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Evaluation of catchment contributing areas and storm runoff in flat terrain subject to urbanisation
O. V. Barron, D. Pollock,W. Dawes
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2011,
Abstract: Contributing Catchment Area Analysis (CCAA) is a spatial analysis technique developed and used for estimation of the hydrological connectivity of relatively flat catchments. It allows accounting for the effect of relief depressions on the catchment rainfall-runoff relationship which is not commonly considered in hydrological modelling. Analysis of distributed runoff was based on USDA runoff curves numbers (USDA, 1986), which utilised the spatial information on land cover and soil types, while CCAA was further developed to define catchment area contributing to river discharge under individual rainfall events. The method was applied to the Southern River catchment, Western Australia, showing that contributing catchment area varied from less than 20% to more than 60% of total catchment area under different rainfall and soil moisture conditions. Such variability was attributed to a compensating effect of relief depressions. CCAA was further applied to analyse the impact of urbanisation on the catchment rainfall-runoff relationship. It was demonstrated that in addition to an increase in runoff coefficient, urbanisation leads to expansion in the catchment area contributing to the river flow. This effect was more evident for the most frequent rainfall events, when an increase in contributing area was responsible for a 30–100% rise in predicted catchment runoff.
Evaluation of catchment connectivity and storm runoff in flat terrain subject to urbanisation  [PDF]
O. V. Barron,D. W. Pollock,W. R. Dawes
Hydrology and Earth System Sciences Discussions , 2009,
Abstract: Contributing Catchment Area Analysis (CCAA) is a spatial analysis technique that allows estimation of the hydrological connectivity of relatively flat catchments and the effect of relief depressions on the catchment rainfall-runoff relationship for individual rainfall events. CCAA of the Southern River catchment, Western Australia, showed that catchment contributing area varied from less than 20% to more than 60% of total catchment area for various rainfall events. Such variability was attributed to a compensating effect of relief depressions. CCAA was further applied to analyse the impact of urbanisation on the catchment rainfall-runoff relationship. It was demonstrated that the change in land use resulted in much greater catchment volumetric runoff than expected simply as a result of the increase in proportion of impervious urban surfaces. As urbanisation leads to an increase in catchment hydrological connectivity, the catchment contributing area to the river flow also becomes greater. This effect was more evident for the most frequent rainfall events, when an increase in contributing area was responsible for a 30–100% increase in total volumetric runoff. The impact of urbanisation was greatest in sandy catchments, which were largely disconnected in the pre-development conditions.
Geomorphological Effects of River Valleys Anthropogenic Transformations in the Perznica Catchment During the Last 200 Years (Drawsko Lakeland, Pars ta River Basin)
Józef Szpikowski
Quaestiones Geographicae , 2011, DOI: 10.2478/v10117-011-0010-4
Abstract: The studies on geomorphological aspects of environmental changes in the river valleys were part of the work carried out under the diagnosis of anthropogenic transformation of the relief of the Perznica basin (West Pomerania, Drawsko Lakeland). Human interference in the river valleys and anthropogenic changes in the natural hydrological systems in the Perznica catchment influenced the transformation of the relief and the intensity of morphogenetic processes. Numerous anthropogenic landforms were formed, including embankments, dams, dykes along the canals, ditches and canals, reservoirs basins, and peat excavations. The drainage resulted in an intensification of the river erosion, straightening, shortening and increase of the river gradient, as well as the increase of quantity of the suspended matter leaving the catchments. An increase of anthropogenic denudation on agricultural lands, due to the entering of the crops grown on drained depressions and valleys, led to the masking of the original relief with deluvial sediments and the formation and expansion of agricultural terraces on the edge of the fields.
Problems of Suspended Sediment Loads in Asa River Catchment, Ilorin, Nigeria
H.I. Jimoh,Ajao Lukman Ishola
Pakistan Journal of Social Sciences , 2012,
Abstract: This research is an assessment of the rate of the presence of sediment loads in Asa river catchment. This is with a view to explaining the inherent problems in such sediment compositions in the water body. To achieve this, data sets were primarily sourced, analysed and the following constitutes as the Observations: The properties of basin that facilitates sediment transportation from source to the destination include depth of water, bank full, average velocity, discharge, river competence and capability. Similarly, these parameters along with circularity ratio, bifurcation ratio, relief, basin length, total mean length, basin size, drainage density among others explains the ability of streams to transport sediment materials in suspension. Thus, problems often created by sediment deposits range from river siltation and eventually drying up. Averting this situation will involve water dredging, straightening of water channels to general environmental education with special reference to watershed management.
The influence of the geomorphological factors on the relief modelling within Eselnita hydrographic basin (Danube catchment/Romania)
DANIELA VLAD,RALUCA-GEORGIANA ALEXANDRU
Cinq Continents , 2012,
Abstract: Developed on the south-eastern side of Alm jului Mountains, E elni adrainage basin neighbours upon the following basins: upon S – SV with Mala, upon SV - V with Mraconia, upon V – NV with Berzasca, upon NV - NNE with Nera and on the NNE – SE direction with Cerna. The basin has a surface of 77 km2 and present a 5th degree hydrographic network according to Horton-Strahler ranking system, tributary to Danube by means of E elni a main collector. Developed in a mountain landscape, the basin presents different levels held between minimum altitude of 64 m at the confluence with the Danube and maximum altitude of 1107 m, thus presenting a difference of 1043 m. Geological formationswithin the basin belong predominant to the Danubian Domain, so in central and upper courses, these are represented by a crystalline foundation and by magmatic rocks of intrusive nature covered by very small areas of sediment located in the northwest (belong to the LowerJurassic) and in the south-eastern (belongs to the Upper Cretaceous) of the basin. But in the lower course, there are both crystalline and the sedimentary formations, last being integrated to Or ova depression and whose presence is related to the evolution of the Danube. Morphometric indices of E elni a basin allows the distinction of a higher sector, mountainous terrain with high energy under a relatively increased fragmentation and depression sector with low relief energy and also with an intense fragmentation of the existing sedimentaryrocks wich favors erosion manifestation in the context of deforestation action.
