bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geographical information system techniques in land use assessment within landscape types in Eastern Poland
Authors: Ołdak A. 
Published: February 2007

AbstractAgricultural land use in much of Poland is based on traditional methods in which innovation plays a small part. The recent economic changes which have swept through Poland will result in many new opportunities for farmers as new crops, new marketing techniques and new markets become available. Intensification of agricultural land (and forestry) land use can be achieved to meet the growing demand for indigenously produced foodstuffs and timber and, at the same time, allow an increase in income generation (in raw and value‐added products) especially from the export market. Intensification of output must be based on sustainable and environmentally friendly methods with minimal reliance on imported fertilizers and pesticides. This paper explains how a database consisting of soil, topography, land use and vegetation data has been used to generate a series of potential land use maps for a small area (25 km2) of Eastern Poland in which different levels of management inputs have been applied. A prime objective of this work has been the development of a sustainable agroforestry system based on the assessment of the landscape's natural conditions. The system, when fully developed, should allow effective economic management of the area with depletion of the environmental resource base reduced to a minimum. The results of this study rely on the use of computer‐generated maps prepared with a widely available geographical information system.
Implications of climate change scenarios for soil erosion potential in the USA
Authors: Phillips D. L. , White D. , Johnson B. 
Published: February 2007

AbstractAtmospheric general circulation models (GCMs) project that increasing atmospheric concentrations of CO2 and other greenhouse gases May, result in global changes in temperature and precipitation over the next 40‐100 years. Equilibrium climate scenarios from four GCMs run under doubled CO2 conditions were examined for their effect on the climatic potential for sheet and rill erosion in the conterminous USA. Changes in the mean annual rainfall factor (R) in the Universal Soil Loss Equation (USLE) were calculated for each cropland, pastureland and rangeland sample point in the 1987 National Resources Inventory. Projected annual precipitation changes were assumed to be from differences in either storm frequency or storm intensity. With all other USLE factors held constant these changes in R translated to changes in the sheet and rill erosion national average of +2 to +16 per cent in croplands, ‐2 to +10 per cent in pasturelands and ‐5 to +22 per cent in rangelands under the eight scenarios. Land with erosion rates above the soil loss tolerance (T) level and land classified as highly erodible (eredibility index >8) also increased slightly. the results varied from model to model, region to region and depended on the assumption of frequency versus intensity changes. These results show the range of sensitivity of soil erosion potential by water under projected climate change scenarios. However, actual changes in soil erosion could be mitigated by alterations in cropping patterns and other management practices, or possibly by increased crop growth and residue production under higher atmospheric CO2 concentrations.
Spreading deserts or spatially confined environmental impacts? land degradation and cattle ranching in the kalahari desert of botswana
Authors: Perkins J. S. , Thomas D. S. G. 
Published: February 2007

AbstractThe Kalahari Desert of Botswana is being increasingly used for livestock production, particularly through the establishment of ranches dependent on borehole water supplies. Reports of the environmental impacts of land use practices in such drylands are conflicting, with livestock systems supplied by boreholes and wells being regarded in some studies as centres for the spread of desertification and in others as having environmental impacts that are overridden by the effects of natural climatic variability. the results of an environmental study focused on a block of borehole ranches established in the eastern Kalahari as part of Botswana's Tribal Grazing Lands Policy dating from the 1970s are reported. the investigations concentrated on ecological, soil chemistry and soil erosion impacts on the study ranches. Although important changes in the ecology and soil nutrient status of the ranches are identified, their contribution to environmental degradation must be viewed in terms of stocking levels, The radial nature of range usage, giving rise to marked spatial variations in impact, and natural climatic variability. Changes are not solely detrimental, but long‐term monitoring, especially in relation to climatic fluctuations, needs to be undertaken to fully establish the dynamic interactions of variables.
Soil erosion and redistribution on cultivated and uncultivated land near las bardenas in the central Ebro river Basin, Spain
Authors: Quine T. A. , Navas A. , Walling D. E. , Machin J. 
Published: February 2007

