查询词典 desertification

This text first from desert, desertification, concept appraised to desertification start with, explain the desertificated purpose and meaning further, desertification purpose lying in explaining why the land is desertificated, desertificated course and desertificated development degree and speed appraised, the fragility of the natural environment, and the reason that the land depredate.

先从荒漠、荒漠化、荒漠化评价的概念入手，阐述了荒漠化评价的目的意义，进而说明土地荒漠化的原因、荒漠化过程和荒漠化发展程度、速率，自然环境的脆弱性，以及土地退化的原因等。

The result shows that desertification is serious in the study area. Various types of desertification land add up to 370000hm~2, accounting for 39% of the total land. From l995 to 2000,the serious desertification land, where vegetation cover is below 30%, extends with the speed of 61hm~2 per year. The increasing landscape fragment reflects the intense intervene that human activities act on landscape. Shape index changes indicate the growing ratio of interior -edge, which is disadvantageous to natural recover of land.

结果表明，研究地区沙漠化现象严重，各种类型沙漠化土地总面积37万hm~2占总土地面积的39％；植被盖度小于 30％的较严重的沙漠化土地从1995年到2000年的五年间以61hm~2／年的速度扩展；景观破碎度变大，反映出人类活动对景观的干预作用不断增强；沙漠化景观要素的形状指数变化表现出内、缘比变大，不利于沙漠化土地的自然恢复。

The preventing and remedying desertification puts into practice prevention as main,principle of combining ecology protection with Prevensing and remedying,principle of preventing and remedy and economy development and utilization coodinated and promoting,comprehensive preventing and remedying and chassified control combines,public particlpation and renovating person benifits combine for different responsibility body bearing different responsibility bearing principle,becanse of man-made fault causing desartification preventing and remedying responsibility carrying out action-person bearing principle,principle of gorernment mainly bearing desertification recovery caused by nature action and benifit's person undertaking reasonable burban and decide unified planing system,systen of desertification status investigation and monitoring early warning system,fallow,limited cultivating hand and help-the poor combined systen,prohibitory systan,priority region and urgent-action region system.

文摘：沙漠化防治实行预防为主，生态保护与防治结合原则，防治与经济开发利用相协调促进原则；综合防治与分类控制相结合；公众参与和整治者受益结合；对不同责任主体实行不同责任承担原则，由人为不当活动造成的沙漠化治理责任，实行行为者负担原则；对自然作用造成的沙漠化治理实行政府负担为主，受益者合理负担原则；确立统一规划制度；沙漠化状况调查评估与监测预警制度，休耕限耕和扶贫结合制度，禁限制度，优先区域与紧急行动区域制度。

Fortunately, the desertification degree decreased obviously, and moderate and light desertification took the leading position. From 1986 to 2003, the spatial centroid of desertification landscape patches expanded southwestward and northeastward, giving serious threat to the ecological safety of the southeast and northeast loess gully and hilly areas.

沙漠化程度明显下降，沙漠化主导类型已由严重沙漠化转变为中度和轻度沙漠化。1986-2003年沙漠化景观整体上向西南和东北方向扩展，严重威胁着西南和东北部黄土丘陵区的生态安全。

The following results are made from this research: Assessing data quality and band combination of different bands in line with geo-target features in desertification areas, and determining basic bands for desertification monitoring. And understanding and studying the spectral features and variation rules of geo-targets in the experimental area, raising that it is the basis of geo-targets information collection with imaging spectrometer data to understand spectral features and variation rules of geo-targets, realizing that in a great extent spectral-integrated-form-based classification method can remove the phenomenon of "different spectrum with same objects" resulted from reflection ratio curve translation because of the angle change among sensor, targets and observation direction, and the average and variance images can be introduced to solve the problem of two kinds of geo-target with similar spectral forms and much different values of whole reflectionratio. It is suggested that "red edge" range bands of vegetation, which has close relationship with vegetation cover and biomass, is the main characteristic bands and important basis for careful vegetation classification and quantitative retrieval, and pixel-based derivative spectral analysis is very useful for removing the effects of soil background values and quantitatively retrieving vegetation biomass and cover. The remote sense quantitative retrieval model is developed for main appraisable factors of desertification monitoring assessment with imaging spectrometer data and then the applicability of model is analyzed.

