查询词典 soil cover

Soil and water conservation protective cultivation is an advanced cultivation technology that avoid cultivation or few cultivation on farmland and with stubble cover.Protective cultivation technology is an integration technology that use stubble cover,no-tillage cultivation,deep-plough with machine,and weeding with chemistry.Adopting soil and water conservation protective cultivation can reduce the loss of soil and water in northeast blackland area and improve the soil anti-erodibility.

中文摘要：水土保持保护性耕作是对农田实行免耕少耕，并用农作物秸秆残茬覆盖地表的一项先进耕作技术，保护性耕作技术是由秸秆覆盖、免耕播种、机械深松和化学除草等核心技术组成的一项集成技术，采用水土保持保护性耕作措施可以有效减少东北黑土区的水土流失，提高黑土区土壤抗蚀性。

They urged "a rapid shift, whenever and wherever conditions permit it, to management systems based on minimal soil disturbance, increased soil cover, and appropriate crop rotation".

他们敦促，"无论何时何地，只要条件许可，应迅速向以最低限度干扰土壤，增加土壤覆被和适当的作物轮作为基础的管理系统转变"。

In experiment,we controlled soil moisture by methods of artificial rainfall and restoring water in soil post;soil treatments included non-cover,mealie haulm cover and gravel cover.

在干旱半干旱的黄土高原和广大的荒漠地区，林地的生态系统十分脆弱，土壤水分动态制约着这些地区生态恢复与植被重建工程的可持续性[1]。

So the Hydrus 2D was selected to simulate the soil water movement in ET covers with different cover thicknesses,the simulations shown that the optimal ET cover in Wuhan area should be 120-140 cm loamy soil layer with shrub.

因此采用Hydrus 2D软件对不同土层厚度腾发覆盖系统的渗沥控制效果进行数值模拟，结果表明，在武汉地区采用120～140 cm厚度壤土层和灌木构成的腾发覆盖系统是确保渗沥控制效果的经济合理方案。

This showed that capacity of water-holding in biological soil crusts were obvious improve,and effected precipitation permeate or water second distribute process.The study results of"fertile islands"formation mechanism in biological crusts showed that biological crusts layer cover could increased nutrients content for below sand soil through precipitation permeate washing,and it promoted plants assimilate more nutriment.The matter import ways of biological soil crusts fertility island had many ways,including the effection of living macrobiotics metabolism in crusts levels,wind-sand flow of near surface,dust deposition and plants decomposition course,etc.Source of particle matter in biological soil crusts was wind-sand flow of near surface,and not dust deposition.Biological crusts layer cover had preserved effection for nature water content in 0-5cm soil layer,compared with the sand of no biological crusts layer,effecting precipitation permeate,and could not obvious restrained from the water evaporate process indoor experiment.

生物结皮层肥岛形成机制的研究结果表明：生物结皮层覆盖能够通过降水淋溶作用而增加下层土壤养分的含量，进而促进植物对养分的吸收；生物结皮层养分输入有结皮生物代谢、降尘、风沙流和植物分解矿化作用等多(来源：A73e3B3eC论文网www.abclunwen.com)种途径，但生物结皮层的颗粒物质来源主要是近地表风沙流，而不是大气降尘；生物结皮层覆盖对0-5cm土层自然含水量有一定的保护作用，并影响降水向深层渗透，不能有效的阻止表层水分的蒸发进程；研究表明采取人工促进技术能够在流动沙丘上形成生物结皮层，实现流动沙地的快速治理。

So karst vegetation is charactered by Petrophile, Xerophile and Calciphihe in those areas where soil cover is very thin, and the underground drainage system is well developed. The running of karst ecosystem is controlled by two subsystems, which are karst dynamic system in inorganic life and genetic information transmitting system in organic life.