AbstractThe semiarid regions of Spain, including the central part of the Ebro River basin, are under threat due to desertification. Severe erosion, as a result of poor land management, has led to degradation of the soil resource, and there is a clear need for quantitative erosion rate data to evaluate the problem. This study aimed to examine the potential for using caesium‐137 to identify the patterns and rates of soil erosion and redistribution within this semiarid environment. Samples for the determination of caesium‐137 were collected from uncultivated slopes and cultivated valley floor sites near the head and outlet of a small representative basin in the Las Bardenas area. The measured patterns of caesium‐137 mobilization, redistribution and export provide a semiquantitative indication of the variation in erosion within the study site. Calibration of the caesium‐137 measurements, taking account of the differing behaviour of radiocaesium on cultivated and uncultivated land, allows estimation of the actual rates of erosion and deposition involved. The results show (1) the erosion rates on the cultivated land (1.6–2.5 kg m−2 yr−1) are typically more than five times those seen on the uncultivated land (0.2–0.4 kg m−2 yr−1), and (2) erosion on the uncultivated land is significantly less severe at the head of the basin than at the outlet. Study of the vegetation cover suggests that lower growing shrubs and grasses may be more effective in reducing erosion in this environment than trees.
Agroforestry techniques for the rehabilitation of degraded salt‐affected lands in India
Authors: Singh G. , Singh N. T. , Abrol I. P. 
Published: February 2007

AbstractThe development of appropriate technologies for the judicious use of India's 8.11 million ha of salt‐affected lands would give increased food, fodder and fuelwood production. A sizeable portion of the salt‐affected lands of the Indo‐Gangetic plain have been reclaimed through chemical amendments and are being commercially used for arable farming. However, large areas of salt‐affected common lands, village and government lands and waste lands near cities, along railway tracks and roads do not have any productive use. Owing to their sparse vegetative cover such lands are vulnerable to further degradation and can be a source of runoff causing floods, especially where cows congregate. Research at the Central Soil Salinity Research Institute, Karnal has generated agroforestry techniques which could enable the economic exploitation of such marginal lands. This paper deals with various aspects of these techniques, which have been applied to over 50 000 ha by 1994.Based on eight to ten years of growth and biomass figures, the most salt‐tolerant woody species identified were: Prosopis juliflora, Acacia nilotica, Casuarina equisetifolia, Tamarix articulata, Leptochloa fusca (a palatable forage grass which was found to be a promising primary colonizer of salt lands). Agronomic practices for the successful establishment of trees such as planting methods, amendment use, irrigation, spacing and lopping schedules are discussed. A Prosopis juliflora‐leptochloa fusca silvipastoral model was found to be excellent for fuelwood and forage production and for the amelioration of high pH soils. This system, when followed for little more than four years, reclaims alkali soils to such an extent that normal agriculture crops such as Trifolium alexandrinum and T. resupinatum can be grown successfully. A ridge‐trench system of tree planting was found to be helpful in alkali soils, the in situ rainwater conservation it led to assisting biomass production. Eucalyptus tereticornis, Populus deltoides and Tectona grandis based agroforestry were promising for reclaimed salt‐affected lands. The short‐ and long‐term effects of various tree plantations on the physicochemical properties of the soil and on soil‐water relations are also discussed. Agroforestry options for the development of salt‐affected lands found in various agroclimatic zones of India are explored.
The rehabilitation of degraded soils in eastern bolivia by subsoiling and the incorporation of cover crops
Authors: Barber R. G. , Navarro F. 
Published: February 2007

