Context: The UV-Vis absorbance collection using online optical captors for water quality detection may yield outliers and/or missing values. Therefore, pre-processing to correct these anomalies is required to improve the analysis of monitoring data. The aim of this study is to propose a method to detect outliers as well as to fill-in the gaps in time series. Method: Outliers are detected using Winsorising procedure and the application of the Discrete Fourier Transform (DFT) and the Inverse of Fast Fourier Transform (IFFT) to complete the time series. Together, these tools were used to analyse a case study comprising three sites in Colombia ( (i) Bogotá D.C. Salitre-WWTP (Waste Water Treatment Plant), influent; (ii) Bogotá D.C. Gibraltar Pumping Station (GPS); and, (iii) Itagüí, San Fernando-WWTP, influent (Medellín metropolitan area) ) analysed via UV-Vis (Ultraviolet and Visible) spectra. Results: Outlier detection with the proposed method obtained promising results when window parameter values are small and self-similar, despite that the three time series exhibited different sizes and behaviours. The DFT allowed to process different length gaps having missing values. To assess the validity of the proposed method, continuous subsets (a section) of the absorbance time series without outlier or missing values were removed from the original time series obtaining an average 12 % error rate in the three testing time series. Conclusions: The application of the DFT and the IFFT using the 10 % most important harmonics of useful values, can be advantageous for its later use in different applications, specifically for time series of water quality and quantity in urban sewer systems. One potential application would be the analysis of dry weather affecting rainy seasons, a feature achieved by detecting values that correspond to unusual behaviour in a time series. Additionally, the results hint at the potential of the method in correcting other hydrologic time series.

No abstract

Abstract-The measurement of the solar resource has been important for applications in engineering, architecture, and hydrology, among others. For this reason it is necessary to know the behaviour of daily global solar radiation over long periods of time. The spatial distribution of solar radiation usually is presented via solar radiation maps that recorded the average daily solar radiation for each month of the year. In Colombia the last maps recompilation was published in 2004. Currently it has greater coverage of radiometers making measurements, for this reason exists more updated and more reliable records. Solar radiation maps for Cundiboyacense area were built based on the data of global radiation of the local network of the Regional Autonomous Corporation of Cundinamarca (CAR) are presented in this paper. Resumen-La medición del recurso solar es necesaria para aplicaciones en ingeniería, arquitectura, hidrología, entre otras. Por esta razón es necesario conocer el comportamiento de la radiación solar global diaria en periodos largos de tiempo. La distribución espacial de la radiación solar por lo general se presenta en forma de mapas de radiación solar que consignan la radiación solar diaria promedio para cada mes del año. En Colombia el último mapa fue publicado en el año 2004. En la actualidad se cuenta con un mayor cubrimiento de radiómetros lo que hace que se cuenten con registros más actualizados y más confiables. En el presente trabajo se presenta los mapas de radiación solar para la zona Cundiboyacense, construidos basados en los datos de radiación global de la red local de la CorporaciónAutónoma Regional de Cundinamarca (CAR). KeywordsPalabras Claves-Mapas, Radiación solar, Radiómetros, Región Cundiboyacense.Abstract-The measurement of the solar resource has beenimportant for applications in engineering, architecture, and hydrology, among others. For this reason it is necessary to know the behavior of daily global solar radiation over long periods of time. The spatial distribution of solar radiation usually is presented via solar radiation maps that recorded the average daily solar radiation for each month of the year. In Colombia the last maps recompilation was published in 2004. Currently it has greater coverage of radiometers making measurements, for this reason exists more updated and more reliable records. Solar radiation maps for Cundiboyacense area werebuilt based on the data of global radiation of the local network of the Regional Autonomous Corporation of Cundinamarca (CAR) are presented in this paper.

Context: Signals recorded as multivariate time series by UV-Vis absorbance captors installed in urban sewer systems, can be non-stationary, yielding complications in the analysis of water quality monitoring. This work proposes to perform spectral estimation using the Box-Cox transformation and differentiation in order to obtain stationary multivariate time series in a wide sense. Additionally, Principal Component Analysis (PCA) is applied to reduce their dimensionality. Results: Absorbance time series dimensionality reduction using PCA, resulted in 6, 8 and 7 principal components for each study site respectively, altogether explaining more than 97 % of their variability. Values of differences below 30 % for the UV range were obtained for the three study sites, while for the visible range the maximum differences obtained were: (i) 35 % for El-Salitre WWTP; (ii) 61 % for GPS; and (iii) 75 % for San-Fernando WWTP. Conclusions:The Box-Cox transformation and the differentiation process applied to the UV-Vis absorbance time series for the study sites (El-Salitre, GPS and San-Fernando), allowed to reduce variance and to eliminate tendency of the time series. A pre-processing of UV-Vis absorbance time series is recommended to detect and remove outliers and then apply the proposed process for spectral estimation.

Urban environments become the main scenarios of human life, where the greatest environmental transformations are presented to meet the needs and interests of the inhabitants. Their housing habits, transport methods, spaces of coexistence and consolidation of environmentally balanced environments are a permanent global need. Climate change has a high level of impact on the quality of urban life, therefore it is a global condition that must be managed, mitigated and adapted, so that living environments are consolidated sustainably. The research, in a first phase, analyzed information from two moments, one, theory and experiences of how climate change affects urban environments; two, how these climate change variables affect a specific urban scenario.In the second phase, the study defined Commune 13, Eastern Commune, in the city of Bucaramanga, where the information of phase one was verified, analyzing the level of threat, risk and vulnerability of this environment to climate change. In phase three, determined the levels of Vulnerability, intervention mechanisms are proposed in the commune, from the social, physical and environmental, to influence the urban environment, under conditions of mitigation and adaptation, that improve the conditions of the commune before climate change and potentialize the living conditions of its inhabitants and, by extension, the entire city.