65 research outputs found
Assessing water availability in Mediterranean regions affected by water conflicts through MODIS data time series analysis
Water scarcity is a widespread problem in arid and semi-arid regions such as the western Mediterranean coastal areas. The irregularity of the precipitation generates frequent droughts that exacerbate the conflicts among agriculture, water supply and water demands for ecosystems maintenance. Besides, global climate models predict that climate change will cause Mediterranean arid and semi-arid regions to shift towards lower rainfall scenarios that may exacerbate water conflicts. The purpose of this study is to find a feasible methodology to assess current and monitor future water demands in order to better allocate limited water resources. The interdependency between a vegetation index (NDVI), land surface temperature (LST), precipitation (current and future), and surface water resources availability in two watersheds in southeastern Spain with serious difficulties in meeting water demands was investigated. MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI and LST products (as proxy of drought), precipitation maps (generated from climate station records) and reservoir storage gauging information were used to compute times series anomalies from 2001 to 2014 and generate regression images and spatial regression models. The temporal relationship between reservoir storage and time series of satellite images allowed the detection of different and contrasting water management practices in the two watersheds. In addition, a comparison of current precipitation rates and future precipitation conditions obtained from global climate models suggests high precipitation reductions, especially in areas that have the potential to contribute significantly to groundwater storage and surface runoff, and are thus critical to reservoir storage. Finally, spatial regression models minimized spatial autocorrelation effects, and their results suggested the great potential of our methodology combining NDVI and LST time series to predict future scenarios of water scarcity.Published versio
Multitemporal Analysis in Mediterranean Forestland with Remote Sensing
The study employs a Fourier transform analysis approach to assess the land-cover changes in a mountainous Mediterranean protected area using multi-temporal satellite images. Harmonic analysis was applied to a time series of Landsat satellite images acquired from 1984 to 2008 to extract information about land cover status with a vegetation spectral index, the Normalized Difference Vegetation Index (NDVI). Ancillary cartographic information depicting land cover classes and the enlargement of the protected area over time (i.e., maps showing the original delineation in 1995 and subsequent enlargement in 2007) were employed as additional factors to understand vegetation-cover changes. Significant differences in the NDVI and harmonic components values were observed with respect to both factors. The application of the Fourier transform was particularly successful to extract subtle information. The harmonic analysis of the NDVI time series revealed valuable information about the evolution of the landscape. The initially protected area (northern sector) seems more affected by human activities than the southern sector (enlarged area in 2007) as revealed by the analysis of the first harmonic component that was closely related with vegetation coverage. Rural abandonment is a major driver of land-cover changes in the study area
Environmental factors influencing DDT–DDE spatial distribution in an agricultural drainage system determined by using machine learning techniques
The presence and persistence of pesticides in the environment are environmental problems of great concern due to the health implications for humans and wildlife. The persistence of DDT–DDE in a Mediterranean coastal plain where pesticides were widely used and were banned decades ago is the aim of this study. Different sources of analytical information from water and soil analysis and topography and geographical variables were combined with the purpose of analyzing which environmental factors are more likely to condition the spatial distribution of DDT–DDE in the drainage watercourses of the area. An approach combining machine learning techniques, such as Random Forest and Mutual Information (MI), for classifying DDT–DDE concentration levels based on other environmental predictive variables was applied. In addition, classification procedure was iteratively performed with different training/validation partitions in order to extract the most informative parameters denoted by the highest MI scores and larger accuracy assessment metrics. Distance to drain canals, soil electrical conductivity, and soil sand texture fraction were the most informative environmental variables for predicting DDT–DDE water concentration clusters
Occurrence of Pesticides Associated with an Agricultural Drainage System in a Mediterranean Environment
Surface water pollution (as a result of pesticides) is a major problem, due to the negative
impact on human health and ecosystems. The excessive use and persistence of surface water pollution
in the environment may present a notable risk. In this article, DDT and its metabolite DDE hereafter,
DDT–DDE), and a commonly used pesticide (herbicide) glyphosate, were analyzed in agricultural
drainage waters; afterward, a spatial analysis was applied to identify potential areas of high pesticide
occurrence in an agricultural Mediterranean coastal floodplain. The spatial distribution of banned
(Directive 79/117/EEC), yet highly persistent pesticides in the environment, such as DDT (and
metabolites), was compared with the (currently and mostly used) glyphosate. A sequence of various
point patterns, spatial analysis methods, and non-parametric statistics, were computed to elucidate
the pesticide pollution hotspots. As a reference value, almost 70% of the water samples were above
the World Health Organization (WHO) guideline for DDT (and metabolites) for drinking water
(1 g/L), with a maximum of 6.53 g/L. Our spatial analysis approach revealed a significantly
high concentration of DDT–DDE clusters close to wetlands in natural parks, where mosquitos are
abundant, and pesticides persist and flow to the surface waters from soil and groundwater pools.