AbstractA high proportion of the soils in the central zone of Santa Cruz, eastern Bolivia, are chemically and physically degraded, with low organic matter and N contents, compacted subsoil layers and a propensity to crusting, hardsetting and wind erosion. The aim of the experiment discussed in this paper was to identify suitable cover crops to be used in combination with subsoiling for the rehabilitation of degraded soils and the improvement of crop yields in eastern Bolivia. Fertilizers were not used because of their high cost. An experiment with a split complete block design, with subsoiling and no‐subsoiling as the main treatments, 14 cover crops and a continuously cultivated soybean/wheat control as the subtreatments, and four replications, was established on a degraded site comprising a mosaic of two compacted siliceous isohyperthermic soils (a coarse loamy Typic Ustropept and a fine loamy Typic Haplustalf). After a two‐year fallow period, the cover crops were incorporated and test crops were sown for five seasons to evaluate the effects of the treatments on subsequent crop yields. Soil samples were taken to measure changes in chemical fertility. The only significant cover crop effect on soil nutrients was an increase in exchangeable K from 0.47 to 0.56 cmolc kg−1 by Lablab; subsoiling had no effect on chemical fertility. For all treatments there was an average 24 per cent increase in soil organic matter from 13.1 g kg−1 at 3 months after cover crop incorporation to 16.3 g kg−1 at 19 months after incorporation. No significant differences in total N were found during this period. Test crop yields were not influenced by subsoiling, but were significantly increased by some of the cover crops as compared to the soybean/wheat control during the first three seasons only. Evidence from foliar analysis suggests that the effects of the cover crops on soybean yields were not nutritional and so presumably were physical in nature, whereas the benefits on wheat yields were possibly related to increased N availability. Panicum maximum var. Centenario and P. maximum var. Tobiatá gave the highest total yield increases over the first three cropping seasons (101 and 85 per cent, respectively), but these yield increases would not compensate the farmer for the loss of four crop harvests whilst the land was in fallow. These results highlight the difficulties of rehabilitating soil fertility and increasing crop yields through the use of subsoiling and cover crop fallows on compacted, low organic matter soils in eastern Bolivia.
Loess erosion in relation to land‐use changes in the ganspoel catchment, central Belgium
Authors: Fu B. , Gulinck H. , Masum M. Z. 
Published: February 2007

AbstractThis paper examines the changes of land uses and landscape patterns in the Ganspoel Catchment, central Belgium, using aerial photography interpretation (photographs taken in 1947, 1969 and 1986). The comparison of land cover areal changes and a transition matrix were used to assess land‐use changes in time and space. The size, fractal dimension and elongation index of patches were quantified for landscape pattern analysis. Grassland increased and farmland decreased in the study area from the 1940s to the 1980s. Forest increased from 1947 to 1969 and decreased from 1969 to 1986. About 49 per cent of the study area experienced changes of land use between 1947 and 1969, and about 36 per cent between 1969 and 1986. The landscape of the study area is more fragmented than it was in the 1940s. Patches have generally increased in number and decreased in size, although the landscape was most fragmented in 1969; fractal dimension of patches are lower, indicating less complex shapes. From 1969 to 1986, 59 per cent of the area of change was on 0–3 degree slopes, and from 1969 to 1986 6.7 per cent was on >8 degree slopes. Changing land uses and landscape patterns may have important ecological implications.
Geomorphic estimates of the stability of a uranium mill tailings containment cover: Nabarlek, Northern Territory, Australia
Authors: Riley S. J. 
Published: February 2007

AbstractThe geomorphic stability of the cover (cap) over the pit of Nabarlek Uranium Mine in Arnhem Land, Northern Australia, is important because radon gas and other long‐lived radio‐nuclides arising from mill tailings must be contained for long periods. The primary agents of denudation in the region's seasonally wet tropical environment of low relief are rainwash, overland flow, rilling and gullying. Other agents of erosion are of less concern, although biogenic agents of erosion (e.g. termites and windthrow) may enhance fluvial activity.A combination of modelling, using the Universal Soil Loss Equation, and analogue estimates of denudation and thresholds of rilling and gullying from areas with similar geology, topography and climate are used to estimate the stability of the Nabarlek cover. Denudation rates are conservatively estimated at less than 100mm ky−1. It is suggested that with some minor design modifications the cover will retain its integrity for several thousand years.
Condition of rehabilitated coal mines in the Hunter Valley, Australia
Authors: Dragovich D. , Patterson J. 
Published: February 2007

