Hydrological-hydraulic modelling of the bench terraces in hilly and mountain areas

Terrace building have been expanded in the 19th century because of the increased demographic pressure and the need to crop additional areas at steeper slopes. Terraces are also important to regulate the hydrological behavior of the hillslope. Bench terraces, reducing the terrain slope and the length of the overland flow, quantitatively control the runoff flow velocity, facilitating the drainage and thus leading to a reduction of soil erosion. The study of the hydrologic-hydraulic function of terraced slopes is essential in order to evaluate their possible use to cooperate for flood-risk mitigation also preserving the landscape value. Few studies in literature are available on rainfall-runoff transformation and flood risk mitigation in terrace areas. Then, research results in this field are still scarce. The goal of this work is to improve knowledge on hydrological processes affecting a terraced slope and their effect on flood control. Specific researches objectives are: • Studing the the reduction of peak runoff at the toe of a hillslope and the delay in the passage of peak flow, which are provided by sequence of dry-stone walls under different space arrangements along the hillslope; • Understanding the rainfall-runoff separation mechanism and the superficial and subsurface flow propagation in case of terraced slopes. In order to reach the above objectives the hydrological response of a bench terrace was investigated by using a research approache based on modelling and experimental activities. In the first part of the thesis the The FLO-2D model is used to analyse the runoff propagation mechanism of a terraced slope (sequence of dry-stone walls) by varying number and spacing of terraces and assuming two hydrological soil setting scenarios in terms of antecedent moisture conditions within the Soil Conservation Service-Curve Number method. The model analysis shows that the majority of runoff modifications at the outlet of a terraced system result from topographical modifications rather than local variations of the infiltration capacity at the dry-stone wall zone. Repeated modelling applications show that, given a quite-typical scenario of a 20°-sloped hillslope and a reference intense rainstorm, the peak discharge reduction at the hillslope outlet depends on the percentage of the area managed with terraces. The reduction can be calculated with a logarithmic-type function (for example, an increase of terraced area from 10% to 30% might bring to runoff peak reduction of almost 45%). This information can help determine where terrace additions are more effective in terms of hydrological benefit. The second part of the thesis focus on an experimental/modelling research that aims to better focus the times of the hydrological response, which are determined by a hillslope plot bounded by a dry-stone wall, considering both the overland flow and the groundwater. A physical model, characterized by a quasi-real scale, has been built to reproduce the behavior of a 3%, 6% and 9% outward sloped terrace at bare and vegetated soil condition.The model consists of a steel metal box (1 m large, 3.3 m long, 0.8 m high) containing the hillslope terrain. The terrain is equipped with two piezometers, 9 TDR sensors measuring the volumetric water content, a surface spillway at the head releasing the steady discharge under test, two scales one at the wall base to measure the groundwater discharge and another at the top of the wall to measure the surface runoff. The experiments deal with different initial moisture condition (high and low degree of saturation), and discharges of 19.5, 12.0 and 5.0 l/min. Each experiment has been replicated, conducting a total number of 35 tests. The volumetric water content analysis produced by the 9 TDR sensors was able to provide a quite satisfactory representation of the soil moisture during the runs. Then, different lag times at the outlet since the inflow initiation were measured both for runoff and groundwater. Moreover, the time of depletion and the piezometer response have been monitored and analyzed, well corroborating the findings on the kinematics of the terrace plot. Finally, the computation of the specific Curve Number (Soil Conservation Service) of the physical model has revealed values rather large if compared with those reported in the literature. This phenomenon was likely caused by the high values of the inflow discharge, the limited cross-width of the model (1 m), the increasing compactness of the soil owing to the experiment repetition and the confined waterproof box). The experimental results indicate that terrace soil was highly heterogeneous, including discontinuities and piping systems that facilitated a rapid infiltration and the development of fast subsurface flow. The Groundwater in general is a small part of the total outflow but in case the presence of pipe is important it is coupled with impulsesive infiltration rates. A conceptual hydrological model was implemented and calibrated based on the experimental data. The model results fit well the measurements even if the groundwater component is not properly modelled. This is due to the activation of important piping systems during some of the tests; the physical proces that describ this located losses were not studied and integrated in the model. These pioneering experiments have produced some remarkable outcomes on the important role of lag-times (runoff and groundwater) and provided new knowledgement on the hydrological functioning of bench terraced systems for addressing more efficient management and maintenance issues of this important agricoltural structures.I sistemi terrazzati si sono diffusi nel diciannovesimo secolo a seguito della crescente pressione demografica e della conseguente necessità di estendere le coltivazioni anche su terreni ad elevata