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Geomorphology

Volume XVII |

Study of Landscape Evolution in North Koel River Basin, Jharkhand, India: Tectonic and Structural Implications Based on Hypsometric Analysis

Abstract: Hypsometry is widely used for inferring tectonic effects and erosion status of landscapes. Tectonics, structural inhomogeneity, lithologic differences, and climatic variations lead to topographic undulations discerned into discrepancies in the values. Hypsometric index (and curve), indicative of frequency distribution of proportional elevation with the respective proportional area, is used as a tool to describe characteristics of landscape morphology, lithological variability, and degree of fluvial dissection. Many workers have used to infer comparison of rates of erosion with tectonic uplift rates. However, there are many other factors reported to influence topographic undulations other than tectonics which lead to a variety of hypsometries. Morphotectonic index, hypsometric integral, calculated using digital elevation models (DEMs) in GIS environment has been widely used for inferring tectonic effects, status of erosion, and structural controls. The present study is conducted in the North Koel River basin. This river rises in the Ranchi plateau and joins the Son River a few miles north-west of Haidarnagar, is the right bank tributary of the Son River. Along its entire course of flow, North Koel river (260 km) flows through plateau region mostly formed of metamorphic rocks. Hence, structural control seems to be the primary control on the landscape evolution of this sub-basin. In this study, hypsometric integral (and curve) has been calculated for third order and upper order streams to look whether this morphotectonic index shows any sign of tectonic, structural, or lithologic control on the landscape evolution in the North Koel River basin.

Volume XVII |

Lateral migration of the Jiu river course between 1864 and 2018. Case study: Craiova – Zăval sector

Abstract: During the last 154 years, the Jiu river course that stretches from its confluence with the Amaradia down to the outlet has undergone serious lateral and length changes. The main purpose of this article is to highlight these changes, to determine their magnitude, and to understand the future evolution of the Jiu course.
The results of our analysis showed that from 1864 until 2018, the Jiu river became shorter in the lower section, decreasing with 38.1 km, from 134 km to 95.9 km. The shorten-ing of the course happened gradually. Thus, between 1864 and 1910, the length of the course decreased by 25.6 km, from 134 km to 108.4 km. From 1910 until 1970 there was a shortening of 11.9 km and between 1970 and 2018, the river shortened its course by about 0.6 km. The greatest lateral distance between its historical and present channels showed a maximum of 11.22 km on the outlet.

Volume XVII |

The analysis of relationship between microclimate and microbial carbon-dioxide production in the soils of the Tapolca and Gömör-Tornai karst terrains, Hungary

Abstract: In the karst areas, the epikarst system is a very sensitive environment, due to its position at the interface between soil and vadose zone. The epikarst is a weathered zone that develops as a result of both abiotic and biotic processes. In this paper we present the result of the complex investigations of epikarst zone which overlap dolines within two typical karst areas (Gömör-Torna and Tapolca) from Hungary, based on multicriteria analysis techniques (microbiological activity assessed as biomass amount and CO2 production, seasonality of air and soil microclimate, slope orientation and exposition), in order to reveal control factors of karst processes, the territorial and local distinctions of karst dissolution that occur in the epikarst zone. The data were compared, taking into account the human activities’ impact on both sampled study areas. After four years of monitoring, the results show that there are significant seasonal and diurnal variations of physical, chemical and biotic parameters of soil that cover and affect the epikarst zone. Spatial variations of these parameters were recorded as well.

Volume XVI |

A web-map of the landscapes of Vitosha Mountain and the development of landscape science in Bulgaria

Abstract: On the first hand, the purpose of this article is to present the map and classification of the landscapes of Vitosha Mountain. On the other hand, it aims to present this map as an example and illustration in the context of traditionally applied approaches in Bulgaria in defining the landscape, as well as in researching and classifying the landscapes. There is also a brief overview of the development of land-scape science in Bulgaria.
The choice of the territory in study relates to the fact that Vitosha Mountain is a protected area, i.e. a Nature park declared in 1934, now part of the NATURA 2000 network.
The Vitosha Landscape Map is developed by using GIS tools and it is implemented as a web-map, which makes it much easier to access, examine and work with it, as com-pared to static maps.

Volume XVI |

The impact of the urban expansion on the Jiu floodplain. Case study –Craiova, Romania

Abstract: The urban expansion of any settlement implies changing natural environment and gradually transforming it into an anthropogenic one to assure the needs of the community. A first step in urban planning is to identify the changes that have been made, and this study reconstructs the anthropogenic changes induced to the Jiu floodplain in the last 150 years, through multi-temporal spatial comparisons, geomorphological characteristics and anthropological and environmental transformation indicators. The processing of historical cartographic materials and current satellite imagery highlights the dynamics of the wetlands and the built-up area in the Jiu floodplain between 1864 and 2017. The urban expansion required flood protection works that were carried out along the canals and lakes resulting from the drainage of the ponds and marshlands. On the course of the Jiu hydro-technical works of straightening, embankment and regularization were achieved, which led to the transformation of the course from a highly meandered one as it was in the second half of the 19th century into a sinuous one in 2017. The study is a useful tool in urban planning, by centralizing the changes in the floodplain, the anthropogenic works carried out and the changes of the Jiu course within the analyzed sector.