彩色合成选择法及其在黄河入海口研究中的应用     

张昭贵 《遥感学报》1992,(4)

彩色合成选择法是根据色度学原理,求出地物之间在各种彩色合成方案中的色差,以选择彩色合成方案。将此方法应用到黄河入海口,提取黄河水、海水、沙滩、陆地等主要地物信息,效果明显。  相似文献   

ANALYSIS OF SOIL EROSION CHARACTERISTICS AND SEDIMENT SOURCES FOR THE YANTZE THREE GORGES REGION     

SHI Deming  YANG Yansheng  LU Xixi  and LIANG Ying 《国际泥沙研究》1992,(2)

In this paper the researches made in 1981-1990 have identified that the annual soil loss in the Three Gorges region is 157 million t. and the annual incoming sediment load of the Three Gorges reservoir is 40 million t. Soil erosion increases with the destruction of vegetative cover and its subsequent evolution. The annual amounts of sediment erosion for forest land, shrub land, grassland and farmland make up respectively 6.19%, 10.76%, 23.05% and 60% of the total erosion of the Three Gorges region; the quantities of incoming sediment load to the Yangtze River from the above four types of land account for 5.95%, 12.42%, 35.46% and 46.1 % of the total amount of sediment transported to the reservoir. The farmland of offers the main source of sediment. Gravitational erosion produces more bed loads, which will present serious threat to the Three Gorges Project if entering the reservoir. Resettlement of people to the upper parts of the mountainous areas for agricultural production will increase the sediment yield of the Three Gorges region by 10-20 million t and increase the incoming sediment of the Yangtze River by 50-60 million t. Consequently, it is necessary to make a realistic assessment of the soil erosion in the Three Gorges region.  相似文献   

用气象卫星资料推算黑河地区地表特征参数   总被引：7，自引：5，他引：7  

陈添宇  陈乾 《高原气象》1992,11(4):431-439

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Long-term drainage evolution in the shoalhaven catchment,southeast highlands,Australia     

Jonathan F. Nott 《地球表面变化过程与地形》1992,17(4):361-374

The long-term evolution of streams in the Shoalhaven catchment of southeast New South Wales has been a contentious issue for decades. Several authors have suggested that the Shoalhaven River was captured at the sharp eastward bend near Tallong: this has been used as evidence for the westward migration of the east Australian divide in this area. Other workers, however, have argued that capture did not occur and that the location of the divide has been stable throughout the Tertiary. A vast sheet of sediments which spread across and infill a palaeovalley network cut into a broad undulating plain in the middle Shoalhaven catchment provides a record of stream behaviour since at least the start of the Tertiary. This record shows that the Shoalhaven River and many of its tributaries have maintained almost the same courses since at least the very Early Tertiary. This provides strong evidence against the capture hypothesis. The record further suggests that during the Paleogene these streams were graded to a level within the southeast Australian highlands; their depths of incision thus cannot be used as evidence for the extent of uplift of the southeast Australian highlands during this time.  相似文献   

A 3-d model of quaternary terrace development,simulations of terrace stratigraphy and valley asymmetry: A case study for the allier terraces (limagne,France)     

A. Veldkamp 《地球表面变化过程与地形》1992,17(5):487-500

The combined effects of climate and tectonism on general terrace stratigraphy and valley asymmetry during the last half million years in the Allier system (France) are simulated by a 3-D conceptual model (LIMTER). This model allows the formulation and evaluation of long term terrace formation scenarios for the Allier system. Simulation results suggest that terrace stratigraphy in the study area is mainly the result of internal dynamics and climatic change. Local tectonism contributed to the development of unpaired terraces while the general regional uplift played a dominant role in determining terrace formation and preservation in general.  相似文献   

乌鲁木齐河流域季节积雪的基本特征   总被引：5，自引：0，他引：5  

张志忠  杨大庆 《冰川冻土》1992,14(2):129-133

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基于RS和GIS的石羊河流域近50年土地覆被类型变化研究     

卢辉雄  聂振龙  刘敏  冯博  程旭  王金哲  王茜  崔浩浩  范芳 《地质与资源》1992,29(2):165

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沿黄河地带——我国国土开发布局轴线   总被引：2，自引：1，他引：2  

魏心镇  韩百中 《地理学报》1992,(1)

沿黄河地带是我国重要能源和金属资源富集区,发挥组合资源优势,强化以水资源为特色的复合轴线的作用,发展多元主导工业部门,构成大范围线状分布和小范围点状集中相结合的点轴系统,进一步完善我国沿海、沿江、沿黄三大经济开发轴线的互补格局。  相似文献   

长江三角洲及其邻近地区的现代地壳垂直运动   总被引：11，自引：0，他引：11  

胡惠民  黄立人等 《地理学报》1992,47(1):22-30

本文根据50－80年代复测的精密水准成果，分析了长江三角洲及其邻近地区的地壳垂直运动,并与沿海海面变化在同一均衡基准下进行比较。本区近代地壳垂直运动受区域构造控制，形变速度不高，变化平缓，区内海岸带以下降为主。  相似文献   

长江口及其邻近海域粘性泥沙的数量与输移   总被引：5，自引：1，他引：5  

林承坤 《地理学报》1992,47(2):108-112

长江口的粘性泥沙有89.6%以上来源于长江补给区,一部分来源于废黄河与黄海补给区。长江补给区的粘性泥沙的汇入百分数及其输沙量两者均为已知,据此计算出长江口粘性泥沙沉积量为4.554×10~7t/a,从长江口输向杭州湾与东海补给区的粘性泥沙输沙量为2.247×10~7t/a,废黄河与黄海补给区输向长江口的输沙量为2.730×10~7t/a。长江口粘性泥沙的数量同1915年与1963年实测地形图比较量算的数量为4.469X10~7t/a基本相符。  相似文献