Design of a VTOL UAV for Anti-poaching Surveillance Missions in the Danube Delta

The main objective of the research paper is the theoretical and experimental analysis of the method proposed for sealing (clogging) cracks in asphalt, by means of a cylindrical bitumen bar, enriched with plastic and rubber granules (obtained from the use of waste), which melts and infuses into the cracked zone by rotation and friction against it. After analyzing the technical characteristics of the sealed area and the time required to apply the bitumen layer, this method can be chosen in the future to the detriment of the expensive operations of partial milling of the cracked wear layer, making possible the repair of cracks by sealing(clogging), using the friction procedure. The research results highlighted the diminution of road maintenance costs using the method of friction, the decrease of cracks repair time, maintaining the initial characteristics of the repaired area, incorporating a waterproofing material (plastic and rubbber granules from recycled waste), keeping the wear layer in good conditions, possibility of embedding an intelligent system of traffic monitoring at low costs etc.

Contribution to the knowledge of the Curculionoidea fauna of the Danube Delta and the Dobruja Region (Romania)

Presently 724 species are known from the Danube Delta and Dobruja. From these, 270 in the Danube Delta and Dobruja, 50 to Romania and 2 to science are new (the description of the species is in progress). The species new to Romania are the following: Noxius curtirostris (Mulsant & Rey, 1861); Bruchela cana (Küster, 1848); B. concolor (Fåhraeus, 1839); B. parvula (Motschulsky, 1875); Perapion (Perapion) connexum (Schilsky, 1902); Ceratapion (Echinostroma) scalptum caviceps (Desbrochers des Loges, 1870); Metapion ermischi (Voss, 1969); Protapion angusticolle (Gyllenhal, 1833); Allomalia quadrivirgata (Costa, 1863); Corimalia fausti fausti (Reitter, 1890); Bagous (Macropelmus) claudicans Boheman, 1845; B. (Macropelmus) dieckmanni Gratshev, 1993; B. (Macropelmus) lothari Caldara & O'Brien, 1998; Brachycerus lutosus Gyllenhal, 1833; Stenopelmus rufinasus Gyllenhal, 1835; Tanysphyrus ater Blatchley, 1928; Aulacobaris kiesenwetteri (Faust, 1890); Labiaticola despicatus Faust, 1889; L. melas (Boheman, 1836); Ceutorhynchus levantinus Schultze, 1898; C. merkli Korotyaev, 2001; C. scrobicollis Neresheimer & H. Wagner, 1924; C. talickyi Korotyaev, 1980; C. varius Rey, 1895; Microplontus millefolii (Schultze, 1897); Ranunculiphilus (Austroceutorhynchus) italicus (C. N. F. Brisout de Barneville, 1869); Thamiocolus roubali Dieckmann, 1973; T. sinapis (Desbrochers des Loges, 1893); Gymnetron tibiellum Desbrochers des Loges, 1900; Miarus hellenicus Dieckmann 1978; M. solarii Smreczyński, 1957; Philernus ponticus Korotyaev, 1979; Sibinia (Sibinia) femoralis Germar, 1823; S. (Sibinia) variata Gyllenhal, 1835; Tychius (Tychius) ochraceus Tournier, 1873; T. (Tychius) subsulcatus Tournier, 1874; Ptochus (Ptochus) porcellus Boheman, 1834; Omias murinus (Boheman, 1842); Otiorhynchus (Pseudocryphiphorus) zebei Stierlin, 1861; Argoptochus (Argoptochus) markovensis Angelov, 1987; Polydrusus (Conocetus) baudii (Faust, 1889); Sitona ophthalmicus Desbrochers des Loges, 1869; Chlorophanus viridis balcanicus Behne, 1989; Rhabdorrhynchus echii Brahm, 1790; Bangasternus planifrons (Brullé, 1832); Larinus (Larinomesius) atomarius Capiomont, 1874; L. (Larinomesius) canescens Gyllenhal, 1835; L. (Larinomesius) syriacus Gyllenhal, 1835; L. (Phyllonomeus) filiformis Petri, 1907; Lixus (Epimeces) scolopax Boheman, 1835.

Anthropogenic impact on the shores and the bottom of the Jebriyan bay in the Northwestern part of the Black Sea

The Jebriyan Bay is located in the northern part of the Kiliya Danube Delta, at a junction of the delta cone and the indigenous coast. This is a zone of very high anthropogenic impact on the Danube Biosphere Reserve. The two opposite shores of this bay are fundamentally different. Along the northern shore, the Northwest coastal sand sediment flows discharge from the Cape of the Great Fontanne to the Jebriyan Bay. That is why the northern coast of the bay is made up of sandy forms of coastal topography (marine accumulative terrace and spit). The southern coast is deltaic; composed of a mixture of muddy, siltstone and sandy sediments. The area of the bay is limited to isobaths –11 m and is about 80 km2. The bottom of the bay has a gentle relief, made up of smooth outlines, with an average depth of 6.2 m. The shape of the transverse profile of the underwater slope is mostly convex. The natural system of the bay was affected by fishing, recreation, shipping and industrial sand production on coastal accumulative landforms. Coastal fishing uses a system of fixed bottom seines and small motorized floating equipment. Recreational facilities are designed to serve about 350 thousand people during the warm period each year. The impact of shipping was expressed in the construction and operation of the seaport of Ust-Dunaysk, together with suitable canal and the technical canal between the sea and the branch of the delta breakthrough the system of the large Ochakov branch. The ladle port had an area of about 1.5 km2, a maximal depth of 16 m, and an average depth of 13.7 m. The trough was connected to the Ochakov branch of the Danube Delta by a technical canal with a depth of 4 m. Vessels could enter the harbor of Ust-Danube through an access navigation channel with a depth of 11–12 m and a bottom width of 125 m. The port was used for the transshipment of large containers, general forest cargo from ocean vessels (displacement of 60–100 thousand tons) on regular sea lines from the countries of Southeast Asia to the Black Sea, to the Danube and further to the countries of Central Europe and to the ports of the North and the Baltic Seas. But it was unfortunate that the port construction site did not last as expected. Between 1980–2010 the harbor and approach canal of Ust-Dunaysk were filled with Danube river sediments. The example of Jebriyan Bay has shown that when executing any type of sustainable nature management project, it is very important to take into account the natural milieu.

