Soil Water Content Estimated by Support Vector Machine for the Assessment of Shallow Landslides Triggering: the Role of Antecedent Meteorological Conditions

Soil water content is a key parameter for representing water dynamics in soils. Its prediction is fundamental for different practical applications, such as identifying shallow landslides triggering. Support vector machine (SVM) is a machine learning technique, which can be used to predict the temporal trend of a quantity since training from past data. SVM was applied to a test slope of Oltrepò Pavese (northern Italy), where meteorological parameters coupled with soil water content at different depths (0.2, 0.4, 0.6, 1.0, 1.2, 1.4 m) were measured. Two SVM models were developed for water content assessment: (i) model 1, considering rainfall amount, air temperature, air humidity, net solar radiation, and wind speed; (ii) model 2, considering the same predictors of model 1 together with antecedent condition parameters (cumulated rainfall of 7, 30, and 60 days; mean air temperature of 7, 30, and 60 days). SVM model 2 showed significantly higher satisfactory results than model 1, for both training and test phases and for all the considered soil levels. SVM models trends were implemented in a methodology of slope safety factor assessment. For a real event occurred in the tested slope, the triggering time was correctly predicted using data estimated by SVM model based on antecedent meteorological conditions. This confirms the necessity of including these predictors for building a SVM technique able to estimate correctly soil moisture dynamics in time. The results of this paper show a promising potential application of the SVM methodologies for modeling soil moisture required in slope stability analysis.     

The dynamics of landfill diversion: Economic drivers, policy factors and spatial issues: Evidence from Italy using provincial panel data

Waste disposal is an issue that is becoming increasingly important in policy terms in the European Union, and in Italy, a country showing strong geographical heterogeneity in waste management. This paper analyses the process of decoupling/delinking between economic growth and landfilling trends in a framework where economic, policy, geographical elements and spatial issues are all considered as drivers behind the phenomenon. We exploit an original and very rich provincial panel dataset over 1999–2005 for the 103 Italian provinces. Evidence shows that the observed ‘absolute’ decoupling between economic growth and landfilling is driven by a mix of structural factors. Among the main factors, population density, more than the provincial income level, emerges as a crucial driver: local opportunity costs and landfill externalities matter in shaping waste policies and local commitment to a transition away from landfilling of waste (landfill diversion). However, not only structural factors are relevant. If on the one hand landfill taxes are not a significant driver of the phenomenon, waste management tools, such as separated collection for recycling, and the tariff system connected to waste services, bring about significant effect on the amount of landfilled waste. Moreover, regarding the analysis of spatial interrelations across provinces, we note that the presence of incinerators in nearby provinces increases landfill diversion, due probably to free riding behaviour or intra-provinces ‘agreements’ on waste management; this is not true for nearby landfill sites, that cause for a given province a strong lock in effect. Future research could strengthen the analysis of policy effectiveness at regional level, focusing on policy endogeneity, and the full investigation of spatial correlations in waste disposal performances.     

Efficient removal of pollutants from olive washing wastewater in bubble-column bioreactor by Trametes versicolor

The white-rot fungi Panus tigrinus, Funalia trogii and Trametes versicolor have been tested in shake flasks for the reduction of olive washing wastewater (OWW) pollutants and production of oxidases on OWW-based media. P. tigrinus was rejected for its scarce performance. F. trogii showed best production of laccase (27 000 U g⁻¹), while T. versicolor appeared a good pollutant degrader reducing colour, COD and phenols by 60, 72 and 87%, respectively. Only T. versicolor grew well in bubble-column bioreactor: its OWW depollution, in continuous process, led to colour, COD and phenols reduction by 65%, 73% and 89%, respectively. Optimal dilution rate was 0.225 d⁻¹ (0.225 m³ of effluent treated daily per m³ of bioreactor). Thus, a small bioreactor (10 m³) could treat daily the amount of OWW produced by a standard olive washing machine (2 m³ d⁻¹). For these reasons, this process could be proposed as a simple, efficient and low-cost OWW treatment.     

Separate waste collection in Italy: the role of socio-cultural factors and targets set by law

The aim of this paper was twofold: on the one hand, we analyse the results achieved in terms of percentages of separate collection in Italy by testing the effectiveness of Legislative Decree 152/2006 in improving the separate collection process; and on the other hand, we investigate on some of the factors, related to the sociocultural local context, that could explain the different impacts of the law in the three macro-areas considered (North, Central and South Italy). To this purpose, an econometric analysis on the Italian regions for the 1996–2013 period is performed, comparing the period before (1996–2006) and after (2006–2013) the date of entry into force of the new law. The results show the effectiveness of Legislative Decree 152/2006 in promoting separate collection, although a regional difference in terms of separate collection rate is observed. Northern regions proved to be more dynamic and reactive to the above-mentioned legislation, while Central and especially Southern regions achieved poorer results in moving to higher separate waste collection rates. Finally, our work provides evidence on some local factors that may have hampered an effective policy implementation in Southern regions, among them, the presence of criminal activities and the lack of citizen participation in politics.     

