Small Catchment Area Research Articles

Distribution and Environmental Risk Evaluation of Metals in Sediment Cores from Marmara Ereğlisi Shelf, Marmara Sea, Turkey

This paper studies trace element contents in core sediments from Marmara Ereglisi on the northern shelf of the Marmara Sea. The main objective is to detect the concentrations of the selected elements (Al, As, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn) and historical evolution of sediment quality. The average concentrations of elements in mg/kg are 17,500 for Al, 5 for As, 70 for Cr, 12 for Cu, 10,742 for Fe, 137 for Mn, 44 for Ni, 20 for Pb, 43 for V and 44 for Zn. The average percentages of the sand, silt and clay fractions are 17%, 36% and 47%, respectively. Based on contamination factor, enrichment factor and pollution load index, computed from carbonate-free metal values, the core sediments are unpolluted for Al, Cr, Cu, Fe, Mn, Ni and V for the entire length of the cores and moderately polluted for As, Pb and Zn in the upper parts of the cores. The relative metal enrichment in cores starts at core depths of 13 to 39 cm depending on sedimentation rates, which commonly increase from the outer shelf toward the coast. Considering the sedimentation rates, the metal pollution on outer and inner shelf areas started about 400–500 years ago. Contamination of the northern shelf sediments is insignificant compared to those of the southern shelf, the semi-enclosed bays and gulf areas of the Marmara Sea with large catchment areas having a high population density and agricultural activities, as well as with similar marine shelf areas elsewhere in the world. This is mainly due to the small catchment area and the dynamic circulation system of the Marmara Ereglisi Shelf area.

Community phylogenetic structure reveals the imprint of dispersal-related dynamics and environmental filtering by nutrient availability in freshwater diatoms

Despite important progress, uncertainty persists regarding the ecological forces driving microbial community assembly. Here, we present the first study to use phylogenetic information to interpret the structure and diversity of diatom communities. We examined local phylogenetic divergence and beta- phylogenetic diversity in a large dataset of 595 freshwater benthic diatom communities and we investigated how this diversity is influenced by gradients in nutrients, pH, organic matter and catchment size. Overall, we found that diatom communities were phylogenetically clustered, i.e. species within communities were more closely related than expected by chance. Phylogenetic clustering was stronger in nutrient-poor environments and in sites with a small catchment area. The variation of the phylogenetic beta-diversity index was much better explained by space and environment than the variation of the taxonomic index was. Both approaches detected a significant effect of environment and space on diatom community turnover. Our results support the view that diatom communities are primarily shaped by environmental filtering, in particular by nutrient availability. Moreover, they highlight the importance of considering dispersal-related processes and the depth of phylogenetic signal in functional traits when interpreting patterns of diversity.

Assessing the characteristics and drivers of compound flooding events around the UK coast

Abstract. In low-lying coastal regions, flooding arises from oceanographic (storm surges plus tides and/or waves), fluvial (increased river discharge), and/or pluvial (direct surface run-off) sources. The adverse consequences of a flood can be disproportionately large when these different sources occur concurrently or in close succession, a phenomenon that is known as “compound flooding”. In this paper, we assess the potential for compound flooding arising from the joint occurrence of high storm surge and high river discharge around the coast of the UK. We hypothesise that there will be spatial variation in compound flood frequency, with some coastal regions experiencing a greater dependency between the two flooding sources than others. We map the dependence between high skew surges and high river discharge, considering 326 river stations linked to 33 tide gauge sites. We find that the joint occurrence of high skew surges and high river discharge occurs more frequently during the study period (15–50 years) at sites on the south-western and western coasts of the UK (between three and six joint events per decade) compared to sites along the eastern coast (between zero and one joint events per decade). Second, we investigate the meteorological conditions that drive compound and non-compound events across the UK. We show, for the first time, that spatial variability in the dependence and number of joint occurrences of high skew surges and high river discharge is driven by meteorological differences in storm characteristics. On the western coast of the UK, the storms that generate high skew surges and high river discharge are typically similar in characteristics and track across the UK on comparable pathways. In contrast, on the eastern coast, the storms that typically generate high skew surges are mostly distinct from the types of storms that tend to generate high river discharge. Third, we briefly examine how the phase and strength of dependence between high skew surge and high river discharge is influenced by the characteristics (i.e. flashiness, size, and elevation gradient) of the corresponding river catchments. We find that high skew surges tend to occur more frequently with high river discharge at catchments with a lower base flow index, smaller catchment area, and steeper elevation gradient. In catchments with a high base flow index, large catchment area, and shallow elevation gradient, the peak river flow tends to occur several days after the high skew surge. The previous lack of consideration of compound flooding means that flood risk has likely been underestimated around UK coasts, particularly along the south-western and western coasts. It is crucial that this be addressed in future assessments of flood risk and flood management approaches.

