A large volume of paleogeomorphological studies had been carried out in the USSR since the Plenum of the Geomorphological Commission in Ufa, 1967. During this time the paleogeomorphological analysis evolved into a separate method of studies in the Earth sciences with manifested bias toward applied geomorphology. Among most important achievements a few publications should be mentioned such as «Paleogeomorphological Atlas of the USSR» (1981) and a series of monographs «History of relief evolution in Siberia and Far East». The prospects of further development of paleogeomorphological approach depend on progress in theoretical studies.

The scale problem is treated in a broad sense, the scale shows in which detail the studies are carried out. In the geomorphology the scale depends on the range of landforms' dimensions. The Earth surface may be considered as a fractal; and with enlargement of scale smaller and smaller landforms come into view of researcher. A system of geomorphological legends applicable to different scales and based on hierarchic classification of landforms should be preferred over a unified legend for all the scales.

A theory of geomorphological concepts formalization has been put forward by A. E. Scheidegger as a basis for euristic modeling. It is of prime interest for geomorphologists as it permits both verbal (semiformal) and rigorous (formal) models of processes and phenomena to be used in the process of synthesis.

A series of levels of the Earth surface organization is distinguished, such as space level, global, continental, local, and mesa-microlocal levels, different in forces and pattern of their action. Boundaries between the levels become less distinct with increasing the levels' rank, the exogenic factor gains in importance, processes characteristic of the levels require less time to become evident. Each level calls for individual methodical approach. The latter thesis is explicated with reference to the fluvial relief dynamics.

Significant differences in the intensity of the present-day genetically different geomorphic processes should be taken into account when classifying natural hazards, some catastrophic processes, such as infrequent but extreme (in wave height) storms, and even more so tsunamis, cause damage comparable to that resulting from long-term marine erosion by medium-high waves. Natural-technogenic processes are close in their destructive power over short time interval to anomalous and catastrophic natural phenomena.

During the cultivation of the upper Oka drainage basin the river's level and channel floor were continuously rising owing to alluviation which resulted from active erosion of watersheds. In the past three decades gravel extraction and dredging initiated bottom erosion. The volume of the gravel extraction is 10 times as large as the total solid discharge of the river. The erosion may slow down on the condition the gravel extraction by channel quarrying does not exceed channel-forming alluvium supply.

The paper discusses natural and anthropogenic factors of the foeman River longitudinal profile formation. The rate of natural erosion processes was estimated within the upper and middle reaches of the river, and so was the alluviation rate in the lower reaches. The down cutting is shown to accelerate owing to land reclamation, channel straightening and guarring. The construction of the Kaunas Hydropower Station led to inversion of processes of erosion and alluviation.

Вклад П. А. Кропоткина в познание рельефа и оледенения Сибири

A method of calculation of gully growth rate (in terms of volume) is introduced, which is based on knowing regularities of changes in sediment yield from the catchment in the course of erosional rills development. Formulae have been developed to calculate total time of gully formation and rates of its growth (both in length and volume) at different stages of the gully development.

Digital photogrammetric models of topography (based on phototheodolite survey data) and calculated mass of snow stored within small mountain catchments are proposed to use for compiling maps of maximum snow thickness within foci of water-and-snow avalanches formation. The method had been field tested within a catchment in the Khibines and proved to be able to identify avalanches' foci and tracks, and to calculate their characteristics.

At the Pliocene-Pleistocene boundary a cooling of climate resulted in that the broad-leaved forests were replaced by coniferous-birch ones, climatic fluctuations during the Quaternary did not show in species composition. Only the Late Pleistocene glaciations can be identified beyond any doubt. Glacial deposits overlay older loose formations on planation surfaces, therefore old placers would be also expected to conserve under the till.

The authors consider badland to be a result of an exotectonic process and a manifestation of tension stresses of rocks and soils in the morphostructure. In their opinion the badland is rather closed than open morphosystem with respect to climatic, and exogenic in general, factors. It does not relate directly neither to endogenic nor to exogenic factors.

The paper summarizes long-term measurements of slope and gully erosion and sedimentation within elementary catchments in the Kursk region. Soil erosion and sedimentation dynamics on slopes and bottoms of elementary rills is traced on daily, seasonal, and yearly basis. The processes appeared to relate to spatial differentiation of the catchment surface, its morphology in the first place. Quantitative data are given on the erosion and sedimentation dynamics in the gully and on its elements. The gully growth and its elements development is concluded to be of cyclic character.

На пути к созданию мировой карты эрозии - М.И. Львович, Л.Я. Карасшс, Н.Л. Братцева, Г.П. Медведка, А.В. Мелешко «Современная интенсивность внутриконтинентальной эрозии суши земного шара» (М.: Междуведомственный геофизический комитет при Президиуме АН СССР, 1991. 336 с.).

Рельеф Мексики в национальном атласе страны 

30 марта 1992 г. скончался профессор Католического университета в Лувене (Бельгия) Жан Де Плой. Он был одним из тех, кто внес наиболее ощутимый вклад в развитие полевой экспериментальной геоморфологии.