pendenza. Oltre che dal punto di vista agrario tali sistemi sono importanti ai fini della regolazione della risposta idrogeologica di un versante. Infatti essi riducono la pendenza e la lunghezza dello scorrimento superficiale, controllando quindi quantitativamente la velocità del deflusso superficiale, facilitando il drenaggio e contribuendo in questo modo alla riduzione dei fenomeni erosivi. Lo studio della funzione idrologico-idraulica dei versanti terrazzati è essenziale per valutarne il possibile utilizzo come misure di mitigazione del rischio idraulico capaci anche di preservare il valore paesaggistico dei territori su cui essi insistono. In letteratura sono disponibili pochi studi inerenti la risposta idrologica di versanti terrazzati; l’avanzamento della ricerca in tale ambito è l’obiettivo principale di questo lavoro. In particolare vengono affrontate le seguenti tematiche: - la valutazione degli effetti di mitigazione della pericolosità idraulica (riduzione del picco di piena e suo ritardo temporale) a scala di versante indotti dalla presenza di sistemi terrazzati; - lo studio dei meccanismi di trasformazione afflussi-deflussi e dei processi di propagazione degli stessi in sistemi terrazzati; Al fine di raggiungere tali obiettivi è stato implementato un approccio integrato basato su attività sperimentali e modellistiche. Nella prima parte del lavoro è stato utilizzato il modello idraulico FLO-2D per analizzare i processi di propagazione in atto in un versante terrazzato (composto da una sequenza di muri a secco) al variare del numero e della disposizione spaziale dei terrazzi e assumendo due diversi scenari di saturazione del suolo rappresentati da diversi valori di umidità iniziale antecedente l'evento, come previsto dal metodo Soil Conservation Service - Curve Number. L'analisi modellistica mostra che la riduzione del deflusso alla base del sistema terrazzato dipende maggiormente dalle modifiche topografiche piuttosto che dalle variazioni della capacità di infiltrazione del suolo adiacente il muro. Le simulazioni eseguite su di un versante con una pendenza di 20° e alimentato da un evento di precipitazione intensa, mostrano che il picco di piena alla sezione di chiusura si riduce in funzione della percentuale di area terrazzata. Tale riduzione può essere valutata attraverso una specifica funzione logaritmica (per esempio, al crescere dell'area terrazzata da 10% a 30% la riduzione del picco di piena può essere quasi del 45%). Questa informazione può aiutare a individuare il corretto inserimento dei terrazzi per una maggiore efficace in termini di benefici idrologici. La seconda parte del lavoro riguarda lo studio della risposta idrologica di un’unità terrazzata con un muro a secco attraverso attività sperimentali e modellistiche. In particolare è stato costruito un modello fisico a scala reale per riprodurre il comportamento di un terrazzo al variare della sua pendenza (3%, 6% e 9%) e del tipo di copertura del suolo (suolo nodo o inerbito). Il modello consiste in un box metallico (1 metro di larghezza, 3.3 metri di lunghezza e 0.8 m di altezza) che contiene al suo interno un terrazzo composto da un versante delimitato a valle da un muro a secco. Tale versante è stato strumentato con 9 sensori TDR per la misura del contenuto di umidità del suolo, uno sfioratore delle portate liquidi in ingresso al versante a monte dello stesso, due bilance per la misura del deflusso, una posizionata alla base del muro per la misura del deflusso sotterraneo e una in corrispondenza della parte superiore del muro per la misura del deflusso superficiale. Gli esperimenti sono stati caratterizzati da differenti condizioni di umidità iniziale (ad alto e basso grado di saturazione) e da portate liquide in ingresso costanti e pari a 19.5, 12 e 5 l/minuto. Ogni esperimento è stato replicato per un totale di 35 esperimenti eseguiti. L'esame delle misure dei 9 sensori TDR ha fornito una soddisfacente rappresentazione dell'andamento dell'umidità globale del suolo nel corso di ogni esperimento. Sono stati poi misurati diversi tempi caratteristici della risposta idrologica alla sezione di chiusura sia per il deflusso superficiale che per il deflusso sotterraneo. I risultati ottenuti aiutano a comprendere la cinematica dei processi idrologici che caratterizzano l’unità terrazzata. E’ stato calcolato uno specifico Curve Number (Soil Conservation Service) associato all’unità terrazzata che assume valori piuttosto alti se comparati a quelli riportati in letteratura. Questo comportamento è probabilmente legato alle alte portate in ingresso, alla limitata sezione idraulica (1m), alla crescente compattazione del suolo causata dal susseguirsi delle prove e al fatto che il terrazzo è confinato all'interno di una struttura metallica impermeabile. Un innovativo modello idrologico è stato implementato e calibrato sui dati sperimentali. I risultati modellistici riproducono in modo soddisfacente le misure soprattutto per quanto riguarda il deflusso superficiale che è la componente prevalente di deflusso. In generale il deflusso sotterraneo non risulta invece essere propriamente simulato in quanto il modello non tiene conto di particolari fenomeni di infiltrazione impulsiva presenti in alcune prove. Infatti, i risultati sperimentali indicano che il suolo all'interno del terrazzo è altamente eterogeneo, con la presenza di discontinuità e sistemi di canali sotterranei che facilitano una rapida infiltrazione e lo sviluppo di deflusso sub-superficiale impulsivo che va a sommarsi al deflusso profondo (generalmente di modesta entità) alimentato dall’infiltrazione connessa agli strati superficiali del suolo. La sperimentazione effettuata risulta innovativa e fornisce nuove conoscenze sulla funzione idrologica-idraulica di un sistema terrazzato che possono servire per indirizzare in modo più efficiente la gestione e la manutenzione di queste importanti sistemazioni agrarie