Experimental Study of Runoff Coefficients for Different Hill Slope Soil Profiles

The estimation of peak discharge from a catchment due to intense rainfall is a difficult task that may occur in a return period. If cannot be estimated accurately, it may lead to serious problem in hydraulic structure design like bridge, culvert across a river and drainage system. The main parameter which affects the peak flow is runoff coefficient of the catchment which directly depends on the soil type, its slope and land use pattern with vegetation covers. For the purpose, this study was carried out to estimate maximum runoff coefficients for different land profiles and soil types in hill slope model developed in 10 degree with the horizontal to the rainfall simulator rig (Basic Hydrology system-S12) experimentally which can give more reliable value than the real field test method as it is easier than field test especially in hill slope. The soil slope preparation was made of sand, silt and clay separately and the experiments were carried out in a controlled system. The slope prepared represented a small catchment on a plot of 2.02 meter length, 1 meter wide and 0.15 m depth soil plots (at the slope of 10° to the horizontal plane). From the experiment in different soil plots, the rainfall runoff coefficients were observed as 0.428 - 0.53 for sand soil slope, 0.46 - 0.55 for silt soil slope and 0.42 - 0.51 for clay soil slope under uniform rainfall rate of 4 lpm to 13 lpm in each soil slope. Rainfall runoff correlation equation was found with the values of R above 90% in each soil slope. The value observed is within the range of rational value of 0.05 to 0.95 as standard which concluded that the performance of simulator was found good to deal with rational values. And the runoff coefficients for these soil types can be taken within the range obtained to estimate peak discharge in any small catchment area depending on the soil types.

The spatial distribution of fractions and the total content of 24 chemical elements in soil catenas within a small gully's catchment area in the Trans Urals, Russia

Background data for a generalized model of the distribution of 24 chemical elements (Al, As, Ba, Ca, Co, Cr, Cu, Fe, P, K, Mg, Mn, Na, Ni, Pb, Rb, S, Si, Sr, Th, Ti, U, V and Zn) in soil catenas within the forest-steppe zone were obtained as a result of analysing total concentrations and mobile fractions of these elements in Chernozem-Planosol catenas (soil sequences down the slopes) within the catchment area (480 000 m2) of a U-shaped gully in Kurgan Region, Trans Urals, Russia. The data obtained on total organic carbon, particle-size distribution and pH in 51 samples from the soils studied allowed the identification of factors that controlled the vertical and spatial distribution of the chemical elements. Factors affecting chemical element migration were similar in Chernozems on interfluves and slopes, which together significantly differed from Planosols at the bottom of the gully. The chemical elements were ordered according to their mobility levels within Chernozems and Planosols as follows: Ca, Mn and Co > Ni and Pb > Ba, Cu, Na, Sr and Zn > Mg and V > Fe and Al > Cr, K and Rb > Si and Ti. Mobile Ca, Sr and to lesser degrees Ba and Mg were found mostly in the F1 fraction (weakly bound by acid-soluble carbonate compounds), while other chemical elements were more strongly held by the soils, particularly, mobile Mn, Pb, Co, Ni, Cu and Ca which were concentrated within the F2 fraction (bound by humic substances) and mobile Fe, Cr, Mg and Ba which occurred mostly within the F3 fraction (bound by Fe and Mn hydroxides). On the basis of the observed contents and migration factors of the 24 chemical elements, the studied Chernozem-Planosol sequence was defined as a ‘low-contrast translocation catena’.

Natural flood management: small-scale progress and larger-scale challenges

ABSTRACTManagement of fluvial flood risk in the UK is undergoing a paradigm shift, with a change in emphasis from solely working with structural defences to considering catchment-based measures which attenuate flood runoff. Natural Flood Management (NFM) is promoted as a method that can reduce flood risk through the alteration, restoration or use of landscape features. Here we highlight the potential to manage runoff locally in the rural landscape using NFM by targeting flow pathways and utilising floodplains and riparian zones. Using two case study examples from the UK, we show that by accumulating dispersed small-scale storage in small catchment areas (<10 km2) can assist in attenuating flood runoff. However, there is currently a lack of evidence of measure effectiveness at larger catchment scales and for managing extreme flood events. Nevertheless, there is a strong evidence base to suggest many of these measures deliver a range of different ecosystem services if installed in the correct location in the landscape.

