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Water scarcity has increased in the last century due to the effects of climate change and the over-exploitation of anthropic activities that deteriorate strategic ecosystems in watersheds. This study quantified the water consumption of anthropic activities according to the water footprint (WF) and the water supply available (WSA) using the GR2M hydrological simulation model in the Quenane-Quenanito basin in Colombia. The objective of this study was to analyze the dynamic supply–demand of water and identify potential conflicts associated with the use of water. The results of this study show that the WF of the basin was 17.01 million m3/year, 79.97% of which was the green WF and 20.03% of which was the blue WF, and that the WSA of the basin was 272.1 million m3/year. In addition, potential conflicts over the use of water were identified due to water scarcity in 11 sub-basins during the months of January to March. In conclusion, analyzing the demand and supply of water in basins and taking into account their spatiotemporal distribution allows us to measure the impacts of anthropic activities on water resources, which can prevent potential conflicts associated with the use of water between sectors or the involvement of ecological dynamics.

Globally, it is estimated that 20 million hectares of arable land are irrigated with water that contains residual contributions from domestic liquids. This potentially poses risks to public health and ecosystems, especially due to heavy metals, which are considered dangerous because of their potential toxicity and persistence in the environment. The Villavicencio region (Colombia) is an equatorial area where rainfall (near 3000 mm/year) and temperature (average 25.6 • C) are high. Soil processes in tropical conditions are fast and react quickly to changing conditions. Soil properties from agricultural fields irrigated with river water polluted by a variety of sources were analysed and compared to non-irrigated control soils. In this study, no physico-chemical alterations were found that gave evidence of a change due to the constant use of river water that contained wastes. This fact may be associated with the climatic factors (temperature and precipitation), which contribute to fast degradation of organic matter and nutrient and contaminants (such as heavy metals) leaching, or to dilution of wastes by the river.

Urbanization-induced land-use changes cause several environmental problems, especially in developing countries due to a lack of sufficient urban planning. This study was performed in a medium-size city of Villavicencio, Colombia. Copper, lead, nickel, zinc, chromium, manganese, and cadmium in road-deposited sediment (RDS) from different land uses were determined. Multiple geo- and statistical approaches of geographic information system mapping, Pearson correlation, Kruskal-Wallis H, hierarchical cluster analysis (HCA), and principal component analyze (PCA) were employed to assess the influence of land use on the metals' spatial distribution. The enrichment of given metals in RDS was evaluated by geo-accumulation (I) and pollution load (PLI) indexes. The exposure human health risk was assessed by hazard index (HI). Results show that the average contents of the given metals decreased in the order of commercial > residential > highway > government institutions and public parks areas. Commercial areas thereafter always have the highest metals enrichment (I) and pollution level (PLI). HI assessment indicates that child has a higher health risk than adult due to the exposure to metals in RDS. HCA analysis reveals that surface roughness had a more direct influence than land-use type on metals' distribution. Kruskal-Wallis H test further suggests land-use type had a significant influence on certain metals' spatial variation. Two potential (group) sources of geochemical and vehicular sources, along with leaded petrol and paintings, were inferred to be the main contributors to metals in RDS by PCA analysis.

RESUMENLa gestión de los recursos hídricos en las zonas rurales depende en gran medida de la participación de las comunidades en la administración y en el uso del recurso. El presente estudio tiene como objetivo identificar los sistemas de gestión del recurso hídrico en las comunidades rurales de la cuenca del río Guayuriba. Dentro del marco metodológico este estudio de caso se aborda en el marco de la investigación exploratoria. Entre los resultados que se destacan, se identificaron diferentes formas de abastecimiento y disposición de las aguas residuales domésticas de acuerdo con el tipo de asentamiento, sean de población dispersa o aglomerada, y asimismo, la debilidad de las instituciones locales para gestionar el agua en este tipo de comunidades. Finalmente, este estudio de caso se podrá utilizar como herramienta para la gestión integral del recurso hídrico en la cuenca del río Guayuriba. Palabras claveSistemas de abastecimiento, acueducto comunitario, aguas residuales domésticas, trasvase. WATER MANAGEMENT IN RURAL COMMUNITIES; CASE STUDY OF THE GUAYURIBA RIVER BASIN, META, COLOMBIA ABSTRACTThe management of water resources in rural areas depends, to a large extent, on the participation of communities in the administration and use of the resources. This study aims to identify the water resource management systems in rural communities of the Guayuriba river basin. Within the theoretical framework this case study is addressed from the exploratory research structure. Among the most protruding results, different forms of supply and disposal of domestic sweage water were identified according to the type of settlement, whether they are dispersed or agglomerated, and also the weakness of local institutions to manage and administer water in this type of communities was evident. Finally, this case study can be used as a tool for the comprehensive management of water resources in the Guayuriba river basin.

Recibido: marzo 02 de 2015.Aceptado: junio 11 de 2015. ResumenLa implementación de tecnologías enfocadas hacia el aumento en los rendimientos de los sistemas agrícolas han generado diversas problemáticas ambientales; así cabe citar, los plagicidas y fertilizantes, ya que son potenciales fuentes de metales pesados. El objetivo de esta investigación fue determinar las concentraciones de metales pesados (Cu, Zn, Ni, Pb, Cd, Cr) en suelos tipo Oxisol, sometidos a usos agrícolas intensivos, durante un tiempo superior a 10 años en la región del Ariari. Las concentraciones de los metales obtenidas siguen la siguiente secuencia Zn>Cu>Pb>Cr>Ni, y en ninguno de los casos superan los límites máximos permisibles planteados por la Agencia de Protección Ambiental de Estados Unidos EPA. Así mismo, según los parámetros físico-químicos, es probable que los metales pesados estén movilizándose en la matriz suelo-planta. Palabras clave: Contaminación de suelos, insumos agrícolas, metales pesados, suelo agrícola AbstractUsing technologies focused on agricultural systems' increased performance/yield has led to various environmental issues, including pesticide and fertiliser use since these are potential sources of heavy metals. This research was aimed at determining the concentration of heavy metals (i.e. Cu, Zn, Ni, Pb, Cd, Cr) in highly weathered tropical soils (oxisol) subjected to intensive agricultural use over a period of time lasting more than 10 years in the Ariari region. The following sequence gives the concentration of the metals so obtained: Zn>Cu>Pb>Cr>Ni; in no case did this exceed the maximum permissible limits set by the United States' Environmental Protection Agency (EPA). Likewise, it is likely that the heavy metals are mobilising in the soil-plant matrix, according to the physicochemical parameters.

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La pérdida de alimentos a lo largo de la cadena de suministro se ha convertido en un tema de gran interés en el mundo, debido a que afecta la seguridad alimentaria de la sociedad. Uno de estos eslabones de la cadena de distribución de alimentos son las centrales de abasto local, donde diariamente se pierden importantes cantidades de alimentos especialmente por carencia de protocolos de poscosecha. El objetivo del presente estudio consistió en analizar la pérdida de alimentos en la central de abastos del municipio de Acacias, Colombia y evaluar el sistema de compostaje como alternativa de gestión ambiental. Se realizó mediante el método de cuarteo la estimación de la cantidad y tipo de residuos desperdiciados, que posteriormente se sometieron al proceso de compostaje donde se evaluó la calidad del producto. En conclusión, los residuos orgánicos son un problema ambiental que requiere de alternativas como el compostaje, que permite reducir la cantidad y aprovechar el contenido nutricional de la fracción orgánica, generando subproductos con alto valor agregado.