This paper describes a new type of transformed Landsat images (LBV images) and their application in discriminating soil gleization in subtropic region of China. LBV transformation was worked out by the present author ...This paper describes a new type of transformed Landsat images (LBV images) and their application in discriminating soil gleization in subtropic region of China. LBV transformation was worked out by the present author for extracting useful information from original landsat images. Using this method three black and white images, L image, B image and V image, were computer generated from original bands of a Landsat scene, which covers a.large area of 34 528 km2 in Hubei and Hunan provinces in south China. Then a color composite was produced by these three images. This kind of black-and-white and color images contained rich and definite geographic information. By a field work, the relationship between the colors on the composite and the land use/cover categories on the ground was established. 37 composite colors and 70 ground feature categories can be discriminated altogether. Finally, 17 land use/cover categories and 10 subregions suffering from soil gleization were determined, and the gleization area for the study area was estimated to be 731.3 km2.展开更多
Afghanistan is located in the Eurasian loess belt,however,there is little information on the soils in the area.Loess has covered the Herat Plain in western Herat City,Afghanistan.Despite the diversity of landform and ...Afghanistan is located in the Eurasian loess belt,however,there is little information on the soils in the area.Loess has covered the Herat Plain in western Herat City,Afghanistan.Despite the diversity of landform and parent material,there is no information on the soil and landform evolution in this area.The objectives of this study were to identify the soils along a transect of different landforms in the Herat Plain and determine the role of geomorphic processes on the soil and landform evolution.Five pedons from an alluvial fan,the depression between alluvial fan and piedmont plain,saline and non-saline piedmont plains,and the flood plain of the Hariroud River,were sampled.Then,the physical-chemical properties,mineralogy,and micromorphology of the samples were determined.Results showed that the soil parent material in the piedmont plain is loess,whereas,in the flood plain it is a combination of loess and river alluvial sediments.Calcification,lessivage,salinization,and gleization are the most important pedogenic processes.The calcification and lessivage appear to be the result of a wetter climate during the late Quaternary,whereas the present topography causes the gleization and salinization.Clay coatings on carbonate nodules and iron nodules are abundant pedofeatures in the Btk(argillic-calcic)horizon.Iron oxides nodules are common in the soils of the flood plain.The formation of palygorskite in both alluvial-and loess-derived soils implies the onset of aridity and the trend of increase in environmental aridity in the region.It seems that after the formation of a well developed paleosol on the alluvial fan in a more humid climate in the past,the piedmont plain has been covered by loess deposits,and the calcification,gleization,and salinization cause the formation of weakly developed surficial soils.This study highlights the role of the late Quaternary climatic changes on the evolution of landforms and soils in western Afghanistan.展开更多
文摘This paper describes a new type of transformed Landsat images (LBV images) and their application in discriminating soil gleization in subtropic region of China. LBV transformation was worked out by the present author for extracting useful information from original landsat images. Using this method three black and white images, L image, B image and V image, were computer generated from original bands of a Landsat scene, which covers a.large area of 34 528 km2 in Hubei and Hunan provinces in south China. Then a color composite was produced by these three images. This kind of black-and-white and color images contained rich and definite geographic information. By a field work, the relationship between the colors on the composite and the land use/cover categories on the ground was established. 37 composite colors and 70 ground feature categories can be discriminated altogether. Finally, 17 land use/cover categories and 10 subregions suffering from soil gleization were determined, and the gleization area for the study area was estimated to be 731.3 km2.
基金the Ferdowsi University of Mashhad,Iran(3/39455:1394/09/10).
文摘Afghanistan is located in the Eurasian loess belt,however,there is little information on the soils in the area.Loess has covered the Herat Plain in western Herat City,Afghanistan.Despite the diversity of landform and parent material,there is no information on the soil and landform evolution in this area.The objectives of this study were to identify the soils along a transect of different landforms in the Herat Plain and determine the role of geomorphic processes on the soil and landform evolution.Five pedons from an alluvial fan,the depression between alluvial fan and piedmont plain,saline and non-saline piedmont plains,and the flood plain of the Hariroud River,were sampled.Then,the physical-chemical properties,mineralogy,and micromorphology of the samples were determined.Results showed that the soil parent material in the piedmont plain is loess,whereas,in the flood plain it is a combination of loess and river alluvial sediments.Calcification,lessivage,salinization,and gleization are the most important pedogenic processes.The calcification and lessivage appear to be the result of a wetter climate during the late Quaternary,whereas the present topography causes the gleization and salinization.Clay coatings on carbonate nodules and iron nodules are abundant pedofeatures in the Btk(argillic-calcic)horizon.Iron oxides nodules are common in the soils of the flood plain.The formation of palygorskite in both alluvial-and loess-derived soils implies the onset of aridity and the trend of increase in environmental aridity in the region.It seems that after the formation of a well developed paleosol on the alluvial fan in a more humid climate in the past,the piedmont plain has been covered by loess deposits,and the calcification,gleization,and salinization cause the formation of weakly developed surficial soils.This study highlights the role of the late Quaternary climatic changes on the evolution of landforms and soils in western Afghanistan.
