我国城市垃圾现状与可持续发展研究

首先分析我国城市垃圾问题的现状,介绍了我国目前城市垃圾处理技术,并对城市可持续发展垃圾治理问题进行了探讨。     

Assessment of the red-crowned crane habitat in the Yellow River Delta Nature Reserve, East China

As wildlife habitat is in constant evolution, periodic monitoring is essential to assess its quality. In this study, the change to the red-crowned crane habitat in the Yellow River Delta Nature Reserve was detected from multi-temporal remote sensing data from 1992 to 2008 in a geographic information system. Habitat fragmentation was derived from both physical constraints and human disturbance. The changing habitat quality was assessed against five landscape indices. The results obtained from Landsat TM images indicate that potential habitat shrank 37.9 % during 1992–2001, but recovered 99.4 % by 2008. Suitable habitat shrank by 4,329 ha to a level below that of 1992 despite an increase of 4,747 ha in potential habitat due to an increase of 9,075 ha in fragmented areas. Both landscape indices and the red-crowned crane population reveal that suitable habitat was the most fragmented in 2001, but the least fragmented in 1992. Therefore, it is inadequate to just restore wetland through artificial diversion of channel flow to the Reserve to preserve the crane habitat. Commensurate efforts should also be directed at improving habitat quality by minimizing human activities and spatially juxtaposing water and reed marshes harmoniously inside the Reserve.     

Sustainable Tourism Development Management of Local Cultural Landscapes

Abstract

Nowa days, ecological and cultural tourism, especially those ancient villages and towns in China, have attracted an increasing number of tourists because of their unique cultural features. However, rapid development of tourism brings economic benefits, but results in a series of problems that threaten further tourism development and protection of ancient towns, such as over-commercialization and tourism urbanization. Taking Longmen ancient town as an example, this paper presented a sustainable way of preserving and developing resources of ancient villages and towns. First, identify cultural features and the extent of ancient villages and towns, and find the approach through which a cultural landscape zoning can be applied. Second, define a cooperative function area to release the pressure on core areas and protect their authentic cultures by extending tourism space. Third, balance tourism development with traditional industries to enhance the sustainability of community economies.     

Impacts of the Rising Opportunity Cost of Farm Labor on Agricultural Land Use Structure: Theory and Empirical Evidences

Abstract

Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low’s model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure.     

Effects of the "Conversion of Cropland to Forest and Grassland Program" on the water budget of the Jinghe River catchment in China

In 1999 China adopted the "Conversion of Cropland to Forest and Grassland Program" (CCFGP), a nationwide ecological recovery program, to minimize wide-scale soil erosion and vegetation degradation in China, as well as to improve water budgeting results. In the 10 yr since implementation, the CCFGP has resulted in the recovery and reforestation of >100,000 km of cropland and bare land, though the quantitative effect of this program on catchment water budget is not entirely clear. Therefore, we used the Soil and Water Assessment Tool to evaluate and quantify the effects of the CCFGP on the water budget of the Jinghe River catchment, a tributary of the Yellow River covering the central region of the Loess Plateau. Our results indicated that precipitation had dropped by 12.0% from the 1970s (611.6 mm) to the 2000s (538 mm) and that there was a corresponding 25.2% decrease in humidity index from 0.48 to 0.36. Before the CCFGP's implementation, forest and grassland had been decreasing, while bare land, cropland, and shrub land had been increasing. After the implementation of the CCFGP, the opposite trend was observed. Moreover, streamflow increased by about 15 and 20% for the upstream and middle stream subbasins, respectively, while soil water content also showed an obvious increase. Over the same period, evapotranspiration decreased by 5.2 and 13.5 mm and runoff decreased by 37.5 and 38.6% in the two subbasins. The same trends were obtained in the downstream subbasin, where changes were even greater. As a result of the reduced runoff and evapotranspiration, utilization of water resources was more efficient and ecological environment was improved under the CCFGP policy. Our results indicate the CCFGP resulted in a favorable ecological impact and should therefore be maintained.     

