Based on an analysis of the history and present status of the farmland-pastoral ecotone in the northern part of China, a new point of view was proposed in this paper for the construction  of eco-environmental systems, namely, the industrial structure has to be modified so as to make  a functional integration between different parts of the whole system: ①To give priority to a combination between cultivated grassland and in-shed feeding of domestic animals, and at the same time, to employ a new model of animal husbandry so that the degradated natural grassland can be recovered; ②To develop a new type of processing industry for agricultural and forestal products so as to  create a pluralistic enterprise structure; ③ To make a better use of water resources by taking advantages of the abundant resources of energy and minerals, and to restrain the expansion of industries of high environmental cost; ④To employ techniques of integration management and restoration ecology, and to speed up the process of woodland and grassland recovery; ⑤To make a thorough plan for arrangements of hills, waters, roads, farmlands, forests and pastures in order to gain an integration at landscape level.

在简要分析中国北方农牧交错带形成历史和现状的基础上，提出了北方地区生态环境建设必须从产业结构调整出发、进行系统功能整合的思路：①把人工饲草业-舍饲畜牧业摆在农牧交错带经济发展的优先位置，推行新型畜牧业经营管理模式，促进天然草场改良复壮；②发展"绿色"农林牧产品精细加工业，建立多元化产业结构；③发挥能源和矿产资源优势，合理利用水资源，限制以破坏环境为代价的产业的发展；④推广区域综合治理与生态恢复技术，加大退耕还林还草的力度；⑤山、水、路、农、林、牧统一规划，实现生态系统在景观水平上的整合。

By using NOAA temporal series data during the period 1985一1990 (69 months),this study examines the Vegetation-Cover change with time and space in China. Furthermore, the ana1ysis about correlation . between Vegetation-Cover change and environmental factors is also accomplished by combining simu1taneous average temperature and precipitation .data in each month. The methods employedinclude Sample Transect Ana1ysis, Partia1 Correlation Ana1ysis, and GIS Spatia1 Calcu1ation.From the above ana1ysis, we can draw the following conclusions:1. The vegetation index generally represents the situation of the superficial vegetation cover. Heat and water condition determine the whole spatia1 distribution pattem of vegetation index and build the regional attribute in longitude and latitude. The partia1 fluctuation of the vegetation index is essentia11y affected by landscape and soil conditions. This defines its regiona1 distribution pattem.2. Lying on the same longitude, the vegetation index obviously. corresponds to the seasonal movement law, and span of the movement in time and space is much greater than that along the same latitude. The type and ways of the green wave movement synchronize with the seasonal movement of the continenta1 main controlling air mass and are influenced by it.3.The vegetation index increases and decreases with the warming and cooling of the climate.So it has typically seasona1 change characteristics. Along the same longitude, the higher the latitude is,the greater the scope of seasonal change will be. In summer there is no evident difference of vegetationindex between southem and northem region. But in winter，this difference is quite obvious.4. In a large range, the vegetation index change is driven by water and heat conditions. In eastem moist monsoon zone of China,along. the same longitude,the temperature is the most important influential parameter.The correlation between the vegetation index change and monthly average temperature is obvious.So the heat is key natural limited factor for the growth of the vegetation. Yet,in northem China, along the same latitude, from east to west，it sequentially covers the humid monsoon zone, semi-arid and arid desert zone. The relationship between the vegetation index change and monthly average precipitation is well correlated positively. It proves that in a dry area, water source is the essential limited condition for the growth of the vegetation.

本文利用1985-1990年连续69个月的NOAA时间序列数据, 进行中国植被覆盖变化的空间, 以及时间序列分析, 并且结合同期的月平均气温、降水数据, 进行植被覆盖变化与气候因子相关性分析。该文证实了在中国植被覆盖随时间的推移规律, 空间分布规律, 以及植被覆盖变化与气温、降水的定量关系。

利用GIMSS/NDVI数据对黄土高原地区1982-2003年期间植被覆盖变化的研究表明:黄土高原地区植被覆盖整体呈现增加趋势,并存在明显的空间差异.植被覆盖改善区域主要分布在河套平原、鄂尔多斯高原、兰州北部等黄土高原的北部地区,而退化区从西峰、延安向东到离石、临汾以至太原以西呈条带状分布.值得关注的是虽然20世纪80年代植被覆盖增加趋势明显,但90年代中期以来植被覆盖退化趋势非常显著.降水是影响黄土高原地区植被覆盖变化的重要因素,月降水量小于40-60 mm期间,植被NDVI和降水量呈线性关系,但当月降水超过60 mm之后,植被NDVI不再有明显的增长趋势.

