scholarly journals Historical medium-scale maps as a source of information on the overgrowing of lakes

2013 ◽  
Vol 13 (3) ◽  
pp. 155-162 ◽  
Author(s):  
Mariusz Ptak
Keyword(s):  
Aerial Photographs ◽  
Topographic Maps ◽  
Water Level Fluctuations ◽  
Individual Object ◽  
Medium Scale ◽  
Emergent Plants ◽  
Main Lake ◽  
Source Of Information ◽  
Calculated Average ◽  
Different Parts

AbstractIn the work, medium-scale topographic maps from the first half of the 20th century and aerial photographs from the first decade of the 21st century were used to determine the rate of overgrowing of lakes. A comparison of results for lakes located in different parts of Poland demonstrated that the process of proliferation of emergent plants dominated - such a situation was recorded for 14 out of the 15 lakes analysed in the work. The calculated average overgrowing rate for all the lakes in the years 1945-2010 was 0.4 ha yr-1. Lake Karaś (1.83 ha yr-1) and Lake Oświn (1.2 ha yr-1) were characterized by the highest overgrowing rates. Moreover, the work presents an attempt at discovering the factors which determine the scale of the lake overgrowing process. To this end, the main lake parameters were analysed and it was concluded that the rate of overgrowing of lakes was influenced, inter alia, by water level fluctuations and the shape and depth of a given lake. However, each lake should be treated as an individual object which responds to the processes occurring in its environment in a unique way.

scholarly journals Drivers of Macrophyte and Diatom Diversity in a Shallow Hypertrophic Lake

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1569
Author(s):  
Kateřina Šumberová ◽  
Ondřej Vild ◽  
Michal Ducháček ◽  
Martina Fabšičová ◽  
Jan Potužák ◽  
...  
Keyword(s):  
Fish Farming ◽  
Spatial Diversity ◽  
Spatiotemporal Variability ◽  
Water Level Fluctuations ◽  
Nutrient Requirements ◽  
Diatom Assemblages ◽  
Climatic Extremes ◽  
Growing Seasons ◽  
High Species Richness ◽  
Different Parts

We studied macrophyte and diatom assemblages and a range of environmental factors in the large hypertrophic Dehtář fishpond (Southern Bohemia, Czech Republic) over the course of several growing seasons. The spatial diversity of the environment was considered when collecting diatoms and water samples in three distinct parts of the fishpond, where automatic sensor stations continually measuring basic factors were established. Macrophytes were mapped in 30 segments of the fishpond littoral altogether. High species richness and spatiotemporal variability were found in assemblages of these groups of autotrophs. Water level fluctuations, caused by the interaction of fish farming management and climatic extremes, were identified as one of the most important factors shaping the structure and species composition of diatom and macrophyte assemblages. The distance of the sampling sites from large inflows reflected well the spatial variability within the fishpond, with important differences in duration of bottom drainage and exposure to disturbances in different parts of the fishpond. Disturbances caused by intensive wave action are most probably a crucial factor allowing the coexistence of species with different nutrient requirements under the hypertrophic conditions of the Dehtář fishpond. Due to a range of variables tested and climatic extremes encountered, our study may be considered as a basis for predictive model constructions in similar hypertrophic water bodies under a progressing climate change.

scholarly journals Geomorphological mapping based on DEMs and GIS: A review

2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Takashi Oguchi
Keyword(s):  
Remote Sensing ◽  
Laser Scanning ◽  
Aerial Photographs ◽  
Topographic Maps ◽  
Formation Processes ◽  
Geomorphological Mapping ◽  
Topographic Data ◽  
Aerial Photogrammetry ◽  
Landform Classification ◽  
Shape Characteristics

