查询词典 desertification

It indicates that speed of desertification in pasturing areas is faster than that of agri-grazing-oecotone and there has universally exited an increasing serious phenomenon of desertification in recent years.

结果表明，近年来，研究区普遍存在沙漠化加剧的现象，牧区土地沙漠化发展的速度快于农牧交错区。

In 1990s, the third stage is the most important period of research on sandy desertification in Qinghai-Xizang plateau, the sandy desertification problem in almost all over the Qinghai-Xizang plateau was studied, its research content is comprehensive and systematic and a lot of research results were gotten.

最后，分析了研究中存在的主要问题，如研究区域不尽平衡、基础研究较为薄弱、理论研究有待深入和防治技术亟待提高等，提出今后青藏高原沙漠化研究的主攻方向与主要研究项目。

At the South Edge of the Tengger Desert, the sampled sites of mobile sanddune, semi-fixed sand-dune and fixed sanddune were selected as the different stages of the reversion process of desertification with the method of substituting time with space, and topsoil mineral elements of the decertified land were studied reversion process of desertification.

以腾格里沙漠南缘沙漠化土地为研究对象，应用时空替代法选择流动沙丘、半固定沙丘、固定沙丘的沙漠化逆转序列样地，研究了沙漠化逆转过程土壤矿质元素的变化特征。

Sandy desertification and soil salinization are two types of desertification in western Northeast Plain of China.

中国东北平原西部土地荒漠化，主要表现为土地沙漠化和土地盐碱化，它属于荒漠化的两种类型。

Some conclusions from the study on human driving factor are:(1) the human activity is much more active factor to the process of desertification which mainly incarnates on the changes of the landuse fashion (from traditional rangeland 100 years ago come to interlacing agro-pastoral region) and enhance of landuse intensity (over-cultivation, over-grassing and over-fuel collection);(2) the natural vegetation had been destroyed suicidally by human activities that had accelerated to the development desertification.

在人为驱动力的分析中，得到以下一些初步的结论：（1）人类活动是本地区沙漠化过程中更加活跃的驱动因子，体现在土地利用方式的转变（从传统的牧业草原到今日的农牧交错区）和强度的增加（过度开垦、放牧、樵采等）；（2）由此对自然植被群落毁灭性的破坏，加速沙漠化的进程。

The analysis of chorological and spatial changes of desertification indicates that expansion of desertification mostly takes place around the four main sandy lands: Keerqin, Hulunbeier, Hunshandake and Maowusu, while situation in the central part of sandy land is kept relatively steady, with some part of these areas tending to take a favorable turn.

通过沙漠化时空演变过程分析表明：沙漠化的发展主要集中在科尔沁沙地、呼伦贝尔沙地、浑善达克沙地和毛乌素沙地的边缘，而沙地的内部则相对稳定，部分地区有逆转的趋势。

The historical process of transition between cultivation and pasture animal husbandry and its ecological impact has been analyzed by demonstration to explore the large-scale laws.(2). The driving process has been analyzed and behavior mechanism of local people was also construed.(3) The new interpretation of desertification causes has been made to search root of estrepement, overgrazing and excessive firewood gathering.(4) The comparison and selection have been made to explore new changing direction of integrated land desertification control strategy.

主要进行了：①农、牧业变化的历史轨迹与生态环境演变的实证研究，从大的历史尺度寻求农、牧业变化与沙漠化之间的互动关系；②农、牧业选择变化的驱动过程研究，从较短的时间尺度进行高分辨率的过程跟踪与解析，重点分析农牧民的行为机制；③农、牧业选择变化对沙漠化过程的动因解析研究，重点解析&滥垦、滥牧、滥樵&产生的深层次根源，为沙漠化防治战略的制定提供理论依据；④生态建设策略的比较与转型方向的研究。

ABSTRACT This dissertation, based on the theories of geography, ecology, economics, sociology and environmental sciences, has analyzed the impact of transition between cultivation and pasture animal husbandry on the mechanism of desertification in Kerqin Sandy Region, of which behavior mechanism of local people was emphasized. The changing direction of integrated land desertification control strategy in semi-arid regions was discussed after having explored the primary reasons of estrepement, overgrazing and excessive firewood gathering. Followings are the main research works having been done.

本文选取科尔沁沙地作为研究区域，以两种最主要的土地利用方式、也是两种最主要的生产方式——农、牧业作为研究对象，依据地理学、生态学、经济学、社会学与环境科学的基本理论与方法，基于现有研究资料的系统整合，结合野外调查的结果，从更加综合的角度，来研究农、牧业选择变化对沙漠化过程的影响机理，从农、牧业选择变化的角度来揭示&滥垦、滥牧、滥樵&的本质，进而寻求中国北方半干旱地区生态环境综合整治的对策。

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。

Therefore, in order to control desertification effectively, we should not only deeply understand the physical environment factors, but also pay more attention to human activities resulting in desertification in the headwater area of the Yellow River.

黄河源区自然因素与人为因素共同作用，互相激发，最终导致沙漠化的不断扩展及其程度的日益加重。在本区沙漠化的治理、生态环境恢复中，既要认识到生态环境的脆弱性，更要重视人为因素的负面影响。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。