The Laccaria species of Transylvania
Denes PAZMANY
Notulae Botanicae Horti Agrobotanici Cluj-Napoca , 1990,
Abstract: A new denomination is given for the section concerning the species evidencing the violet-amethystine colour, sect. Violaceae sect. nov. Four Laccaria species found in Transylvania are presented: L. amethystea, L. farinacea, L. bicolor and L. transsilvanica sp. nov., as well as two varieties: L. bicolor var. pseudobicolor (BON) comb. nov. and var. subalpina (SING.) comb. nov. Taxonomic problems, morfology and microscopical structure are discussed.
Estimating soil plasticity properties from pedological data  [cached]
G C Fanourakis
Journal of the South African Institution of Civil Engineering , 2012,
Abstract: A number of pedological soil classification systems have been developed worldwide. These include an internationally accepted system and various national systems, some of which have been incorporated into databases which include maps. Such information is used primarily for agricultural purposes. Various physical and chemical soil properties are used for classifying soils according to these pedological systems. This paper proposes an approach, based on a research project, which may be used to statistically significantly determine the plasticity characteristics of soils from the physical and chemical properties that are used to pedologically classify soils by systems, such as the South African Binomial System. These plasticity characteristics may be used to establish the engineering soil classification groups which may, in turn, be used as a means of rapidly determining the general suitability of areas for proposed developments, particularly during the preliminary stages of transportation route locations and township developments, with a resultant saving of time and money.
A Page from the History of the Principality of Transylvania  [PDF]
Mariana Borcoman
Bulletin of the Transilvania University of Bra?ov. Series VII : Social Sciences and Law , 2009,
Abstract: The history of the Principality of Transylvania was marked by great political unrest. The small region was coveted on one hand by the Turks and on the other hand by the Hapsburgs. The internal policy led by the princes of Ardeal contributed for Transylvania to keep pace with the evolved Occident. Through the participation in the War of 30 years, the small principality asserted itself as a power that should be taken into consideration at the demarcation between Central and South-Eastern Europe.
Observed precipitation trends in the Yangtze river catchment from 1951 to 2002

SU Buda,JIANG Tong,SHI Yafeng,Stefan BECKER,Marco GEMMER,

地理学报 , 2004,
Abstract: The monthly, seasonal, and annual precipitation trends in the Yangtze river catchment have been detected through analysis of 51 meteorological stations' data between 1950-2002 provided by National Meteorological Administration. Results reveal that: 1) Summer precipitation in the Yangtze river catchment shows significant increasing tendency. The Poyanghu lake basin, Dongtinghu lake basin and Taihu lake basin in the middle and lower reaches are the places showing significant positive trends. Summer precipitation in the middle and lower reaches experienced an abrupt change in the year 1992; 2) The monthly precipitation in months just adjoining to summer shows decreasing tendency in the Yangtze river catchment. The upper and middle reaches in Jialingjiang river basin and Hanshui river basin are the places showing significant negative trends; 3) Extreme precipitation events show an increasing tendency in most places, especially in the middle and lower reaches of the Yangtze river catchment.
Hyporheic fauna from interstitial of the Some River basin (Transylvania, northwestern Romania)
Ioana Meleg,Mirela C?mpean,Claudia Pavelescu
Travaux de l'Institut de Speologie Emile Racovitza , 2009,
Abstract: Biodiversity in hyporheic habitats (interstitial water habitats in river bank sediments) has been studied on Some ul Cald (Warm Some ) and Some ul Rece (Cold Some ) River (north-western Romania, Transylvania), from March to October 2004. pH and electrical conductivity were measured monthly at each site, and animals were collected with the Karaman-Chappuis method and by filtering water through a hand-net. The relative abundance of the best-represented hyporheic invertebrates (oligochaetes and insect larvae) was higher in Some ul Cald interstitial habitats than in Some ul Rece. The focus was directed to the role of water mites (Acari, Hydrachnidia), cyclopoid copepods (Crustacea, Copepoda, Cyclopoida) and oligochaetes (Annelida, Oligochaeta) in hyporheic communities. Nine water mites and five cyclopoid species were identified in five sampling sites of the two rivers. Their higher diversity was recorded in two stations on the Some ul Cald River. The cyclopoid copepod Diacyclops disjunctus (Thallwitz, 1927) is a new record for Romania. As for oligochaetes, 17 species were identified and their higher diversity was recorded on Some ul Rece River. Canonical Correspondence Analysis (CCA) shows that presence of some water mites and cyclopoid species can be associated with measured physicochemical parameters (pH, electrical conductivity). Principal Component Analysis (PCA) shows similarities between stations and the dominant taxa in some samples.
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