Keywords: nest site distribution, Red-backed Shrike, Lesser Grey Shrike, karst poljes, Bosnia and Herzegovina INTRODUCTION Abandonment of the village and thus arable land leads to changes in the ...natural environment resulting in varying habitats, many of which are extreme for birds, for example Emberiza citrinella or Passer domesticus, however, for some species this had a favourable effect (Marie 2022b). According to Marie (2022a) L. collurio inhabits six different habitat types, and L. minor three in the Grabovo's poljes. According to Cramp (1994) and Yosef (2008) L. minor inhabits open habitat with plenty of scattered or grouped trees, and fewer bushes, requires presence of features offering perches, shade and accessible food. According to Block and Brennan (1993) the breeding habitat is selected based on nesting requirements, whereas the non-breeding habitat use is strongly associated with food abundance.
Karst poljes are the most characteristic feature of Dinaric karst area. The number of poljes identified on the island of Vis (Croatia) differs according to the various authors who have studied the ...island. Considering the various existing definitions of polje in previous studies, in this paper we propose a set of criteria for identifying poljes in karst terrain using Geographic Information System. This enabled the identification of six poljes on the Vis Island, whose formation is predetermined by tectonic structures. Moreover, processes are frequently inferred by neotectonic (both uplift and subsidence) according to the analysis of longitudinal and transverse profiles gradients affecting balance of these morphologies. Since they are not hydrologically active in present hydrological conditions, poljes on Vis Island can be considered to be paleo - overflow or structural poljes.
The Bokanjačko blato karst polje (field) is a typical depression along the eastern Adriatic coast that is filled with lake sediments. This large-scale structure is also an hydrologically important ...region as wells in southern part of the karst polje comprise the water supply for surrounding towns and villages. The evolution of this polje, however, remains poorly understood. A 7.8 m long sediment core from the south-eastern part of the karst polje is utilized in this study to enable a multiproxy approach to the reconstruction of depositional processes that have occurred over the last 10.3 ka cal BP. The sedimentological, mineralogical and geochemical characteristics, as well as palynological analyses of this core indicate that the whole sediment sequence consists of lake sediments alongside a variable amount of carbonates and silicates. The lake existed for approximately 10,300 years before it was drained for agricultural purposes in the 1960s. Depositional changes are also evident throughout the core; between 10.3 and 4.2 ka cal BP, a higher values of magnetic susceptibility (MS) and concentrations of lithogenic elements indicate increased erosion and input of material from the catchment and therefore wetter climatic condition. Deposition of siliciclastic detrital material gradually decreased from 4.2 ka cal BP onwards, replaced by carbonate sedimentation alongside minimal input of the former. The carbonate-based sandy silt sedimentation remains until hydromelioration of the depression. The results of this study show that the lake level gradually increased between 4.2 and 2.9 ka cal BP, evidenced by a higher carbonate content and a lower proportion of detrital material, reaching a maximum between 2.9 and 1.6 ka cal BP. Data also show that at 1.6 ka cal BP, the lake level was likely lowered due to higher nutrient content, including sulfur (S) and phosphorus (P), as well as organic compound levels, prior to human intervention and hydromelioration for agriculture. High concentrations of the nutrient elements, lead (Pb), copper (Cu), and zinc (Zn) in the upper 40 cm of this sequence are indicative of the influence of agricultural activities across the karst polje as well as anthropogenic atmospheric pollution. Geochemical and sedimentological proxies illustrate centennial-scale variability in carbonate deposition and erosional runoff processes comparable with the natural climatic and anthropogenic factors that are known to influence the evolution of Holocene karst poljes across the central Mediterranean.
Eastern Herzegovina is highly karstified area, with porosity of karstified rock mass between 0.8 and 2%. It is an area with high precipitation (average annual values in wet year are around 2450 mm), ...but its distribution is uneven, with 70% of annual precipitation occurring during the wet season (late fall to early spring). The outflow coefficients are very high, between 0.7 and 0.8. The ratio between flow in the low water period (
Q
95%
) and in the period of high water flow (
Q
1%
) is 1:4000(5000). Due to such hydrological conditions, with limited dewatering capacity of karst channels and ponors, floods of karst poljes occur frequently. This article presents, in very general terms, the properties of the natural water regime of the Gatačko Polje, highest polje in Eastern Herzegovina, including some hydrological and hydrogeological specificity. Special attention is referred to floods and possible ways to mitigate such events, as there are coal mine and coal power plant “Gacko” situated in the polje. Several possible measures are presented in the paper, such as passive protection measures, active flood protection by proper reservoirs management, as well as spatial planning measures. Also, the possibility of transferring part of the water from the Gatačko Polje watershed to the multipurpose hydrosystem Trebišnjica for usage in hydropower production, irrigation, water supply and other secondary benefits is considered.
Imotsko-Bekijsko Polje has an area of 9 500 ha and is one of the biggest karst fields (polje) in the Dinaric Mountains, extending over the territory of two states: Croatia and Bosnia and Herzegovina. ...Many hydraulic structures (reservoirs, retentions, tunnels, etc.) have been built since the middle of 20ᵗʰ century in order to protect polje against floods. Therefore, the security from flooding has increased substantially. However, there is still periodical flooding in the southeastern lowest part of the polje. The largest flood in recent times was in January 2010, when 2676 ha (28% of the area) was flooded. The polje is a typical karst with very complex hydrological and hydrogeological relations. In this paper two hydrological stations, Nuga at the lowest part and Kamenmost in the central part of the polje with respectable hydrological series, are statistically analysed. In particular, the efficiency of existing hydraulic structures for flood mitigation is estimated. The research points out that floods in Imotsko-Bekijsko Polje are largely influenced by water management objects (reservoir, retention, tunnel) and only indirectly by precipitation.
This paper analyzes the process of socio-geographic transformation of rural settlements in Mostarsko Blato, karst polje in the Neretva River drainage area. Many changes in spatial organization and ...landscape have been determined by deagrarization and deruralization, which had been, on the other hand, influenced by various geographic factors: neighboring towns, inadequate infrastructure, profound changes in job offers related to the problems of economic development at the end of socialist period and in transitional period, and particularly by Serbian aggression on Croatia and Bosnia and Herzegovina.Despite numerous problems, socio-economic development of Mostarsko Blato is possible due to natural and human resources. Its development should be based on organic farming, and on development of different types of tourism (ecologic, rural, camping, fishing and summer tourism).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
As the region of Eastern Herzegovina and the Boka Kotorska (Kotor Bay) area is one of the most highly karstified areas in the world, its hydrogeological properties, typical for karst, are extremely ...exposed. The main erosion base-levels for surface and underground waters of that region are: the Neretva River valley in the west, the Adriatic Sea and Dubrovnik littoral in the south and Boka Kotorska in the east. At the same time it belongs to one of the most investigated karst regions in the world known as the Dinaric Karst. The basic theories related to the nature of karst are based on the multidisciplinary and long-lasting investigation of this particular region. World famous karstologists such as Cvijić, Grund, Katzer and many others created crucial theories of karstology based on investigations and analysis of the Dinaric Karst. Many large and successfully constructed structures (dams, reservoirs and tunnels) of the region also became the basis for the development of engineering karstology. Massive karst investigation works were also performed during the twentieth century. The accumulated data and knowledge have been presented at many scientific conferences and has also appeared in many publications. The text below presents in brief, the general natural properties of the region and represents only a small part of the available data.
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