AbstractLegislation requiring the rehabilitation of new opencast coal mines came into effect in New South Wales, Australia, in 1973. Mining companies now stockpile original topsoil which is later spread with fertilizer over re‐shaped overburden and waste carbonaceous material. Problems in successfully revegetating new surfaces are exacerbated by the thinness and infertility of natural soils, which are deficient in phosphorus and moderately acid. Revegetation has not been successful on untreated mine waste and overburden. This study provides a general overview of some aspects of post‐rehabilitation soil chemistry and vegetation on these soils. A limited number of samples, collected from three mine sites having different rainfall and varying ages of rehabilitated areas, were tested for pH, EC, organic carbon, total phosphorus and available aluminium. Rehabilitated areas were all characterised by very low levels of total phosphorus, neutral pH, and variable and relatively low organic carbon, and some showed aluminium toxicity. Heavy application of gypsum at one of the steeper sites was associated with acid pH, high EC values, low total P, Al toxicity, some soil erosion and little plant cover. Except for this site, the variable vegetation cover at the sites studied seemed adequate for long‐term re‐establishment, despite serious weed invasion at some non‐studied sites, soil loss on newly re‐formed surfaces, and generally poor natural and rehabilitated soils.
An approach to land‐use planning in a hilly watershed using geographical information system
Authors: Adinarayana J. , Krishna N. Rama 
Published: February 2007

AbstractThe eco‐socio‐economic balance of a region can be preserved by proper land‐use planning, particularly in hilly watersheds where erosion caused by rainfall is an ever‐present threat. This paper describes a methodology developed to compile a treatment‐oriented land‐use planning scheme for a hilly watershed using a geographical information system (GIS). A remote sensing based physiographic soils map and a digital elevation model (DEM) are the sources of soil depth and slope steepness classes, respectively, and are the information databases for GIS analysis. The GIS was used to integrate these databases and provide tools for manipulation of the data. A set of knowledge‐based rules was formed from the classification scheme formulated by Sheng and Stennett (1975) for hilly watersheds, modified to allow for the local land‐use patterns. These rules were used to manipulate the databases and allow the establishment of a sustained land‐use system in the watershed with proper soil and water conservation measures. This biological engineering scheme would be a safeguard against soil erosion and other environmental threats. A priority sub‐watersheds delineation survey conducted in the watershed indicates significant variation in the silt yield index values, which calls for conservation planning in earnest in cases of high and very high priority sub‐watersheds.
The influence of parent material on soil fertility degradation in the coastal plain of Tanzania
Authors: Hartemink A. E. , Bridges E. M. 
Published: February 2007

AbstractDifferences in the vulnerability of soils to fertility degradation are compared for two major soil groups located in the coastal plain of Tanzania and cropped with sisal (Agave sisalana). Ferralsols derived from intermediate gneiss of Precambrian age and Cambisols developed in Jurassic and Neogene limestones partly covered with Quaternary deposits were selected for comparison. A clear influence of parent material was apparent when soils were continuously cropped with sisal and no fertilizers were applied. Serious soil fertility decline occurs in Ferralsols, but Cambisols are resilient to chemical degradation and the fertility decline in these soils was very limited. The differences in degradation rates are explained by the lower initial fertility and low nutrient reserve of Ferralsols, while the Cambisols had higher initial fertility levels and nutrients removed by the sisal crop are replenished by the weathering of the underlying parent material. Sustainable soil fertility management of Cambisols includes only NPK fertilization, but heavy dressings of lime, organic manures and/or chemical fertilizers are required to improve the fertility status of the Ferralsols and to produce crops in a sustainable manner.
Interaction of (Hydroxypropylmethyl)cellulose with Anionic Surfactants
Authors: de Martins Ricardo M. , Becker Cristiane M. , Samios Dimitrios , Bica Clara I. D. 
Published: February 2007

