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1.
南京市溧水区土壤重金属污染不同插值方法的对比研究 总被引：3，自引：1，他引：2
《土壤通报》2014,(6):1325-1333
为探讨不同插值方法对南京市溧水区土壤重金属污染模拟结果的影响,本研究分析了该区245个表层土壤样点的As、Cd、Cr、Cu、Hg、Ni、Pb和Zn 8种重金属的空间相关性,分别比较了反距离权重法(IDW)、局部多项式法(LPI)、径向基函数法(RBF)和普通克里格法(OK)的插值精度、插值结果、空间分布,以及不同插值方法对污染评价的影响。研究得出:空间插值后数据的范围、均值和变异系数一般低于采样数据,且空间插值会增大安全区而减小污染区,平滑效应是主要原因。LPI的平滑效应中最严重,OK次之,IDW和RBF不明显。溧水区As、Cd和Zn的最优插值方法为OK,Cr、Cu和Hg的最优插值方法为RBF,Ni和Pb的最优插值方法为IDW。在实际操作中,应该根据插值精度、插值结果的数据统计和空间表达去具体选择合理的插值方法。 相似文献
2.
《中国生态农业学报》2021,(8)
土壤磷素含量是反映农业生态系统土壤肥力的重要指标。准确预测磷素空间异质性是评价土壤生产力和质量的关键。本研究采用反距离加权法(IDW)、径向基函数法(RBF)、普通克里金法(OK)、全局多项式法(GPI)、局部多项式法(LPI)、地理加权回归(GWR)和地理加权回归克里金法(GWRK)等插值方法,分别预测了三江平原白浆土典型灌区八五三、七里沁以及大兴灌区土壤磷素分布,并运用交叉验证法,通过平均误差(ME)、均方根误差(RMSE)和改进效果(RI)对各种方法精度进行比较,以期确定同一土壤类型不同采样密度土壤中磷素空间异质性最佳插值方法。对比7种插值方法,在空间插值平滑性方面,LPI、GPI、GWR、GWRK表现较好,在插值速度方面, IDW、RBF、LPI、GPI、OK较快, GWR和GWRK方法运算复杂、速度较慢。IDW、RBF等6种方法与OK相比,根据RI判定, GWRK方法提高了磷素空间分布模拟精度, IDW、GPI和LPI方法降低了磷素空间分布模拟精度, RBF方法在提高磷素空间分布模拟精度上表现不一致。采样密度会影响预测结果,对于本文而言,不论采样密度如何,GWRK方法均方根误差(RMSE)均最低,为最佳插值方法,而RBF方法是在采样密度较低时一种可选方法。GWRK法在本文是最佳的插值方法,但其结果会受到辅助变量多少和各变量之间是否存在共线性的影响。 相似文献
3.
基于全国第二次土壤普查东北地区土壤数据,以ArcGIS和GS+软件为支撑,对比分析了反距离加权法(IDW)、径向基函数(RBF)、普通克里金(OK)和回归克里金(RK)4种地统计空间插值方法在7个不同样本容量下土壤全氮含量(STNC)的空间插值效果。结果表明,由普查数据得到的东北地区STNC在0.08~21.48 g/kg之间,数据变异性较大;STNC空间结构表现出中强度空间自相关性,空间自相关范围大于同区域的小尺度采样研究;样本容量<171时,STNC空间变异性发生变化,空间结构特征和精度检验水平难以确信。4种空间插值方法对STNC空间趋势表达均呈现从东北向西南方向递减规律,空间趋势预测效果为:RK >OK >RBF >IDW。RK方法通过线性回归分析添加了阳离子交换容量(CEC)、年均温(MAT)、土层厚度(d)和pH值等辅助信息,比IDW,RBF和OK方法的插值精度分别提高了19.40%,18.50%和16.15%;在不同样本容量下RK方法的插值精度较为稳定且对无样点区STNC的空间趋势预测也体现出了更多细节信息,因此对于大尺度低密度采样的土壤属性空间插值可重点考虑RK方法。 相似文献
4.