Conversely, glyphosate concentrations were below WHO guidelines; their spatial patterns were
related more toward current agricultural uses in the southern sector of the study area
Live the Unab - Issue 479
Ulibro 2019 será una feria con cambios sustanciales. El primero es que ya no se llevará a cabo en las instalaciones de la Universidad Autónoma de Bucaramanga – como en las anteriores 16 ediciones– sino en el centro de convenciones Neomundo (ubicado en inmediaciones del Viaducto ‘Armando Puyana Puyana’ y el centro comercial Cacique). El segundo es que se extenderá del lunes 26 de agosto al domingo 1 de septiembre y no hasta el día sábado, como había sido la costumbre. Otra novedad de la Feria del Libro de la UNAB es que tendrá nuevamente país invitado y en esta ocasión será Corea del Sur, que hará presencia con una delegación encabezada por su embajador Kim Doosik, quien dictará una charla sobre las relaciones entre estos dos países y las claves del desarrollo económico.Toda una semana de Ulibro; Por Pastor Virviescas Gómez…01
Presidenta de la Corte Constitucional: “Los jueces no puede terminar siendo la censura de la sociedad”; Por Luis Fernando Rueda Vivas…05
Una ‘Lección Inaugural’ diferente; Por Pastor Virviescas Gómez…06
Elecciones UNAB 2019: el poder de ser elegido; Por Luis Fernando Rueda Vivas…07
Decano de Ingeniería…07
Autonomía, ética y creatividad, basamentos del modelo UNAB…08
Cinco Magna Cum Laude y 27 Cum Laude; Por Pastor Virviescas Gómez…11
“El éxito duradero depende del trabajo arduo y de la autoexigencia”; Por Pastor Virviescas Gómez…12
“La educación es nuestra revolución”; Por Pastor Virviescas Gómez…13
La UNAB ingresa a la Asociación Internacional de Presidentes de Universidades; Por Natalia Gómez Uribe…14
La UNAB publica libro sobre ‘casos trágicos’ en la Corte Constitucional; Por Vilma Alexandra Blanco Meléndez…15
Homenaje a docentes de Unisangil…15
Brindis por María Victoria y Gilberto…16
Almuerzo por Alfredo y Germán Darío…16Ulibro 2019 will be a fair with substantial changes. The first is that it will no longer be held at the facilities of the Autonomous University of Bucaramanga - as in the previous 16 editions - but at the Neomundo convention center (located near the 'Armando Puyana Puyana' Viaduct and the Cacique shopping center ). The second is that it will run from Monday, August 26 to Sunday, September 1 and not until Saturday, as had been the custom. Another novelty of the UNAB Book Fair is that it will once again have a guest country and this time it will be South Korea, which will be present with a delegation led by its ambassador Kim Doosik, who will give a talk on the relations between these two countries and the keys to economic development
Live the Unab - Number 478
Una de las personas más felices con la noticia que Telepacífico estaba transmitiendo en la noche del pasado domingo 2 de junio era su cómplice y abuela Martha Cecilia Serrano, quien con más de la mitad de su escuálido salario en una cafetería escolar hizo el sacrificio para obsequiarle la primera guitarra a los 14 años. El otro fue Rafael Ardila Duarte, presidente de la Junta Directiva de la Universidad Autónoma de Bucaramanga, quien en una tertulia en la capital guanentina el año anterior tuvo la ocasión de escucharlo y le instó a que viniera a estudiar en la UNAB.Ganador del ‘Gran Mono Núñez’ y alumno de Música en la UNAB; Por Pastor Virviescas Gómez…01
Juan Manuel Santos estará en Ulibro con “La batalla por la paz”; Por Lynda Vanessa Bula Barbosa y Vilma Alexandra Blanco Melendez…04
La Sinfónica UNAB ‘embrujó’ al público del Teatro Santander; Por Pastor Virviescas Gómez…06
Los estudiantes de Derecho también realizan experimentos; Por Pastor Virviescas Gómez…08
La diáspora venezolana supera cualquier cálculo; Por Pastor Virviescas Gómez…10
Las dos primeras patentes UNAB; Por Ludy Carolina Toscano Vargas…14
UNAB abre espacios para entender los procesos de justicia transicional; Por Lynda Vanessa Bula Barbosa…15
Misión a Washington…15
Partieron los ‘Embajadores’ UNAB…16
Actualización en vacaciones…17
Dirección de actores…17
Se marcha María Nuria…17
Camino a la Acreditación Internacional…18
Tecnología en Dirección Comercial…18
Los mejores de ExpoConCiencia…18
Primer y tercer puestos…19
Foros Canal 1 en la UNAB…19