AbstractThe aggregation process between (hydroxypropylmethyl)cellulose (HPMC 0.20% m/m) and three anionic surfactants namely sodium cholate (CS), sodium deoxycholate (DC) and sodium dodecylsulphate (SDS), in aqueous dilute solutions, was investigated by fluorescence, electrical conductivity, dynamic light scattering (DLS) and small angle X‐ray scattering (SAXS) techniques. Through fluorescence, the critical micelle concentration (CMC) and critical aggregation concentration (CAC) of the systems were obtained in good agreement with those obtained from conductivity. Also by means of conductivity measurements, once the experiments were undertaken at four temperatures, the thermodynamic parameters of the micellization process were calculated. From DLS, the relaxation time distribution functions were analyzed by REPES Routine, revealing that the surfactants bind to the polymer before CAC as well as the formation of free micelles at high surfactant content. The SAXS technique confirmed the existence of such free micelles.
Characterization and Properties of Some Polysaccharides Used as Biomaterials
Authors: Rinaudo Marguerite 
Published: February 2007

AbstractThis paper described three natural or pseudo natural polysaccharides often used as biomaterials. Their development opens a large field of applications taking advantage of their specific properties (renewable, biodegradable, biologically active). They are good thickeners and/or gelling polymers in determined thermodynamic conditions. As many polysaccharides they are rich in OH groups allowing stabilization of H bonds network and giving good film forming properties. The polysaccharides described in this paper are water soluble and have a net charge which allows to form electrostatic complexes which are much developed for biomedical or pharmaceutical applications.
Generalized financial ratios
Authors: Nadarajah Saralees , Kotz Samuel 
Published: January 2007

AbstractRatios of random variables are prevalent in finance. Examples include: current ratio, sales margin, changes in capital employed, interest cover, liabilities ratio and financial leverage ratio. In this note, we derive the exact distribution of the ratio X/(X + Y) when X and Y are independent generalized Pareto random variables, Pareto distribution being the first and the most popular distribution used in finance. Copyright © 2007 John Wiley & Sons, Ltd.
Numerical modelling of fault generation in the extensional tectonic regime of the Gulf of Corinth
Authors: Stavropoulou M. 
Published: January 2007

AbstractThe aim of this work is to investigate the extent to which a relatively simple mechanical model (both at constitutive and boundary conditions levels) can reproduce the main features of a typical extensional part of European continent such as the Gulf of Corinth (or Korinthos). A second step is performed here for the investigation of this problem, following a first one consisted of appropriate downscaled sandbox model tests and continuum mechanics numerical modelling. A more suitable numerical method, namely the distinct element method implemented in Universal Distinct Element Code (UDEC), is employed in this second attempt to study faulting and the associated deformations in extensional tectonic regimes. The hypothesis that an inherited listric normal fault with high dip angle ( ∼ 60°) at the surface transforming into a gently dipping normal fault at larger depths ( ∼ 10° ) subjected to extensional strain rate may reproduce the major structural features of the Gulf is herein investigated. This study shows that sliding on the listric fault produces a second high‐angle antithetic normal fault that initiates at the point of change of curvature of the initial listric fault and propagates upwards until it reaches the surface. A second model that takes into account both listric and antithetic faults as boundary conditions, produces under extension, a third normal fault dipping as the first master listric fault and initiating close to the root of the antithetic fault, ultimately propagating upwards up to the free surface. Finally, a third model that starts with the three faults, results in a system of conjugate normal faults lying between the master listric fault and the first antithetic fault. This structure of normal faults resembles closely both the structure of normal faults observed at the Gulf of Corinth and the history of their formation, indicating that the Gulf is a half‐graben. Copyright © 2007 John Wiley & Sons, Ltd.