Vegetation cover is a major feature for ecological system. The change of vegetation cover in large area is mainly caused by climate and human activities. The Yellow River, the second largest river in China with a basin of 752,443 km2, includes semi-arid and arid environment. Therefore, it is necessary to study the change of vegetation cover in the Yellow River Basin, which will help us understand climate influences and impacts of human activities. In order to understand the change of vegetation cover in the Yellow River Basin and its influencing factors, we use the data of AVHRR-NDVI and the information of 76　meteorological stations in the Yellow River Basin covering 1982-1999 to analyze their spatial distribution and dynamic change in spring, summer and autumn. On the basis of calculating the NDVI mean deviation and Moisture Index (MI) mean deviation, we study the feature of MI mean deviation, the speed of NDVI mean deviation and the correlation between them. Finally, some conclusions are drawn. Firstly, the climate was relatively humid from 1982 to 1992 and relatively dry since 1993. The environment in the Yellow River Basin tended to be desiccated, but the vegetation cover is increasing. Secondly, the correlation between NDVI mean deviation and MI mean deviation demonstrates that the humid climate was helpful for vegetation cover. Thirdly, the average speed of vegetation cover increase was 0.58%. The speed of vegetation cover increase in the loess region and catchment area is 0-3.8%, which shows the achievement of ecological measurements in China. The vegetation cover in desert and riverhead region is decreasing, the speed of which is 0-3.0%, a reflection of the climate change.

利用1982~1999年AVHRR－NDVI数据和对应年份黄河流域气象观测数据,通过计算、分析春季、夏汛及伏秋黄河流域NDVI距平值和湿润指数距平值的年际变化,得出了20世纪80年代至90年代初黄河流域气候相对湿润,90年代中后期相对干旱,植被覆盖状况总体一直处于上升趋势的结论,并评估了黄河流域近20年来生态保护和建设工作成效。

土地是人类赖以生存和发展的最基本的自然资源,是人类生存和发展的物质基础。土地利用 不仅是人类最古老、最基本的生产活动,而且是关系到人类生存与发展的社会问题和生态环境问题。研究土地利用变化是为了更好的调整土地利用结构,如何把这两 者更紧密的结合起来,重点内容在土地利用结构的调整。土地利用结构调整作为当前农村产业结构调整的基础,其合理配置与结构优化直接决定着经济的发展和效益 的提高,是增加农民收入、促进农村经济发展的必经途径。 沽源县地处坝上高原,是我国北方农牧交错带中段的典型地区,在自然地理上有其独特的空间分布,在生... 展开 土地是人类赖以生存和发展的最基 本的自然资源,是人类生存和发展的物质基础。土地利用不仅是人类最古老、最基本的生产活动,而且是关系到人类生存与发展的社会问题和生态环境问题。研究土 地利用变化是为了更好的调整土地利用结构,如何把这两者更紧密的结合起来,重点内容在土地利用结构的调整。土地利用结构调整作为当前农村产业结构调整的基 础,其合理配置与结构优化直接决定着经济的发展和效益的提高,是增加农民收入、促进农村经济发展的必经途径。 沽源县地处坝上高原,是我国北方农牧交错带中段的典型地区,在自然地理上有其独特的空间分布,在生态上具有显著的脆弱的生境特征和演化规律。因而,深入分 析其土地利用的动态变化,并探讨其土地利用结构的调整,既是土地资源合理利用的途径,也是保护环境和实现区域可持续发展的根本要求。 本论文以土地利用的现状及存在问题-土地利用的动态变化-分区土地利用结构的调整为主线,以数学模型分析、统计分析等为主要研究方法,进行了以沽源县土地 利用结构调整为目标的初步研究。 正文分为四部分。其中,第一章和第二章概述了区域土地利用变化研究的背景及意义；全面总结了土地利用变化研究的国内外进展；详细介绍了研究区的地理环境背 景,并对土地利用现状及存在问题进行了诊断分析。 第三章主要依靠构建多个相关数学模型,分区分乡镇分析了研究期内沽源县土地利用变化的途径、特点,初步预测了土地利用变化的趋势。具体分析结果显示,沽源 县土地利用变化表现出如下态势：①在数量上,该县土地利用类型以耕地、林地、牧草地为主,共占研究区土地利用总面积的92％左右。1996-2006年, 土地利用变化较剧烈,其中林地面积增长较快,居民点及工矿用地、水域、交通用地增长缓慢。耕地减少速度较快,牧草地面积从2001年后开始减少。②在利用 程度上,该县土地利用程度综合指数一直处于下降的趋势,全县的土地利用处于调整期,分乡镇看,只有平定堡镇和闪电河乡的土地利用处于发展期。③在区域差异 上,全县的平均多样化指数低于土地利用类型数目相同、分布均匀情况下的多样化指数,但也处于缓慢增加状态。各乡镇的多样化指数相差不大,都在平均数左右, 多样化特征不明显。各乡镇的土地利用变化区域差异较显著,但空间格局不明显。④在土地利用变化趋势上,除牧草地和园地面积没有预测外,该县耕地和未利用地 面积还是持续减少,其它用地类型缓慢增加,与现在的发展趋势保持一致。⑤国家生态建设政策引导和调控下的人力活动是导致沽源县土地利用变化的最主要原因, 而农业结构调整,尤其是近年来大力实施的退耕还林还草则是耕地减少、林地增加的重要原因。第四章在前述研究的基础上,通过对土地利用现状类型区划分的结 果,综合考虑各乡镇农业自然条件和社会经济条件的相似性和差异性,以及农业土地利用方向的相对一致性,并保持各乡镇界限的完整性,将全县分为四个区：西南 部波状高原林牧农土地利用区,中北部波状高原牧农土地利用区,东部低山丘陵牧农林土地利用区,南部中低山牧林土地利用区,对土地利用结构进行了分区的调整 研究,列出各个区的土地利用结构调整方略。 收起