“Their Body, Their Choice. Your Body, Your Choice. Your Baby, Your Choice.”: A Reflexive Thematic Analysis Of Vaccine Access And Acceptance Among U.s. Pregnant People On Reddit

Compared to the general population, pregnant people and newborns are at a higher risk of contracting infectious diseases and experiencing worse adverse outcomes. Vaccines delivered during pregnancy, known as prenatal vaccines, represent a critical yet underused form of preventive care for these populations in the United States. Increasing successful prenatal vaccination uptake requires a focus on both access and acceptance, which pregnant people may experience differently than non-pregnant people due to their unique physiological and social state. Given the evolution of vaccine hesitancy following the COVID-19 pandemic, coupled with the recent expansion of the U.S. prenatal immunization schedule, this study seeks to explore elements shaping pregnant people’s experiences of access and acceptance with prenatal vaccines during the last respiratory virus season (September 1, 2023-January 31, 2024). Using reflexive thematic analysis, the current study analyzed Reddit discussion threads (59 primary posts and 2535 comments/replies) to produce themes and subthemes focused on pregnant people’s access and acceptance of CDC-recommended prenatal vaccines (flu, Tdap, COVID-19, and RSV). Four overarching themes were constructed: pressures of the biological time crunch, divergent interpretations of vaccine science, expanded ideals of pregnancy and parenthood, and external endorsements in a polarized climate. Results showed that pregnant people were intensively concerned with not only their own vaccination, but also the vaccination of their family members. Findings found that pregnant people’s experiences of access were shaped by factors concerning the introduction of the new RSV vaccine, the time sensitivity of female reproductive biology, and the utility of relationships with different healthcare providers, whereas experiences of acceptance were shaped by individual understandings of science and sexual health, the social experience of pregnancy and vaccination, and the stigmatization of vaccine uncertainty. Study findings carry actionable implications for advancing future public health research, policy, and practice: these insights are crucial for enhancing prenatal vaccine access and acceptance in the United States, particularly given anticipated introductions of new prenatal vaccines and changing attitudes in the COVID-19 context

An exploration of the Velten Mood Induction Procedure on psychological symptomology

