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In this paper, we present an approach to evaluate the hydrological alterations of a temporary river. In these rivers, it is expected that anthropogenic pressures largely modify low-flow components of the flow regime with consequences for aquatic habitat and diversity in invertebrate species. First, by using a simple hydrological index (IARI) river segments of the Celone stream (southern Italy) whose hydrological regime is significantly influenced by anthropogenic activities have been identified. Hydrological alteration has been further classified through the analysis of two metrics: the degree (Mf) and the predictability of dry flow conditions (Sd6). Measured streamflow data were used to calculate the metrics in present conditions (impacted). Given the lack of data from pristine conditions, simulated streamflow time series were used to calculate the metrics in reference conditions. The Soil and Water Assessment Tool (SWAT) model was used to estimate daily natural streamflow. Hydrological alterations associated with water abstractions, point discharges and the presence of a reservoir were assessed by comparing the metrics (Mf, Sd6) before and after the impacts. The results show that the hydrological regime of the river segment located in the upper part of the basin is slightly altered, while the regime of the river segment downstream of the reservoir is heavily altered. This approach is intended for use with ecological metrics in defining the water quality status and in planning streamflow management activities.

As most of the rural areas in Mediterranean Region, the Celone river basin (Apulia, Italy) is characterized by diffuse pollution from agriculture. Nutrient export from terrestrial ecosystem to the river is controlled by hydrological processes and nutrient input from point and non-point sources. In the present paper, anthropogenic nitrogen input and the riverine export of nitrate-N (N-NO) were quantified through several survey campaigns, continuous measures of streamflow and discrete determinations of concentrations. A different frequency for water sampling was used, respectively, during floods and during normal- or low-flow state. Nitrate-N concentrations in surface waters were found to vary considerably across the seasons. The riverine N-NO export was estimated to be about 14 kg N ha year. Major N inputs derived from fertilizers and animal manure correspond to 68.2 and 24 kg N ha year, respectively. Nitrate-N fluxes in stream during flood events (21 days) accounted for about 63% of the annual loading. This study clearly demonstrates the importance of flood event contributions to the annual nutrient loading delivered to the reservoir and that more efficient fertilizers and management practices are needed to reduce N input. [ABSTRACT FROM AUTHOR]

In this paper, the results obtained from multivariate statistical techniques such as PCA (Principal component analysis) and LDA (Linear discriminant analysis) applied to a wide soil data set are presented. The results have been compared with those obtained on a groundwater data set, whose samples were collected together with soil ones, within the project 'Improvement of the Regional Agro-meteorological Monitoring Network (2004-2007)'. LDA, applied to soil data, has allowed to distinguish the geographical origin of the sample from either one of the two macroaeras: Bari and Foggia provinces vs Brindisi, Lecce e Taranto provinces, with a percentage of correct prediction in cross validation of 87%. In the case of the groundwater data set, the best classification was obtained when the samples were grouped into three macroareas: Foggia province, Bari province and Brindisi, Lecce and Taranto provinces, by reaching a percentage of correct predictions in cross validation of 84%. The obtained information can be very useful in supporting soil and water resource management, such as the reduction of water consumption and the reduction of energy and chemical (nutrients and pesticides) inputs in agriculture. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study which characterizes the hydrological regime of a temporary river at reach scale and analyzes the hydrological alterations due to anthropogenic pressures using the SWAT model to estimate the daily streamflows and the periods without flow which would occur in natural conditions. The study area is the Salsola and Celone river basins, located in SE Italy. In a first part, we identified six classes of flow, the so-called Aquatic States (ASs), which play a major role in determining the available mesohabitats and subsequently the characteristics of the aquatic life. The monthly occurrence of the different ASs over a long period has been evaluated in order to provide useful information to design biological samplings. The results show that dry bed conditions can occur from May to January and arheic state from April to January in the reaches located in the upper part of the basin. The impacted river reaches showed a different behavior depending on the anthropogenic impacts. In a second part, two indicators based on the statistics of the periods without flows were used, monthly flow permanence and dry season predictability, for describing the flow regime components which may have been altered by anthropogenic pressures. The indexes, which were computed in impacted and natural conditions, were used as coordinates in a plot to obtain a graphical vision of the regimes. The distance between the points representing the actual (impacted) and natural states in the plot were used to classify the hydrological alterations. [ABSTRACT FROM AUTHOR]

The Celone River Basin (Puglia, Italy) is characterized by a diffuse pollution from agricultural sources. Like most intermittent rivers in the Mediterranean area, this stream is not well monitored; only few water quality data are available. Thus, due to high variability in streamflow and nutrient concentrations, which characterizes this type of rivers, it is difficult to estimate accurately nutrient loads from point and non point sources and consequently anthropogenic activities impact on the river. In this work, a detailed study was carried out on the Celone river to identify the chemical characteristics of the water and to quantify the annual nutrient loads delivered to the downstream reservoir. An automatic sampler and a flow module were set up in a section of the river. Continuous measures of flow were carried out using a different frequency for water sampling when floods occurred and during normal or low flow state. Nutrient concentrations in the water samples were accurately determined in laboratory. Water quality of the river was found to vary considerably along the year in terms of nutrient concentration. Nitrate and total phosphorus are the main cause of water pollution. Nutrient losses by surface runoff were essentially a winter process. The contribution per hectare of non point sources can be estimate at about 39 kg/ha of total nitrogen and 2.4 kg/ha of total phosphorus. Estimates of loads in terms of TN and TP for the 21-day period of flood were calculated in 55 and 81% of annual loads, respectively. This study clearly demonstrates the importance of flood event contribution to the annual nutrient load. [ABSTRACT FROM AUTHOR]