样点数量与空间分布对县域尺度土壤属性空间预测效果的影响 总被引：4，自引：1，他引：3
明确样点数量和空间分布对土壤属性空间预测的影响,有助于科学制定土壤采样策略、有效提高土壤空间预测精度。从5 403个土壤样点中随机抽取验证数据集以及包含不同样点数量的训练数据子集(每个子集包括五种样点空间分布实例),在研究区表层土壤有机质含量普通克里格(Ordinary Kriging,OK)和反距离加权(InverseDistanceWeighted,IDW)插值结果的基础上,分析和探讨样点数量与空间分布对土壤空间预测效果的影响。结果显示,当样点数量从5000降至39个时,OK和IDW插值图的局部变异信息逐渐减少,基于20和10个样点的插值图存在失真畸变。当样点数量从5 000降至1 250个时,OK插值精度相近(r变幅为0.55～0.59、RMSE变幅为3.03～3.15);从样点数量减少至625个开始,OK插值精度明显下降,同一训练子集不同样点空间分布的插值精度分异明显。IDW插值精度随样点数量与空间分布的变化与OK插值相似,不同的是从1 875个样点开始出现插值精度的明显下降和不同空间分布插值精度的明显分异。在插值图发生失真畸变之前,OK平均插值精度大于IDW。研究结果表明,样点数量及空间分布均可在不同程度上影响土壤属性空间预测结果,当样点数量足够多时,样点数量和空间分布对预测结果的影响非常有限;当样点数量减少至一定程度时,随着样点数量的减少,空间预测图的局部变异信息逐渐减少,预测精度逐渐下降,同时样点空间分布对预测结果的影响开始凸显;在空间预测结果发生失真畸变之前,与OK相比,IDW插值精度较低且更早响应样点数量和空间分布的变化。 相似文献
5.
不同插值方法模拟四川省逐月降水量的对比分析 总被引：1，自引：0，他引：1
我国西部地区气象观测点较少,致使一些地区的降水信息无法直接获取,采用空间插值方法来推测相邻地区的降水量是重要手段之一。针对四川地区观测点少的现状,结合空间分辨率为90m×90m的数字高程数据(DEM),分别采用常规反距离加权插值(IDW)、考虑各点高程的反距离加权插值(IDW)、局部多项式(LPI)、普通克里金(OK)、协同克里金(CK)对每个月降水量和1年平均每月降水量进行插值,并采用交叉检验法来验证插值结果,将平均误差(MAE)和均方根误差(RMS)作为评估插值效果的标准。结果表明:考虑高程的IDW插值误差小于常规IDW,可明显提高插值精度,克里金方法平均误差和均方根误差较小,优于反距离加权和局部多项式插值,在两种克里金方法中,与数字高程模型结合的CK方法的插值效果更好,更加适合四川省山区地形降水量数据的插值。 相似文献
6.
基于余江县中部地区土壤密集采样点,通过重采样获得4个集聚度样点分布等级,每个等级取5个重复,其分布VMR均值(样方分析中的样点数变差–均值比)分别为0.13、0.83、1.49和2.16,利用普通克里金(OK)和结合土地利用信息的克里金(KLU)方法对土壤全氮(STN)含量进行空间预测,并通过验证样点比较了4种集聚度采样点的STN空间预测精度,以揭示土壤采样点集聚度对STN空间预测精度的影响。研究结果表明:通过两预测方法得到的验证点实测值与预测值散点图的相关系数(r)均随采样点集聚度的增加而降低,其中OK方法的r值由0.400降低至0.142,KLU方法的r值由0.718降低至0.542;两方法的预测平均绝对误差(MAE)和均方根误差(RMSE)随着集聚度的增加均呈现增加趋势,OK和KLU方法的MAE分别又由0.49和0.33增加至0.61和0.44,RMSE则分别由0.56和0.39增加到0.65和0.47。表明在土壤采样点数量相同的前提下,采样点的空间集聚度越低,即样点分布越均匀,克里金方法的预测精度越高,这说明对STN进行空间预测时,基于规则网格的采样点更有利于克里金方法的空间估算;同时,采样点空间集聚度对不同克里金方法预测精度的影响也存在差异,对KLU方法的影响大于OK方法。 相似文献
7.
