SOME GEOMORPHOLOGICAL AND GEOECOLOGICAL IMPACTS OF THE 2010 EXTREME RAINFALLS IN HUNGARY

Some geomorphological and geoecological impacts of the 2010 extreme rainfalls in Hungary. The extreme rainfall events in the unusually wet year of 2010 brought about major changes in the floodplains of several streams in Hungary. On the small watercourses in low mountain or hill environments flash floods were generated. In the floodplains of medium-sized rivers, like the Kapos River in Southern Transdanubia, lasting inundations transformed the landscape. The system of wetlands preceeding the 19th-century river regulation and land drainage measures was restored by natural processes and within a very short time as excess water filled the entire broad valley sections in a shallow layer temporarily, for some weeks, and the former oxbows for several months. The nature conservation value of the river valley increased: reed and sedge beds and the brooding colonies of aquatic birds extended. There are, however, unfavorable impacts as well. Denser wetland vegetation significantly contributes to the organic filling of floodplain landforms. The spreading of invasive plants (allergetic ragweed, Ambrosia artemisiifolia, in the first place) was promoted by the prolonged survival of extensive bare but moist silt surfaces in the floodplain. The long-term effects of this colonization on floodplain communities are unpredictable. A delayed and indirect impact of extreme rainfalls was the breach of a red sludge reservoir near the Ajka alumina plant in October, 2010 and the resulting environmental disaster. After the gradual accumulation of rainwater in the reservoir, the dyke breach happened, released 600-700 thousand m3 of basic (up to pH 13!) sludge over the floodplain of the Torna Stream, a tributary of the Marcal and Rába rivers in an area of ca 40 km2. The emergency mitigation measures (spreading gypsum from power plants to neutralize the strong base) over the layer of red sludge accumulation proved unfortunate as it prevented that the sludge should be washed downstream and diluted. The gypsum crust hindered the natural regeneration of aquatic life. With serious damage to residential buildings, the ecological impacts on the floodplain may not be as long-standing as predicted

Karsztvidékek sérülékenységi értékelésének lehetőségei = Approaches to the vulnerability assessment of karst regions

As other landscape units, karst regions have various functions and thus they can be evaluated for various purposes: for their origin, ecological, nature conservation and environmental potentials. For practical purposes assessments for water supply, recreation and health, forestry and agriculture, cultural (paleontological or archaeological) significance or development perspectives are feasible. The increasing pressure on the environment calls for detailed inventories in order to provide fountation for regional planning and conservation measures. The paper investigates the opportunities for the vulnerability assessment of karst areas, primarily on the basis of a procedure applied in British Columbia, Canada

Gondolatok a magyar földrajzi társaság feladatairól a másfél évszázados évforduló kapcsán

In the different periods of its 150-year-long history the Hungarian Geographical Society faced different kinds of challenges: at the beginning the organization and financing of geographical expeditions, launching research projects and popular science book series, while in more recent times the dissemination of geographical knowledge acquired prominence. The contacts with public education (and secondary school teachers) have been of variable intensity but the Society has ever been active in strengthening the position of geography as a school subject. The jubilee year is a good opportunity for the revitalization of social life within the Society and establishing new links with the earth sciences at home and abroad. All these efforts are also meant to strengthen the positions of geography in academic and public life

The Impact of Microtopography and Drainage on Land Use and Settlement Development in the Hungarian Drava Plain

Prirodni okoliš i društvo tijesno su povezani, a uloga prirodnih obilježja izravno se odražava na ekonomski razvoj i širenje naselja u mađarskom dijelu dravske ravnice. Topografska i hidrografska obilježja oduvijek utječu na način uporabe zemljišta istraživanog područja. Denivelacija od metra ili dva imala je odlučujuću ulogu u razgraničavanju površina pogodnih za ribarenje od onih pogodnijih za sakupljanje plodova, šumarstvo ili uzgoj usjeva. Iako se regulacijom toka rijeke Fekete-viz i drenažom močvarnog zemljišta krajem 19. stoljeća smanjila opasnost od poplava i dobilo novo obradivo zemljište, siromašnije stanovništvo nije moglo nastaviti tradicionalni način života, tj. sakupljanje plodova, ribarenje i lov. Naselja su se razvila na ocjeditim uzvišenjima, gdje nema opasnosti od poplava (ormány). U ovom se radu analizira prostorno širenje najvećeg naselja, grada Sellye, uz pomoć geografskoga informacijskog sustava (GIS). Zaključeno je da se površine ispod sto metara nadmorske visine mogu razvijati samo nakon što ih se drenira.The physical environment and society are closely interrelated and the role of physical conditions can be detected in the economic development and spreading of settlements in the Hungarian section of the Drava Plain. Throughout the history of the region, land use has always been fundamentally controlled by the topographic and hydrographic situation. Even relief of a metre or two has been decisive in delimiting areas suitable for fishing, gathering, forests or crop cultivation. Although the flow regulation of the Fekete-víz and the drainage of swamp-lands at the end of the 19th century reduced flood hazards and made new land available for cultivation, at the same time, they made the traditional life-style of gathering, fishing and hunting unfeasible for the poorer layers of society. Settlements formed on the higher-lying flood-free mounds ("ormány"-s). The paper employs GIS techniques in the study of spatial expansion of the largest of the settlements, the town of Sellye. It is concluded that the areas below 100 m elevation could only be developed following drainage measures