The objective of the present work is a spatial analysis aimed at supporting hydrological and water quality model applications in the Canale d'Aiedda basin (Puglia, Italy), a data-limited area. The basin is part of the sensitive environmental area of Taranto that requires remediation of the soil, subsoil, surface water, and groundwater. A monitoring plan was defined to record the streamflow and water quality parameters needed for calibrating and validating models, and a database archived in a GIS environment was built, which includes climatic data, soil hydraulic parameters, groundwater data, surface water quality parameters, point-source parameters, and information on agricultural practices. Based on a one-year monitoring of activities, the average annual loads of N-NO3 and P-PO4 delivered to the Mar Piccolo amounted to about 42 t year−1, and 2 t year−1, respectively. Knowledge uncertainty in monthly load estimation was found to be up to 25% for N-NO3 and 40% for P-PO4. The contributions of point sources in terms of N-NO3 and P-PO4 were estimated at 45% and 77%, respectively. This study defines a procedure for supporting modelling activities at the basin scale for data-limited regions. [ABSTRACT FROM AUTHOR]

Hydrological indicators (HIs) are commonly used in eco-hydrological studies (i.e. environmental flow and hydrological status assessment). Their computation is based on streamflow data, and if measured data are not available, hydrological models can be used to generate flow data. The present paper describes a study that aimed to predict streamflow in a temporary river and to analyze the general reliability of some hydrological indicators evaluated by using simulated data instead of measured flow data. The SWAT model was used to predict daily streamflow in a river section of the Celone river (Puglia, Italy). Several HIs characterizing the patterns of river flow or specific hydrological components were evaluated using observed and simulated streamflow. The results show that the SWAT model is able to simulate streamflow in temporary river systems, but its performance under extreme low flow conditions may be a weak point. When simulated streamflow time series were used, the replicability of the HIs evaluated using a rigorous statistical methodology ranged from good to limited. Good performance was found for the magnitude of discharge in wet months (average monthly flow from November to May), for the high flow indicators (annual maxima, 1-, 3-, 7-, 30-, 90-day mean flow) and timing, while limited performance was detected for low flow indicators (annual minimum 1-, 3-, 7-, 30-, 90-day mean flow) and the number of zero flow days. Better performance for low flow indicators was found after introducing the zero-flow threshold. This type of eco-hydrological study may contribute to characterizing the flow regime and its alterations in regions with scarce data. [ABSTRACT FROM AUTHOR]

• SFD MBR is a suitable technology for treatment of agro-industrial wastewater. • In SFD MBR, filtration is more sensitive to operating conditions than bioprocess. • Feed composition can affect relevantly the filtration process. • Cleaning needs and effluent quality depend on activated sludge characteristics. • CST can be used as an early warning for filtration performance. Two bench-scale Self-Forming Dynamic Membrane BioReactors (SFD MBR), equipped with 50 μm nylon meshes were set up and operated under aerobic conditions in order to treat canning and winery wastewaters. The results showed different behaviors of the two systems, confirming the strong dependence of SFD MBR performance on the type of biomass and, in turn, on the type of stream being treated. Both plants achieved good results in terms of effluent quality, demonstrating the suitability of the proposed technology. Median values of effluent turbidity were 2.7 and 15.4 NTU (Nephelometric Turbidity Units) in the reactors fed with canning wastewater and winery wastewater, respectively. The removal of organic matter (as COD, Chemical Oxygen Demand) was consistently above 90 %, although the retention of suspended solids was variable and somewhat dependent on operating conditions and feed composition. The activated sludge characteristics were observed to affect filtration performance and in particular the capillary suction time (CST) was a possible indicator of efficiency, with a threshold value of 11 s above which filtration performance decreased. This parameter is proposed as an early warning tool for changes in the filtration performance of an SFD MBR, both for effluent quality and cleaning requirements. [ABSTRACT FROM AUTHOR]

In a catchmnent, nitrogen (N) export from terrestrial ecosystems to rivers is controlled by the hydrological processes and N balance. In the present paper, the soil system N budget and riverine export were quantified in a Mediterranean watershed, the Celone (South-East, Italy). The study area (72 km 2 ) consists of agricultural land (70%) and deciduous forests with three small residential areas. Major N inputs derived from fertilizers and animal manure, corresponding for the whole watershed area to 68 and 12 kg N ha −1 yr −1 , respectively. N input from point sources was 1% of total input and atmospheric depositions measured in a gauging station near the study area was quantified in ∼6 kg N ha −1 yr −1 . Crop N uptake was the main N output from agricultural land; it was estimated in ∼37 kg N ha −1 yr −1 by using data on crop yields provided by local farmers. Total flux of N in surface water was quantified for a year at the outlet of the study area by using continuous measures of flow and discrete measures of N concentrations carried out with a different frequency during the normal and low flow and when floods occurred. The hydrological regime of the stream, which is a temporary river, plays an important role in N transport. Water quality was found to vary considerably through the year in terms of both nutrient concentrations and loads. Riverine N export was quantified in 41% of total N input, and it was mainly transported during flood events, ∼60% of the annual load was delivered during floods occurred in 38 days. Organic nitrogen and nitrate were the main N forms in surface water, and the contribution per hectare was about 24 and 14 kg N, respectively. On a yearly basis, the difference between N inputs and outputs including riverine export was estimated in about 4 kg N ha −1 yr −1 for the whole watershed area. This amount partly accumulates in soils in different N forms and the remaining part, mainly in form of nitrate, percolates through unsaturated soil towards groundwater. This study reports an important analysis of N pollution in a Mediterranean watershed with a temporary river system and limited data availability. Data acquisition and handling have proved to be an important challenge to overcome in N balance quantification. The results and the methodology of the present work can be useful for understanding nitrogen loss dynamics and for functional water management and land use planning. [ABSTRACT FROM AUTHOR]