Spatial correlations between urbanization and river water pollution in the heavily polluted area of Taihu Lake Basin, China

Water pollution in the Taihu Lake Basin has been the focus of attention in China and abroad for a long time, due to its position in the forefront of urban development in China. Based on data gathering and processing from 84 monitoring sections in this heavily polluted area, this study first analyzes spatial patterns of urbanization and the distribution of river water pollution, and then uses the GeoDa bivariate spatial autocorrelation model to investigate the spatial correlation between urbanization and river water pollution at the scale of township units. The results show that urbanization has adverse impacts on water pollution, and the influence varies in different levels of development areas. The urban township units have the highest level of urbanization and highest pollution, but the best water quality; the suburban units have lower level of urbanization, but higher pollution and worse water quality; however the rural units have the lowest level of urbanization and lowest pollution, mainly affected by upstream pollution, but worst water quality. Lastly, urban and rural planning committees, while actively promoting the process of development in the region, should gradually resolve the issue of pollution control lagging behind urban life and urban develop- ment, giving priority to construction of centralized sewage treatment facilities and associated pipeline network coverage in the rural areas and suburban areas.

Characteristic Analysis of Atmospheric Electric Field in Contaminated Areas

[Objective] The research aimed to analyze characteristics of atmospheric electric field in polluted area. [Method] By using data of atmospheric electric field meter in Taiyuan in 2009, daily and annual changes of atmospheric electric field in Taiyuan were analyzed. [ Result] Atmospheric electric field intensity in Taiyuan was higher than that in other areas. Daily change was double-peak double-valley type. The first highest value appeared at nightfall, and the second highest value was before the noon. The first lowest value appeared in early morning, while the second low- est value appeared after the noon. Annual change was single-peak single-valley type. The maximum appeared in winter, while the minimum ap- peared in summer. [ Conclusion] When forecasting thunderstorm, in the area with higher aerosol content, alarm threshold of electric field should be adjusted via comparison with actual observation, which had very strong regional characteristics. By analyzing real-time monitoring data of atmospheric electric field, thunderstorm forecast could be realized, and timeliness and accuracy of warning and forecast could be increased.

Random walk modeling of wake dispersion for the exhaust tower of an underground tunnel in urban area

In this paper, some experimental studies on the impact of effluent from an exhaust tower of an underground tunnel with special construction are reported. By measuring the flow field downstream of the tower in NJU meteorological wind tunnel, some flow characteristics in the make area were established. Based on these, an advanced random\|walk dispersion model was set up and applied successfully to the simulation of dispersion in the wake area. The modelling results were in accordance with wind tunnel measurements. The computed maximum of ground surface concentration in the building case was a factor of 3-4 higher than that in the flat case and appeared much closer to the source. The simulation indicated that random walk modelling is an effective and practical tool for the wake stream impact assessment.

Scientifically advanced woody media for improved water quality from livestock woodchip heavy-use areas

Overwintering cattle on pastures in many areas can damage the pasture and lead to impaired water quality. During these times, use ofa woodchip heavy-use area （HUA） presents advantages such as a soft, supportive, and dry toot surface for animals and protection of the pasture and pasture soils. However, woodchip HUAs can also be a centralized source of high nutrient loads due to their drainage outflows. A column study was conducted to assess the nutrient load reduction potential of： 1 ） six types of wood media （including torrefied wood media and biochar） that could be used in a woodchip HUA versus a gravel control, and 2） providing a 48 h retention time within the wood media to enhance nitrogen removal through denitrification. The woody media provided significant liquid waste volume reduction compared to the gravel in simulated events （53%-61% vs. 39% reductions, respectively）, and there may be additional liquid storage capacity in the woodchips not utilized during these rapid events. Substantial total nitrogen removal by the wood treatments （mean removal efficiencies 〉 50%） was observed across the sinmlated events, although nitrate leaching also occurred. Nitrate removal was enhanced during the 48 h retention test which showed removal was governed by availability of labile carbon （i.e., fresh woodchips exhibited 〉 70% nitrate removal）. The retention test also indicated biochar mixtures provided some of the best total phosphorus removal, but the greatest benefits across all parameters was provided by the Mixed Hardwood treatment.

生计多样化背景下种植业非点源污染负荷演变（英文）

Based on objective data collected from interviews in typical villages of the Three Gorges Reservoir Area, the present study devised three livelihood scenarios related to rural transformation development： agriculturally dominant livelihood, multiple-type livelihood and non-agriculturally dominant livelihood. Moreover, the present study reports the trend characteristics of nonpoint source pollution load of crop farming in relation to the transformation of dominant livelihood types, and discussed the primary factors which affect livelihood type transformations. Results indicated the following：（1） The current farmland pattern shows a trend of diversification as self-cultivation, cropland transfer and fallow in the sample region. Dynamic characteristics of cultivated land present a special feature that is more ＂transfer-into＂ than ＂transfer-out＂. Various scales of planting are represented among the various households, according to the following decreasing order： half-labor household ＆gt; non-labor household ＆gt; adequate labor household.（2） The highest pollution loading produced by crop farming occurs in half-labor households while the lowest occurs in non-labor households. With increasing labor, the pollution load per unit area tends to first increase and then decrease within families with enough labor.（3） As the type of livelihood transitions from agriculturally dominant to non-agriculturally dominant, the maximum reduction of total pollution loading produced by the agricultural industry can reach 72.01%. Compared to agriculturally dominant livelihoods, multiple-type livelihoods produce a pollution load reduction yield of 19.61%-29.85%, and non-agriculturally dominant livelihoods reduce the pollution load yield by 35.20%-72.01%. However, the rate of reduction of total nitrogen is not the same as total phosphorus.（4） The non-agricultural characteristics of labor allocation and income promote the transformation from dominant livelihood types to non-agricultural livelihoods, while potential revenue conversion follows a similar trend. In addition, different household types do not display identical conversion rates, according to the following decreasing order： enough labor household ＆gt; half-labor household ＆gt; non-labor household.（5） During rapid urbanization and the building of new industrial systems, the livelihood types of rural households have been further transformed to off-farm household types in the mountainous region; this process will lead to the further reduction of pollution load generated by planting and agriculture. Hence, significant decreases in the planting pollution load necessitate the development of control measures to enhance transformations from agricultural to off-farm livelihoods.