以安徽省境内80个气象站点2011—2014年的降水量和2015年的逐日气温数据为基础,结合该区30 m的DEM数据,选取反距离权重加权法（IDW）、径向基函数法（RBF）、普通克里金法（OK）和协同克里金法（CK）对降水和气温数据分别进行了空间插值,并对模拟结果进行了交叉验证。结果表明:考虑了纬度和高程的协同克里金插值效果最好,降水和气温的插值误差排序均为:CK < OK < RBF < IDW,并对插值结果进行分析,发现研究区降水和气温空间分布均呈现由南向北逐渐递减的特点,并与经纬度、高程进行相关系数和回归分析,表明气象要素纬度地带性显著,降水量主要由纬度和高程决定,气温则主要受纬度的影响,月均气温与经度和纬度有一定的季节性规律。 相似文献
8.
采用反距离加权法(IDW),克里格法(Kriging),径向基函数法(Spline)对河南省安阳县385个土壤样点的全氮进行空间插值,通过交叉验证和样点检验对不同空间插值方法进行分析,结果表明,Spline优于IDW和Kriging,并且不同插值方法有不同的最优插值点数;基于不同样条函数的径向基函数法插值结果的平均相对误差MRE不同,其中平面样条函数表现最差,高次曲面函数,张力样条函数、规则样条函数和反高次曲面函数之间差异不显著。检验分析结果也显示,Spline优于IDW和Kriging,因此,相对于IDW和Kriging,Spline更适合用于全氮的空间插值。 相似文献
9.
土壤速效钾养分含量空间插值方法比较研究 总被引：33，自引：0，他引：33
土壤养分连续空间分布数据是土壤信息系统工作的基础，土壤养分空间插值的研究因此变得尤为重要。对陕西省周至县北部猕猴桃适生区土壤进行采样，以对猕猴桃生长作用较为密切的土壤速效钾含量为研究对象，用普通克里格（OK）、样条函数（Spline）、趋势面拟合（TSA）、距离权重反比法（IDW）等常用插值方法对采样点进行插值获取土壤速效钾空间分布图，进行交叉验证，结果表明能够反映出结构性影响的克里格插值方法明显优于其它方法，其中又以球形模型为最佳，样条函数、距离权重反比法在采样点密集区也能内插出较好的效果，但其受采样点密度影响较大．在采样点稀疏的地区内插结果较差。 相似文献
10.
基于RBF神经网络的土壤有机质空间变异研究方法 总被引：11，自引：4，他引：7
通过研究土壤性质的空间变异和空间插值方法,快速准确获取土壤性质的空间分布是精确农业和环境保护的基础。该文以四川眉山一块约40 km2的区域为试验区,采集表层土壤（0～20 cm）样点80个,利用径向基函数(RBF)神经网络建立空间坐标和邻近样点与土壤有机质间的非线性映射关系（RBF2）,模拟土壤有机质的空间分布。与普通克里法（OK）和仅以坐标为网络输入的神经网络方法（RBF1）相比,RBF2的插值精度有显著的提高;相同样点密度下其相对预测误差分别较OK和RBF1减小了9.87%、1.97%（样本A）和13.09%、2.36%（样本B）;即使样点数减半的情况下RBF2的相对预测误差也分别较OK和RBF1减小了10.23%和2.33%,并且插值图差异相对较小,可以更好地反映土壤有机质空间分布的异质性。因此,利用以坐标和邻近样点为输入的神经网络方法可以相对准确、快速地获取区域土壤性质空间分布的异质性信息。 相似文献
11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响 总被引：2，自引：2，他引：0
【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。 相似文献
12.
Aleš Lebeda Ivana Doležalová Eva Křístková Barbora Mieslerová 《Genetic Resources and Crop Evolution》2001,48(2):153-164
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions. 相似文献
13.
Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing. 相似文献
14.
Thomas Larsen Jesper Luxhøi Jakob Magid Lars Stoumann Jensen Paul Henning Krogh 《Biology and Fertility of Soils》2007,44(1):59-68
We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization
and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition
with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the
decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots
with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass,
soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration,
N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially
(<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation
in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils,
indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but
the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation
for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community
performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea. 相似文献
15.
《中国生态农业学报》2014,(6)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
16.
《中国生态农业学报》2014,(7)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
17.
《中国生态农业学报》2014,(8)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
18.
M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. 相似文献
19.
I.L. Boyd 《Biological conservation》2010,143(7):1664-1674
“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options. 相似文献
20.
Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage 总被引：1，自引：0，他引：1
Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate. 相似文献