A key component in the implementation of Water Framework Directive is the development of a river basin management plan for each river basin district. Water quality models are important tools to test the effectiveness of alternative management plans on the water quality of the respective water bodies. The main objective of the present study was to develop and demonstrate the use of a rather simple water quality model as a tool for the evaluation of alternative water management scenarios for the river basin district of Evrotas. Furthermore an extension of the water quality model based on Monte Carlo simulation to provide for uncertainty identification is also exhibited. The model is based on the basic principles of the Streeter-Phelps model. A hierarchical approach was developed in order to delineate a complex hydrographic network into a series of water bodies being connected by convective terms. The pollution loads which were used as input data were related both to point sources and non-point sources. Based on the results a substantial removal of organic carbon load originating from the industrial activities is needed in order to achieve high dissolved oxygen concentrations throughout the entire hydrosystem even at the dry period.
The coastal plain of Corinth, known also as Vocha plain is one of the fast-growing rural areas due to its relatively short distance from Athens. In conjunction with the fast development, water use has also increased. On a large part of the Plain area, irrigated agriculture is practiced and fertilizers are applied. The groundwater is extracted by wells (boreholes) drilled in the alluvium of Vocha Plain to meet municipal, agricultural and other water requirements. Groundwater contamination by nitrates is a problem related mainly to the spreading of organic and chemical fertilizers by farmers and, to some extent, to effluents from domestic sewage systems. Groundwater pollution in the alluvium aquifer of the Vocha Plain was investigated during a field study from July 2000 to July 2001 at eight (8) sampling periods. In this paper, the characteristics, distribution and variation of the NO3 pollution are presented using a transport model.
Procedures for compiling a national inventory of contaminated sites must take into account the technical state-of-the-art in the area of subsurface contamination and restoration, the national and supranational regulatory environment, as well as the national administrative infrastructure. Within this framework, this paper proposes a methodology of building a national inventory of potentially contaminated sites, which is based on activities of environmental relevance to the subsurface, i.e. soil and groundwater. As a next step, a screening system was developed, capable of estimating pollution potential of each site, for variable amount of available site-specific data. Depending on the nature of site data (actual or estimated) and the screening outcome, a site can be (i) delisted, (ii) assigned to an inactive list of potentially contaminated sites (iii) recommended for further desktop study and site visit or, (iv) recommended for both further study and in situ sampling. The advantage of the proposed approach is the identification of potentially contaminated sites on the basis of financial records linking activities with enterprises, which are more readily accessible compared with environmental records. The feasibility of transitioning from activities to sites has been demonstrated elsewhere. The present paper describes how data gaps are addressed by the site screening methodology with the aid of an application to a randomly selected real site in Greece.
Geologic storage of carbon dioxide (CO2) has been proposed as a viable means for reducing anthropogenic CO2 emissions. Once injection begins, a program for measurement, monitoring, and verification (MMV) of CO2 distribution is required in order to: a) research key features, effects and processes needed for risk assessment; b) manage the injection process; c) delineate and identify leakage risk and surface escape; d) provide early warnings of failure near the reservoir; and f) verify storage for accounting and crediting. The selection of the methodology of monitoring (characterization of site and control and verification in the post-injection phase) is influenced by economic and technological variables. Multiple Criteria Decision Making (MCDM) refers to a methodology developed for making decisions in the presence of multiple criteria. MCDM as a discipline has only a relatively short history of 40 years, and it has been closely related to advancements on computer technology. Evaluation methods and multicriteria decisions include the selection of a set of feasible alternatives, the simultaneous optimization of several objective functions, and a decision-making process and evaluation procedures that must be rational and consistent. The application of a mathematical model of decision-making will help to find the best solution, establishing the mechanisms to facilitate the management of information generated by number of disciplines of knowledge. Those problems in which decision alternatives are finite are called Discrete Multicriteria Decision problems. Such problems are most common in reality and this case scenario will be applied in solving the problem of site selection for storing CO2. Discrete MCDM is used to assess and decide on issues that by nature or design support a finite number of alternative solutions. Recently, Multicriteria Decision Analysis has been applied to hierarchy policy incentives for CCS, to assess the role of CCS, and to select potential areas which could be suitable to store. For those reasons, MCDM have been considered in the monitoring phase of CO2 storage, in order to select suitable technologies which could be techno-economical viable. In this paper, we identify techniques of gas measurements in subsurface which are currently applying in the phase of characterization (pre-injection); MCDM will help decision-makers to hierarchy the most suitable technique which fit the purpose to monitor the specific physic-chemical parameter.
