Evaluación del funcionamiento hidráulico de las estructuras de descarga y análisis del comportamiento térmico de la cortina del proyecto Bicentenario, ubicado en el sitio Los Pilares, sobre el río Mayo, Sonora

JUAN ANTONIO LOPEZ OROZCO (2018, [Documento de trabajo])

El proyecto ha tenido como objetivo la realización de un estudio hidrológico con el fin de obtener la avenida de diseño de la obra de excedencias de la presa Bicentenario, por un periodo de retorno de 10,000 años, mediante el análisis de gastos máximos anuales registrados en la estación hidrométrica San Bernardo y mediante la modelación del proceso lluvia escurrimiento. La determinación de la avenida de diseño (para el periodo de retorno de 10,000 años) se realizó mediante dos criterios: el primero, a través de un análisis del escurrimiento, el cual consistió en el análisis de frecuencias de gastos máximos registrados en dicha estación hidrométrica, y el segundo, mediante la modelación del proceso lluvia escurrimiento.

Presas Control de crecidas Evaluación del riesgo INGENIERÍA Y TECNOLOGÍA

Regulación de una red de canales de riego

FELIPE BENJAMIN DE LEON MOJARRO VICTOR MANUEL RUIZ CARMONA LUIS RENDON PIMENTEL (2002, [Artículo])

La mayor parte de la producción agrícola de México se genera en las zonas denominadas distritos y unidades de riego. En estas áreas, la disponibilidad y la competencia por el agua ha obligado a emprender programas de tecnificación integral que permitan mejorar el uso eficiente del agua y su productividad. Así, de 1996 a 2001 se tecnificaron alrededor de 700 mil hectáreas con sistemas de riego de baja y alta presión y se construyeron redes colectivas de baja presión en superficies de 500 a 4000 hectáreas en varios de estos distritos. Asimismo, la transformación de los sistemas de riego parcelario y de la distribución inter-parcelaria necesita de un cambio en la regulación de los canales principales, a fin de que se pueda brindar a los usuarios un servicio de riego flexible, seguro, equitativo y eficiente. En varias zonas de riego del país los canales laterales se han sustituido por redes colectivas de baja presión, entubadas con materiales plásticos y alimentadas por estaciones de bombeo o por los propios canales cuando ha existido carga suficiente. La regulación de canales de riego consiste en optimar el proceso de conducción y distribución del agua desde la fuente de abastecimiento hasta los sitios de utilización para satisfacer la demanda evapotranspirativa de los cultivos existentes en una zona de riego. Esta optimación consiste en generar y aplicar reglas de control para adaptar el transporte y la distribución del agua en los canales principales a los programas de extracción de las tomas laterales. Aunque la regulación de canales puede abordarse bajo diferentes puntos de vista, la metodología de regulación propuesta resulta fácilmente adaptable a redes de canales de diferente configuración sujetas a variaciones temporales. Los resultados obtenidos permiten concluir que la aplicación de la teoría de control en la regulación de canales es una alternativa que ayuda a reducir las pérdidas de agua debidas a la operación, así como a mejorar el servicio de la irrigación en los distritos de riego.

Regulación de canales Algoritmos de control CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Object manipulation by collaborative autonomous underwater vehicles driven by a model-free second-order sliding mode controller with finite-time convergence

JOSUE GONZALEZ GARCIA (2023, [Artículo])