The purpose of this study was to examine the effects of the Velten (1968) Mood Induction Procedure (VMIP) on psychological symptomology. Velten created a series of 60 statements designed to produce a particular mood: elated, depressed, or neutral. The VMIP came out of the cognitive movement, has undergone permutations over time, and other MIPs have been developed. Criticisms of the MIPs are discussed. The VMIP is feasible as a therapeutic tool due to flexibility and ease of use; In this study, the VMIP was utilized to induce an elated, depressed, or neutral mood. Hypotheses included: for elated condition (EC), report of symptoms would decrease; for depressed condition (DC), report of symptoms would increase; for the neutral condition (NC), there would be no change, and the DC would show a greater change than the EC, and both would show greater change than the NC. A total of 314 participants were given three measures in a pretest/posttest design: the Multiple Affect Adjective Checklist-Revised (MAACL-R), the Symptom Checklist-90-Revised (SCL-90-R), and 10 frequency questions (FQs). The VMIP was administered as the independent variable; The FQs were included to detect participant bias. Differences were found using ANOVA. The MAACL-R was used as a manipulation check for the VMIP. For the EC, mood changed in the expected direction, significantly for anxiety, depression, and positive affect. For the DC, mood changed significantly in the expected direction for all subscales. For the NC, mood changed significantly in a mixed way. The SCL-90-R was used to test for differences in the report of psychological symptomology. The EC changed significantly in the expected direction for all scales. The DC changed significantly in the expected direction for some subscales. The NC changed significantly in the same direction as the EC for all scales. A visual examination of the means showed that the DC created a greater mood change than the EC or NC. The EC created a greater mood change in the area of positive affect than the NC. The utility of using the VMIP as a therapeutic tool is discussed

An exploration of the inner experience of depression

This study explored the inner experience of people with depression using the Descriptive Experience Sampling method. Participants were screened with the SCL-90-R and then selected for the depression group or the control group. Participants were asked to complete the BDI-II and the VAS as pre-test and posttest measures. Participants used the Descriptive Experience Sampling method, which entails random cueing by a beeping device and recording of inner experiences including thoughts, images, and feelings. Samples were discussed thoroughly by the participants and the researchers. Summaries of the samples were then coded for prominent characteristics. The most frequent codes for the depression group were feelings, sensory awareness, and unsymbolized thinKing The most frequent codes for the control group were feelings, images, and sensory awareness. The depression group also tended to have more experiences per sample overall than the control group

Tecnologie per l'Evoluzione Assistita (TEA): breeding cisgenico ed editing genomico per il miglioramento genetico delle specie vegetali agro-alimentari

openPer ulteriori informazioni contattare la Biblioteca di Agripolis al seguente indirizzo: [email protected]

Hydrological-hydraulic modelling of the bench terraces in hilly and mountain areas

