Solution of the linear diffusion equation for modelling erosion processes with a timevarying diffusion coefficient
predictions are tested on a hill of the southern part of the Ural mountainous region. The results and conclusions of this study may be useful in estimating in quantitative terms the morphological evolution of a hill or a mountain with time.
Assam-Bengal relations : from the earliest times to the twelfth century A.D.
The work deals with the varied aspects of the life of the people of the two regions, Assam and Bengal, from the pre-historic time till the end of the twelfth century AD. Similarities and differences that marked the two geographical regions are shown
with reasons for such trends and their resultant reaction on the people at large. In response to the demand, Assam-Bengal relations were marked by conflicts as well as cooperation, at time unwittingly. - (GL)
Time-averaged flow structure in the central region of a stream confluence
flow structure in this part of the CHZ varies with changes in hydrologic conditions and bed morphology. A particular focus is to document the presence or absence of time-averaged, helical motion in the central region of the confluence.
This paper examines the time-averaged, two-dimensional (downstream and cross-stream) flow sructure within the central region of the confluence hydrodynamic zone (CHZ) at a small stream confluence with an asymmetrical planform. It also examines how
Evidence from Ar40/Ar39 ages of individual hornblende grains for varying Laurentide sources of iceberg discharges 22,000 to 10,500 yr B.P.
The abundance and lithic content of ice rafted detritus in glacial North Atlantic sediment cores vary abruptly on millenial time scales that have been correlated to Dansgaard-Oeschger cycles in the Greenland ice cores. There is growing evidence
that various ice sheet outlets contributed increased iceberg fluxes at multiple discrete intervals, and the relative timing of iceberg discharges from different sources is important for understanding interactions between oceans and ice sheets. The AA. present
In the USA one distinctive feature of Amish identity, an ethnic-base sect that originated in Switzerland in 1690, is their skill in patchwork quilting. Designs, colors, and method of construction vary with time period and region of Amish settlers
A modelling approach is presented to predict local scour under timevarying flow conditions. The model is based on a number of hypotheses concerning the characteristics of the flow hydrograph, the temporal evolution of the scour and the geometry
of the scour hole. A key assumption is that, at any time, the scour depth evolves at the same rate as in an equivalent steady flow. Experimental data are presented that show the scour hole development downstream of bed sills due to flood hydrographs follow
Economic regionalization divisions vary with authors and sometimes even the existence of economic regions is disputed. The author states that economic regions exist objectively, they are specialized in production but are of complex character
at the same time. They include regional production complexes and have their own history. (DLO).
AIDS ; Diffusion ; Epidemiology ; Simulation ; Space time ; Spatial interaction
An appropriate form of a multiregion disease model is fitted to the spread of the 1957 Asian influenza pandemic and then used to examine the distributions of warning times associated with varying the location of the source region. Disease parameters
the shapes of the storm outlines, their areal extent, and location frequency. The time distributions of the storms were also examined to develop a greater appreciation of how the frequency of these events varies over time.
Czech Republic ; Regional development ; Time series
This paper empirically examines the role of West-East gradient for regional development. Despite problems with consistency of the data, the authors made an attempt to establish long-term time series of at least basic data covering the following
spheres : demography, economy and social sphere. The results are rather varied, but the main conclusion is that despite a clear manifestation of the role of West-East gradient in several spheres, there is no fatalism (determinism) stemming from geographic
Criminality ; Geographical information system ; Seasonal variation ; Social geography ; Space time ; Stockholm ; Sweden ; Urban transport ; Vulnerability
suggest that the role of the stations’ environment on crime causation varies over time—an important fact for safety interventions.
On identifying the most time-saving walking route in a trackless mountainous terrain
The A. presents a procedure to find the most efficient walking route to inspect 16 rain gauges within a mountainous location on the Faeroe Islands. Measured walking times on varying slopes and crossing shallow rivers were used as inputs to establish
a friction-based cost surface. Subsequently, a cost path analysis led to identification of a web of least-cost paths between the locations. Finally, the most time-saving route to visit all rain gauges in one round trip from the base camp was found using
Climatic trend ; Correlation ; Scandinavia ; Seasonal variation ; Temperature ; Time series ; Zonality
and that any distinct periods are hard to identify, except for a phase with low ZI for winters over the North Atlantic area during 1955-70. The correlation between ZI and temperature is shown to vary over time (especially for spring and autumn) indicating
Monthly zonal indices (ZI:s) from January 1899 to August 1992 in a North Atlantic area (40°W-5°W) and a north European area (5°E-40°E) are analysed. Time series analysis show that the ZI:s for each area does not show the same evolutionary trends
Embanked floodàplains in the Netherlands. Geomorphological evolution over various time scales
in the Netherlands. The study focused on the river Rhine distributaries. One of the conclusions is that overbank sedimentations have varied in previous centuries between about 5 and 30 mm per year. Contemporary overbank sedimentation rates are highly variable
in space and time. As a result of climatic change, floodplain sedimentation rates may increase by a factor 1.5 to 2 over the forthcoming century. -(AGD)
Impact of the timing and duration of seasonal snow cover on the active layer and permafrost in the Alaskan Arctic
This study addresses the impact of variations in the timing and duration of seasonal snow cover on the thermal regime of the active layer and permafrost in the Alaskan Arctic through numerical modelling. Meteorological data from 1995 to 1998
by varying the snowpack onset date in autumn and the disappearance date in spring.