https://orcid.org/0000-0001-5657-380X

The use of Autonomous Underwater Vehicles (AUV) has expanded in recent years to include them in inspection, maintenance, and repair missions. These missions require the automation of tasks such as autonomous navigation and station-keeping, which are pretty challenging due to the complexity of the vehicle itself and the underwater environment. Traditional control strategies have been used to deal with those problems before, but their performance is limited since they do not consider non-linearities, external disturbances, or model uncertainties. Non-traditional controllers have been explored too, but have shortcomings such as being model-based, parameter-dependant, or so. Additionally, the nature of some objects implies the involvement of multiple vehicles to manipulate them, making the manipulation mission even harder. Collaboration of AUVs is a strong challenge since underwater communications are limited or null. An advanced control strategy dealing with the trajectory tracking and the station-keeping problem would be desirable for simplicity and robustness. If this controller could also help coordinate multiple vehicles without requiring them to communicate with each other, it would make collaborative manipulation tasks reachable. For this purpose, a model-free high-order Sliding Mode Controller (SMC) is presented in this project. Unlike other control approaches, the proposed control strategy achieves finite-time convergence to a practical zero error in a time-base that the user can arbitrarily define. This characteristic will be used to coordinate the navigation of two AUVs to manipulate an object underwater. The performance of the proposed controller was evaluated by numerical simulations and experiments in a semi-Olympic swimming pool and compared with classic and state-of-the-art control strategies regarding trajectory tracking and station-keeping problems. Results have shown that the proposed controller can achieve finite-time convergence of the tracking errors to a practical zero value in the predefined time-base. Results also demonstrated that the convergence time could be arbitrarily selected by the user and achieved by the controller resulting in, as far as the author knows, the first controller with this characteristic for AUVs navigation. The simulations and experiments also showed that the proposed controller outperformed classical and state-of-the-art controllers regarding the Root Mean Square of the tracking errors and energy consumption. Finally, the proposed model-free high-order SMC coordinated two BlueROV2 vehicles in a collaborative manipulation mission without vehicle-to-vehicle communication. Numerical simulation results confirmed that the proposed controller could manage the vehicles to follow a predefined coordinated trajectory to approach, grip, transport, and release an object without communicating with each other.

Doctor of Philosophy In Engineering Science

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LA INSTRUMENTACIÓN INGENIERÍA DE CONTROL INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA NAVAL VEHÍCULOS SUBMARINOS

Weed management and tillage effect on rainfed maize production in three agro-ecologies in Mexico

Simon Fonteyne Abel Jaime Leal González Rausel Ovando Ravi Gopal Singh Nele Verhulst (2022, [Artículo])

Maize (Zea mays L.) is grown in a wide range of agro-ecological environments and production systems across Mexico. Weeds are a major constraint on maize grain yield, but knowledge regarding the best weed management methods is lacking. In many production systems, reducing tillage could lessen land degradation and production costs, but changes in tillage might require changes in weed management. This study evaluated weed dynamics and rainfed maize yield under five weed management treatments (pre-emergence herbicide, post-emergence herbicide, pre-emergence + post-emergence herbicide, manual weed control, and no control) and three tillage methods (conventional, minimum and zero tillage) in three agro-ecologically distinct regions of the state of Oaxaca, Mexico, in 2016 and 2017. In the temperate Mixteca region, weeds reduced maize grain yields by as much as 92% and the long-growing season required post-emergence weed control, which gave significantly higher yields. In the hot, humid Papaloapan region, weeds reduced maize yields up to 63% and pre-emergence weed control resulted in significantly higher yields than treatments with post-emergence control only. In the semi-arid Valles Centrales region, weeds reduced maize yields by as much as 65%, but weed management was not always effective in increasing maize yield or net profitability. The most effective weed management treatments tended to be similar for the three tillage systems at each site, although weed pressure and the potential yield reduction by weeds tended to be higher under zero tillage than minimum or conventional tillage. No single best option for weed management was found across sites or tillage systems. More research, in which non-chemical methods should not be overlooked, is thus needed to determine the most effective weed management methods for the diverse maize production systems across Mexico.

Corn Integrated Weed Management Manual Weed Control CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MAIZE WEED CONTROL MINIMUM TILLAGE ZERO TILLAGE

Estimación de parámetros de infiltración a partir de mediciones de avance de riego por melgas empleando las ecuaciones de Saint-Venant, y Green y Ampt

Heber Saucedo MANUEL ZAVALA TREJO CARLOS FUENTES RUIZ (2016, [Artículo])

Se presenta un método para realizar la estimación de parámetros de infiltración con base en el empleo de las ecuaciones de Saint-Venant para describir el flujo del agua sobre el suelo, y la ecuación de Green y Ampt para representar el flujo del agua en el suelo. La estimación de los parámetros hidrodinámicos de conductividad hidráulica a saturación y presión en el frente de humedad, se realiza aplicando el método Levenberg-Marquardt. El modelo así obtenido, permite el ajuste de los parámetros hidrodinámicos a partir de datos de pruebas de avance de riego por melgas y de la textura del suelo.

