优势种的高寒草甸的土壤水分垂直变异特征、水平空间异质性以及分布特征进行了系统分析. 结果表明：在垂直方向上,0~100 cm土壤水分含量随深度的增加而逐渐减少,土壤水分含量的变化速度随深度的增加也趋于减少;土壤水分分布的变异系数在浅层和深层土壤较大,在中层土壤较小. 在水平方向上,0~40 cm土壤水分具有中等空间变异性,其中10~20 cm土壤水分变异性主要受根系的影响,随机部分引起的变异性最大;而在其他土壤层,随着深度的增加土壤水分含量由随机部分引起的空间异质性程度减弱,由空间自相关部分引起的异质性程度增强. 整体上,土壤水分含量与微地形关系密切,与距离溪流的远近程度正相关,与高程分布负相关. 相似文献