Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

For two decades, the estimation of Design Floods of reservoirs has been addressed with the simplest multivariate approach, the bivariate. This has been accepted because it was proven that the reservoirs are not time sensitive to maximum flow, moreover, that such flow and volume are correlated with each other and the latter, with the total duration of the flood hydrograph. In this study, the bivariate Gumbel distribution or Logistics model was adjusted to the 61 annual data of peak flow and volume of floods entering the Adolfo Ruiz Cortines (Mocúzari) dam in the Río Mayo of the state of Sonora, Mexico. This process comprehends the following eight stages: (1) selection and testing of records to be processed; (2) verification of the randomness of the annual records; (3) acceptance of Gumbel marginal functions; (4) estimation of the joint empirical probabilities; (5) validation of the Logistic model; (6) verification of probability constraints; (7) estimation of design events, peak flow and volume, hybrid univariates, and (8) estimation of joint design events. In stage 1, first a subjective selection is made and then it is verified with the PPCC Test. Stage 2 is carried out based on the Wald-Wolfowitz Test. Stages 3 and 5 use the Kolmogórov-Smirnov Test. In stage 7, design flows are defined, and volumes are obtained by regression and conditional probability. In contrast, in stage 8, several peak flow and volume events are obtained, belonging to the subgroup of critical pairs, in the graphs of the joint return period T'(Q,V). Towards the last part of this work, conclusions are formulated, which highlight the advantages of the bivariate joint frequency analysis and the simplicity of application and testing of the Logistic model.  

This study assesses an estimate of the potential rainfall infiltration in the northern area of Loreto in the state of Baja California Sur, Mexico. The basins of Gombedor, Loreto, and San Bruno are included. The analysis is based on precipitation and temperature data from the climatic stations near the municipality of Loreto. This study is in response to the scarcity within the matter and the urgency that the pressure on water resources represents to the region. Precipitation and temperature models were estimated using the Kriging interpolation method. The evapotranspiration, runoff, and potential infiltration were calculated from these models. The results obtained were 5.37 Mm3 year-1 for the Gombedor basin, 13.37 Mm3 year-1 in the San Bruno basin, and 7.62 Mm3 year-1 north of Loreto. The San Bruno basin is where the extraction wells that supply the city of Loreto are located. In the San Bruno basin, a potential recharge of 1.97 Mm3 year-1 was estimated with an average annual rainfall of 207 mm. Rainfall infiltration is one of the most important sources of aquifer recharge, in addition to groundwater flows and induced recharge. The hydrogeological model allows for addressing the situation of the basin to develop management strategies. These models can be efficient in regions without surface waters and readily available information. Moreover, hydrogeological models provide a good forecast for the Loreto region since the data are insufficient. The results for the variables show the potential of the methods based on techniques of Geographical Information Systems and geostatistics.

Over last decades, water demand has increased, and with it the need to store runoff artificially. This way reservoirs have emerged; structures considered high risk, in the event of failure. The work of spillway of the Endhó dam presents important water shocks in the coating slabs of the discharge channel, specifically in the final part of the rapids in relation to the trajectory, which delivers water to the buffering pond, which puts at risk the reservoir stability. According to the geological and hydraulic features of the work, it is probable that the subpressure force is the main cause of the wear, rupture and detachment of the slabs. To determine the causes that originate the failure, a 1:100 scale physical model was built. In this, the laws of resemblance (Froude) and similarity (geometric, kinematic and dynamic) were met, and the underground flow with soil from of the dam was simulated. The maximum flow that was passed on the spillway work was 11 l/s (equivalent to 1 100 m3/s in the prototype), it was operated for 240 continuous hours. With seven pressure sensors the values were recorded in the area of interest and data up to 9 220 kgf/m2 (prototype) were obtained. The subpressure values obtained in the physical model were higher than those estimated with Lane's methodology. The structural analysis indicates that the weight of the structure is not sufficient to counteract the subpressure in the rapid parabolic.

This work's objective is to analyze the dominant dimensions of the simulated bed forms using a three-dimensional hydrodynamic model coupled with particle transport processes and useful numerical methodologies to estimate the changes in the morphology of free surface flows. In this sense, descriptive and spectral statistical techniques were applied to the simulated bed forms geometries, obtaining a spatial and temporal discretization of the dominant dimensions in the study domain of the Tercero river as it passed through the city of Villa María, Argentina. The characteristics of the selected domain correspond to that of a river with shallow waters and a bed slope corresponding to that of a plain channel.