化学事故危害后果评估与应急救援的辅助决策系统设计

根据重大城市的化学事故后果评估与应急救援的实际需要出发,提出了研制辅助决策系统任务需求和设计构想,阐述了该系统的系统结构、系统实现的流程和系统功能,并做了可行性分析。系统的模块包括：化学品基础信息模块、化学事故类型划分模块、地理信息系统模块、化学源周围道路交通模块、实时的天气预报模块、数学模型模块、危害后果评估模块、救援方案生成模块、人员疏散撤离方案生成模块、人机交互模块。系统与地理信息系统（G IS）、卫星导航系统（GPS）、遥感成像技术结合后能够实现精确定位、快速评估。将物联网技术与系统结合,还可实现对大型固定化学源远程时时监控,确保在事故发生后第一时间掌握信息,为后果评估和应急救援赢得时间,将化学突发事故的危害降到最低。该系统在信息化条件下,较好地为决策者进行化学事故后果评估,为应急救援决策提供了依据,可大幅度提高应急救援效能。     

老鹰岩滑坡基本特征及危害性分析

通过分析老鹰岩滑坡的地质环境特征和形态特征,揭示其形成机制和产生的危害,最后根据该区地质灾害特点,提出了灾后恢复重建的相关建议。     

Optimizing model for land use/land cover retrieval from remote sensing imagery based on variable precision rough sets

The suitable spectral mode in remote sensing is often desirable to facilitate the inversion of ecological environment and landscape. This paper put forward an optimizing model based on variable precision rough sets (VPRS) for the land cover discrimination in wetland inventory. In the case study of Lake Baiyangdian which has important ecological functions to the northern China, this model is established successfully according to the domain-experts knowledge. The procedure is as follows. First step is data collection, including remote-sensing data (e.g., Landsat-5 TM bands), the digitized relief maps, and statistical yearbooks. Second, the remote sensing imagery (RSI) and relief maps are co-registered into the same resolution. Third, a condition set, including various attributes is derived from spectral bands, band math or ratio indices based on previous studies, at the same time, the decision set is derived from true land types after investigation and validation. Then, the remote sensing decision table (RSDT) is constructed by linking condition set with decision set according to the sequential pixels in RSI. Fourth, we create one forward greedy searching algorithm based on VPRS to handle this RSDT. After adjusting parameters such as β and knowledge granularity diameter (KGD), we obtain the stable optimized results. Comparative experiments and evaluation show that the discrimination or retrieval accuracy of VPRS model is satisfying (overall accuracy: 87.32% and KHAT: 0.84) and better than original data. Moreover, data dimension has been decreased dramatically (from 12 to 3) and key attributes found by the model may be useful for specific retrieval in wetland inventories.     

硫酸锰废渣浸出液对斑马鱼的毒性及抗氧化酶活性的影响

已有研究表明,堆积在湘西花垣河河岸的硫酸锰废渣含有多种重金属,可能是导致花垣河河水和沉积物重金属污染的主要原因.为了评价硫酸锰废渣的潜在生态风险和对水生动物的毒性,本研究分析了硫酸锰废渣浸出液中的主要重金属成分,用漫出液对斑马鱼进行了急性毒性实验,观察在急性胁迫下斑马鱼的体征变化,测定了斑马鱼在亚致死浓度下的生化指标的...     

Polycyclic aromatic hydrocarbons in effluents from wastewater treatment plants and receiving streams in Tianjin, China

Surface water, suspended particulate matter, pore water, and sediment samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) in Yongding New River, South Drainage Canal and North Drainage Canal, which receive most of wastewater from industrial city of Tianjin. PAH concentrations in effluent samples of wastewater treatment plants (WTP) discharging into the South Drainage Canal and North Drainage Canal were quantified for the first time. The results showed that the discharge of the WTPs recently only contributed to the PAH contamination in the canals near the outlets of the WTPs. PAH levels in sediments of the streams were greatly higher than those in soils by riverbank probably due to receiving large amounts of untreated wastewater. Unusually high benz[a] anthracene concentration strongly influenced the seasonal and spatial variation of total PAH concentrations in South Drainage Canal. Paired samples t test of ??Nap, Fl, Phe, Fluo and ??Nap, Phe, Fluo, Chry concentrations, which were dominant components in the air samples from non-heating and heating season, respectively, in the suspended particulate matters from the streams showed that PAH source from air deposition was more important for Yongding New River than that for South Drainage Canal and North Drainage Canal. Source apportionment based on PAH profiles indicated that coal combustion was the major PAH contamination source, and coke oven sources and wood combustion also contributed to the PAH contamination of the streams. This was further indicated by organic petrography analysis.