Terrace building have been expanded in the 19th century because of the increased demographic pressure and the need to crop additional areas at steeper slopes. Terraces are also important to regulate the hydrological behavior of the hillslope. Bench terraces, reducing the terrain slope and the length of the overland flow, quantitatively control the runoff flow velocity, facilitating the drainage and thus leading to a reduction of soil erosion. The study of the hydrologic-hydraulic function of terraced slopes is essential in order to evaluate their possible use to cooperate for flood-risk mitigation also preserving the landscape value. Few studies in literature are available on rainfall-runoff transformation and flood risk mitigation in terrace areas. Then, research results in this field are still scarce. The goal of this work is to improve knowledge on hydrological processes affecting a terraced slope and their effect on flood control. Specific researches objectives are: • Studing the the reduction of peak runoff at the toe of a hillslope and the delay in the passage of peak flow, which are provided by sequence of dry-stone walls under different space arrangements along the hillslope; • Understanding the rainfall-runoff separation mechanism and the superficial and subsurface flow propagation in case of terraced slopes. In order to reach the above objectives the hydrological response of a bench terrace was investigated by using a research approache based on modelling and experimental activities. In the first part of the thesis the The FLO-2D model is used to analyse the runoff propagation mechanism of a terraced slope (sequence of dry-stone walls) by varying number and spacing of terraces and assuming two hydrological soil setting scenarios in terms of antecedent moisture conditions within the Soil Conservation Service-Curve Number method. The model analysis shows that the majority of runoff modifications at the outlet of a terraced system result from topographical modifications rather than local variations of the infiltration capacity at the dry-stone wall zone. Repeated modelling applications show that, given a quite-typical scenario of a 20°-sloped hillslope and a reference intense rainstorm, the peak discharge reduction at the hillslope outlet depends on the percentage of the area managed with terraces. The reduction can be calculated with a logarithmic-type function (for example, an increase of terraced area from 10% to 30% might bring to runoff peak reduction of almost 45%). This information can help determine where terrace additions are more effective in terms of hydrological benefit. The second part of the thesis focus on an experimental/modelling research that aims to better focus the times of the hydrological response, which are determined by a hillslope plot bounded by a dry-stone wall, considering both the overland flow and the groundwater. A physical model, characterized by a quasi-real scale, has been built to reproduce the behavior of a 3%, 6% and 9% outward sloped terrace at bare and vegetated soil condition.The model consists of a steel metal box (1 m large, 3.3 m long, 0.8 m high) containing the hillslope terrain. The terrain is equipped with two piezometers, 9 TDR sensors measuring the volumetric water content, a surface spillway at the head releasing the steady discharge under test, two scales one at the wall base to measure the groundwater discharge and another at the top of the wall to measure the surface runoff. The experiments deal with different initial moisture condition (high and low degree of saturation), and discharges of 19.5, 12.0 and 5.0 l/min. Each experiment has been replicated, conducting a total number of 35 tests. The volumetric water content analysis produced by the 9 TDR sensors was able to provide a quite satisfactory representation of the soil moisture during the runs. Then, different lag times at the outlet since the inflow initiation were measured both for runoff and groundwater. Moreover, the time of depletion and the piezometer response have been monitored and analyzed, well corroborating the findings on the kinematics of the terrace plot. Finally, the computation of the specific Curve Number (Soil Conservation Service) of the physical model has revealed values rather large if compared with those reported in the literature. This phenomenon was likely caused by the high values of the inflow discharge, the limited cross-width of the model (1 m), the increasing compactness of the soil owing to the experiment repetition and the confined waterproof box). The experimental results indicate that terrace soil was highly heterogeneous, including discontinuities and piping systems that facilitated a rapid infiltration and the development of fast subsurface flow. The Groundwater in general is a small part of the total outflow but in case the presence of pipe is important it is coupled with impulsesive infiltration rates. A conceptual hydrological model was implemented and calibrated based on the experimental data. The model results fit well the measurements even if the groundwater component is not properly modelled. This is due to the activation of important piping systems during some of the tests; the physical proces that describ this located losses were not studied and integrated in the model. These pioneering experiments have produced some remarkable outcomes on the important role of lag-times (runoff and groundwater) and provided new knowledgement on the hydrological functioning of bench terraced systems for addressing more efficient management and maintenance issues of this important agricoltural structures.I sistemi terrazzati si sono diffusi nel diciannovesimo secolo a seguito della crescente pressione demografica e della conseguente necessità di estendere le coltivazioni anche su terreni ad elevata pendenza. Oltre che dal punto di vista agrario