Riego por inundación controlada Modelos matemáticos Método Levenberg-Marquardt CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Agroecology can promote climate change adaptation outcomes without compromising yield in smallholder systems

Sieglinde Snapp Yodit Kebede Eva Wollenberg (2023, [Artículo])

A critical question is whether agroecology can promote climate change mitigation and adaptation outcomes without compromising food security. We assessed the outcomes of smallholder agricultural systems and practices in low- and middle-income countries (LMICs) against 35 mitigation, adaptation, and yield indicators by reviewing 50 articles with 77 cases of agroecological treatments relative to a baseline of conventional practices. Crop yields were higher for 63% of cases reporting yields. Crop diversity, income diversity, net income, reduced income variability, nutrient regulation, and reduced pest infestation, indicators of adaptative capacity, were associated with 70% or more of cases. Limited information on climate change mitigation, such as greenhouse gas emissions and carbon sequestration impacts, was available. Overall, the evidence indicates that use of organic nutrient sources, diversifying systems with legumes and integrated pest management lead to climate change adaptation in multiple contexts. Landscape mosaics, biological control (e.g., enhancement of beneficial organisms) and field sanitation measures do not yet have sufficient evidence based on this review. Widespread adoption of agroecological practices and system transformations shows promise to contribute to climate change services and food security in LMICs. Gaps in adaptation and mitigation strategies and areas for policy and research interventions are finally discussed.

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CLIMATE CHANGE CROPS FOOD SUPPLY GAS EMISSIONS GREENHOUSE GASES FARMING SYSTEMS AGROECOLOGY FOOD SECURITY LESS FAVOURED AREAS SMALLHOLDERS YIELDS NUTRIENTS BIOLOGICAL PEST CONTROL CARBON SEQUESTRATION LEGUMES

Does access to improved grain storage technology increase farmers' welfare? Experimental evidence from maize farming in Ethiopia

Hugo De Groote Bart Minten (2024, [Artículo])

Seasonal price variability for cereals is two to three times higher in Africa than on the international reference market. Seasonality is even more pronounced when access to appropriate storage and opportunities for price arbitrage are limited. As smallholder farmers typically sell their production after harvest, when prices are low, this leads to lower incomes as well as higher food insecurity during the lean season, when prices are high. One solution to reduce seasonal stress is the use of improved storage technologies. Using data from a randomised controlled trial, in a major maize-growing region of Western Ethiopia, we study the impact of hermetic bags, a technology that protects stored grain against insect pests, so that the grain can be stored longer. Despite considerable price seasonality—maize prices in the lean season are 36% higher than after harvesting—we find no evidence that hermetic bags improve welfare, except that access to these bags allowed for a marginally longer storage period of maize intended for sale by 2 weeks. But this did not translate into measurable welfare gains as we found no changes in any of our welfare outcome indicators. This ‘near-null’ effect is due to the fact that maize storage losses in our study region are relatively lower than previous studies suggested—around 10% of the quantity stored—likely because of the widespread use of an alternative to protect maize during storage, for example a cheap but highly toxic fumigant. These findings are important for policies that seek to promote improved storage technologies in these settings.

Hermetic Storage Randomised Controlled Trial CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA STORAGE PILOT FARMS SEASONALITY WELFARE MAIZE

Forest proximity positively affects natural enemy mediated control of fall armyworm in Southern Africa

Frédéric Baudron Terence Sunderland (2022, [Artículo])

Insectivorous Birds Bat Predation Maize Cultivation CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA FALL ARMYWORMS BIOLOGICAL PEST CONTROL INSECTIVOROUS ANIMALS MAIZE PREDATOR PREY RELATIONS

Monitoreo de playas prioritarias

NORMA RAMIREZ SALINAS JUAN LEODEGARIO GARCIA ROJAS (2011, [Documento de trabajo])

El objetivo general del proyecto fue llevar a cabo un análisis de Enterococos en agua de mar, cada quince días, para el sistema de monitoreo de playas proritarias de Semarnat.