Diplomado de conciliación…19
Inducción a docentes Instituto Caldas…20
Partió Vladimir Rojas…20
“Divertimento”…20One of the happiest people with the news that Telepacífico was transmitting last Sunday night, June 2, was his accomplice and grandmother Martha Cecilia Serrano, who with more than half of her meager salary in a school cafeteria made the sacrifice to give him a gift. the first guitar at age 14. The other was Rafael Ardila Duarte, president of the Board of Directors of the Autonomous University of Bucaramanga, who in a gathering in the Guanentina capital the previous year had the opportunity to listen to him and urged him to come to study at UNAB
Parasitología Interactiva
Desarrollo de una guía interactiva donde se muestran los ciclos biológicos,imágenes y dibujos de los estadios evolutivos de los principales géneros y especies de parásitos protozoos relevantes en al ámbito veterinario
Monitoring biological wastewater treatment processes: Recent advances in spectroscopy applications
Biological processes based on aerobic and anaerobic technologies have been continuously developed to wastewater treatment and are currently routinely employed to reduce the contaminants discharge levels in the environment. However, most methodologies commonly applied for monitoring key parameters are labor intensive, time-consuming and just provide a snapshot of the process. Thus, spectroscopy applications in biological processes are, nowadays, considered a rapid and effective alternative technology for real-time monitoring though still lacking implementation in full-scale plants. In this review, the application of spectroscopic techniques to aerobic and anaerobic systems is addressed focusing on UV--Vis, infrared, and fluorescence spectroscopy. Furthermore, chemometric techniques, valuable tools to extract the relevant data, are also referred. To that effect, a detailed analysis is performed for aerobic and anaerobic systems to summarize the findings that have been obtained since 2000. Future prospects for the application of spectroscopic techniques in biological wastewater treatment processes are further discussed.The authors thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors also acknowledge the financial support to Daniela P. Mesquita and Cristina Quintelas through the postdoctoral Grants (SFRH/BPD/82558/2011 and SFRH/BPD/101338/2014) provided by FCT - Portugal.info:eu-repo/semantics/publishedVersio
An Estimation of the Extent of Cropland Abandonment in Mountainous Regions of China
With the wages for migrant workers increasing dramatically in China since 2003, the size of the agricultural labour forces has been shrinking rapidly. Intensively substituting agricultural machinery for the shrinking farm labour force is hardly possible for croplands in the mountainous regions of China where mechanization is difficult to achieve due to small field size and rough terrain. This has eventually led to cropland abandonment in these regions. Considering the high pressure for food security in China, cropland abandonment in the mountainous regions should not be ignored. By employing a novel method, this study estimates the extent of recently abandoned croplands (period 2000–2010) and the changes that can be expected in the future in China's mountainous areas. The results show that the total extent of abandoned croplands in Chinese mountainous counties during the period 2000 to 2010 is estimated at 147 million mu (1 mu = 666.67 m2); in total, about 28% of croplands in mountainous counties was abandoned, including croplands converted in the Grain for Green Programme. With 3 scenario assumptions, a sizeable extent, 114 to 203 million mu, of croplands may be abandoned from 2010 to 2030 with the rapid decrease and ageing of projected farm labour forces. This could exacerbate the future challenges of maintaining China's food security. A substantial increase in agricultural project investments, including land consolidation and agricultural productive fixed assets, especially microtillage machines, could help mitigate the risk of cropland abandonment. Additionally, land‐use and environmental policymaking should take into account the expanding cropland abandonment in mountainous regions
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