Drainage Density as Slope Failure Susceptibility Index in Small Catchment Area

流域スケールにおける斜面崩壊の潜在的危険度を評価することを目的として，谷密度のみを変数とする簡便な評価手法を提案し，その有効性，適用性を検討した．国土地理院発行2万5千分の1地形図及び10mDEMを用いた地形解析から谷線を抽出し，谷密度を算出した．谷線はコンターの平均曲率（H）から求め，H＞0.1を閾値とすることで，谷地形としての再現性が高くなることを確認した．表層崩壊，土石流を主とする既往土砂災害を対象として，災害発生斜面の流域の谷密度と比較した結果，谷密度が高い流域ほど豪雨時に不安定となり崩壊が発生しやすい場所が多く存在すること，また，谷頭付近を発生源とする崩壊が多いなどの傾向が認められた．谷密度と崩壊頻度との関係は，0.5～1.5km2程度の流域において比較的良い相関（r＝0.60～0.66）を示した．このことから，対象とする解析領域の大きさを考慮することで，本手法は表層崩壊や土石流といった斜面崩壊の危険度評価に有効な手法となり得ると考えられる．今後さらに既往災害事例との比較を重ね，また，地形地質的素因が谷密度に与える影響を考慮するなどで，様々な崩壊タイプに対する本手法の汎用性，適用性の拡大が期待される．

Tsunami history over the past 2000 years on the Sanriku coast, Japan, determined using gravel deposits to estimate tsunami inundation behavior

At Numanohama Marsh on the rocky Sanriku coast in northeast Japan, we identified 17 sand layers with sedimentary structures characteristic of event deposits (i.e., a sharp erosional contact with the underlying unit, a normal and/or inverse grading structure, parallel/cross lamination, mud clasts, and/or a thin mud layer). Abundant marine nannofossils, coccoliths, and the small catchment area in the narrow valley suggest that these event layers were likely formed by inundations during tsunamis or storms. Among the 17 sand layers, nine contained gravels derived from the beach, riverbed, or slope areas. Six event layers contained all three of these gravels, suggesting a strong inflow current that transported round pebbles from the beach, erosion of wall rock in the valley during the inflow and outflow phases, and a backwash current that caused sub-angular riverbed gravel to accumulate in lowland areas. These six layers were traced up to 490 m inland from the coastline (present elevation: 7 m above mean sea level) and were several cm thick at almost every survey point. We concluded that these six event layers are tsunami deposits, and dating results revealed that they correlate with the 2011 Tohoku-oki earthquake; the 1933 and 1896 Sanriku-oki earthquakes; any of the 1763 Aomori-oki, 1793 Miyagi-oki, and 1856 Aomori-oki earthquakes; the 1611 Tohoku-oki earthquake; and the 869 Tohoku-oki (Jogan) earthquake. In addition, changes in the sedimentary environment inferred from diatom assemblages were well correlated with the deposition of three of the event layers. Two historical earthquakes — the 1454 and 1611 Tohoku-oki earthquakes — have been previously suggested as being the immediate predecessors of the 2011 Tohoku-oki earthquake, and our dating results favor the 1611 earthquake. Although the source region of the 869 Tohoku-oki (Jogan) earthquake has been estimated to have been off the Fukushima and Miyagi prefectures, our results suggest that the source region extended further north along the Japan Trench.

