Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
w słowach kluczowych:  geoindicators
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
During the last two decades of the 20th century and first years of the 21st century more intensive karst processes have been witnessed in North Lithuania. The intensity of the karst process is visible as new sinkholes appearing that severely damage crops, constructions and communication systems. Explanation and forecast of these hazardous phenomena requires knowledge based on systematic monitoring data and adequate interpretation with identification of relevant geoindicators of the intensive sulphate karst processes which are of primary significance for environmental planning and management of the region. Two geoindicators, gypsum chemical denudation and the intensity of appearance of new sinkholes, were selected for monitoring of karst processes in North Lithuania. Chemical denudation has been measured since 1964 in this region. These geoindicators show that since 1978 the intensity of karst denudation has increased by 30%, with more frequent formation of sinkholes. A correlation of this phenomenon with climate change — increasing air temperature and decreasing of the duration of seasonally frozen ground — is proposed and discussed in this paper.
Content available remote Geoindykatory strefy brzegowej : rejestracja i analiza procesów i zjawisk
The goal of the project was to evaluate methods for recording and analysing the geoindicators related to the coastal zone. Geoindicators, according to the definition elaborated by the IUGS, are measures (magnitudes, frequencies, rates and trends) of geological processes and phenomena occurring at or near the Earth’s surface and subject to changes over periods of 100 or less years. Shoreline changes are one of the most important geoindicators of processes on the coastal areas because of their importance to economy and nature conservation. Investigations were carried out on the southern and western coast of the Gulf of Gdańsk: in the Vistula river mouth, on cliffed coast south of Gdynia and at the tip of the Hel Peninsula. Shoreline changes in different time scales were identified by analyses of aerial photos, analyses of digital terrain models and GPS measurements.
Long-term multipurpose geochemical studies in Lithuania show that the chemical composition of surface sediment can be used as an indicator of geological process: duration of weathering, soil formation and thickness of sediment. The chemical composition of upper and lower soil layers and of lake sediments gives information on past sedimentation: the type and age of Quaternary deposits and the location and depth of Pleistocene glaciolacustrine basins. We therefore have a baseline to predict changes in surface chemistry provoked by current anthropogenic pressures.
Indicators of topographic relief change are proposed for environmental monitoring, and environmental impact assessment (EIA). Changes in relief pattern reflect human impact on the land surface due to small- and large-scale development projects. Landform diversity, relief resilience and impact-response approaches allowing measurement of changes in relief pattern are described. These approaches are based on a number of integrated environmental indices that may be used together or separately to assess anthropogenic alteration of landscape elements. Several examples their practical use are given in the paper. Other possible applications of geoindicator measures for different EIA techniques are briefly described.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.