tali sistemi sono importanti ai fini della regolazione della risposta idrogeologica di un versante. Infatti essi riducono la pendenza e la lunghezza dello scorrimento superficiale, controllando quindi quantitativamente la velocità del deflusso superficiale, facilitando il drenaggio e contribuendo in questo modo alla riduzione dei fenomeni erosivi. Lo studio della funzione idrologico-idraulica dei versanti terrazzati è essenziale per valutarne il possibile utilizzo come misure di mitigazione del rischio idraulico capaci anche di preservare il valore paesaggistico dei territori su cui essi insistono. In letteratura sono disponibili pochi studi inerenti la risposta idrologica di versanti terrazzati; l’avanzamento della ricerca in tale ambito è l’obiettivo principale di questo lavoro. In particolare vengono affrontate le seguenti tematiche: - la valutazione degli effetti di mitigazione della pericolosità idraulica (riduzione del picco di piena e suo ritardo temporale) a scala di versante indotti dalla presenza di sistemi terrazzati; - lo studio dei meccanismi di trasformazione afflussi-deflussi e dei processi di propagazione degli stessi in sistemi terrazzati; Al fine di raggiungere tali obiettivi è stato implementato un approccio integrato basato su attività sperimentali e modellistiche. Nella prima parte del lavoro è stato utilizzato il modello idraulico FLO-2D per analizzare i processi di propagazione in atto in un versante terrazzato (composto da una sequenza di muri a secco) al variare del numero e della disposizione spaziale dei terrazzi e assumendo due diversi scenari di saturazione del suolo rappresentati da diversi valori di umidità iniziale antecedente l'evento, come previsto dal metodo Soil Conservation Service - Curve Number. L'analisi modellistica mostra che la riduzione del deflusso alla base del sistema terrazzato dipende maggiormente dalle modifiche topografiche piuttosto che dalle variazioni della capacità di infiltrazione del suolo adiacente il muro. Le simulazioni eseguite su di un versante con una pendenza di 20° e alimentato da un evento di precipitazione intensa, mostrano che il picco di piena alla sezione di chiusura si riduce in funzione della percentuale di area terrazzata. Tale riduzione può essere valutata attraverso una specifica funzione logaritmica (per esempio, al crescere dell'area terrazzata da 10% a 30% la riduzione del picco di piena può essere quasi del 45%). Questa informazione può aiutare a individuare il corretto inserimento dei terrazzi per una maggiore efficace in termini di benefici idrologici. La seconda parte del lavoro riguarda lo studio della risposta idrologica di un’unità terrazzata con un muro a secco attraverso attività sperimentali e modellistiche. In particolare è stato costruito un modello fisico a scala reale per riprodurre il comportamento di un terrazzo al variare della sua pendenza (3%, 6% e 9%) e del tipo di copertura del suolo (suolo nodo o inerbito). Il modello consiste in un box metallico (1 metro di larghezza, 3.3 metri di lunghezza e 0.8 m di altezza) che contiene al suo interno un terrazzo composto da un versante delimitato a valle da un muro a secco. Tale versante è stato strumentato con 9 sensori TDR per la misura del contenuto di umidità del suolo, uno sfioratore delle portate liquidi in ingresso al versante a monte dello stesso, due bilance per la misura del deflusso, una posizionata alla base del muro per la misura del deflusso sotterraneo e una in corrispondenza della parte superiore del muro per la misura del deflusso superficiale. Gli esperimenti sono stati caratterizzati da differenti condizioni di umidità iniziale (ad alto e basso grado di saturazione) e da portate liquide in ingresso costanti e pari a 19.5, 12 e 5 l/minuto. Ogni esperimento è stato replicato per un totale di 35 esperimenti eseguiti. L'esame delle misure dei 9 sensori TDR ha fornito una soddisfacente rappresentazione dell'andamento dell'umidità globale del suolo nel corso di ogni esperimento. Sono stati poi misurati diversi tempi caratteristici della risposta idrologica alla sezione di chiusura sia per il deflusso superficiale che per il deflusso sotterraneo. I risultati ottenuti aiutano a comprendere la cinematica dei processi idrologici che caratterizzano l’unità terrazzata. E’ stato calcolato uno specifico Curve Number (Soil Conservation Service) associato all’unità terrazzata che assume valori piuttosto alti se comparati a quelli riportati in letteratura. Questo comportamento è probabilmente legato alle alte portate in ingresso, alla limitata sezione idraulica (1m), alla crescente compattazione del suolo causata dal susseguirsi delle prove e al fatto che il terrazzo è confinato all'interno di una struttura metallica impermeabile. Un innovativo modello idrologico è stato implementato e calibrato sui dati sperimentali. I risultati modellistici riproducono in modo soddisfacente le misure soprattutto per quanto riguarda il deflusso superficiale che è la componente prevalente di deflusso. In generale il deflusso sotterraneo non risulta invece essere propriamente simulato in quanto il modello non tiene conto di particolari fenomeni di infiltrazione impulsiva presenti in alcune prove. Infatti, i risultati sperimentali indicano che il suolo all'interno del terrazzo è altamente eterogeneo, con la presenza di discontinuità e sistemi di canali sotterranei che facilitano una rapida infiltrazione e lo sviluppo di deflusso sub-superficiale impulsivo che va a sommarsi al deflusso profondo (generalmente di modesta entità) alimentato dall’infiltrazione connessa agli strati superficiali del suolo. La sperimentazione effettuata risulta innovativa e fornisce nuove conoscenze sulla funzione idrologica-idraulica di un sistema terrazzato che possono servire per indirizzare in modo più efficiente la gestione e la manutenzione di queste importanti sistemazioni agrarie

