NATURAL AND ENVIRONMENTAL VULNERABILITY OF THE JAURU RIVER BASIN-MATO GROSSO, BRAZIL

The disorderly use of land is currently one of the main causes of environmental problems. From this perspective, the objective of this study was to determine the natural and environmental vulnerability of the Jauru river basin in the Brazilian state of Mato Grosso. This goal was made from the perspective that the results generated contribute to environmental planning and management, considering that the Jauru river is tributary of the Paraguay river, responsible for the flooding of the Pantanal plain and, that possible impacts caused by the basin may compromise the dynamic equilibrium of the Pantanal's flood pulse. The model of assessment of natural and environmental vulnerability was adopted, with the identification of the following environmental characteristics: geology, slope, agricultural aptitude and vegetation cover and land use. Data were related through Geographic Information Systems to generate natural and environmental vulnerability maps. It was verified, through the data obtained, that in both vulnerabilities studied there was a predominance of the middle class, mainly resulting from the presence of fragile soils. Also, the predominance of the classes of agricultural aptitude found in the basin, as well as the suppression of the natural vegetation to expand the pasture areas. It was concluded that the areas covered by natural vegetation and/or pastures, in the Jauru river basin, present average natural vulnerability and state of medium to high environmental vulnerability, evidencing that livestock, the main activity regional economic development, has been developed in disagreement with environmental aptitude, contributing to the elevation of the state of environmental vulnerability in the basin

Conserving land, protecting water

Water resource management / Water productivity / Water conservation / Recycling / Land management / Soil conservation / Ecosystems / Ecology / Evapotranspiration / Food security / Poverty / River basins / Irrigated farming

Long-lived Ra isotopes by counting or by mass spectrometry: What’s the better method?

The radium isotopes 226Ra and 228Ra have traditionally been determined by counting methods, mostly by gamma counting, or via their shorter-lived daughter isotopes. With increasing sensitivity of mass spectrometers, in particular ICP-MS, attempts have been made to measure 226Ra and 228Ra via mass spectrometry. While the more abundant (in terms of atoms) 226Ra is relatively well established and several datasets have been published, only a few analyses have been published for 228Ra. ICP-MS methods, if fully developed, promise improved precision and therefore an extended applicability of radium isotopes. However, there are still a number of unresolved issues that prevent mass spectrometric techniques from being used more widely. Complications often arise from (1) pre-concentration methods, often including manganese dioxide, and strontium or barium salts. (2) Separation of adsorbers and carriers from the Ra-containing solution (3) Availability of a 228Ra-spike for isotope dilution methods and (d) Sensitivity of the mass spectrometer, which also needs to allow controlling possible interferences. Here I will give an overview of the pros cons of counting vs. mass spectrometry, and discuss possible ways to address some of the key problems for radium measurements via ICP-MS