БАГАТОРІЧНА МІНЛИВІСТЬ АБСОЛЮТНИХ РІЧНИХ МІНІМУМІВ СТОКУ ВОДИ РІЧОК УКРАЇНИ

Studies of the variability of the minimum flow of water, which relates to the extreme regime characteristics of river water flow during periods of low water, are relevant. Such information, in general, is the limiting criteria for water consumption, water use and protection of water resources from pollution and depletion, and sometimes are indicators of danger and catastrophe, in particular, during periods of prolonged droughts. This is especially important in the conditions of modern climate change, in which the probability of occurrence of extreme hydrological phenomena increases significantly. To assess the long-term variability of the absolute annual minima of the flow of water from the rivers of Ukraine, sequences of minimum daily average water flows for a multi-year period from 294 gauging stations from the beginning of the observations to 2015 inclusive were formed. The methods of statistical processing of random variables (for determining the norms of runoff, coefficients of variation and asymmetry) and random functions (for constructing integral difference curves) were used. The study of the spatial specifics of changes in the absolute minima of the water flow of the rivers of Ukraine is based on the "Hydrographic zoning of Ukraine's territory". According to it, the territory of Ukraine is divided into hydrographic units — nine areas of river basins and nine sub-basins. The absolute annual minima of river runoff on the territory of Ukraine are recorded during periods of summer-autumn or winter low-water periods. High values of absolute annual minima in the modules of water flow are observed on the rivers of the Carpathian region and reach 8,7 l· s – 1 · km – 2. Basically, such values are on mountain rivers with small catchment areas; on rivers with large catchment areas that extend from the mountain and foothill areas of their flow to the plains, up to 0,9 l· s – 1 · km – 2; on the rivers of the Crimea, the absolute annual minimums in the water flow modules, in the vast majority, vary from 0,0 to 1,8 l· s – 1 · km – 2. Regarding flat river basins, for the rivers of the Vistula basin, the sub-basins of the Pripyat and the Desna, the left-bank part of the Dniester river basin, the range of changes in the absolute annual minima of the water flow modules is 0,20 ÷ 2,9 l·s– 1 ·km– 2. To the south of the indicated flat river basins, the ranges of absolute annual minima are gradually decreasing. On the rivers of the sub-basin of the Middle Dnieper there is 0, 19 ÷ 1,19 l·s– 1 ·km– 2, the subbasin of the Lower Dnieper – 0,04 ÷ 0,42 l · s – 1 · km – 2, the basin of the Southern Bug – 0,09 ÷ 1,75 l· s – 1 · km – 2. And in the basin of the rivers of the Black Sea region there is 0,0 ÷ 0,001 l· s – 1 · km – 2. For river basins of the flat part of Ukraine, the variation of annual minima is within 0,30 ÷ 2,83, the smaller one is the range of variability for the rivers of the Carpathian region – 0,20 ÷ 0,90. The asymmetry coefficients of the minimum river flow during the year for the whole territory of Ukraine range from negative -0,11 ÷ -2,01 to positive values 1,30 ÷ 6,4. The long-term variability of the absolute annual minima of the water flow of the rivers of Ukraine has been studied. Analysis of generalized difference integral curves for the entire set of rivers within the basins and sub-basins of the hydrographic zoning of Ukraine showed for the period of joint observations from 1947 to 2015 marked cyclic component. It manifests itself in a long period of decreasing absolute annual minimum values until 1968-1974, then there is an increase, and at the present time period, after 2006-2010, there is a tendency to decrease.

Comparison of urban residential storm water runoff quality in Bucharest, Romania with international data

Diffuse pollution is a major source of contaminants to surface waters in urban areas. Land use activities and the degree of imperviousness have a strong influence on the pollutant loadings and the pattern and distribution of the pollutograph. Uncontrolled discharges of contaminated urban storm water runoff contribute to impairments of water quality in receiving waters. In this study, grab samples of storm water runoff were collected from a small high-density residential catchment area in Bucharest. The pollutant concentrations were analysed for several water quality physical and chemical parameters including pH, conductivity, oil and grease, nutrients, pathogen indicator bacteria and some heavy metals. The storm events were monitored through grab sampling. The sample results for this representative residential catchment area in Bucharest were then compared with data reported from other regions of the world. The analysis demonstrates that the characteristics of the urban runoff quality from residential areas in Bucharest were comparable with data obtained from other areas in the world.