<p><strong>Abstract.</strong> Geomorphology is a scientific discipline dealing with the characteristics, origin, and evolution of landforms. It utilizes topographic data such as spot height information, contour lines on topographic maps, and DEMs (Digital Elevation Models). Topographic data were traditionally obtained by ground surveying, but introduction of aerial photogrammetry in the early 20th century enabled more efficient data acquisition based on remote sensing. In recent years, active remote sensing methods including airborne and terrestrial laser scanning and applications of satellite radar have also been employed, and aerial photogrammetry has become easier and popular thanks to drones and a new photogrammetric method, SfM (Structure from Motion). The resultant topographic data especially raster DEMs are combined with GIS (Geographic Information Systems) to obtain derivatives such as slope and aspect as well as to conduct efficient geomorphological mapping. Resultant maps can depict various topographic characteristics based on surface height and DEM derivatives, and applications of advanced algorithms and some heuristic reasoning permit semi-automated landform classification. This quantitative approach differs from traditional and more qualitative methods to produce landform classification maps using visual interpretation of analogue aerial photographs and topographic maps as well as field observations.</p><p>For scientific purposes, landforms need to be classified based on not only shape characteristics but also formation processes and ages. Among them, DEMs only represent shape characteristics, and understanding formation processes and ages usually require other data such as properties of surficial deposits observed in the field. However, numerous geomorphological studies indicate relationships between shapes and forming-processes of landforms, and even ages of landforms affect shapes such as a wider distribution of dissected elements within older landforms. Recent introduction of artificial intelligence in geomorphology including machine learning and deep learning may permit us to better understand the relationships of shapes with processes and ages. Establishing such relationships, however, is still highly challenging, and at this moment most geomorphologists think landform classification maps based on the traditional methods are more usable than those from the DEM-based methods. Nevertheless, researchers of some other fields such as civil engineering more appreciate the DEM-based methods because they can be conducted without deep geomorphological knowledge. Therefore, the methods should be developed for interdisciplinary understanding. This paper reviews and discusses such complex situations of geomorphological mapping today in relation to historical development of methodology.</p>

Access to Internet and Internet Shutdown: A Rights Perspective

2021 ◽  
Vol 08 (1&2) ◽  
pp. 7-14
Author(s):  
Ajay Kumar ◽  
Keyword(s):  
Human Rights ◽  
The Internet ◽  
Important Concern ◽  
The World ◽  
Current Scenario ◽  
History Of ◽  
Internet Freedom ◽  
Source Of Information ◽  
Union Territory ◽  
Different Parts

Access to the internet is fast becoming a basic right given the plethora of information available on the net these days. In the current scenario, the issue of internet shutdown has become an important concern in India. Internet shutdown affects people socially, psychologically and economically. On one hand, many democratic countries of the world are discussing about digital freedom and human rights, while on the other hand, some countries including India are continuously practicing Internet shutdowns in different parts of their countries. India has become the top country of the world in terms of the numbers of Internet shutdowns. The Internet has become such a prominent source of information for all of us that when Internet connectivity is suspended, many people are affected as they depend on the Internet services for various purposes. Internet shutdown is not only harmful to democracy and governance but also to the economy of the country. Internet shutdowns are direct violations of digital freedom and human rights. The main objective of this paper is to argue that access to internet is a basic right and highlight the problem of Internet shutdown in India and its adverse impact on the lives of Indians. In addition, this paper attempts to highlight a brief history of Internet shutdowns in India. The paper shows how frequent clampdowns on internet affects the economy, as has been the case of Union Territory of Jammu & Kashmir thereby highlighting the case for internet freedom for the survival of the economy especially in Digital India.

Recent Changes of Nordbogletscher and Nordgletscher, Johan Dahl Land, South Greenland

1986 ◽  
Vol 8 ◽  
pp. 106-110 ◽  
Author(s):  
N.Tvis Knudsen
Keyword(s):  
19Th Century ◽  
Climatic Conditions ◽  
Transport Rate ◽  
Aerial Photographs ◽  
Topographic Maps ◽  
Historical Time ◽  
Surface Movement ◽  
The 19Th Century ◽  
Inland Ice ◽  
Surface Changes

Generally, outlet glaciers from the Inland Ice in South Greenland have retreated and thinned considerably since the 19th century. A sector in Johan Dahl Land, comprising the glaciers Nordbogletscher, Nordgletscher, and Eqalorutsit kangigdlît sermiat, has no trim-line zones. These glaciers have probably reached their most advanced position in historical time and are advancing further. Marginal and surface changes of the glaciers, over the last 30 years, are determined, using topographic maps based on aerial photographs taken in 1953, 1977, and 1981 and compared with ablation and surface movement of ice measured at stakes, established in 1978 at Nordbogletscher. The conclusion, made on the basis of the observations, is that the advance is the result of a higher transport rate of ice from the accumulation area than can ablate during the summers in the ablation area, under prevailing climatic conditions.

scholarly journals Cartographic Remote-Sensing Monitoring of Glaciological Systems (Example, Mount El‛ Brus, U.S.S.R.) (Abstract)

1987 ◽  
Vol 9 ◽  
pp. 247-248
Author(s):  
Yu. F. Knizhnikov ◽  
V.I. Kravtsova ◽  
I.A. Labutina
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Large Scale ◽  
Quantitative Information ◽  
Snow Accumulation ◽  
Aerial Photographs ◽  
Small Scale ◽  
Medium Scale ◽  
Remote Sensing Monitoring ◽  
Periglacial Zone

