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1.
用于矿区、建筑工地及复垦土地的修订通用土壤流失方程   总被引:1,自引:0,他引:1  
修订的通用土壤流失方程(RUSLE)在环境评价、荒地开垦、矿区及建筑工地的土壤流失量计算中应用得越来越广泛。对通用土壤流失方程(USLE)和1.04版、1.06版RUSLE修订的通用土壤流失方程进行逐因子比较表明:1.06版RUSLE在计算矿区建筑工地及复垦土地的土壤流失量方面较准确。因此,1.06版RUSLE最适于特殊场地的土壤流失量计算,而USM和1.04版RUSM 4不再适用。  相似文献   

2.
RUSLE侵蚀模型及其应用(综述)   总被引:7,自引:0,他引:7  
在对RUSLE和USLE进行分析和比较的基础上,探讨了RUSLE对USLE的改进内容和形式:UUSLE模型所用的数据量比USLE大得多,产正了USL分析中的错误,填补了原始数据的空白,且增加了其灵活性,使能模拟不同的系统和替代方法和侵蚀量,对RUSLE模型的应用前景作了展望。  相似文献   

3.
水土流失定量遥感方法及其应用的研究   总被引:82,自引:6,他引:76       下载免费PDF全文
本文介绍了水土流失定量遥感方法,应用实验和结果,并讨论了它的实质和应用前景等。该法的监测模型虽有与USLE和RUSLE相同的表达形式,但其因子琥式算法系由我国实测资料所建,故有更人合我国实际的应用效果,尤其它适用于遥感和GIS数据的微机处理。  相似文献   

4.
土壤侵蚀模型研究进展   总被引:3,自引:0,他引:3  
本文分三部分综述了国内外土壤侵蚀模型研究进展。第一部分分三个阶段,即1958年通用流失方程(USLE)诞生前、1958年USLE诞生至1978年以及1978年以后,综述了以美国、澳大利亚和英国为代表的国外研究进展;第二部分从流失量与影响因子的关系方程及美国通用流失方程(USLE)的应用二个方面,介绍了国内研究现状;第三部分就侵蚀模型的发展作了展望。  相似文献   

5.
应用USLE模型与地理信息系统IDRISI预测小流域土壤侵蚀量的研究   总被引:279,自引:27,他引:252  
依据实地调查资料,建立了典型小流域地理数据库,应用径流小区观测结果,确定了定量计算通用土壤流失方程因子指标方法,在地理信息系统IDRISI支持下,根据USLE土壤侵蚀预测模型对数据库实施运算操作,预测了小流域土壤侵蚀量。结果表明,占流域面积67%的区域土壤侵蚀微弱或轻度,这一区域对流域土壤侵蚀量的贡献率仅为3%,而流域80%的泥沙来自于占流域面积仅20%的极强度和剧烈侵蚀区域。  相似文献   

6.
在改进能通用土壤流失方程式中,坡长坡度复合因素(LS)是对地表径输沙能力的量度。在Hairsine-Rose的WEPP理论和集水区发展侵蚀理论中,通过考虑输沙能力对泥沙通量的限制,我们可以计算与流量指数和坡度成非线性函数关系的无量纲输沙能力指数。在一个二维的山坡上,这个指数就相当于RUSLE中的复合因素LS,其主要优点是可以扩展到三维地域空间。  相似文献   

7.
依据近期对美国水土新技术考察,介绍了美国水土流失预测预报和动态监测最新进展。美国目前正在研究和应用的水土流失预测预报模型主要包括,一类是以通用土壤流失方程式修订版(RUSLE)为代表的基于经验和统计的回归模型;一类是以水力侵蚀预报项目研究成果(WEPP)为代表的着重过程研究的模型,前者主要用于估算一定区域的土壤侵蚀量。后者用于研究土壤侵蚀随时间和空间变化的规律,模型所需水土流失动态数据的采集,传输  相似文献   

8.
应用水土流失定量遥感方法监测山东全省山丘区的研究   总被引:40,自引:8,他引:32  
本文简要介绍了水土流失定量遥感方法的组成和基本原理,重点叙述了它在山东全省山丘区的应用作业和应用结果,并讨论了它的准确性,实用性和应用前景等。该法的监测模型可与美国近年刊出的RUSLE相媲美,且其因子算式算法系由我国实测资料所建,故有更合我国流失实际的应用效果,尤其它适用于遥感和GIS数据的微机处理,其应用结果,不仅有比常规调查法和定性遥感法更准确实用的流失总量、各级面积的统计数据和流失现状图,而  相似文献   

9.
在印度尼西亚,土壤侵蚀是导致环境恶化的主要原因,因此需要利用土壤侵蚀模型来估算土壤侵蚀率及产沙量。研究人员1991~1992年应用改进的农业非点源污染模型(AGNPS)对印度尼西亚爪洼2592km2的Citarik小流域林地及农林地的土壤侵蚀率及产沙量进行了估算,并把计算结果与用美国土壤流失方程(USLE)的计算结果进行了比较,认为AGNPS模型更精确,使用起来更方便。t检验表明:林地和农林地的土壤侵蚀率没有明显差异,侵蚀模数分别为9497t/(km2·a)及10309t/(km2·a)。但农林地是既减少侵蚀,又能使农民增加收入的最好的土地利用方式。  相似文献   

10.
福建省土壤流失预防研究   总被引:33,自引:5,他引:28  
该研究采用通用方程(USLE)和数量化理论I分别预报了福建省顺坡撂荒和具有生物工程措施的坡地土壤流失量,结果表明,顺坡器撂荒区土壤流失的预报粗度较高,说明确定的R,K,LS算法更符合福建的具体条件,从统计意义上看,数量化理论I可以用于福建省生物工程措施区的土壤流失预报。  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.
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   

13.
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   

14.
李聃枫  朱春梧 《土壤》2020,52(3):561-566
自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。  相似文献   

15.
Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.  相似文献   

16.
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   

17.
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   

18.
Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.  相似文献   

19.
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  相似文献   

20.
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.  相似文献   

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