Contemporary Trend in Erosion of Arable Ordinary Chernozems (Haplic Chernozems (Pachic)) within the Volga Upland (Saratov Oblast, Russia)

The current trend in erosion rate of ordinary chernozems in Saratov oblast has been assessed. Detailed studies have been performed in a small catchment area of the Bolshoi Kolyshley River (Medveditsa River basin) using the radiocesium and soil-morphological methods. Data of long-term hydrometeorological observations in the region, reported results of observations of water runoff and soil loss on the runoff plots of the South-Eastern Research Institute of Agriculture (Saratov oblast), results of analysis of the grain size and mineral composition of stratozems developed on the catchment valley bottom were also used for analysis. The quantification of sedimentation rate in the valley bottom during two time windows (1963–1986 and 1986–2017) based on the sediment dating using 137Cs as a chronomarker indicates their decrease at least in 4–6 times after 1986, which points to a proportional reduction in erosion rate on the plowed slopes of the catchment area. The analysis of the temporal variability of suspended yields in the regional rivers (Medveditsa and Khopyor) during the period from 1940 to the present time allows us to draw an analogous conclusion for the Volga Upland within Saratov oblast. The decrease in the erosion rate of ordinary chernozems could be mainly caused by the reduction in water runoff from slopes during the spring snowmelt because of reduction in soil freezing depth against the background of rising air temperature in winter and spring. This decrease in erosion rate during the snowmelt period was not balanced by the regional increase in rainfall erosion related to some increase in the rate of runoff-forming rainfalls. In the part of Saratov oblast, located within the Volga Upland, where the studied catchment is situated, on the contrary, even a reduction in the frequency of rains with a rainfall depth of more than 30 mm occurred over the last decades. The reduction in the cultivated land area since the late 1980s because of the abandonment of plowlands on the steepest slopes also contributed to the decrease in total soil loss by erosion at the river basin scale. Within the studied small catchment, the share of perennial grasses in crop rotations increased after 1986, which also led to reduction of the rate of erosion of ordinary chernozems.

Romanian River Basins Lag Time Analysis. The SCS-CN Versus RNS Comparative Approach Developed for Small Watersheds

Romanian policy makers have to perceive that human intervention on river basins land cover is influencing rainfall-runoff relation and the used methodology cannot accurately estimate watershed surface flow transformations. Global water cycles and energy fluxes understanding is leading to better predictions of land atmosphere interaction and local hydro-climates evolution. The water transfer time determination from rainfall to runoff needs accurate measurements of river basins hydrological parameters. Here, we analyzed and compared the lag time value results of two different methodologies (curve number and rational methodology) used for 54 Romanian small catchment areas study. The focus of this paper is the lag time evaluation and interpretation for an effective implementation of the best methodology approach in the Romanian geographical space. Our research in small river basins was developed using remote sensing technology maps, GIS and environmental datasets in combination with field work on every drainage basin in order to assess the specific morphological features and validate the land cover typology. We found that Soil Conservation Service - Curve Number (SCS-CN) method is widely used according to USA landscape features classification, but not necessarily applicable to Romanian river basins characteristics. Our results show how the official Romanian rational methodology national standard (RNS) can be improved and the limits of SCS-CN method.

Interpretation and significance of combined trace element and U–Pb isotopic data of detrital rutile: a case study from late Ordovician sedimentary rocks of Saxo-Thuringia, Germany

The U–Pb age and trace element composition of detrital rutile provide information about the metamorphic history of the source region that cannot be constrained by traditional U–Pb dating of detrital zircon. Previous provenance investigations focussed on only one of these methods. Based on a large LA-ICP-MS trace element and U–Pb isotopic dataset of detrital rutile and U–Pb isotopic data of detrital zircon from late Ordovician sedimentary rocks of Saxo-Thuringia, Germany, this paper discusses the application and significance of combining these methods in provenance investigations. U–Pb age spectra from the detrital zircons analysed show multiple age components (multimodal age spectra) in all samples. This is in contrast with the detrital rutile data, as only one sample yielded a multimodal U–Pb age distribution. Multimodal age spectra of detrital rutile are most likely preserved in sediments from (large) catchment areas with complex geological histories. They may also be related to specific sedimentation events, such as glacial washout during the retreat of large ice shields (e.g. the Hirnantian glaciation of Gondwana). Unimodal age spectra are however not restricted to small catchment areas, if the provenance region is characterized by a pervasive thermal overprint such as the Pan-African orogeny throughout Gondwana. Unimodal age distributions may further consist of overlapping age cluster detectable by different trace element composition of the detrital rutile grains. The combined U–Pb age and trace element data from detrital rutile grains demonstrate that rutile sourced from metapelitic rocks yield reliable and precise U–Pb ages. In contrast, detrital rutile classified to be of metamafic origin generally has too low uranium concentrations to be dated reliably by LA-ICP-MS. Detrital rutile records low- to medium-grade metamorphic events in the source region and therefore has the potential to better constrain the maximum depositional age of sedimentary rocks in comparison to U–Pb dating of detrital zircon.