研究结果如下：首先针对荒漠化地区的地物特征，对高光谱数据不同波段的数据质量、波段组合进行了评价，提出了适用于荒漠化监测的基本波段选择集；初步了解和掌握了研究地区的地物光谱特性及变异规律，进一步明确了掌握地物光谱特征和变异规律是用成像光谱仪数据提取地物信息的基础；发现了基于光谱整体形状的分类方法在很大程度上能够消除由于传感器、地物目标观测方向之间的角度变化引起的反射率曲线整体平移的"同物异谱"现象，对于谱形相似而整体反射率的值相差较大的两类地物，通过引入均值和方差图像参与分类得到解决；研究还表明在植被"红边"范围内的波段是进行荒漠化监测的主要特征波段，这些波段与植被生物量和盖度都有密切的关系，是开展精细植被分类研究和植被定量反演的重要基础；像元的导数光谱分析可以消除土壤背景的影响，是进行植被生物量和盖度定量反演的有力工具；建立了荒漠化监测主要评价因子的定量反演模型，并分析了模型的适用性。

In the light of field features in desertification areas, the data quality and band combination of different bands are assessed, the indicators, principles and methods for data assessment and band option are put forward to, and optional band combination for desertification monitoring is determined primarily. The data pre-treatment model for desertification monitoring is developed after studying the pre-treatment algorithm of restoration and rebuilding of hyperspectral resolution data. The spectral features and variation rules of different objects in experimental areas are understood and analyzed. The different classified methods are given and discussed on the basis of characteristics of desertification region. The remote sensing quantitative retrieval model for the appraisable factors of desertification monitoring are founded.

针对荒漠化地区的地物特征，对高光谱数据不同波段的数据质量、波段组合进行定性和定量的评价，提出用于数据评价、波段选择的指标、原则和方法；初步确定一个适用于荒漠化监测的优化波段组合，建立适合于荒漠化监测的数据预处理模式；初步分析、掌握研究区内各类地物的光谱特性及变异规律；针对荒漠化地区特点对多种分类方法进行探讨分析；建立荒漠化监测主要评价因子的定量反演模型。

The following results are made from this research: Assessing data quality and band combination of different bands in line with geo-target features in desertification areas, and determining basic bands for desertification monitoring. And understanding and studying the spectral features and variation rules of geo-targets in the experimental area, raising that it is the basis of geo-targets information collection with imaging spectrometer data to understand spectral features and variation rules of geo-targets, realizing that in a great extent spectral-integrated-form-based classification method can remove the phenomenon of "different spectrum with same objects" resulted from reflection ratio curve translation because of the angle change among sensor, targets and observation direction, and the average and variance images can be introduced to solve the problem of two kinds of geo-target with similar spectral forms and much different values of whole reflectionratio. It is suggested that "red edge" range bands of vegetation, which has close relationship with vegetation cover and biomass, is the main characteristic bands and important basis for careful vegetation classification and quantitative retrieval, and pixel-based derivative spectral analysis is very useful for removing the effects of soil background values and quantitatively retrieving vegetation biomass and cover. The remote sense quantitative retrieval model is developed for main appraisable factors of desertification monitoring assessment with imaging spectrometer data and then the applicability of model is analyzed.