Remote-sensing methods in monitoring the glacierization of Mount EI‛ brus are used to produce base and dynamic maps, and to obtain quantitative information (dynamic indices) about the rate, intensity, and variations of the process. The monitoring system is divided, according to scope and territory covered, into small-scale for total glacierization and the periglacial zone, medium-scale for separate glaciers, and large-scale (detailed) for part of the glaciers or sectors of the adjoining slopes. The approximate relationship of even scales is 1 : 4. Small-scale monitoring remote-sensing systems are important for making maps showing the complex characteristics of the glaciological system. A series of maps was produced including geographical, those of high-altitude zones, slope and exposure angles, geological, glaciomorphological, climatic (temperature, precipitation, and winds), distribution of direct solar radiation, hydrological (source of streams), seats of avalanches, and landslides. All these data serve as a cartographical basis in monitoring the glacierization of Mount EI‛ brus. They are compiled from remotely sensed and Earth-based data. Current monitoring on a small scale includes observations of the conditions which determine the existence of the glacial system - this includes data on winter snowfall and the period of snow cover. These observations were obtained from meteorological and resource satellites, and from scanner data of medium and high resolution. Also important are observations of changes in the outline of glaciers, times of snowfall and character of the distribution of snow, and its redistribution due to avalanches and snowstorms. High-resolution space photographs, small-scale aerial photographs, and aerovisual observations provide the data for these observations. It has been determined that the area of the glaciers of Mount El‛ brus has been reduced by 1 % in the last 25 years, i.e. the rate of its deglacierization dropped sharply as compared to preceding decades. The role of quantitative information gains importance in the medium-scale level of monitoring. Topographical maps of separate glaciers compiled from aerial photographs or data from ground stereo-photogrammetric surveys constitute the base maps at this level. The main method used in monitoring were large-scale surveys from aircraft, perspective surveys from helicopters, and phototheodolite surveys. Multi-date surveys of the glaciers provide data about the changes in their outlines and height, the character of their relief, their moraines, the amount of snow accumulation and ablation in separate years, the surface rates of ice flow and their fluctuations. The techniques by which quantitative information is obtained about changes in the glaciers are derived from processing the data of multi-date surveys. The organization and techniques of phototheodolite surveys have been improved. A theory evolved for determining the surface-ice movement by stereo-photogrammetric means and the technique for it has also improved; algorithms and programs for machine processing of the data of multi-date surveys (ground and from aircraft) have been produced At this level of monitoring, it has been found that the retreat rate of most glaciers has slowed down and several glaciers are now in equilibrium. Several glaciers became active at the beginning of the 1970s and 1980s; this was accompanied by an increase in their height and forward movement. For example, activation of Kyukyurtlyu Glacier has been recorded (higher surface and increasing flow rate) which has caused the glacier to move forward 100 m. Surveys at an interval of 2 years recorded the beginning of the process of retreat of this glacier. Detailed monitoring is used to detect the mechanism of the dynamic processes and to study it on local representative sectors. On a glacier it may take the form of annual surveys of its tongue, which makes it possible to observe the processes of formation of moraines and glacio-fluvial relief. Studies may also be made of the mechanism of the movement of avalanches and landslides, deducing their quantitative characteristics and appraising the results of avalanches and landslides. Multi-date surveys of sectors of the slopes provide information about processes in the periglacial zone. At this level, regularly repeated ground stereo-photogrammetric surveys are the main means of observation. Glaciological remote-sensing monitoring provides a wealth of data for theoretical development in the field of glaciology. It makes it possible to forecast and produce warnings about hazardous processes and phenomena.

scholarly journals Shoreline and surface area changes induced by floating islands in peatland lakes (Tuchola Pinewood Forest, Poland)

2011 ◽  
Vol 11 (4) ◽  
pp. 151-162
Author(s):  
Grzegorz Kowalewski
Keyword(s):  
Surface Area ◽  
Aerial Photography ◽  
Small Area ◽  
Aerial Photographs ◽  
Topographic Maps ◽  
Low Resolution ◽  
Shoreline Changes ◽  
The Past ◽  
Floating Mat ◽  
Observation Period

Shoreline and surface area changes induced by floating islands in peatland lakes (Tuchola Pinewood Forest, Poland)Multitemporal aerial photography and topographic maps were applied to investigate shoreline and surface area changes induced by floating islands in three small (area < 1 ha) peatland lakes in the Tuchola Forest. The observation period covers the last 60 years (1951-2011). Shorelines of peatland lakes are stable, unless parts of them detach as floating mats and become floating islands which could have migrated sporadically in the past. Currently, they are rooted permanently to the mat (Dury I and Dury V Lakes) or float loose (Kozie Lake). In the observation period, movement of the islands and closing of lake bays due to overgrowing were the main reasons of shoreline changes. Due to low resolution of old aerial photographs, other changes are not decipherable and can be treated as negligible. Therefore, no reasonable conclusions can be drawn regarding the actual floating mat encroachment during the last 60 years, and the rate of lake shrinking, based of aerial photographs.

