Calibration of the Transport Parameters of a Local Problem of Water Quality in Igap\'o I Lake

The calibration of a model refers to the process by which one can estimate some parameters by comparisons with observed data. Due to the dynamical nature of the environment, variations between predicted and observed values occur. Thus, the environmental parameters may vary due to random temperature changes, time of discharge flow, time of the day, and other conditions. Such variations can be minimized by identifying and optimizing some parameters of the transport model, like the values of diffusion coefficients in x and y directions and the kinetic parameter that describes the process of removing pollutants. This paper presents results concerning the calibration of transport parameters for two-dimensional problems of water quality (fecal coliform control) at Igap\'o I Lake, located in Londrina, Paran\'a, Brazil. Thus, the convection-diffusion-reaction equation, which describes mathematically the process studied in this work, is resolved by a semidiscrete finite element method (SUPG) which combines finite differences in time and finite elements in space.Comment: 8 Pages, 3 figures, 2 tables, XVIII International Conference on Water Resources CMWR 2010 - J. Carrera (Ed) - CIMNE, Barcelona 201

Aquifers Shared Between Mexico and the United States: Management Perspectives and Their Transboundary Nature

Totally 36 aquifers have been identified along the Mexico-U.S. border. Of these, only 16 have adequate data to provide a reasonable level of confidence to categorize them as transboundary. Limited and/or contrasting data over the other aquifers in the region reflects the void in transboundary groundwater management and assessment mechanisms throughout much of the Mexico-U.S. border. This paper identifies management mechanisms, structures, and institutional prioritization related to transboundary aquifers shared between Mexico and the United States. It also evaluates the differences in the transboundary nature of these aquifers, and how their combined hydrological and geographical considerations interrelate with local and regional social, economic, political, and even scale dimensions to create complex management challenges

Effects of Drought on Crop Production and Cropping Areas in Texas

Increased crop yield is required to meet the needs of future population growth, but drought causes significant yield reductions for rainfed and irrigated crops. This study evaluates the impact of drought on crop yield and cropping area over 10 climate zones in Texas from 2008 to 2016. It also depicts the spatiotemporal distribution of crop yield and cropping area changes at each climate zone across the state. We analyzed the impact of drought on crop yields and cropping areas before and after the 2011 severe drought using annual crop yields of four major crops. Results show that drought had a greater impact on winter wheat ( L.) and corn ( L.) and lesser impact on cotton ( spp.) and sorghum [ (L.) Moench] production across Texas. Cotton and corn hectarages were reduced during the drought period and increased after that, whereas winter wheat hectarage was reduced in the northern climate zones and increased in the southern climate zones before the drought. Results also indicate that drought impact on crop production may be reduced by replacing water-demanding crops such as corn with drought-tolerant crops such as sorghum and expanding irrigation hectarage during drought periods. It may be beneficial for Texas agricultural production to increase the hectarage of sorghum and other grains especially during drought periods. This study provides valuable information that can be used to adopt appropriate measures to cope with future drought challenges in drought-prone regions