Environmental conservation from man-induced deterioration due to technological impact and urbanization is an urgent task in the presentday Japan. Contribution from Quaternary research should be expected to provide most essential data for the conservation of natural environment. The changes of environment, especially higher order changes, should not occur without close relation to the natural systems, even if the changes may cause due to man's impact. So that, comprehensive and historical understanding of natural environment consisting of physical, chemical and biological systems and their dynamics must be the foundation for the systematic analysis of spatial and sequential processes of environmental changes induced by man's impact.
Standing on this point of view, the author discusses on the basic problems for studying environmental deterioration. As for deterioration resulting from urbanization, he suggests a framework of studying (Fig. 1). In this chart, complex land system is divided into five subsystems, i. e. rainfall-runoff, erosion-transportation-deposition, ground-earthquake motion, ground-groundwater, and surface morphology-wind subsystems, and relation of man-induced sequential changes of these subsystems to the occurrence of natural hazard is presented schematically.
In conclusion, such future problems as spatial analysis and prediction of environmental changes which are necessary for the establishment of conservation systems are discussed briefly.
