This paper addresses the distribution and occurrence of harmful organic substances in coal gangue dump from Jiulong Coal Mine
and its influence on the environment. The samples were taken from the coal gangue dump and coal waste water stream and analyzed
by organic geochemical methods. The results indicate that the coal gangues contain abundant harmful organic substances like
polycyclic aromatic hydrocarbons. The TOC and sulfur contents of the samples are much higher than those of the background
sample except Sample JL7. The contents of organic bulk parameters are relatively high. Ten carcinogenic PAHs were identified
and these harmful organic substances have influenced the surrounding area. Along the waste water stream, organic substances
pollute at least 1,800 m far from the coal gangue dump. 相似文献
The objective of this study is to measure and evaluate the ecosystem health levels of 31 Chinese capital cities in 2004 through an emergy synthesis framework. A system of indicators was developed corresponding to the four factors of urban ecosystem health including efficiency, structure, impact and flux. Furthermore, combined with individual indices, an emergy-based urban ecosystem health index (EUEHI) was proposed to measure and evaluate the health levels among various typical cities in China, which offers an integrated evaluation tool in view of urban production, trade and consumption. The results showed that there are intrinsic differences among six clusters associated with driving mechanisms distinguishing the rankings of urban health levels. After lining the cities of similar health levels with cluster map, the spatial distribution of the urban health is found to be arch-shaped, increasing initially and then decreasing from coast to inner land. This kind of spatial hierarchy is per se compatible and consistent with the hierarchical theory of emergy synthesis. The results also revealed double restrictions of urban health between economy and environment. Moreover, the interaction analysis was used for mirroring the driving mechanism of urban ecosystem health. Three conclusions were arrived at. Firstly, environmental health is inversely related to the economic health in China, indicating that cities cannot achieve win–win between environment and economy in the current urban development mode. Secondly, based on economy-driven mode, four quadrants were divided in the city division map, wherein 43.33% of the concerned cities developed in high economy-restriction mode, which means low economic level is still an important limiting factor for the major cities of China. Finally, based on environment-driven mode, two sections were divided, of which weak environmental dominance mode expounds the special characteristics of urban environment with obvious fragility. 23.33% of the 30 cities were in the intermediate state, which means a few correspondingly unhealthy cities should develop concrete polices for the urban ecosystem restoration. 相似文献
This paper explores the crucial part that faith‐based organisations (FBOs) play in acting as intermediaries between international donors and local faith communities (LFCs) implementing humanitarian relief projects for Syrian refugees. Humanitarian responses to the mounting Syrian refugee crisis have coincided with greater collaboration between international donors and LFCs. This cooperation often is facilitated by a complex web of non‐state intermediaries at the international, national, and local level. This study probes the breadth of roles of these intermediaries, drawing on primary data from case studies of two Christian intermediaries supporting Christian LFCs as they deliver aid primarily to Muslim Syrian refugees in Jordan and Lebanon. The results of the study are connected to the wider literature on LFCs in humanitarian response, revealing how intermediaries address issues of accountability, capacity‐building, impartiality, neutrality, and professionalism. The paper concludes by offering suggestions for further research on intermediaries as key actors in the localisation of humanitarian assistance. 相似文献
The objectives were to (1) delineate the complex set of rules governing the fate and transfer of water rights as agricultural land is urbanized in Texas and New Mexico in the United States and Chihuahua in Mexico and (2) estimate the change in water use as a result of such urbanization. Important additional determinants of water use in the region include intensification of agriculture and the hydroschizophrenic policy framework. We conducted interviews with key informants to identify the possible outcomes for changes in water rights as land is urbanized. We constructed decision trees for each of the three jurisdictions, Chihuahua, Texas, and New Mexico, that identified the possible outcomes from urbanization. For each of the possible outcomes in the decision tree, we estimated a range of potential water use outcomes and the most likely water use outcome on a per unit of land area basis. Results show that urbanization of agricultural land has almost no impact on the aggregate demand for or use of surface water. However, the impacts of urbanization on groundwater use vary considerably over the region from Texas to New Mexico to Chihuahua. In New Mexico and Chihuahua where groundwater rights can be leased or sold to other users, the likely impact is a net increase in groundwater use as land is urbanized, ranging from 0 to 3,000 m3/ha in New Mexico and averaging 3,000 m3/ha or more in Chihuahua. In Texas, there is a net benefit in groundwater savings, but those savings are subject to being offset by increased groundwater pumping to meet the needs of expanding pecan production. The net result is continued groundwater depletion, threatening the life of the transboundary aquifers, the Hueco Bolson and the Mesilla Bolson, in the Middle Rio Grande basin (defined as the part of the basin between Elephant Butte Reservoir in New Mexico to the confluence of the river with the Rio Conchos from Mexico). 相似文献
