荒漠化

Government takes lots of measures to combate desertification on serious condition. This thesis study on theory and method about desertification combating engneering profit evaluation.

在荒漠化形势非常严峻的情况下，国家采取了相应的荒漠化防治措施，在此本文对荒漠化防治、防沙治沙工程效益评估的理论和方法进行了研究，在此基础上对沽源县京津风沙源治理工程的效益进行了计算和分析。

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 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。

Based on a rather long temporal series of remote sensing data, employing RS and GIS as its tool and FVC that is of rather high sensitivity over the coverage of vegetation in arid area as its monitoring index of desertification, the dissertation analyzes the features of the dynamitic variation of desertification in Xinjiang over the years by using the slop variation to reflect the features of temporal-spatial distributing and the changes of areas of the desertification in Xinjiang.

以较长时间序列的遥感数据为基础，以RS和GIS为工具，选择了在干旱区对植被覆盖度上有较好敏感性的FVC的斜率作为荒漠化监测指标，利用1982~2000年期间新疆FVC斜率变化来反演新疆土地荒漠化的时空分布、面积变化，分析新疆荒漠化多年来动态变化特征； 3。

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。

By overlapping the charting of land desertification and the types of soil, the writer concludes that desertification is common to semi- hydromorphic soil and desert soil. And the reversion of alkaline soil shows the achievements of improvement of quality of alkaline soil.

将土地荒漠化图与土壤类型进行叠加，发现荒漠化在半水成土和漠土上发育比较普遍，而盐碱土类型上出现荒漠化逆转，说明多年来新疆对于盐碱地的改良和利用取得了有效的改善； 5。

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。