Necesidades financieras del Decenio Internacional del Agua Potable y del Saneamiento Ambiental en América Latina = Financial demands of the International Drinking Water Supply and Sanitation Decade in Latin America

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Resolución 441(XIX): Apoyo al Decenio Internacional del Agua Potable y del Saneamiento Ambiental = Resolution 441(XIX): Support for the International Drinking Water Supply and Sanitation Decade = Résolution 441(XIX): Mesures d'appui à la Décennie internationale de l'eau potable et de l'assainissement

Publicado separadamete en cada idioma

Resolución 442(XIX): Medidas para promover el cumplimiento de los objetivos del Decenio Internacional del Agua Potable y del Saneamiento Ambiental en América Latina = Resolution 442(XIX): Measures to promote the achievement of the objectives of the International Drinking Water Supply and Sanitation Decade in Latin America = Résolution 442(XIX): Mesures destinées à faciliter la réalisation des objectifs de la Décennie internationale de l'eau potable et de l'assainissement

Publicado separadamete en cada idioma

Abastecimiento de agua potable y el saneamiento ambiental para la población rural dispersa en América Latina = Drinking water supply and sanitation for the dispersed rural population in Latin America

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Informe del Segundo Seminario Latinoamericano sobre Cooperación Horizontal para el Decenio Internacional del Agua Potable y del Saneamiento Ambiental = Report of the Second Latin American Seminar on Horizontal Co-operation for the International Drinking Water Supply and Sanitation Decade

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Water supply and sanitation for the poor: the achievements of the International Drinking Water Supply and Sanitation Decade in Latin America and the Caribbean = Abastecimiento de agua y saneamiento ambiental para los pobres: los logros del Decenio Internacional del Agua Potable y del Saneamiento Ambiental en América Latina y el Caribe

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Abastecimiento de agua potable y el saneamiento ambiental para la población rural dispersa en América Latina = Drinking water supply and sanitation for the dispersed rural population in Latin America

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Our land and water resources; current and prospective supplies and uses.

Bibliography: p. 51.

Water rights for variable supplies

The relative merits of different systems of property rights to allocate water among different extractive uses are evaluated for the case where variability of supply is important. Three systems of property rights are considered. In the first, variable supply is dealt with through the use of water entitlements defined as shares of the total quantity available. In the second, there are two types of water entitlements, one for water with a high security of supply and the other a lower security right for the residual supply. The third is a system of entitlements specified as state-contingent claims. With zero transaction costs, all systems are efficient. In the realistic situation where transaction costs matter, the system based on state-contingent claims is globally optimal, and the system with high-security and lower security entitlements is preferable to the system with share entitlements.

Arsenic and Chromium in Brazilian Agricultural Supplies

Arsenic (As) and chromium (Cr) contents were measured in agricultural supplies used at different farms in Sao Paulo State, Brazil. The highest mass fractions of As were found in thermophosphates, reaching levels of 4 mg/kg. The highest mass fractions of Cr (21 g/kg) were found in calcium magnesium silicate, while the thermophosphates also presented high values reaching approximately 1 g/kg. The levels of As were within Brazilian guidelines, but the values of Cr in thermophosphates exceeded the levels permitted in Brazil. The As content in fertilizers may be considered safe (5 mg/kg) in terms of environmental pollution. However, the Cr content in calcium magnesium silicate following continuous use may constitute a significant problem in Brazil due to potentially increasing levels of this metal in soils.

Production and carbon allocation in a clonal Eucalyptus plantation with water and nutrient manipulations

We examined resource limitations on growth and carbon allocation in a fast-growing, clonal plantation of Eucalyptus grandis x urophylla in Brazil by characterizing responses to annual rainfall, and response to irrigation and fertililization for 2 years. Productivity measures included gross primary production (GPP), total belowground carbon allocation (TBCA), bole growth, and net ecosystem production (NEP). Replicate plots within a single plantation were established at the midpoint of the rotation (end of year 3), with treatments of no additional fertilization or irrigation, heavy fertilization (to remove any nutrient limitation), irrigation (to remove any water limitation), and irrigation plus fertilization. Rainfall was unusually high in the first year (1769mm) of the experiment, and control plots had high rates of GPP (6.64 kg C m(-2) year(-1)), TBCA (2.14 kg C m(-2) year(-1)), and bole growth (1.81 kg C m(-2) year). Irrigation increased each of these rates by 15-17%. The second year of the experiment had average rainfall (1210 mm), and lower rainfall decreased production in control plots by 46% (GPP), 52% (TBCA), and 40% (bole growth). Fertilization treatments had neglible effects. The response to irrigation was much greater in the drier year, with irrigated plots exceeding the production in control plots by 83% (GPP), 239% (TBCA), and 24% (bole growth). Even though the rate of irrigation ensured no water limitation to tree growth, the high rainfall year showed higher production in irrigated plots for both GPP (38% greater than in drier year) and bole growth (23% greater). Varying humidity and supplies of water led to a range in NEP of 0.8-2.7 kg C m(-2) year. This difference between control and irrigated treatments, combined with differences between drier and wetter years, indicated a strong response of these Eucalyptus trees to both water supply and atmospheric humidity during the dry season. The efficiency of converting light energy into fixed carbon ranged from a low of 0.027 mol C to a high of 0.060 mol C per mol of absorbed photosynthetically active radiation (APAR), and the efficiency of bolewood production ranged from 0.78 to 1.98 g wood per MJ of APAR. Irrigation increased the efficiency of wood production per unit of water used from 2.55 kg wood m(-3) in the rainfed plot to 3.51 kg m(-3) in irrigated plots. Detailed information on the response of C budgets to environmental conditions and resource supplies will be necessary for accurate predictions of plantation yields across years and landscapes. (V) 2007 Elsevier B.V. All rights reserved.