Partition among niche and neutral explanations for metacommunity patterns of fish from Cerrado streams

The Species-Sorting concept, one of the models developed to explain patterns in metacommunity structure, suggests that relationships between biological communities and environmental conditions is the basic means of the species selection processes. A second concept is Neutral Theory, and the idea of neutral dynamics underpinning metacommunity structure, cannot be overlooked. The third mechanism is the Mass-Effect concept, that focuses on the interaction between environmental condition and neutral effects. In the present study, we partitioned fish communities in streams between niche and neutral theory concepts, identifying the best representation of metacommunity structure, and assessed if linear and hydrographic distance were equivalent in the representation of neutral processes. The result points to the importance of species sorting mechanisms in structuring fish communities with neutral processes best represented by the linear distances. These results are important for the fish fauna conservation leading to three considerations: (i) the variation of the landscape and habitat is important for the stream fish, (ii) the natural barriers are an important landscape component to be considered, and (iii) the artificial barriers (dams and impoundments) need to be planned taking in account the catchment basin as the landscape unit.

Morphometric analysis for flood flow formation feature identification (on example of Ulaanbaatar agglomeration)

Water flows with significant flow rate feature a high destructive force and can lead to catastrophic consequences. Fluvial processes caused by uneven distribution of rain precipitation over the area pose risks to the developed inland foothill territories. The purpose of this study is to carry out a quantitative morphometric analysis of the territory in order to identify the formation features of flood flows. The analysis and ranking of catchment basins are performed using a basin approach. On the basis of SRTM images and the use of stock cartographic material in the GIS program the authors have built specialized electronic maps that allow to obtain quantitative parameters reflecting the morphometry of the basins under analysis including basin geometry, drainage network and terrain relief. On example of the Ulaanbaatar agglomeration territory it is shown how initial morphometric parameters of basins and watercourses (length, width, area, perimeter, erosion dissection, drainage network density, terrain relief coefficient, Melton coefficient, etc.) form the features of flood flow. For developed territories, the initial data on the catchment basin morphometry constitute the basis for compilation of specialized maps to be used in planning and construction. The combination of morphometric indicators on the territory of the Ulaanbaatar agglomeration indicates that there is possibility of large flood formation and development of dangerous mudstone flows in some catchment basins.

Terrestrial records of glacial terminations V and IV and insights on deglacial mechanisms

40Ar/39Ar geochronology constraints to aggradational phases and grainsize variations show that the sedimentary filling of the Liri fluvial-lacustrine basin (central Italy) recorded the occurrence of deglaciation events associated with global meltwater pulses. Integrating these data with those from the Tiber River catchment basin, we find a precise match between the ages of gravel deposition and the occurrence of moderate sea-level rise events which anticipate those more marked during the glacial termination V and IV in the Red Sea relative sea level curve. Such correspondence suggests that gravel deposition is facilitated by melting of Apennine mountain range glaciers, which provide the water transport energy and a surplus of clastic input to the rivers draining the mountain regions and flowing into the Tyrrhenian Sea. Therefore, the thick gravel beds intercalated in the sedimentary filling of the catchment basins of the major rivers in central Italy may be regarded as an equivalent proxy of large deglaciation events, similar to the ice-rafted debris in northern Atlantic. Consistent with this hypothesis, we also show the close correspondence between the occurrence of particularly mild (warmer) minima of the mean summer insolation at 65° N and these early aggradational phases, as well as with other anomalous early sea-level rises occurred 750 ka and 540 ka at the onset of glacial termination VIII and VI, and 40 ka at the onset of the so-called Heinrich events.

An Assessment of the Potential, Suitability and Sustainability of the Sand Mining Site in the Kemaman River Basin, Terengganu Using Acoustic Doppler Current Profiler

Sand mining from the catchment basin for building is a worldwide issue. The increasing demand for sand in the construction industry has led sand suppliers to look for alternative methods by which they can obtain source of sand from the riverbed. Floodplain and river slabs can be used as new sources of sand mining. In Sungai Kemaman, during September until March a high precipitation can cause high flow in river. This high flow can cause riverbank erosion which leads to instability of river. Therefore, river erosion can probably be reduced by identifying the potential area for sand mining. This research was conducted to analyse sand capability on floodplain and riverbed by integrating resistivity method and sediment transport loads using Acoustic Doppler Current Profiler (ADCP). Resistivity survey is used in determining the availability of potential soil at the study area and the equipment could measure subsurface profile up to 80 meters depth. Meanwhile, ADCP survey is utilized to make river profiler in term of velocity meshes and riverbed depth. The primary data collected was from 20 January 2014 to 19 February 2014. The findings found that the samples trapped in the Helly-Smith grabber were majority of the samples consisted more than 93% of gravel and sand materials and from the resistivity analysis, it is verified that the surrounding materials along the Sungai Kemaman is sandy material and high potential of the sand mining site.

RECONSTRUCTION OF THE WATER SUPPLY AND SEWERAGE SYSTEMS OF A CAST-IRON FOUNTAIN IN PAVLOVSK

Introduction: The restoration of old fountains is essential to the cultural life of society since it preserves the architectural spirit of the past and conveys the historical heritage to the present day. Besides, fountains create a favorable atmosphere in summer, humidifying the air. In the course of the study, we developed an approach to the restoration of the engineering systems and the technology of operation of an old fountain in St. Petersburg. Methods: We performed a detailed survey of the cast-iron fountain body and the pits next to it to discover the catchment basin of the fountain and establish its dimensions, assess the operation of similar fountains, analyze historical documents (old photos), and design engineering systems. Results and discussion: As a result of the study, the dimensions of the fountain and the catchment basin as well as the diameters of the orifices were obtained. The trajectories of the water jets and the scheme of the fountain’s operation were determined. Besides, we performed a hydraulic analysis of the systems and selected the necessary equipment. In this paper, we also present the scheme of the fountain’s operation in the following modes: filling with water, normal operation, and shut-down for winter.