We investigated the impact of copepods on the seston community in a mesocosm set-up, and assessed how the changes in food quantity, quality and size affected the condition of the grazers, by measuring the RNA:DNA ratios in different developmental stages of Calanus finmarchicus. Manipulated copepod densities did not affect the particulate carbon concentration in the mesocosms. On the other hand, chlorophyll a content increased with higher copepod densities, and increasing densities had a positive effect on seston food quality in the mesocosms, measured as C:N ratios and 3:6 fatty acid ratios. These food quality indicators were significantly correlated to the nutritional status of C. finmarchicus. In contrast to our expectations, these results suggest a lower copepod growth potential on higher quality food. However, in concordance with earlier studies, we found that when copepods were in high densities the large particles (>1000 µm3) decreased and that the smaller particles (<1000 µm3) increased in number. These patterns were closely linked to the condition of C. finmarchicus, which were of better condition (RNA:DNA ratios) with increasing biovolumes of large particles, and, conversely, lower RNA:DNA ratios with increasing biovolumes of smaller particles. Consequentially, the selective grazing by copepods stimulated increased biovolumes of smaller plankton, and this increase was responsible for the increased food quality, in terms of C:N and 3:6 ratios. Thus, we conclude that the decreasing growth potentials of C. finmarchicus were a result of a decrease of favourably sized food particles, induced by copepod grazing.Communicated by O. Kinne, Oldendorf/Luhe 相似文献
Phylogenetically informed imputation methods have rarely been applied to estimate missing values in demographic data but may be a powerful tool for reconstructing vital rates of survival, maturation, and fecundity for species of conservation concern. Imputed vital rates could be used to parameterize demographic models to explore how populations respond when vital rates are perturbed. We used standardized vital rate estimates for 50 bird species to assess the use of phylogenetic imputation to fill gaps in demographic data. We calculated imputation accuracy for vital rates of focal species excluded from the data set either singly or in combination and with and without phylogeny, body mass, and life-history trait data. We used imputed vital rates to calculate demographic metrics, including generation time, to validate the use of imputation in demographic analyses. Covariance among vital rates and other trait data provided a strong basis to guide imputation of missing vital rates in birds, even in the absence of phylogenetic information. Mean NRMSE for null and phylogenetic models differed by <0.01 except when no vital rates were available or for vital rates with high phylogenetic signal (Pagel's λ > 0.8). In these cases, including body mass and life-history trait data compensated for lack of phylogenetic information: mean normalized root mean square error (NRMSE) for null and phylogenetic models differed by <0.01 for adult survival and <0.04 for maturation rate. Estimates of demographic metrics were sensitive to the accuracy of imputed vital rates. For example, mean error in generation time doubled in response to inaccurate estimates of maturation time. Accurate demographic data and metrics, such as generation time, are needed to inform conservation planning processes, for example through International Union for Conservation of Nature Red List assessments and population viability analysis. Imputed vital rates could be useful in this context but, as for any estimated model parameters, awareness of the sensitivities of demographic model outputs to the imputed vital rates is essential. 相似文献
Contamination of coastal water is a persistent threat to ecosystems around the world. In this study, a novel model for describing the dispersion, dilution, terminal layer formation and influence area from a point source discharge into a water body is presented and compared with field measured data. The model is a Combined Integral and Particle model (CIPMO). In the initial stage, the motion, dispersion and dilution of a buoyant jet are calculated. The output from the buoyant jet model is then coupled with a Lagrangian Advection and Diffusion model describing the far-field. CIPMO ensures that both the near- and far-field processes are adequately resolved. The model either uses empirical data or collects environmental forcing data from open source hydrodynamic models with high spatial and temporal resolution. The method for coupling the near-field buoyant jet and the particle tracking model is described and the output is discussed. The model shows good results when compared with measurements from a field study.
Environmental Geochemistry and Health - Biochar (BC) is a porous, carbonaceous material produced by slow pyrolysis of biomass under oxygen-limited conditions. BC production has been attracting... 相似文献