Use of the self-organising map network (SOMNet) as a decision support system for regional mental health planning

BackgroundDecision-making in mental health systems should be supported by the evidence-informed knowledge transfer of data. Since mental health systems are inherently complex, involving interactions between its structures, processes and outcomes, decision support systems (DSS) need to be developed using advanced computational methods and visual tools to allow full system analysis, whilst incorporating domain experts in the analysis process. In this study, we use a DSS model developed for interactive data mining and domain expert collaboration in the analysis of complex mental health systems to improve system knowledge and evidence-informed policy planning.MethodsWe combine an interactive visual data mining approach, the self-organising map network (SOMNet), with an operational expert knowledge approach, expert-based collaborative analysis (EbCA), to develop a DSS model. The SOMNet was applied to the analysis of healthcare patterns and indicators of three different regional mental health systems in Spain, comprising 106 small catchment areas and providing healthcare for over 9 million inhabitants. Based on the EbCA, the domain experts in the development team guided and evaluated the analytical processes and results. Another group of 13 domain experts in mental health systems planning and research evaluated the model based on the analytical information of the SOMNet approach for processing information and discovering knowledge in a real-world context. Through the evaluation, the domain experts assessed the feasibility and technology readiness level (TRL) of the DSS model.ResultsThe SOMNet, combined with the EbCA, effectively processed evidence-based information when analysing system outliers, explaining global and local patterns, and refining key performance indicators with their analytical interpretations. The evaluation results showed that the DSS model was feasible by the domain experts and reached level 7 of the TRL (system prototype demonstration in operational environment).ConclusionsThis study supports the benefits of combining health systems engineering (SOMNet) and expert knowledge (EbCA) to analyse the complexity of health systems research. The use of the SOMNet approach contributes to the demonstration of DSS for mental health planning in practice.

Understanding the spatial distribution and physical attributes of upland swamps in the Sydney Basin as a template for their conservation and management

ABSTRACTTemperate Highland Peat Swamps on Sandstone (THPSS) and Coastal Upland Swamps in the Sydney Basin (CUSSB) are listed as endangered ecological communities under Australia's national and state legislation. They are threatened by a range of human and climate impacts. Across the region there are 3208 individual, valley-bottom, elongate-shaped, upland swamps that drain first- or second-order drainage lines and small catchment areas (mean = 0.25 km2). They occur at a median distance of 57 km from the coast in areas with an average annual rainfall of 1505 mm/year and average annual temperature of 15°C. Those closer to the coast occur on elevations as low as 160 m a.s.l., and those further from the coast, on plateau country, occur up to 1172 m a.s.l. (median 634 m a.s.l.). The valleys that contain these swamps terminate downstream at a valley constriction or bedrock step, behind which alluvial materials have accumulated, and peat has formed to produce relatively steep swamps (median slope 6.2 per cent). Understanding the spatial distribution and physical attributes of these systems, and having the accompanying maps as a resource, is critical for development of sound, well-informed conservation, rehabilitation and monitoring programs, and for analysing the ecosystem services they provide.

Analysis of sediment from steps in a small catchment in the Polish Carpathians in relation to the transition zone between the hillslope and fluvial system

An investigation to determine the transition zone between the hillslope system and the fluvial system in connection with the degree of differentiation of sediment located upstream and downstream of log steps (LS) and boulder steps (BS) was undertaken in the channel of a stream located in a small mountain catchment area in the Silesian Beskidy Mts. (Polish Carpathians), a stream channel into which large wood was introduced artificially several years ago. Granulometric analyses of 41 samples taken from upstream (21) and downstream (20) of steps were performed to analyze the effectiveness of log steps and boulder steps in the differentiation of mineral sediment.It was demonstrated that log steps have a significant impact on the functioning of the channel by shaping its longitudinal profile and affecting the transport of mineral material, whereas boulder steps retain less sediment, showing the beneficial effects of artificial creation of log steps in mountain stream channels. Results of granulometric analyses suggested the location of the theoretical transition zone between the hillslope system and the fluvial system, suggesting the location and range of this zone in small mountain catchment areas can change depending on the intensity and range of slope processes in the longitudinal profile of the channel.