Continuous monitoring of odours from a composting plant using electronic noses

The odour impact of a composting plant situated in an urbanized area was evaluated by continuously monitoring the ambient air close to the plant during a period of about 4 days using two electronic noses. One electronic nose was installed in a nearby house, and the other one inside the perimeter of the composting plant in order to compare the response of both instruments. The results of the monitoring are represented by tables that report the olfactory class and the odour concentration value attributed to the analyzed air for each of the 370 measurements carried out during the monitoring period. The electronic nose installed at the house detected the presence of odours coming from the composting plant for about 7.8% of the monitoring total duration. Of the odour detections, 86% (25 of 29 measurements) were classified as belonging to the olfactory class corresponding to the open air storage of the waste screening overflows heaps, which was therefore identified to be the major odour source of the monitored composting plant. In correspondence of the measurements during which the electronic nose inside the house detected the presence of odours from the composting plant, the olfactory classes recognized by both instruments coincide. Moreover, the electronic nose at the house detected the presence of odours from the composting plant at issue in correspondence of each odour perception of the house occupants. The results of the study show the possibility of using an electronic nose for environmental odours monitoring, which enables the classification of the quality of the air and to quantify the olfactory nuisance from an industrial source in terms of duration and odour concentration.     

Measurement of phase-distributed nitrophenols in Rome ambient air

Atmospheric nitrophenols (NPs) were determined both in the gas and particle phases by combining the annular denuder sampling technique with GC-MS analysis. The phase distribution of six mono-NPs identified in air sampled in downtown Rome was assessed. 4-NP, 3-methyl-4-NP and 2,6-dimethyl-4-NP were found for more than 75% in the particle phase, whilst 2-NP, 4-methyl-2-NP and 5-methyl-2-NP predominated in the gas phase. Concentration levels lower than 20 ng m-3 were observed for all NPs, among which 4-NP (17.8+/-5.6 ng m-3) and 2-NP (10.4+/-4.2 ng m-3) were the most abundant congeners in the two phases, respectively.     

A new practical aid to regional hydrogeologic planning: The runoff coefficient map

The principal aim of this research is to solve problems of water-budget estimation in particularly indeterminate conditions, of the kind that are frequently encountered in the field, in which absence or insufficiency of hydrographic instrumentation prevents the adequate evaluation of runoff.To do this we have developed techniques that are based on the method of Kennessey (1930), in which the runoff coefficient of a watershed in estimated using three physiographic variables (slope angle, permeability, and vegetation cover) and a parameter that defines the climatic conditions of the local area. Our comparison of the Kennessey method with instrumental records from a wide variety of instrumented drainage basins in central Italy shows that the method provides reliable estimates of runoff. Our analysis also indicates the best criteria for its application, as shown by the examples and results presented in this article.This research enables us to present a new application of the method, namely the runoff coefficient map, which, in addition to its specific usefulness for the evaluation of runoff, has three advantages. First, it supplies a more realistic vision of the local distribution of runoff/rainfall ratios; second, it allows one to overcome the spatial constraints imposed by the narrow frame of reference represented by the watershed; and third, it makes an important contribution to the solution of other hydrogeological problems, such as the evaluation of the amount of water required for adequate recharge of the intake areas of deep aquifers or the maintenance of geothermal processes.Hence we propose this mapping technique as a valuable practical aid to regional hydrogeologic planning.     

Isomeric analysis of BTEXs in the atmosphere using beta-cyclodextrin capillary chromatography coupled with thermal desorption and mass spectrometry

An analytical method capable of determining trace levels of BTEX-aromatics (benzene, toluene, ethylbenzene, m-, p- and o-xylenes) in the atmosphere with as high resolution as possible has been developed. The method is based on the preconcentration of air samples using a multibed tube (Carbopack C, Carbograph 1) at ambient temperature, followed by thermal desorption, and analysis of aromatic species by a beta-cyclodextrin capillary chromatography coupled with mass spectrometry. The resolution achieved was sufficient for individual separation of BTEXs as well as m- and p-xylenes. The BTEX-ratios have been determined in an air tunnel and in on-road, suburban and rural forest atmosphere. The ethylbenzene/m-xylene ratios could provide a deep insight into anthropogenic related NMHC patterns at different locations and under different meteorological conditions and may reflect photochemical processes in the best way.