Deriving hillslope sediment budgets in wildfire-affected forests using fallout radionuclide tracers

Information on post-fire sediment and nutrient redistribution is required to underpin post-fire catchment management decisions. Fallout radionuclide budgets (²¹⁰Pb_xs, ¹³⁷Cs and ⁷Be) were derived to quantify soil redistribution and sediment yield in forested terrain following a moderately severe wildfire in a small (89 ha) water supply catchment in SE Australia. Application of these techniques in burnt terrain requires careful consideration of the partitioning of radionuclides between organic and mineral soil components. Beryllium-7 and ²¹⁰Pb_xs were shown to be closely associated with ash, litter and soil organic matter whereas ¹³⁷Cs was more closely associated with subsurface coarse mineral soil. Comparison of the three tracer budgets indicated that the dominant sediment source areas were ridgetops and steep valley sideslopes, from which burnt surface material was conveyed to the stream network via pre-existing gullies. Erosion was predominantly driven by sheetwash, enhanced by soil water repellency, and modified by bioturbation which both supplies subsurface sediment and provides sinks for erosive overland flow. Footslope and riparian zones were not important sediment source areas. The estimated event-based (wildfire and subsequent rainfall) sediment yield is 58 ± 25 t km^− 2, based on fallout ⁷Be measurements. The upper estimate of total particulate phosphorus yield (0.70 kg ha^− 1) is more than 10 times that at equivalent unburnt sites. This illustrates that, soon after fire, burnt eucalypt forest can produce nutrient loads similar to those of agricultural catchments. The tracer budgets indicate that wildfire is an important control on sediment and phosphorus inputs to the stream network over the decadal timeframe and the pulsed nature of this release is an important concern for water quality management.     

The mesometeorological temperature field in a mediterrannean-alpine region

Summary The structure of the surface-air temperature field in meso-alpha and meso-beta scale is studied for the purpose of regionalisation and for the optimum interpolation meso-analysis in Slovenia. The possibilities of subregionalisation, of the split into the horizontal and the vertical part of autocorrelation function and of separation according to the general weather type have been tested. It was found that the influence of weather type could not be introduced without the simultaneous introduction of first-guess fields for each weather type. The relative importance of first-guess field versus the importance of the type of autocorrelation function is estimated by several tests of the optimum interpolation meso analysis.With 6 Figures     

Knowledge-Driven Prospectivity Mapping for Granite-Related Polymetallic Sn–F–(REE) mineralization,Bushveld Igneous Complex,South Africa

This paper presents mineral prospectivity mapping to identify potential new exploration ground for polymetallic Sn–F–REE mineralization associated with the Bushveld granites of the Bushveld Igneous Complex, South Africa. The Lebowa Granite Suite, commonly known as the Bushveld granites, is host to a continuum of polymetallic mineralization with a wide range of metal assemblages (Sn–Mo–W–Cu–Pb–Zn–As–Au–Ag–Fe–F–U–REE), ranging from a high-temperature to a low-temperature magmatic hydrothermal mineralizing environment. The prospectivity map was generated by fuzzy logic modeling and a selection of targeting criteria (or spatial proxies) based on a conceptual mineral system highlighting critical processes responsible for the formation of the polymetallic mineralization. The spatial proxies include proximity to differentiated granites (as heat and metal-rich fluid sources), Rb geochemical map (fluid-focusing mechanism such as fractionation process), principal component maps (PC 4 Y–Th and PC 14 Sn–W, fluid pathways for both high- and low-temperature mineralization) and proximity to roof rocks (traps for fluids). Logarithmic functions were used to rescale rasterized evidential maps into continuous fuzzy membership scores in a range of [0, 1]. The evidential maps were combined in two-staged integration matrix using fuzzy AND, OR and gamma operators to produce the granite-related polymetallic Sn–F–(REE) prospectivity map. The conceptual mineral system model and corresponding prospectivity model developed in this study yielded an encouraging result by delineating the known mineral deposits and occurrences of Sn–F–(REE) mineralization that were not used to assign weights to the evidential maps. The prospectivity model predicted, on average, 77% of the known mineral occurrences in the BIC (i.e., 56 of 73 Sn occurrences, 12 of 15 F occurrences and 6 of 8 REE occurrences). Based on this validation, 13 new targets were outlined in this study.     

The ethnocultural component of tourism development in the Altai Republic

A characterization is provided for the recreation resources of the Altai Republic. The diversity of the national-ethnical composition of the population of the Altai Republic is determined as well as analyzing the spatial distribution of the ethnoses on its territory. The coefficients of ethnical diversity are calculated for all administrative districts. The territories with a different level of ethnical diversity and a different combination of ethnical groups are determined. The study revealed a connection of ethnical diversity and natural conditions of the territory and the concentration of separate ethnoses in definite landscapes. A characterization is provided for the ethnocultural tourism and recreation resources of the Altai Republic within the context of administrative districts. Information is provided concerning the territorial distribution of separate ethnical groups, traditional kinds of their nature management, religion, main national dishes, elements of national costume, national festivities and rites, etc. An analysis of the spatial distribution of the ethnocultural recreation resources identified promising clusters (nodes) or destinations for the arrangement of special ethnocultural tourist routes. Schematic maps are provided, which display the ethnical diversity in the districts of the region, and promising districts for the organization of ethnocultural tourist routes.     

Accommodation of ecological and economic interests in placer gold mining

An attempt is made to find the answer to the question as to why the measures of the environmental institutions of Russia are ineffective for the avoidance and prevention of the degradation of aquatic ecosystems in placer gold mining. It is established that the size of payments to be made by companies engaged in placer gold mining are such that they almost cannot stimulate any nature conservation initiatives. Moreover, they even cannot be the argument for observance of environmental legislation. It is shown that the high transaction costs borne by the State, with minor expenditures of nature resource users connected with the protection of environmental natural systems fail to achieve the objectives imposed upon the supervising institutions. It is established that local authorities are directly interested in increasing placer gold mining as well as in gaining the loyalty of artels implying registration of the enterprise in this region, because these tax proceeds are exceptionally important for municipal formations facing a chronic financial deficit, a budgetary uncertainty and a dependence on regional and federal subsidies and transfers. Finance flows were calculated and analyzed to show that a very important problem for Russia’s eastern regions that involves reconciling the economic and ecological interests in placer gold mining is not resolved through “cosmetic changes” in organs of state supervision. It is concluded that there is a need for new institutional solutions in order to create and increase incentives for users of mineral resources and local authorities for observance of environmental regulations, the preservation and restoration of disturbed ecosystems, and for the ecologization of production processes.     

Rangeland production: use of models incorporating aggregated knowledge and fuzzy construction

This work reports on a method using fuzzy membership functions to construct an aggregated interaction matrix in which the summation of variables is scaled according to the way rainfall and soil variables affect water availability to plants and hence influence rangeland productivity. Aggregation of the variables gives a comprehensive value which can be used to predict production. The model increases the predicability of production to 81% compared to models using rainfall alone and a multiplicative parametric one which give predictibilities of 61 and 76% respectively. The results showed that (1) the importance of rainfall in determining production was most important at lower rainfalls i.e. <350 mm; (2) soil texture and particularly slope were important through out the rainfall range (149–700 mm) investigated; and (3) soil depth was only important at the higher >350 mm rainfalls. The aggregated interaction matrix gives a measure of land productive capability.