Land area increase in Ukrainian part of the Danube delta

The quantitative indicators of land growth in the Ukrainian part of the Danube delta are considered. Comparison of Landsat satellite images in three key areas of the delta showed that for the period 1975-2020 the area of wetlands at the mouth of the Сhilia channel increased by 1448 hectares due to the accumulation of sediments between the Starostambul and Limba branches and their overgrowth with vegetation. In the area of the Bystroe channel, the area of new lands increased by 1037 hectares due to the artificial deepening of this channel for the Ukrainian ships passage into the Danube River and the deposition of sediments along the coast. A slightly smaller increase in land cover (797 ha) was found in the northern part of the coast of the Ukrainian part of the delta, where saline and carbonate soils are formed. In the future, active land growth is expected in the Musura bay between the mouths of the Starostambul and Sulina branches, ie at the contact of Ukraine and Romania. Some changes in these parameters are expected after a powerful flood in 2021, which will become known after the establishment of a relative equilibrium between the processes of accumulation and erosion after this extreme event.

Physical-chemical properties of the surface water from shallow lakes of the Matita-Merhei Unit, Danube Delta, Romania: current state and environmental significance

This study aimed to assess the water quality of certain lakes (Bogdaproste, Trei Ozere and Radacinos) belonging to the Danube Delta, Romania. Deltaic ecosystems are subject to natural and man-made environmental stressors. If in the past these ecosystems were largely threatened by eutrophication and organic/inorganic pollution, nowadays, we must focus on hydro morphological impact. This refers to the physical character and water content of the aquatic environment, impoundment (dams and flood gate), channelization and embankments, as well as clog/siltation of lakes. Environmental parameters are those physical, chemical and biological indicators used to characterize a freshwater body, and, which vary in time and space. In this regard, 44 water samples were collected in the dry season from the three lakes, for analysis of physical-chemical quality indicators. A series of physical (T, EC, TDS, turbidity, TSS, transparency) and chemical parameters (pH, DO, nutrients, SiO2, TOC, SO42-, ORP, technophilic elements) were considered. The results obtained in the physical-chemical analyses revealed that the majority of parameters were found in line with enforcing environmental regulations. Despite that, P-PO43- and Cd concentration results of some samples were found above certain permissible limits set by the normative. Probably, these inadvertences can be associated with local conditions of the transitional deltaic environment. Further analysis is required conducting repeated measurements with the same question, meaning a routine monitoring, especially P-PO43- and Cd. Finally, it was concluded that the results of this study showed a good quality of water in investigated lakes that did not pose potential health and environmental problems related to the biota.

Perceptions on the Implementation of the Integrated Territorial Investment Mechanism (ITI) and Its Impact on Sustainable Development and Resilience of Danube Delta

The Integrated Territorial Investment mechanism (ITI) was implemented in Romania to the territory of ITI Danube Delta in the 2014-2020 programming period. In this respect, the present article aims to analyze the process of implementation of the ITI mechanism on the Danube Delta territory in order to find out the impact of its implementation on the so­cio-economic development of the area and on its re­silience, as well as the main problems encountered by the responsible authorities for managing this pro­gramme and the beneficiaries of these funds. The research methodology consists of a survey conduct­ed by using two questionnaires designed by the au­thors. The study had 42 participants from the fund managers’ category and 71 participants from the beneficiaries’ group. The study revealed a positive perception among all the participants which consid­ered that ITI impacts the resilience of the Danube Delta territory to a medium extent. The most import­ant problems encountered in the implementation process were the pre-financing process, the guides’ conditions that are not adapted to the beneficiaries’ needs and the public procurement process. The re­search revealed a high degree of satisfaction from both types of respondents regarding the ITI mech­anism and a good relation between the managing institutions and beneficiaries.

Ecological conditions of the Waterchestnut (Trapa natans L.) in the Danube Delta (Romania)

The diversity of water body types in the Danube Delta offers appropriate ecological niches for the colonisation of frequently large stands of the waterchestnut (Trapa natans). Their phytocoenoses were observed in slowly running and standing waters from clear, sediment-poor, to turbid and sediment-rich waters on muddy ground. Trapa natans occurs in standing, and slowly running, waters and is well adapted to fluctuation of water level changes. The water dynamics is responsible for the composition of accompanying species of the phytocoenoses. The particular zonation, demonstrated by a cross section shows the adaption to the structure and the water flow of certain water bodies. Comparing older and newer research data, a decline of the populations of waterchestnuts became visible.