岩溶生态系统的运行受到两个子系统的联合作用驱动，即无机方面的"岩溶动力系统"和生命方面的"遗传信息传递系统"，但主要受以碳、水、钙循环为中心的岩溶动力系统的控制。

Based on soil desertification between agriculture and husbandry interlace zone in north of Shannxi Province, on the basis of theories of landscape ecology、land resource and principle of soil genesic science, through field surveying data and indoor analyzing, the properties of soil physical, chemical and biological characteristics are systemic analyzed about desertification soil of different vegetation cover rate and type, achieving primary achievements and important evolves are as follows:Ⅰ.

本研究基于当前全球荒漠化危害现状及国内外荒漠化防治中恢复生态学的发展需要，以陕北农牧交错带土地荒漠化问题为研究对象，应用景观生态学理论、土地资源学和土壤发生学的基本原理，在野外考察、资料收集和室内测定分析的基础上，对不同植被盖度和植被类型荒漠化土地的土壤理化性质和生物学性质进行系统分析，取得的主要成果如下： 1。

Field survey, sampling and testing were used to discuss the characteristics of soil water content between different subsidence stages. The results show that after mining collapsing, the soil water content and soil water storage capacity of subsidence area is obviously less than the nature area, especially for the fissure zone. It is indicated that the collapsing fissures are extremely disadvantageous for soil water-holding capacity and the conditions of vegetational cover on the subsidence area also confirmed this result.

现以神府东胜煤田为研究背景，选择两个主要塌陷阶段分布区大柳塔矿区双沟村原农场和补连塔矿区原补连沟村作为研究区，采用野外勘查、取样测试与室内参数分析综合研究的方法，对采矿塌陷不同阶段表层包气带土壤水分进行对比分析，结果表明，采矿塌陷后，塌陷区尤其是塌陷裂缝区的土壤含水量与土壤储水量值均小于未塌陷区，说明塌陷裂缝对土壤的持水作用具有非常不利的影响，塌陷区与未塌陷区的地表植被覆盖情况也证实了这一点。

Contaminants can easily enter the subsurface through thin soil cover in stone forest and via swallow holes at the bottom of depression.

究其原因，尽管药池坝洼地底部土壤层覆盖较厚，但存在地表径流集中排向落水洞，生态石林分布区地表裂隙、溶沟发育，可直接接受雨水入渗，因而污染物极易通过降雨和地表径流过程进入含水层。

The main contents are as follows:Firstly, starting with the general situation of soil erosion and the harms caused by it, the causes leading to the local soil erosion problem are analyzed comprehensively in the paper. And connecting with the measures taking place, sticking points towards the career of soil and water conservation are expatiated upon.Secondly, Back-Propagation Neural Network, One of Artificial Neural Network is used to set up a modal about the connection of the soil erosion modulus and seven factors impacts on it, such as, rainfall, rainfall largest intensity in 30 minutes, runoff coefficient, vegetation cover percent, rate of granule, rate of physical viscidity-clay, the rate of organic matter. Through the comparison with linear regression model, the second regression model, the Chinese Soil Loss Equation, it illustrated that BP Neural Network modal is more accurate than the other three modals in forecasting the mount of soil erosion, and the BP Neural Network will have some applicability in forecasting in soil erosion.

本文以霍山县作为皖西大别山区的典型区域，主要研究了以下内容：(1)从介绍霍山县土壤侵蚀状况以及所造成的危害入手，全面分析了导致当地土壤侵蚀发生的原因，并结合当地采取的水土保持相关措施，阐述了当地水土保持工作的症结所在；(2)结合上土市水土保持试验站多年实测资料和2005年实验资料，应用BP神经网络理论，建立了次降雨土壤侵蚀量与次降雨量、最大30min雨强、径流系数、植被覆盖度等因子之间关系的模型，并通过BP神经网络的预测模型与一次回归模型、二次回归模型、CSLE模型之间的对比分析，说明了建立的BP神经网络模型在土壤侵蚀预测可以取得较回归模型和CSLE模型更高的精度，也说明了BP神经网络理论在土壤侵蚀预报中具有一定的适用性。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了