研究结果如下：首先针对荒漠化地区的地物特征，对高光谱数据不同波段的数据质量、波段组合进行了评价，提出了适用于荒漠化监测的基本波段选择集；初步了解和掌握了研究地区的地物光谱特性及变异规律，进一步明确了掌握地物光谱特征和变异规律是用成像光谱仪数据提取地物信息的基础；发现了基于光谱整体形状的分类方法在很大程度上能够消除由于传感器、地物目标观测方向之间的角度变化引起的反射率曲线整体平移的&同物异谱&现象，对于谱形相似而整体反射率的值相差较大的两类地物，通过引入均值和方差图像参与分类得到解决；研究还表明在植被&红边&范围内的波段是进行荒漠化监测的主要特征波段，这些波段与植被生物量和盖度都有密切的关系，是开展精细植被分类研究和植被定量反演的重要基础；像元的导数光谱分析可以消除土壤背景的影响，是进行植被生物量和盖度定量反演的有力工具；建立了荒漠化监测主要评价因子的定量反演模型，并分析了模型的适用性。

This project was conducted starting with the three interrelated subjects the structural characteristics of desertification landscapes in different bioclimatic zones, desertification driving factors and their function mechanism, and the dynamic model of landscape space for the occurrence and development of desertification in representative desertification regions and on the basis of in-depth studies of the relations between landscape structural characteristics and processes of desertification and their stability; the driving force of different time-space scales of desertification and their proportion, manifestation form, and action mechanism in the desertification processes; and the establishment of threshold conditions for the surface wind erosion and has achieved important progress in the definition of desertification conception

本课题从三个相互联系的专题（即不同生物气候区荒漠化景观的结构特征、荒漠化驱动因素及其作用机理、典型荒漠化地区荒漠化发生与发展的景观空间动力学模型）入手，在深入研究荒漠化景观结构特征与过程的关系及其稳定性，不同时空尺度的荒漠化过程驱动力及其在荒漠化过程中所占比重、表现形式及作用机制，地表风蚀临界条件的确定等内容的基础上，虽未建立荒漠化景观空间动力学模型，但在沙漠化概念，末次间冰期以来沙漠化过程时间序列和特征冷暖时期沙漠、沙地空间分布格局，现代沙漠化过程中自然因素和人文因素的作用、贡献率、沙漠化土地对气候的反馈作用以及风蚀临界值，沙粒跃移轨迹参数和能量分布，我国沙漠化防治思路和对策，沙尘暴区划和沙尘暴指数等方面取得了重要进展。

Based on the definition of desertification from the United Nations Convention to Combat Desertification,the potential extent of desertification in China was revised by employing Thornthweite＇s and Penman＇s formulae to calculate humidity index using the records of 671 meteorological stations from 1950 to 1990,and the biogeographical features of the climate types were clarified.

为了客观反映中国荒漠化发生区域，按照联合国防治荒漠化《公约》的定义，利用1950—1990年间全国671个气象站的长时间序列气象数据，分别采用Thornthwaite和Penman计算可能蒸散量的方法计算了湿润指数的分布，然后根据中国气候区划和中国植被区划以及中国荒漠化发生的特点等对计算结果进行了调整，对中国荒漠化潜在发生范围进行了修订，明确了荒漠化各气候类型区的地理涵义。

In order to explore the grain-size distribution characteristics and geo-genetic types of land desertification in Mo Us desert, the research on the grain-size characteristics of sediments since late Pleistocene has been carried out in the desert area and neighboring area such as inside desert, sand covered loess plateau, loess plateau and river valley. The research result shows that sediments of different geologic genetic types are the fundamental material source of sandy desertification in these areas and the distinguishing of different types of the sediments is the theoretical basis of classification of different geogenetic type of sandy desertification. The contribution of different geological roles on the land desertification and its significance to prevent and deal with the land desertification have also discussed.

为了研究毛乌素沙地沉积物的粒度特征与土地沙漠化的地质成因类型，通过系统研究沙地及相邻地区晚更新世以来在沙地内部、覆沙黄土区、黄土高原和河流谷地与湖泊等不同地质构造地貌条件下所形成的沉积物粒度特征，指出不同地质成因类型的沉积物是这些地区土地沙漠化的物质基础，区分不同类型的沉积物也是构成不同地质成因类型土地沙漠化分类的理论基础，探讨了不同地质作用对土地沙漠化的贡献及其对土地沙漠化防治方面的意义。

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。