For an investigation of the degeneration of forest by the air pollution using the satellite remote sens-ing data, it is necessary to confirm by ground truth whether spectral refrectance characteristics of trees are available to indicate damages by air pollution. In this study, the amount of sulfur oxide deposited on leaves and the spectral reflectance chalacteristics of the near infrared band (NIR) and the red band (R) in spectral region of leaves of the trees in the environs of cities and factories were measured. The vegetation activity is defined as the bi-band ratio (NIR/R), and this paper discussed the relationship between (NIR/R) value and the amount of sulfur oxide deposited on leaves in accordance with the pollution level. The conclusions of this paper are as follows. (1) The more the distance from the source of air pollution increases, the more the amount of sulfur oxide diposited on leaves decreases being irrelevant to the environmental condition. (2) In the case of equivalent growth condition, (NIR/R) values of trees become bigger as the distance from the source of air pollution increases. (3) In the case of different growth condition, (NIR/R) values of trees are various being irrelevant to the distance from the source of air pollution. (4) There is a negative correlation (coefficient of correction=-0.968) between the amount of sulfur oxide deposited on leaves and (NIR/R) values.
Unusual growth of Microcystis in Lake Kasumigaura in resent every summer has produced many environmental problems. The management of water quality should be considered from the view point of the hydrodynamics of the lake. Remote sensing technology could have a potential to detect pollution features and water quality parameters, and also to survey the water streams in the lake. Synoptic views from Landsat are useful to grasp hydrodynamic phenomena of large scale of water area. But, Landsat images cas only show a temporal scene of the changing phenomena. To compensate this deficiency, numerical simulation should be introduced. This paper shows an example to solve this problem through a case study of Lake Kasumigaura. The authors investigate a relation between the drift current and dispersion of Microcystis seen on the Landsat false color image. Circumstance of the current was examined by computer simulation with finite difference method. Correlation coefficient, eigen values, and eigen vectors were calculated onLandsat MSS digital counts and ground truth data. The results of this study are summarized as follows : 1) Water qualitie parameters were higily correlated with Landsat MSS computer compatible data. 2) Principal component analysis compressed many water quality parameters into the major two ; suspended sediment and organic compound. 3) The solution of numerical calculation was similar to the false color image one. 4) Drift current may have an imporatant role for the management of water quality in Lake Kasumigaura.
Forests not only produce timber, but also offer us comfortable environment by cultivation of water source, filtration of air and water, prevention of flood and landslide and so forth. They contribute also to the conservation of forest genetics. These days, forests are given higher priority to their environmental resources than their timbers. For build-ing up a more efficient forest management plan, we have to have more detail information about the quantity and quality of forests at rather narrow intervals. Romote sensing systems from space, such as the Landsat sensor system, can provide systematic, repetitive and global data of forest situations and environmental conditions of the earth's surface with adequate accuracy. Remote sensing technology has been approved useful and effective for regional, national and global forest inventories by many application studies organized in Japan and othercountries. The integration of remote sensing technology and geographic information system (GIS) is also considered to be very effective for monitoring forest areas and creating forest management plans. And using the GIS system, more complicated information, such as about environmental preservation functions of forest, is successfully obtained and analyzed. This paper summarizes the present status of the art and makes some remarks on problems and future prospect of remote sensing for forestry.