Analysis of the Floods Effects in June 2016 in the Voronet River Hydrographic Basin

The paper presents an analysis of the hydrological risk parameters registered in the Voroneţ river basin. The studies and researches took place on the Voroneţ River after the June 2016 floods. The research has taken into account the hydrological risk parameters of the last 20 years recorded in the Siret River Basin. The river basin of the Siret River has been affected by multiple floods in recent years. The floods have morphologically modified the minor and the major river Voroneţ, a situation that influenced the floodplain areas in the urban environment and outside. The research analyzed the precipitation, the liquid flows (minimum, average and maximum), the way of formation and evolution of the floods, the volume of the damage produced, etc. The investigation of the precipitation volume indicated a number of factors that have prevailed over the last 20 years. The precipitation value was 71.6 l/m2 in two days. The flow recorded in the downstream section of the river was 118.12 m3/s (the probability of calculation is 1%). The processing of liquid flow data revealed more flood flows in the same year. The effects of the floods have brought about the excessive degradation of shore defense works (about 2600 m) on the Voroneţ River located in the town of Gura Humorului, Voronet neighborhood and outside the city. The county road DJ 177D was degraded on 1600 m and two bridges were destroyed. Floods have resulted in the destruction of some economic and social objectives in the coastal area. The parameters of hydroclimatic risk highlighted by this research require special conditions for the design of works in the riverbed and the riparian area

Rehabilitation and modernization of irrigation plots for current operating conditions

The optimal exploitation of irrigation systems after 1989 imposed a series of conditions determined by the political regime, the form of land ownership, the labor shortage and the influence of climate change in the last period of time. Irrigation plots in Romania, basic components of large irrigation systems built before 1989, are in an advanced wear phase and no longer meet the current technical requirements in terms of management. A requirement for the existence of an irrigation system is dictated by the presence of viable water sources in terms of volume and permanence during the irrigation season. The form of private ownership of agricultural land imposed a restructuring of irrigated areas according to the way of association of owners. Climate change coupled with labor shortages in the agricultural sector has necessitated the adoption of irrigation methods that reduce the rate of irrigation and use automated irrigation equipment. The paper aims to present a series of directions for refurbishment and modernization of irrigation plots based on studies and research conducted in irrigation systems in Moldova

The rehabilitation of pipe network from sprinkler irrigation plots

The paper presents an analysis of the rehabilitation directions for the pipe network from irrigation plots used for aspersion watering. The rehabilitation and modernisation of the pipeline network is differentiated on the structural components: main pipelines - secondary - distribution, hydrants, hydraulic installations, anchorage blocks, undercrossing, overcrossing etc. The case study was drawn up for an sprinkler irrigation plot network, Doniceasa-Falciu Plot 7, Vaslui County. Tertiary irrigation pipes are fed by single-line pumping stations located in the canal. The discharge pipe of the pumping unit is made of 200 mm diameter steel. The tertiary irrigation pipe with a length of 1020- 1400 m is made of asbestos and PVC-G with decreasing diameter from 200 mm to 125 mm for Q = 70-95 l/s and P = 6,50 - 7,50 bar. The pipeline has irrigation hydrants with diameters of 100 mm and 150 mm. The rehabilitation process of the pipeline network is based on a hydraulic and resistance calculation abstracts. The paper presents rehabilitation options for the pipes from the sprinkler irrigation plot

Studies and research on water losses from irrigation systems

The advanced degree of wear of the irrigation system infrastructure determines the occurrence and maintenance of water losses. The research was conducted in irrigation systems located in the eastern part of Romania and which have different periods of operation, but all performed before 1990. The research highlighted the complexity of the process of degradation of structural elements and the development of water loss. The structural degradation of the canals and pipes under the action of natural and anthropogenic factors determined the appearance of water losses and, implicitly, the decrease of the hydraulic efficiency. The research highlighted a degree of degradation of the supply and distribution channels of about 40-60%. An important influence in the degradation action was the absence of maintenance and repair works. Significant water losses are recorded in the pipelines. Their value reaches 18 - 27% of the transported flow, being determined by the wear of the material and the aging of the components of the hydraulic installations. Water losses are of the visible, hidden and background type. The use of European funds to rehabilitate irrigation systems requires reducing water losses

Fast floods on the tributaries of Trotuș river, in the context of current climate change

The paper presents an analysis of the flood formation module in the Trotuș river basin and especially on its tributaries. A special situation was recorded in 2004 when the floods formed on the tributaries presented very high flows, but which did not substantially influence the flow of the main course. The floods produced on the river / stream / torrent type tributaries (example: Asău, Agăș, Goioasa, Iedera) presented flows that exceeded the accepted calculation probabilities. The floods produced were both the effect of torrential rainfall and the configuration of the lower sectors of the riverbeds. The floods produced in 2004 on a series of tributaries of the Trotuș River presented maximum flows that exceeded the calculation probabilities of 0.1% (Agăș - 183 m3/s, Beheghet - 50.70 m3/s, Goioasa - 67.10 m3/s, Iedera - 127 m3/s). The sudden change of the slope on the lower course of the tributaries determined the deposition of a large volume of alluvium, a situation that reduced the flow section and even blocked it. The result of the corroboration of natural and anthropogenic situations in the propagation of these floods is evidenced by the great destruction produced in a territorial area with numerous human communities and important economic activities

