29 research outputs found
Changes in the forest ecosystems in areas impacted by aridization in south-western Romania
BACKGROUND: In the past few decades, global climate change has accentuated the intensification of aridization in South-Western Romania, with direct and indirect consequences on the quality of forest ecosystems. In addition to qualitative deterioration, the quantitative changes brought about by intensive anthropic deforestation have created the conditions for a decline in the size of forest areas on vast tracts of land. The paper aims to analyze the qualitative and quantitative changes in the forest ecosystems in South-Western Romania, changes due to the synergic context of the global climate changes and the anthropic pressures of the past three decades. In order to capture the evolution of aridization in the study area, specific aridization indexes have been calculated, such as the De Martonne index and the UNEP aridity index. 1990 and 2011 satellite images have been used in order to quantify the qualitative changes. RESULTS: The results obtained indicated that, in the past two decades, the quality of the biomass declined as a result of the increase in the climatic aridity conditions (De Martonne si UNEP aridity index, indicating in the last decades, annual values under 15 mm/°C, and under 0.5 mm/mm, that means that the values situated under these thresholds, describe arid and semi-arid climate conditions). Also, the uncontrolled logging across vast surfaces caused the loss of forest ecosystems by 7% in the overall study area, during the last three decades. CONCLUSIONS: The severe effects of aridization meant, first of all, a significant decline in the quality of the ecosystem services supplied by forests. In the absence of viable actions to correct the present situation, the extremely undesirable consequences of an ecological and social nature will arise in the near future
GENERAL CONSIDERATIONS REGARDING THE IMPACT OF THE VIDRARU LAKE HYDRO FACILITIES ON THE ENVIRONMENT
After presenting the morphometric parameters and the initial physicalgeographical conditions of the drainage basin where the Vidraru Reservoir is located, on the bank of the Argeş River, this article briefly analyses the impact of the basin on the riverine and regional environment
Quantification of the aridity process in South-Western Romania
The report released by the Intergovernmental Committee for Climate Change indicates that Romania ranks among the top seven countries in Europe that would be strongly impacted by aridity in the next few years, with climate changes consisting in a rise of average annual temperatures by as much as 5°C. The research work was conducted in the South of the Oltenia South-Western Development Region, where more than 700,000 hectares of farmland is impacted by aridification, more than 100,000 hectares among them impacted by aridity. Research methodology encompassed the analysis of average annual temperatures over the time span data was available for, at three weather stations, an analysis of average annual precipitations, an analysis of the piezometric data, the evolution of land use as a result of the expansion of the aridity process. The assessment of the aridity process also involved taking into consideration the state of the vegetation by means of the normalized difference vegetation index (NDVI), used to assess the quality of the vegetal stratum, an important element in the complex analysis of the territory. The aridity process is an effect of global warming, and, based on the results of this study, the post-1990 escalation of its effects was brought about by socio-economic factors. The destruction of the irrigation systems and protective forest belts because of the uncertain situation of land ownership are the main factors that contributed to amplification of the effects of aridity on the efficiency of agricultural systems that nowadays are exposed to very high risks
Use of hybrid renewable energy systems for small communities
The purpose of this article is to present how the sizing of a hybrid renewable energy system is done for a community of three hundred and five households located in a Delta, starting from the optimization of hybrid energy system for a single household. The methodology used in solving this problem is based on multiple options. The first option consists in determined energy needs, maximum power consumption in cold season and in adapting the solution for the production of electricity by a hybrid plant. The second option consists of energy needs resulted in average consumption of electricity in warm season and in adapting the solution for the production of electricity from a hybrid plant. In conjunction with the demand for electricity for the entire community one will get energy demand by aggregating household level (kWh/household). The novelty of this approach lies in the method used by these hybrid systems for obtaining electricity in small communities, isolated from this case study. Based on the results obtained the method can be expanded the implementation of these projects that use hybrid renewable energy systems
Use of hybrid renewable energy systems for small communities
The purpose of this article is to present how the sizing of a hybrid renewable energy system is done for a community of three hundred and five households located in a Delta, starting from the optimization of hybrid energy system for a single household. The methodology used in solving this problem is based on multiple options. The first option consists in determined energy needs, maximum power consumption in cold season and in adapting the solution for the production of electricity by a hybrid plant. The second option consists of energy needs resulted in average consumption of electricity in warm season and in adapting the solution for the production of electricity from a hybrid plant. In conjunction with the demand for electricity for the entire community one will get energy demand by aggregating household level (kWh/household). The novelty of this approach lies in the method used by these hybrid systems for obtaining electricity in small communities, isolated from this case study. Based on the results obtained the method can be expanded the implementation of these projects that use hybrid renewable energy systems