scholarly journals Glacier Volume Estimation on Cascade Volcanoes: An Analysis and Comparison with Other Methods

1986 ◽  
Vol 8 ◽  
pp. 59-64 ◽  
Author(s):  
C.L. Driedger ◽  
P.M. Kennard
Keyword(s):  
Estimation Method ◽  
Cascade Range ◽  
Volume Estimation ◽  
Aerial Photographs ◽  
Topographic Maps ◽  
Estimation Methods ◽  
Ice Thickness ◽  
Mount Rainier ◽  
Three Sisters ◽  
Mount St Helens

During the 1980 eruption of Mount St. Helens, the occurrence of floods and mudflows made apparent a need to assess mudflow hazards on other Cascade volcanoes. A basic requirement for such analysis is information about the volume and distribution of snow and ice on these volcanoes.An analysis was made of the volume-estimation methods developed by previous authors and a volume- estimation method was developed for use in the Cascade Range. A radio echo-sounder, carried in a backpack, was used to make point measurements of ice thickness on major glaciers of four Cascade volcanoes (Mount Rainier, Washington; Mount Hood and the Three Sisters, Oregon; and Mount Shasta, California), These data were used to generate ice-thickness maps and bedrock topographic maps for developing and testing volume-estimation methods. Subsequently, the methods were applied to the unmeasured glaciers on those mountains and, as a test of the geographical extent of applicability, to glaciers beyond the Cascades having measured volumes.Two empirical relationships were required in order to predict volumes for all the glaciers. Generally, for glaciers less than 2.6 km in length, volume was found to be estimated best by using glacier area, raised to a power. For longer glaciers, volume was found to be estimated best by using a power law relationship, including slope and shear stress. The necessary variables can be estimated from topographic maps and aerial photographs.

scholarly journals The effect of the Cold War era on maps for public use in the Eastern Bloc countries: Tourist maps

2021 ◽  
Vol 3 ◽  
pp. 1-8
Author(s):  
László Zentai ◽  
Gábor Gercsák
Keyword(s):  
Cold War ◽  
Early Years ◽  
Eastern Bloc ◽  
Topographic Maps ◽  
Medium Scale ◽  
Cold War Era ◽  
The Cold War ◽  
The Military

Abstract. Cartography of the Cold War era was very characteristic in the Eastern Bloc countries. The abnormal secrecy instructions forced by military cartographic authorities (following the Soviet advisors) influenced the making of all kinds of large- and medium-scale cartographic products for public use. Most of these maps were somehow distorted, although it was not easy to implement the technology of distortions developed by cartographers in the analogue map production era in the early 1960s. Tourist maps are expected to be created using topographic maps, but the access to classified topographic maps (both civilian and military) was limited for civilian users (even for civilian national mapping agencies, at least in the early years of the Cold War era). The tourist maps of this era were quite different from country to country in the Eastern Bloc, partly due to their cartographic traditions and to the relationships between the military and civilian cartography even influenced by the users’ demands.

scholarly journals Is Menstruation Still a Dark Side of the Society in 21th Century in Nepal?

2020 ◽  
Vol 1 ◽  
pp. 148-155
Author(s):  
Kosh Bilash Bagale
Keyword(s):  
Ethnic Groups ◽  
Dark Side ◽  
Health Post ◽  
Biological Phenomenon ◽  
Knowledge Source ◽  
Poor Knowledge ◽  
Depth Interview ◽  
Home And School ◽  
Source Of Information ◽  
Different Parts

Menstruation is a natural and biological phenomenon, but our patriarchal Nepalese society has practiced different taboos during the menstruation. Due to the taboos, women are deprived of different physical and psychological problems in this period. People are not much discussing the menstrual issues in their home and societies. The aim of this study is to explore the existing practices, prevailing knowledge, source of information and problems facing by girl sat their home and school. In-depth interview was conducted from the purposively selected students from Gongabu Health Post Kathmandu. Collected data were analysed on thematic basis and relevant themes were generated. Study shows that students had a poor knowledge about menarche. Lack of awareness and preparedness most of them used traditional pad during the menstruation and were frightened on their menarche. There are still several taboos about menstruation in different parts of the country and ethnic groups which act for women deprivation to the progress and grip the opportunity.

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