以1987年和1999年 TM遥感图像为数据源,在ERDAS8.4遥感图像处理软件和ArcInfo8.02地理信息系统软件的支持下,获取了坝上研究区两期土地利用/覆盖图.在此过程中,提出和建立了研究区土地利用/覆盖遥感图像分类体系;通过计算机自动分类和分类后人工解译纠错相结合的图像分类提取方案,提高了图像分类提取的效率和精度.动态监测结果表明:从1987～1999年的12年期间,坝上地区土地利用/覆盖动态度由大到小的顺序为:居民建设用地＞林地＞高覆盖度草地＞水体＞沙盐碱地＞低覆盖度草地＞耕地.其中面积增加的是居民地、林地、高覆盖草地和耕地;面积减少的是沙盐碱地、水体和低覆盖度草地.从1987～1999年的12年期间,研究区的沙盐碱地面积从1 985.89 km2减少到 1 250.75 km2,减少了37.02%,年动态度为-3.08%.坝上东部沙漠化得到遏制,而西部张北、康保一带沙盐碱化土地有所扩展.

Using the techniques of RS, GIS and landscape ecology, based on Landsat TM data of 1988, 1995 and 2000, integrating with land use transform matrix and landscapepattern analysis software Fragstats3.3, the dynamic changes of land use and landscape pattern from 1988 to 2000 in the farming-pastoral region of Northern China were studied. The main results show that: ①The reason of farmland decrease is the change from farmland to grassland, and its increase is due to the reclamation of grassland; ②The change from farmland to grassland is well-proportionedwhile the change from grassland to farmland has its distinct regional difference; ③The quantity of land use change is different greatly between 1988 to 1995 and1995 to 2000; ④The reason of sandy land increase is owing to grassland degradation; ⑤Landscape heterogeneity is increased, landscape structure inclines to equilibrium, landscape stability is reinforced, and the interference degree of landscape change by people is being aggravated.

基于1988，1995和2000年3期Landsat TM数据，采用遥感，GIS和景观生态学方法，运用土地利用转移矩阵、景观格局分析软件Fragstats33，对北方农牧交错带土地利用及景观格局变化进行了动态研究.结果表明：①减少的耕地主要转为草地，增加的耕地也主要源于开垦草地；②耕地转为草地的空间分布较均匀，草地转为耕地的区域差异明显；③1988—1995年和1995—2000年2个时段参加变化的土地数量差异显著；④增加的沙地主要源于草地退化；⑤景观异质性上升，结构趋向均衡化，稳定性增强，受人类干扰程度在加大.

