Hviidpate2821

Moreover, the groundwater chemistry in the research area is affected by mining and chemical fertilizer application for agriculture. Furthermore, the hydrochemistry of the Weihe River catchment is affected by cation exchange, although this was not obvious in some regions of the Jinghe River catchment. The overall groundwater quality of the two catchments was good, with the Jinghe River water quality being better than in the Weihe River catchment. Based on SSP, SAR, and PI, the groundwater in some parts of the study area cannot be directly used for irrigation as this would result in salinization and, thus, inhibit plant growth. Overall, the groundwater quality in the south of the study area is better than in the north, and is better in the Jinghe River catchment than in the Weihe River catchment according to these three indicators. This study provides a basis for the sustainable development of two catchments, providing baseline data for groundwater quality management.To elucidate the effects of long-term fertilization and cultivation on runoff rates and runoff-related nitrogen (N) and phosphorus (P) losses, the following five treatments were established on sloping purple soil cropland① no fertilizer with downslope tillage (CK), ② combined application of manure and fertilizer with downslope tillage (T1), ③ chemical fertilizers with downslope tillage (T2), ④ chemical fertilizer with increasing fertilization with downslope tillage (T3), and ⑤ chemical fertilizer with contour tillage (T4). The runoff rate, runoff-related total N (TN), and total P (TP) concentrations and their loss rates from 104 erosive rainfall events were determined for the period 2008-2019. Results showed that although runoff rates were not significantly different among the fertilization treatments (P>0.05), runoff was markedly lower in fertilization treatments than in the CK treatment (P0.05), but were all higher than the contour treatment (P less then 0.05). Runoff rates showed no significant relationships with TN and TP concentrations in the CK, T1, and T2 treatments but were significantly negatively linearly correlated in T3 (P less then 0.05) and significantly positively linearly correlated in T4 (P less then 0.05). These results potentially provide scientific guidance for the prevention and control of agricultural non-point source pollution on sloping croplands in the purple soil area.Non-point source pollution has become an important factor affecting the aquatic ecological environment and human health, and the analysis of spatial-temporal variations in non-point source pollution risks is an important prerequisite for pollution control. Based on land-use and land-cover data from 1980 to 2020, the potential non-point source pollution index (PNPI) model was applied in the upper Beiyun River Basin using different weighting methods. The results showed that① The potential risk of non-point source pollution is high in the southeast and low in the northwest of the basin. Between 1980 and 2020, the total area of extremely high-risk and high-risk non-point source pollution regions showed a decreasing trend, and the main types of land use for extremely high-risk and high-risk regions gradually evolved from paddy fields, drylands, and orchards to urban and rural residential land; ② The weighting of the land use index determined by the mean-square deviation decision, entropy, coefficient of variation, and expert scoring methods was largest among the three PNPI indices, with average weightings of 0.46, 0.53, 0.45, and 0.48, respectively. However, the weightings for runoff and distance indices determined by different weighting methods were notably different, and the proportions of regions with different levels of non-point source pollution risk also varied; ③ The exponential function method, which describes the relationship between source factors and transport factors by constructing the exponential functions of land use, runoff, and distance indices, provided results that are more consistent with the spatial distribution characteristics of non-point source pollution risk in the basin. The proportions of extremely low-risk and extremely high-risk regions are 54.22% and 6.23%, respectively. These results provide scientific reference for risk analysis and the control of non-point source pollution in this basin.In order to explore the characteristics and environmental significance of available nitrogen and phosphorus in different land-water transition zones, soil and sediment samples from three study areas, including the upstream watershed of Minjiang River (MJU), western watershed of Hongze Lake (HZW), and western watershed of Taihu Lake (THW), were collected and analyzed. The results showed that the contents of total nitrogen and phosphorus in THW were higher than those of other two study areas. The contents of nitrogen and phosphorus in sediments were higher than those in soils of HZW. The distribution trend of available nitrogen and available phosphorus was generally consistent with the distribution trend of total nitrogen and phosphorus. selleck chemicals llc The proportions of available nitrogen and phosphorus in THW and HZW were much higher than those in MJU, and the proportions of available nitrogen and phosphorus in sediments were higher than those in soils. The physiochemical properties such as pH value, organic matter, and iron and aluminum oxides were related to the available nitrogen and phosphorus in the soil and sediment, but correlations between them were complex. The distribution patterns of available nitrogen and phosphorus in the soil and sediments of the land-water transition zone reflect the impacts of the natural environment and human activities, particularly those