A bibliographic review was developed by consulting various sources of information (articles, books, abstracts, etc.), obtained from the Web of Science database, Scopus, biological abstracts, etc. They are describing the most relevant studies of the last three decades chronologically, from historical researches, as well as current topics under various sub-themes, critically analyzing nearly 200 articles with the aim to expose simply but the straightforward way the general characteristics of cyanobacteria, the main conditions that favour the formation and persistence of blooms or "CyanoHABs"; negative implications on water resources due to cyanotoxins production, emphasizing the reference limits established for the hepatotoxin Microcystin-LR in water for human consumption, in recreational systems and food products; methodologies developed for monitoring toxic strains and a summary of the research published in Mexico on cyanobacteria and their toxins. Finally, some control procedures used in the remediation of systems with cyanobacterial blooms are discussed.

The following article shows the results of solid waste (SW) characterization from the Robledo campus of the National University of Colombia, Medellín headquarters. The purpose of the study was to determine the total and specific production of non-hazardous waste, in addition to establishing intervention measures related to environmental education, use, recovery, containers purchase, and decrease in the cleaning tax, among others, that can be implemented by the university directives shortly. In the characterized period (one week), all the non-hazardous waste generated in each of the blocks (buildings), restaurants and/or cafeterias was weighed and established their physical composition to determine the kind most predominances generated. The technical standard ASTM D5231-92 and the Pan-American Center for Sanitary Engineering and Environmental Sciences CEPIS/OPS guidelines were used to determine the sampling period, physical composition, per capita production, and density. The results showed that on-campus, 1 146.9 kg of SW are generated per week, 163.7 kg/day, and a per capita production of 0.054 kg/person-day, finding that there is a large generation of organic waste (459.78 kg/week) and that restaurants and/or cafeterias contribute significantly to the generation of waste (50.39 %). These results will also make it possible to establish benchmarks compared with other universities and economic sectors, formulate sustainability strategies and public policies, and correct local and regional environmental problems associated with solid waste management.

Increasing temperature and modifying rain distribution patterns are two of the most widely documented effects of global climate change. The impacts that these changes are causing in agricultural production processes constitute one of the main threats to food production, especially under rainfed conditions. This study aims to show the changes that have taken place in the availability of moisture for crops and that are attributable to climate change in the State of Guanajuato. The analysis consisted in estimating the Growth Period by the availability of moisture (GP) from the daily historical series of the climate of 58 stations of the National Meteorological Service. The historical series were divided into two periods, the first from 1960 to 1979 and the second from 1980 to 2017. In 1960-1979, the GP start, calculated at 80 % cumulative probability, occurred on day 193 (Julian day), which corresponds to July 11, while in the period 1980-2017, it was presented until day 211, which corresponds to July 30. Regarding the GP duration, calculated at 80 % probability of exceedance, a reduction is observed from 110 days in 1960-1979 to only 75 days in 1980-2017. If these trends continue, the agricultural area that can be cultivated under rainfed conditions in the State will be drastically reduced in a few years.

The aim of this paper is to quantify forested land expansion and its effects on groundwater availability, in Mar de las Pampas town, Villa Gesell District, Argentina. Based on satellite imagery and aerial photographs, through detailed hand-digitizing of land-cover classes in the study area, a multi-temporal analysis of land-cover was made for the years of 1975, 1997 and 2014. Water balances were carried out from precipitation data, considering the distinctive hydrologic properties of the soil, in order to determine recharge values for each land-cover class. The results show a 26% reduction in recharge during the 1975-2014 period; this should be taken into account for planning a sustainable use of groundwater resource, in a locality that is currently under growth.

Mexico has numerous lakes with different characteristics and great importance for both biological and social aspects. This work shows the development of a computational system for water quality analysis in lake bodies by measuring relevant physicochemical parameters such as temperature, turbidity, and dissolved oxygen levels. Through the design and construction of a submersible measurement system, the water quality analysis process is automated. The development of specialized software for data management and measurement allows to speed up the process of water quality evaluations. Likewise, mathematical models are defined for the estimation of water quality parameters at different depths. The experimental measurements were carried out in Zirahuén Lake, located in Michoacán de Ocampo state, Mexico, due to the importance of the locality's ecosystem and the diversity of endemic species that reside there. As a result, a tool is obtained to facilitate decision-making to conserve water bodies, generating more advanced assessments.

Rainwater Harvesting Systems (RWH) is an alternative to solve water supply problems in the Upper Mixteco River Basin (UMRB). However, the successful use of RHW depends mainly on its technical design and selection of a suitable site for its construction. The objective of this paper was to identify appropriate sites for the construction of RWH in the UMRB through hydrological modeling with QSWAT+ (QGIS Interface for Soil and Water Assessment Tool) and analysis of geographic information. It was determined that the sites with potential for the construction of RWH cover 7 % of the studied sub-basin surface. In these, check dams and percolation tanks can be built for macro-collection and storage of rainwater. In addition, gully plugs, terraces, contour barriers and trenches, to reduce the surface runoff velocity and soil erosion. In this way, the water availability in the basin for various uses will increase, and soil and water conservation will be favored.