Human interventions in natural systems have resulted in large changes in vegetation composition and distribution pattern.The Land Use Change and Climate Change(LUCC)study under the International Geosphere Biosphere Program(IGBP)is a major initiative in this regard.Ecotone between agriculture and animal husbandry is a special ecological fragile zone in China,especially in northern China.Study on this zone will enable us to find a solution to this problem.Using Landsat TM,all TM images are processed with the aid of geometric correction and project images,getting the landuse dynamic coverage under MGE environment by contrasting the1980s and2000TM images.From the core of ecotone between agriculture and animal husbandry,this paper calculates the distribution of ecotone between agriculture and animal husbandry in China by combining expert knowledge with practice based on RS&GIS.Then it analyses the farmland and grassland dynamic change spatial pattern in ecotone between agriculture and animal hus-bandry during recent ten years.The farmland is mainly converted into forest and grassland with the greatest farmland dynamic change in central and western parts of Inner Mongolia.The grass-land is mainly converted into farmland and land for urban construction,distributing in contigu-ous zones of Inner Mongolia with Heilongjiang,Jilin and Liaoning provinces.Finally,this paper discusses the cause of land use dynamic change.Economic development,population growth and agriculture restructuring are the main causes for farmland conversion.Human activities and na-ture are the driving forces for grassland dynamics change,but human activities play the leading role,obviously due to overgrazing.How is the land use dynamic change in ecotone between agri-culture and animal husbandry related with environmental impact and what does the grassland re-duction limit the regional development are further studied.The main driving force is human eco-nomic activities,which pave the way for us to make best use of land.

以遥感与GIS为技术支撑,运用专家知识,结合实际,从农牧交错区的实质出发,定量地计算出我国的农牧交错区。在此基础上,分析我国农牧交错区近10年的耕地、草地变化的空间格局。整个农牧交错区的耕地以变林地、草地为主。耕地的变化以内蒙古的变化为大,主要分布于它的中、东部地区。草地主要以变耕地、城镇为主,分布于内蒙古与东北三省接壤处。最后探讨这种格局的成因。耕地变化受经济发展、人口增加、农业结构等驱动,主要表现为人文作用。草地变化受人为与自然的驱动,主要为人类活动的影响,表现为经济发展与草地过牧。

该文在对像元二分模型的两个重要参数推导的基础上，对已有模型的参数估算方法进行改进，建立了用NDVI归一化植被指数定量估算植被覆盖度的模型，并根据实际运用时的二种情况，提出了估算植被覆盖度的方案。然后根据研究区密云水库上游的具体特点并结合实际情况设计了模型应用的技术路线和实施方法，对研究区植被覆盖度进行了估算。通过密云流域的实地考察，利用照相法对植被覆盖度的估算结果进行了验证，估算精度达85%，表明使用此改进模型进行植被覆盖度遥感监测是可行的。

In order to combatthe developingtrendof eco-environmentdegradation, a seriesofnational environmental projects\nhave been carried out in frail ecological zone since 1998. The construction measures adopted by the projects include handing\nfarmland backto forestland orgrass land, protecting nature forestry fromdeforestation, planting sheltering forest, conserving soil\nandwater, and so on. To evaluate the effect of the projects on eco-environment, five sites in different eco-environmental\nzoneswere selected as study areas to monitor the change of land cover over 1997―2002. Through analyzing the change of land\ncover, it suggests that as a result of national environmental projects, the eco-environment is rehabilitating gradually except for\nthe study area of East-northern China. The sheltering forestry has increased 1479 hm2, farmland has increased, and forestland\nand grassland decreased in the region of the case site located in East-northern China. In the region of the case site located in\nthe north of Beijing, the total area resulted fromthe construction project is 51492 hm2, farmland has decreased, and forestland\nand grassland have increased. In the region ofthe case site in the north part of Shanxi Province, the total area resulted fromthe\nconstruction project is 11115 hm2, farmland has decreased, and forestland and grassland have increased. In the region of the\ncasesite located in the middle part of Gansu Province, the total area resulted from the construction project is 17437 hm2,\nfarmland has decreased, and forestland andgrassland have increased. Inthe regionofthe case site inSichuanProvince, thetotal\narea resulted fromthe construction project is 65347 hm2, forestland has increased, and farmland and grassland have decreased.

1998年以来中国在生态环境脆弱区实施了一系列生态建设工程，为了评估工程的效益，监测工程实施地区的生态环境变化趋势，在生态脆弱区选择了具有代表意义的5个典型区，采用遥感与地理信息系统技术结合的方法，对这些地区在1997-2002年5年内的生态环境变化进行了动态监测。监测结果表明，这5年来，退耕还林还草、天然林保护、防护林建设和小流域治理等生态环境建设工程已经取得较大进展，各治理区的环境正在逐渐改善。