Geographia Polonica (2013) vol. 86, iss. 4

Abstract

The purpose of this research study was to determine the geospatial and temporal characteristics of the drought years in Zimbabwe for the period between 1940 and 1999. Using time series analysis, spatial analysis and the Kruskal‑Wallistest, the study established that there has been a gradual increase in the frequency of ’drought years’ in the recent past, suggesting that some parts of the country might be experiencing climate change. The study concludes that the nature of government initiated intervention strategies for improving agriculture in arid areas may now have to be considered foradoption in areas normally conceived as moist.

Keywords: Agriculture, Drought, Food security, Geospatial analysis, Rural livelihoods, Time series analysis, Zimbabwe

Geoffrey Mukwada, University of the Free State Department of Geography Private Bag X13, 9866 Phuthaditjhaba: South Africa
Desmond Manatsa, Bindura University of Science Education Department of Geography Private Bag 1020, Bindura: Zimbabwe

Abstract

The study is concerned with the temporal and spatial characterisation of atmospheric thaw variability in Poland. The phenomenon was described on the basis of mean daily values of air temperature for the winter months October-March over the period 1960/61-2009/10 obtained from 34 meteorological stations of the Institute of Meteorology and Water Management (IMGW). It has been shown that atmospheric thaws occur on average as soon as 10 days after the firstinstance of a decrease in temperature below 0ºC lasting at least 3 days. Atmospheric thaws are a constant element ofthe climate in Poland and occur with a frequency of 30-45% of the calendar winter (December-February) and 30% toalmost 50% of the period of the thermic winter, that is the period between the date of the first decrease of mean daily airtemperature below 0ºC with a duration of at least three days and the date of its permanent increase above 0ºC. Thaws are most common in the western part of Poland, particularly in the north-west, which, despite having the latest on set of the first thaws, is characterised by a high proportion of winter thaws of a length of 30 days and more. The spatial distribution of thaw is strongly dependent on longitude and less on height above sea level. Multiyear variability of thawdays is determined by atmospheric circulation. In the whole country (apart from the mountains) the correlation betweenthe frequency of thaw occurrence in January, February, and March and the Jones NAO index is statistically significantat a significance level of α=0.01, and coefficients of determination fluctuate in general from 40 to 50% in January andFebruary, and from 20 to 25% in March. The role of circulation expressed by NAO index in the explanation of the variability of thaw occurrence was statistically insignificant

Keywords: atmospheric thaws, thaw periods ≥ 10, 20, 30 days, thaw-start and thaw-end date, temporal variability, spatial distribution, NAO index

Małgorzata Czarnecka, West Pomeranian University of Technology Department of Meteorology and Climatology Papieża Pawła VI 3A, 71-459 Szczecin: Poland
Jadwiga Nidzgorska-Lencewicz, West Pomeranian University of Technology Department of Meteorology and Climatology Papieża Pawła VI 3A, 71-459 Szczecin: Poland

Abstract

The paper describes the processes associated with sediment deposition in the presence of large blocks of dead or stagnatingice. The study examines a large valley depression in the Grudziądz Basin (lower Vistula Valley) which formed part ofthe area covered by the last glaciation. A detailed description of the glaciolimnic landforms arising in that depositional setting was prepared along with a record of their structural and textural variety and their paleogeographical implicationsare discussed. It is concluded that the whole terrace system of the Grudziądz Basin was mainly formed in the presenceof dead ice.

Keywords: lower Vistula River valley, dead ice landforms, kame terraces, lithofacies analysis, Quaternary, Northern Poland

Jarosław Kordowski [jaroslaw.kordowski@geopan.torun.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Kopernika 19, 87-100 Toruń, Poland

Abstract

The paper presents problems faced when using a new method for defining the growth curves of the thalli of the rockylichen Rhizocarpon spp in the Polish section of the Tatra and Karkonosze Mountains. Lichenometric curves based onpre‑existing data were defined for two climatic‑vegetation zones in the Tatra Mountains. These were mainly representativeof substrates located in the central parts of these zones. In the new lichenometric curve which was constructed forthe Tatra and Karkonosze Mts., the thallus growth curve for the first 100 years was defined in a linear manner in relationto altitude. Therefore the curve can be easily used for dating items located in any part of the altitude zone for which thecurve was defined. The paper also tackles the problem regarding the number of thalli that should be assessed when dating. An approach which assesses a certain number of the largest thalli of a similar diameter seems to be the most suitable for small‑scale landforms (with small numbers of thalli) which were formed during one event. The shape of the thallus growth curve is strongly influenced by the landforms (either convex or concave) and the vertical extent of the zone in which the measurement is performed. The presence of multiannual snow patches in close proximity and air pollution also influence thallus growth onthe mountains investigated. The geomorphic processes taking place turned out to be a significant problem for proper dating of the items – depending on their interpretation they can either help dating or obscure the reconstruction of the event.

Keywords: Rhizocarpon, lichenometry, Tatra Mts., Karkonosze Mts.

Stanisław Kędzia [kedzia@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland

Abstract

Archival maps are an invaluable source of information about the state of the geographical environment. They represent the primary research material for analysis of changes in spatial characteristics of the environment. However, a prerequisite for any reliable analysis is an accurate match between archival maps and contemporary cartographic materials and the estimation of error inherent to every match. The most effective way of achieving this nowadays is to use GIS software. The aim of this work is thus to present and discuss georeferencing methods of archival paper maps that make a precise comparison with contemporary reference layers possible. Two alternative georeferencing methods for maps based or not based on a geodetic network are described, and the georeferencing of archival maps is discussed further by referenceto the First, Second and Third Military Surveys of Galicia conducted by the MGI (Militärgeographisches Institut), and completed in 1783, 1863 and 1879 respectively.

Keywords: historical GIS (HGIS), First, Second and Third Military Surveys, map datum transformation map rectification, Habsburg Empire

Andrzej Affek [a.affek@twarda.pan.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Twarda 51/55, 00‑818 Warszawa, Poland

Abstract

Presented here are the means of generating and possibilities for applying a digital map of sequences of ‘forest/non‑forest’ states in a study area, as based on topographic maps for seven instances in time (between 1800 and the present day). There is also a brief description of cartographic material used, as well as the methods applied in generating a variability model. The study area was then analysed from the point of view of differences in the aforementioned sequences of ‘forest/non‑forest’ states, this revealing marked contrasts between two Polish regions that are adjacent, but were conditioned differently in the past, in political and social terms. The study ends by considering the relationship between the distinguished sequences and habitat type, as referred to in terms of potential natural vegetation.

Keywords: historical maps, changes in forest cover, potential natural vegetation, habitat variation, central Poland

Jan Marek Matuszkiewicz [jan.mat@twarda.pan.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Twarda 51/55, 00‑818 Warszawa, Poland
Jacek Wolski [j.wolski@twarda.pan.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Twarda 51/55, 00‑818 Warszawa, Poland
Anna Kowalska [aniak@twarda.pan.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Twarda 51/55, 00‑818 Warszawa, Poland

Jan Marek Matuszkiewicz [jan.mat@twarda.pan.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Twarda 51/55, 00‑818 Warszawa, Poland