Isotopic tracers and water quality indicators （TDS （Total Dissolved Solid）, Cl^- and NO3^-contents） were used to characterize the recharge and control of the quality of groundwater in the alluvial aquifer beneath ...Isotopic tracers and water quality indicators （TDS （Total Dissolved Solid）, Cl^- and NO3^-contents） were used to characterize the recharge and control of the quality of groundwater in the alluvial aquifer beneath of the N＇djamena city. For this study, a total of 92 waters samples were taken and this included 67 wells, 21 pumps and 4 surface waters. Some groundwater has 6180 and 62H values close to those of the city of N＇djamena and/or the Chad river rains. However, all sampled points are below the Global Meteoric Water Line reflecting their evaporated characters. The interpretation of the isotopic tracers highlights that the recharge of the analyzed ground waters may result from two major mechanisms： （1） direct infiltration of local precipitation; （2） lateral inflow of river waters. The upper aquifer is the most vulnerable to pollution, especially during the recharge period. This pollution is due to the leaching of soils during the rainy season and the rise of the groundwater level which accompanies the overflowing of the Chad and causes the leaching of the polluted horizons of the unsaturated zone. In contrast, the lower aquifer has acceptable concentrations of solutes.展开更多
This paper examines the distribution and structure of populations of a medicinal and culinary herb native to Armenia. As one of the first countries to join the Convention on Biological Diversity （CBD）, Armenia has a...This paper examines the distribution and structure of populations of a medicinal and culinary herb native to Armenia. As one of the first countries to join the Convention on Biological Diversity （CBD）, Armenia has a strong interest in assessing the biodiversity of its native flora and identifying threats to the conservation of these species, particularly those with economic value. Only limited information, however, is available at this time on the genetic biodiversity, population location, structure and size, and conservation status of most of these species. This paper reports the results of five consecutive years of field studies conducted in Armenia to 1） re-locate native populations of the important medicinal and culinary herb, Origanum vulgare L., 2） locate new populations, and 3） assess the growth pattern and dynamics of the populations. The quadrat sampling technique was used to identify key elements that determined population size and abundance. GPS maps of present and past population distributions were created. Particular habitat and environmental factors were identified as crucial to predicting the future conditions of these populations under the impact of global climate change. The research provides a baseline dataset that can be used for the development of further conservation strategies of this important medicinal and culinary species in Armenia.展开更多
文摘Isotopic tracers and water quality indicators （TDS （Total Dissolved Solid）, Cl^- and NO3^-contents） were used to characterize the recharge and control of the quality of groundwater in the alluvial aquifer beneath of the N＇djamena city. For this study, a total of 92 waters samples were taken and this included 67 wells, 21 pumps and 4 surface waters. Some groundwater has 6180 and 62H values close to those of the city of N＇djamena and/or the Chad river rains. However, all sampled points are below the Global Meteoric Water Line reflecting their evaporated characters. The interpretation of the isotopic tracers highlights that the recharge of the analyzed ground waters may result from two major mechanisms： （1） direct infiltration of local precipitation; （2） lateral inflow of river waters. The upper aquifer is the most vulnerable to pollution, especially during the recharge period. This pollution is due to the leaching of soils during the rainy season and the rise of the groundwater level which accompanies the overflowing of the Chad and causes the leaching of the polluted horizons of the unsaturated zone. In contrast, the lower aquifer has acceptable concentrations of solutes.
文摘This paper examines the distribution and structure of populations of a medicinal and culinary herb native to Armenia. As one of the first countries to join the Convention on Biological Diversity （CBD）, Armenia has a strong interest in assessing the biodiversity of its native flora and identifying threats to the conservation of these species, particularly those with economic value. Only limited information, however, is available at this time on the genetic biodiversity, population location, structure and size, and conservation status of most of these species. This paper reports the results of five consecutive years of field studies conducted in Armenia to 1） re-locate native populations of the important medicinal and culinary herb, Origanum vulgare L., 2） locate new populations, and 3） assess the growth pattern and dynamics of the populations. The quadrat sampling technique was used to identify key elements that determined population size and abundance. GPS maps of present and past population distributions were created. Particular habitat and environmental factors were identified as crucial to predicting the future conditions of these populations under the impact of global climate change. The research provides a baseline dataset that can be used for the development of further conservation strategies of this important medicinal and culinary species in Armenia.