Studies and Research on Maximum Flows of the Trotuş River in 1990-2017

Research has analyzed components of the climate and hydrological regime on the Trotuş River and its tributaries over the past 30 years. The hydrological risk was determined by natural causes, but also by anthropogenic causes. Parameters of hydroclimatic risk are represented of the torrential rainfall, flood flows, high frequency of high flows, high erosion speeds etc. The research revealed that at very low intervals (3-5 years) there were floods with very high flows. Changing the climate regime (precipitation concentration on small days) and the natural relief forms in the hydrographical basin (the Eastern Carpathian Mountains) allowed natural risk to occur in the hydrological regime of the Trotuş River. Anthropic factors, in particular, the modification of the leakage coefficient by deforestation of forests and the change of agricultural use of land with large slopes have contributed to the occurrence of anthropogenic risk in the Trotuş River basin. Corroboration of the two types of risk, natural and anthropic, has led to a hydrological disaster regime in the Trotuş River Basin

THE IMPACT OF WATER EXTRACTION FROM DRILLED WELLS ON THE PHREATIC

Abstract. Nowadays, worldwide, even in the economically developed countries, for what is the need to improve irrigation facilities, all kind of technical, organizational, institutional and scientific solutions are sought. The improvement of irrigation systems can be driven by the evolution or the altering of their performance parameters and goals during the operation process. The goals are various: some are related to the achievement of enhanced performances as regards the agricultural, economical and hydraulic efficiency of the irrigation system; some are related to the proper evacuation of excess surface water and the regulation of groundwater levels via drainage systems; some are related to the trend to reduce the amount of eroded soil to a minimum and to ensure a better and cheaper protection of soils. Performance becomes strategic when it takes the form of an activity carried along a number of years, situation when it becomes possible to assess the way in which resources have been used and what has been the value of the operational level. Also it is possible to review the objectives of the long-term operation and of all operational procedures, so to make the irrigation system proper and compliant to the farmers', managers' and community's demands

Research on the Sustainable Development of the Bistrita Ardeleana River through the Resizing of Weirs

The layout of water resources and the complex and rational use of them have an important role in the socioeconomic activities of an urban settlement. Transversal hydrotechnical constructions such as weirs reduce the longitudinal connectivity of rivers and streams, affecting river biodiversity as well as water quality. This paper presents an alternative method that will help restore connectivity. In order to choose the best solution, topographical measurements were taken with a total topographical station, and a professional drone was used to obtain an updated orthophoto plan. After processing the data obtained in the field, engineering software capable of simulating flow, sediment transport, and water quality in rivers was used. With the help of the software, two hypotheses were realized: hypothesis A, the case with only one weir in place, and hypothesis B, when we have the proposed case with the lowering of the height of the weir’s crest and the construction of three new control weirs downstream of it. In conclusion, the lowering of the current weir’s crest and the construction downstream of it of three new weirs of low height would have a favorable effect from an ecological and a morphological point of view, without very big consequences on the disturbance of the flow from a hydraulic point of view

Research on the Sustainable Development of the Bistrita Ardeleana River through the Resizing of Weirs

The layout of water resources and the complex and rational use of them have an important role in the socioeconomic activities of an urban settlement. Transversal hydrotechnical constructions such as weirs reduce the longitudinal connectivity of rivers and streams, affecting river biodiversity as well as water quality. This paper presents an alternative method that will help restore connectivity. In order to choose the best solution, topographical measurements were taken with a total topographical station, and a professional drone was used to obtain an updated orthophoto plan. After processing the data obtained in the field, engineering software capable of simulating flow, sediment transport, and water quality in rivers was used. With the help of the software, two hypotheses were realized: hypothesis A, the case with only one weir in place, and hypothesis B, when we have the proposed case with the lowering of the height of the weir’s crest and the construction of three new control weirs downstream of it. In conclusion, the lowering of the current weir’s crest and the construction downstream of it of three new weirs of low height would have a favorable effect from an ecological and a morphological point of view, without very big consequences on the disturbance of the flow from a hydraulic point of view

Study on bioremediation of heavy metal-contaminated soils using the bacteria-plants synergy

It is well known that different plant species can be associated with microbial communities with unique characteristics. Various groups of viable microorganisms from soils can improve the plant growth mechanism, having the role of hiperaccumulators and mitigate the toxic effects of heavy metals on plants. Moreover, the bioavailability and retention of metals can be changed and improved as a result of microbial activity in soil. In order to survive and grow in soils contaminated by heavy metals, certain species of plants develop a synergistic mechanism with the rizo-associated bacteria, which can immobilize, mobilize or transform metals, making them inactive, thus allowing plants to tolerate them in the absorption process. This paper proposes a management strategy for the microbial populations in the rizosphere, by the application of microbial inoculations, consisting in a consortium of plant growth and promoting the rhizo-and nitrogen-fixing bacteria to act as allies of plants and biofertilizers, which could provide beneficial systems for ecosystem restoration