Self-reported psychopathology and risk-taking behaviors among parentally bereaved adolescents

The research concerning adolescents who have experienced the death of a parent due to AIDS is limited. The purpose of this study was to examine if status of parental death was associated with self-reported psychopathology, risk-taking behaviors and academic success in adolescents. The sample for this study was comprised of 68 adolescents between 12.0 and 18.0 years of age who were residing within a residential treatment center. The participants were divided into three groups: (1) bereaved adolescents who had experienced the death of a parent due to AIDS; (2) bereaved adolescents who experienced the death of a parent due to other causes; or (3) adolescents who had not experienced the death of a parent. The adolescents completed the Youth Self Report Scale and the Youth Risk Behavior Survey. In addition, demographic information including time since parental death, number of foster care placements, and parent drug history was obtained from preexisting records. It was anticipated that parentally bereaved adolescents due to AIDS would: (1) score significantly higher on the Youth Self Report subscales of anxious/depressed, withdrawn, and social problems; (2) report higher incidences of risk-taking behavior on the Youth Risk Behavior Survey; and (3) demonstrate less academic success. Descriptive statistics were used to describe the sample. Oneway Analysis of Variance and Chi-Square statistical procedures were used to examine the research questions. No significant differences were found when the three groups were compared on self-reported psychopathology and risk-taking behaviors. The research question pertaining to academic success could not be tested due to lack of standardized test scores in the adolescents\u27 school records. Overall, the adolescents who participated in this study reported a high degree of risk-taking behavior such as engaging in sexual intercourse at a young age, having multiple sexual partners, and engaging in physical aggression towards peers. In addition, a large percentage of participants reported chronic feelings of sadness, as well as suicidal ideation and actual attempts at suicide. Implications for school/child clinical psychologists working with adolescent youth and suggestions for future research are discussed

On the hydrological modeling of dry-stone walls

Terraces are among the most evident human signatures on the landscape, and they cover large areas of the Earth. The importance of dry-stone terrace walls has always played a key role in the management of the agricultural areas in hilly and mountain environments. They are generally built to allow machinery and ploughs to work in better conditions, to make human work in the slopes easy and comfortable, and to promote irrigation. Few studies in literature are available about rainfall-runoff transformation in terraces areas and its role in flood risk mitigation. Research results in this field are still missing. In fact, bench terraces reduce the terrain slope and the length of the overland flow, quantitatively controlling the runoff flow velocity, facilitating the drainage and thus leading to a reduction of soil erosion. From the point of view of hydrological response, a terraced slope should result in a reduction in the peak runoff at the toe of hillslope and in a delay in the passage of the peak flow. This occurs mainly due to the change of the original topography. The goal of the work is highlighting the benefits in terms of runoff reduction, which is provided by sequence of dry-stone walls under different space arrangements along the hillslope. In particular, the FLO-2D model was applied recursively to a schematic hillslope simulating both the local variation of the hydrological soil characteristics and the morphological stepped profile. The simulations were carried out by varying the basic parameters underlying the design of the terrace system (the spacing, the height and the number of terraces). The results have clearly identified the relationships between the peak discharge reduction of the overland flow and the area managed using series of dry-stone walls. The modeling outcomes well support design criteria and the performances to expect from this consolidation system

Why not study the hydrological behavior of a terraced slope by means of a real scale model?

The use of dry-stone walls to build bench-terraces has traditionally played a key role in the management of hilly and mountainous agricultural areas. They are typically built to increase suitable crop areas, provide safe working conditions and improve terrain stability during rainfall events. Because the mean gradient is greatly reduced by the presence of bench-terraces, the hydrological response of a terraced slope should result in a reduction of peak runoff at the toe of a hillslope and a delay in the passage of peak flows. This research develops and quantifies this hypothesis. The FLO-2D model is used to analyse the runoff propagation mechanism of a terraced slope (sequence of dry-stone walls) by varying number and spacing of terraces and assuming two hydrological soil setting scenarios in terms of antecedent moisture conditions within the Soil Conservation Service-Curve Number method. The model analysis shows that the majority of runoff modifications at the outlet of a terraced system result from topographical modifications rather than local hydrological variations at the dry-stone wall zone. Repeated modelling applications show that, given a quite-typical scenario of a 20\ub0-sloped hillslope and a reference intense rainstorm, the peak discharge reduction at the hillslope outlet depends on the percentage of the area managed with terraces. The reduction can be calculated with a logarithmic-type function (for example, an increase of terraced area from 10% to 30% might bring to runoff peak reduction of almost 45%). This information can help determine where terrace additions are more effective in terms of hydrological benefit