of the latter.To explore the spatial and temporal response of water quality to external load reduction in Lake Taihu, Jiangsu Province, China, and clarify the exogenous load reduction under different water inflow and pollution conditions, a water quality model was constructed and the inflow boundaries were divided into seven groups based on the EFDC model. Taking COD and ammonia nitrogen as output targets, the sensitivities of Taihu Lake water quality boundaries were analyzed using a local sensitivity analysis. The results showed that COD and ammonia nitrogen concentrations of each lake area were more sensitive to the boundary load of the lake area than the rest of the lake area, and the sensitivity index was the highest in the Northwest Lake area. Furthermore, the improvement rates of mean COD concentrations in the whole lake decreased by 28.40%-34.71% in the dry season relative to the wet season, and the ranked sensitivity order of the boundaries was as followsNorthwest Lake boundary > Zhushan Lake boundary > Gonghu Lake boundary > Meiliang Bay boundary > Southwest Lake area boundary > Eastern Lake area boundary > East Lake Taihu boundary. The average improvement rates of ammonia nitrogen concentrations in the whole lake were 41.59%-42.34% higher in the dry season relative to the wet season, and the ranked boundary sensitivity order was as followsNorthwest Lake boundary > Meiliang Bay boundary > Zhushan Lake boundary > Gonghu Lake boundary > Southwest Lake boundary > East Lake Taihu boundary > Eastern Lake area boundary. This difference was affected by algal growth and metabolism, and artificial water diversion and drainage. Therefore, it is necessary to consider the reduction period and inflow location according to different water-quality indicators when planning external prevention and control measures in large lakes.The soil and water assessment tool (SWAT) model is currently one of the most widely used watershed models in China. Since the model has been developed with distributed parameters and is customized to satisfy the environmental characteristics of the U.S.A., determining appropriate parameter values that reflect local features for model application in China is crucial. Some studies have proposed parameter values for the SWAT model by summarizing reported values in the literature; however, these studies neither differentiate the literature with respect to its quality nor consider non-uniformity in parameter values and the impact of extreme values. To address this, an indicator system for assessing the quality of SWAT model research was established, taking into account the process of model development, parameter calibration, and model validation as well as model performance. This screening approach was applied to a total of 428 journal articles on SWAT model research published between 2015 and 2017 were retrieved SWAT model application in China are proposed in the form of confidence intervals, and specific suggestions are also provided based on data availability.To promote the efficient utilization of China's reuse water resources and optimize the allocation of water resources, an analysis of factors influencing the development and utilization of reuse water resources was conducted. The uniqueness and competitiveness of reuse water resources were analyzed, and the driving and constraint mechanisms were revealed. A potential indicator system for the bilateral coordination of the supply and demand of reuse water was also established. Based on redundancy analysis (RDA), key indicators for the prediction of reuse water development and utilization potential were screened. On this basis, a national-scale reuse water development and utilization potential prediction model was constructed (the random effects model, REM). Given some uncertainty in the parameters of the REM model, the confidence interval ranges of the parameters at the 10%-90% quartile levels were identified. The results show that four indicators (ecological water consumption, density of water supply pipelines in built-up areas, fixed asset investment in the construction of reuse water treatment facilities, and total wastewater treatment) are closely related to the development and utilization of reuse water and, hence, are key indicators. The REM for the potential prediction has a high fitting accuracy, which can effectively reflect the fluctuations in the observed values with a maximum fitting error of -8.5%. China's reuse water development and utilization will continue to maintain rapid growth long into the future, reaching 12.9 billion m3 by 2025. This will help optimize national urban water supply structures and improve the reuse rate of regional water resources.Congenital cytomegalovirus (cCMV) is the most common congenital infection in the United States, with 1 of 200 live births affected. It is the leading viral cause of intrauterine fetal demise and miscarriage. It is a common cause of neonatal hearing loss, second only to genetic factors. Yet, health care provider awareness remains low. The purpose of this article is to provide a brief overview of the epidemiology, presentation, diagnosis, and treatment of antenatal cytomegalovirus (CMV) infection and cCMV in the neonate. Maternal CMV infection in pregnancy often presents with mild cold-like symptoms or is asymptomatic. The virus can be vertically transmitted to a growing fetus, the risk of transmission and severity of fetal impact varying by timing of exposure during pregnancy. Most neonates born with cCMV show no signs at birth, yet 15% to 25% will have long-term adverse neurodevelopmental conditions. Misconceptions that cCMV cannot be prevented or that neonates born without signs of the disease will be unaffected are common.