Investigating the Influence of Various Stormwater Runoff Control Facilities on Runoff Control Efficiency in a Small Catchment Area

Urbanization causes an increase in the flood discharge because of the infiltration capacity. Furthermore, extreme precipitation events have been an increasing concern for many regions worldwide. This study aimed to investigate the influence of different outflow control facilities on runoff reduction in a small watershed. We focused on the soil-improvement technology and rainwater tanks as outflow control facilities and conducted a runoff calculation using a rainfall event of a magnitude that is likely to occur once in a hundred years. The calculation showed that the soil-improvement technology reduced runoff during long-term continuous rainfall, whereas in a concentrated short-term rainfall event, a significant difference in the runoff reduction effect between rainfall tanks of various volumes was observed. Since effective countermeasures for runoff reduction differ depending on the rainfall distribution pattern, we suggested both facilities for storing initial rainfall and initiating countermeasures for penetration improvement over the long term.

Measuring and Explaining Airport Efficiency and Sustainability: Evidence from Italy

From an environmental point of view, it is widely recognized in economic literature that an efficient management of regional airports produces positive effects both for congestion reduction in the larger airports and for better use of existing infrastructures. Regional airports generally suffer from economic vulnerabilities because of scarcity of traffic volume; besides, their small catchment areas often determine low cash flow levels. As a result, significant problems of economic sustainability arise. In this context, airport infrastructure providers have the incentive to hide failures in their strategic decisions, justifying the low share of cost recovery through market characteristics. By means of the DEA (Data Envelopment Analysis) method this paper analyses overall technical, pure technical, and scale efficiency of 34 Italian airports in the period 2006–2016 in order to investigate how a number of factors impact on the efficiency and economic sustainability of regional airports. Our findings reveal that airport size, presence of low-cost carriers and cargo traffic have a significant influence on the technical and scale efficiency of Italian airports. In other words, air transport privatization and deregulation can positively affect regional airport efficiency and sustainability. This is to say that the market mechanism is a useful tool in achieving regional airport sustainability even if the empirical analysis of the effects of privatization and deregulation is recommended for evaluating such political programs.

Analysis of Basic Physical-Chemical Parameters, Nutrients and Heavy Metals Content in Surface Water of Small Catchment Area of Karašica and Vučica Rivers in Croatia

This paper deals with the surface water quality of a small catchment area of the Karašica and Vučica rivers based on the analysis of water physical and chemical parameters according to the national Decree on Water Quality Standards (2013). Water samples were collected and analysed monthly at five sampling stations situated along the watercourses in the period between 1998 and 2015. Analysed parameters were pH, chemical oxygen demand (COD-Mn), five-day biochemical oxygen demand (BOD5), nutrients: nitrate compounds (nitrates and total nitrogen), phosphorus compounds (orthophosphates and total phosphorus), and the content of heavy metals. The obtained results indicate a water quality status between moderate and good, depending on the parameter and sampling station.

Integrated mapping of local mental health systems in Central Chile.

ABSTRACTObjectiveTo describe the availability of local mental health (MH) services in small MH catchment areas in Central Chile, using a bottom-up approach.MethodsMH services of 19 small MH catchment areas in five health districts of Central Chile that provide health care to more than 4 million inhabitants were assessed using DESDE-LTC (Description and Evaluation of Services and Directories in Europe for Long-Term Care), a tool for standardized description and classification of LTC health services, in a study conducted in 2012 (“DESDE-Chile”) designed to complement other studies conducted in 2004 and 2012 at the national and regional level using the World Health Organization Assessment Instrument for Mental Health Systems (WHO-AIMS). Key informants from national, regional, and local health authorities were contacted to compile a comprehensive list of MH services or facilities (health, social services, education, employment, and housing). The analysis of local care provision covered three criteria—service availability, placement capacity, and workforce capacity.ResultsThe study detected disparities in all three criteria (availability and placement and workforce capacity) across the five health districts, between urban and rural areas, and between neighboring urban areas. Analysis of service availability revealed differences in the weight of residential services versus day and outpatient care. The Talcahuano area could be considered a benchmark of MH care in Central Chile, based on its service provision patterns, and the criteria of the community care model. The list of MH services identified in this study differed from the one generated in the 2012 WHO-AIMS study.ConclusionsThis survey of local MH service provision in small catchment areas using the DESDE-LTC tool provided MH service provision data that complemented information collected in other studies conducted at the national/regional level using the WHO-AIMS tool. The bottom-up approach applied in this study would also be useful for the assessment of equity and accessibility and local planning.