The aim of this paper is to present in a useful and understandable way how climatic change could be interpreted for tourism and recreation. Future climate change conditions are analyzed using the Climate Version of the Local Model (CLM) based on the COSMO model, which is currently used – among other weather services – by the DWD (Deutscher Wetterdienst) for operational weather forecast. The climate simulations concern the future periods 2021-2050 and 2071-2100 against the reference period 1961-1990, under A1B scenario. Based on regional climate simulations, the analysis for tourism can be performed using the Climate-Tourism-Information-Scheme (CTIS). The CTIS contains detailed climate information, which can be used by tourists to anticipate thermal comfort, aesthetical and physical conditions for planning their vacations. Furthermore, the Physiologically Equivalent Temperature (PET), which is one of the most popular physiological thermal indices derived from the human energy balance, is used in the analysis in order to describe the effect of climate. The future simulations concerning PET and CTIS for the area for Athens have been exemplary used, in order to consider them for tourism industry and local authorities for tourism planning.
This study investigates inert COD levels and toxicity of two different commonly applied textile dye auxiliaries, namely two tannin formulations (Tannin 1: a condensation product of aryl sulphonate; Tannin 2: a sulfonated phenol polymer). The experimental evaluation is performed on samples obtained by simulating the textile bath discharges carrying the tannin formulations. The acute toxicity of tannins is assessed by employing the photobacterium Vibrio fischeri. The results obtained indicated that both of the tannin formulations have high levels of initially inert soluble COD, SI , accounting for 59 and 41 % of the total COD, respectively. Such an outcome necessitates a specific pretreatment on segregated effluents containing these formulations. Acute toxicity data showed that both of the formulations are toxic towards Vibrio fischeri, although Tannin 2 exerts considerably higher toxicity.
The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.
Since a spectrum of hydrological and geomorphological conditions produce flood pulse environment in a riverine or a deltaic system, it is essential to have the knowledge on spatial and temporal distributions of river flow and dependent processes for environmental flow requirements, ecosystem maintenance, water resources management, and hydrological forecasting among others. Such systems being complex as the exchange of flows between the main channel and the flood plains are not well understood, flow partitioning dynamics between the various channels on large water bodies are often difficult to represent even with sophisticated models. In view of this, an attempt has been made to apply a short-term stochastic forecasting model-an Auto Regressive Integrated Moving Average (ARIMA) aided by Artificial Neural Networks (ANNs) to partition flows into the downstream tributaries, viz.: Lopis and Gadikwe channels from the Khiandiandavhu-Maunachira (K-M) Junction Junction (the main river channel) river system of the iconic Okavango delta in Botswana. As such, observed monthly flow data between October 2005 and September 2008 at the K-M Junction, and the two downstream tributaries were used to test the performance of these hybrid models for the complex deltaic system. It was found that the partitioned flows at Lopis and Gadikwe agree very well with observations when using a Single Input Multiple Output (SIMO) ANN (i.e. an inverse variant of the widely used Multi Input Single Output (MISO) ANN architecture) and an ARIMA (1,1,1) model. The Mean Squared Errors (MSEs) in the forecasts were also minimal, thus giving some hope on the use of such a hybrid mode for the rest of the branched river networks of the whole Okavango delta.
This study aims at modelling three-dimensional shoreline change rates using differential interferometric synthetic aperture radar (DInSAR) techinuqe. Neverthless, decorrelation plays significant role to control the accuracy of three dimensional object reconstruction using DInSAR. To solve this problem, multichannel MAP height estimator algorithm is implemented with in ENVISAT ASAR data. Therefore, the proposed method has been applied to coastaline of Johor, Malaysia. The study shows the critical erosion of -3.5 m y-1 with accuracy (RMSE) of ±0.05 m. In addition, the volume rate of shoreline changes of -2343.42 m3 y-1 corresponds to the lowest digital elevation model (DEM) of 7.4 m. It can be said that accurate rate of shoreline change can be achieved with root mean square error (RMSE) of ±0.05 m using multichannel MAP height estimator algorithm.
Deep groundwater data reflects hydrological processes, climate change and variability, as well as any anthropogenic influence. Decomposition of deep groundwater signal examines the history of the groundwater region. Detrending is a vital step in decomposition of groundwater time series because it is expected to remove anthropogenic effects and long-term cyclic patterns. Eight detrending methods were applied to long-term groundwater records monitored in the Lower Chao Phraya basin in Thailand. Detrended residuals and subsequently periodograms of the residuals were computed by applying the Fourier series analysis. The result from this study indicates that the 5th order polynomial interpolation provides the trendlines that significantly relate to the groundwater withdrawal background. The detrended residual function is imbedded with two major cyclic patterns, which can be the result from global climate variability, e.g. Indian Ocean Dipole and the El Niño Southern Oscillation. The magnitude of deep groundwater dynamics as the result from the anthropogenic effect is much greater than that of the climate variability in this region. In addition, this study demonstrates that caution must be exercised when fitting groundwater time series with different detrending techniques can yield mistaken cyclic patterns and may infer to different climate variability phenomenon.