Playas Calidad del agua Monitoreo del agua Agua recreacional Informes de proyectos INGENIERÍA Y TECNOLOGÍA

PROPUESTA DE MANEJO DE LA PESQUERÍA EMERGENTE DE MERLUZA DEL PACÍFICO NORTE Merluccius productus EN EL GOLFO DE ULLOA, BAJA CALIFORNIA SUR

PABLO MORA ZAMACONA (2023, [Tesis de doctorado])

"La merluza del Pacífico Merluccius productus se distribuye desde Alaska hasta el sur de México, con una población particular descrita al sur de la península de Baja California conocida como merluza enana, de la que poco se sabe. Dicha población actualmente no es pescada comercialmente, por lo que representa un recurso con potencial de explotación. Las pesquerías potenciales y emergentes crean desafíos y oportunidades para los administradores pesqueros que necesitan tomar decisiones sobre cómo gestionar de forma sostenible una pesquería previa a su inicio. Este trabajo propone y analiza posibles medidas alternativas de gestión pesquera para esta potencial pesquería, bajo incertidumbre biológica y de mercado. Debido al desconocimiento de diversos aspectos de la biología del recurso primeramente se analizó el crecimiento individual del stock y posteriormente se realizó un análisis bioeconómico de la potencial pesquería.

Para el análisis del crecimiento individual se utilizó un total de 240 otolitos y datos de longitud patrón de 932 especímenes muestreados de mayo a diciembre de 2015. La formación anual de incrementos en los otolitos se verificó mediante la relación de incremento marginal y el análisis de borde. La edad se estimó a partir de recuentos de anillos en secciones sagitales de otolitos y el crecimiento se analizó mediante un enfoque de inferencia multimodelo. Se consideraron los modelos de crecimiento de von Bertalanffy (VBGM), VBGM generalizado, Gompertz, Logístico y Johnson, los cuales se ajustaron a conjuntos de datos de talla a la edad observados y retrocalculados agrupados por sexo. Según el criterio de información de Akaike, el VBGM generalizado fue el más apropiado para las hembras (L∞= 31.36 cm, k= 0.15 cm año-1), mientras que el VBGM proporcionó el mejor ajuste para los machos (L∞= 25.35 cm, k= 0.28 cm año-1).

El análisis bioeconómico de alternativas de manejo para una potencial pesquería de merluza enana indicó que una nueva pesquería de dicho stock podría ser biológicamente sostenible y económicamente rentable, bajo un conjunto de estrategias de gestión y reglas de control. Se recomienda un acceso limitado con bajo esfuerzo pesquero ya que resulta más redituable por barco y biológicamente precautorio, considerando la alta incertidumbre asociada con la explotación de una población virgen..."

"The Pacific hake Merluccius productus is distributed from Alaska to southern Mexico, with a particular population described south of the Baja California peninsula known as dwarf hake, about which little is known. This population is not currently commercially fished; hence it represents a resource with potential for exploitation. Potential and emerging fisheries create challenges and opportunities for fishery managers who need to make decisions about how to sustainably manage a fishery prior to its initiation. This work proposes and analyzes possible alternative fishery management measures for this potential fishery, under biological and market uncertainty. Due to the lack of knowledge of various aspects of the biology of the resource, the individual growth of the stock was first analyzed and subsequently a bioeconomic analysis of the potential fishery was carried out.

A total of 240 otoliths and standard-length data from 932 specimens sampled from May to December 2015 were used for the analysis of individual growth. The annual formation of otolith increments was verified using the marginal increment analysis and the edge analysis. Age was estimated from annuli counts in sagittal sections of otoliths and growth was analyzed using a multi-model inference approach. The von Bertalanffy growth models (VBGM), generalized VBGM, Gompertz, Logistic and Johnson growth models were considered, which were fitted to observed and back calculated length-at-age data sets grouped by sex. According to Akaike's information criterion, the generalized VBGM was the most appropriate for females (L∞= 31.36 cm, k= 0.15 cm year-1), while the VBGM provided the best fit for males (L∞= 25.35 cm, k= 0.28 cm year-1).

The bioeconomic analysis of management alternatives for a potential dwarf hake fishery indicated that a new fishery for said stock could be biologically sustainable and economically profitable, under a set of management strategies and control rules. Limited access with low fishing effort is recommended as it is more profitable by boat and biologically precautionary, considering the high uncertainty associated with the exploitation of an unfished stock. Despite the combination of high fishing costs and low prices, the fishery could still be profitable in the long term, although there is risk of overexploitation if high fishing effort is allowed..."

Merluza enana, stock no explotado, crecimiento individual, análisis bioeconómico, pesquería potencial Dwarf hake, unexploited stock, individual growth, bioeconomic analysis, potential fishery CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS PECES Y FAUNA SILVESTRE REGLAMENTACIÓN Y CONTROL REGLAMENTACIÓN Y CONTROL