Advanced Materials Research Vols. 518-523

Abstract: The seasonal variation and influence factors of emission of greenhouse gasses (CH₄ and N₂O) from the different water depths were studied during the growing seasons in a marsh wetland of Sanjiang Plain of China. The results showed that the wetland was a source of both CH₄ and N₂O during the growing seasons and emissions showed conspicuous temporal and spatial variations. Emission rates of CH₄ were higher in July and August while N₂O were higher in June and July. The highest average CH₄ flux among the four sites was in the water depth at 40cm with a rate of 37.00 mg•m^-2•h^-1 and the lowest was in the water depth at 0cm with a rate of 8.13 mg•m^-2•h^-1. While the highest average N₂O flux was in the water depth at 0cm with a rate of 0.063 mg•m^-2•h^-1 and the lowest was in the water depth at 60cm with a rate of 0.034 mg•m^-2•h^-1. Further analysis indicated that water depth at 40cm and the soil temperature at 5cm were the main factors affecting CH₄ emission. Water depths at 0 and 40cm were the main factors affecting N₂O emission. Air temperature and surface soil temperature were not the main factors affecting CH₄ and N₂O emissions.

Abstract: This paper, through building mathematical models, makes an analysis on the emissions trading system under an abatement framework. And the authors obtained four conclusions: (1) The impact by environmental taxes on the existing firms’ choices of optimal discharging amounts is uncertain, the existing firms’ discharging amounts will be on the decrease with the increased prices of emissions permits, and paid initial emissions allowances will reduce the existing firms’ profits; (2) Under an intertemporal trading system, the existing firms’ holding the permits conforms to the principle of profit maximization; (3) Under the intertemporal trading system, the prices for emissions permits for the entrant firms are always on the rise and so are their access costs into the industries, thus frustrating local governments’ efforts in attracting investments; and (4) Emissions reduction policies are good regulatory instruments for promoting local economic welfare and realizing sustainable development. The paper also gives some suggestions for triggering and activating the emissions trading system and formulating supportive policies.

Abstract: The paper is set out to figure out the framework of the environmental legislation and the environment administration of China by the empirical analysis method. Environmental Legislation Framework of China is composed of various laws enacted by different legal authorities. Constitutions, Acts, Rules and Regulations are basic legal choices for China to carry out environmental legislation at both central and local levels. The Environmental Administrative Management Framework of China is very complex and far from perfect because of the overlap between different governmental branches at the same level. China decides to do something to solve the problem through reformation of the political mechanism.

Abstract: The paper selects slope, aspect, Relief Degree of Land Surface, land use, vegetation index, hydrology, transportation density and climate as evaluation indexes and sets up the Human Settlements Environmental Index (HEI) model to evaluate the environmental suitability for Human Settlements in Shiyang river basin. Through using spatial analysis technology of GIS such as spatial overlay analysis, buffer analysis and density analysis to establish the spatial situation of nature suitability and spatial pattern for human settlement. The Results showed that: the index of nature suitability for human settlement in Shiyang river basin was between 17.13 and 84.32. In general, nature suitability for human settlement decreased from southwest to northeast. Saw from area pattern, the suitable region mainly distributed in Minqin oasis, Wuwei oasis and Changning basin, which accounting for about1080.01 km2, 2.59% of the total area. Rather and comparatively suitable region mainly distributed around the county in Gulang, Yongchang and north of Tianzhu, which accounting for about1100.30 km2.The common suitable region mainly distributed outside of the county inYongchang, Jinchuan and most area of Minqin county, which accounting for about 23328.04km2, 56.08% of the total area. The unsuitable region mainly distributed upstream and north of river, which accounting for about 9937.60 km2, 23.89% of the total area. Meanwhile, the least suitable region distributed around the Qilian Mountain which covered by snow and cold desert and the intersecting area between Tenger Desert and Badain Jaran Desert. The total area was about 6154.05 km2, which accounting for 14.79% of the total area. Suitable regions for human inhabitance mainly distributed around rivers in the form of ribbons and batches, while others are scattered. Their distribution pattern was identical with the residential spatial pattern. In addition, the relationships between HEI and some factors were also analyzed. There was a clear logarithm correlation between situation of residential environment and population, that is, the correlation coefficient between evaluation value and population density reached 0.851. There was also positive correlation between situation of residential environment and economics, which reached 0.845 between evaluation value of residential environment and GDP. Results also showed the environment was out of bearing the existing population in Shiyang river basin. Spatial distribution of population was profoundly affected by severe environment such as the expanded deserts, the wavy terrains, and the changeful climate. Surface water shortage and slowly economic growth was the bottleneck of nature suitability for human settlement in Shiyang river basin. So according to these problems and various planning, some of residential parts need to relocate in order to improve situation of residential environment.

Abstract: Agro-ecological system in Hubei province was comprehensively analyzed and evaluated by using emergy analysis method. The result shows that the local resources have been utilized effectively in Hubei, the agricultural modernization is high, however, Hubei’s agricultural ecosystems is unsustainable consumption-based system owing to the higher degree of environmental stress and resource dependence. Suggestions to reinforce the sustainable development of agriculture in Hubei were put forward.

Abstract: Overuse of fertilizers in agriculture could cause groundwater nitrate pollution. However, this is related to nitrate input, soil moisture movement (direction and rate), and depth of water table in (semi)arid areas, where nitrate can be preserved and nitrate loss by denitrification can be limited. A 18-m soil profile to water table in Daxing, Beijing shows that the nitrate is accumulated in the upper unsaturated zone and has not reached water table; and then groundwater nitrate remains at baseline level (5.6 mg/L). The soil moisture movement velocity is 0.28 m/yr based on nitrate use history. It takes another ~35 years for the moisture with high nitrate content to reach water table and pollute groundwater, to which attention should be paid in water quality management.

Abstract: Three typical karst rocky desertification sites in Guizhou including Yachi demonstration site in Bijie, Huajiang demonstration site in Guanling-Zhenfeng and Hongfeng Lake demonstration site in Qingzhen were chosen to research the low-carbon community construction under the perspective of ecological civilization. Many times investigations and discussions were carried out. Conclusions were drawn that: the ecological civilization has special meanings and characteristics featured by strong regionalism and entire systematicness; the key points for the construction of low-carbon community in karst rocky desertification areas includes low carbonization of ecological environment, low carbonization of productivity activities, low carbonization of energy consumption structure, low carbonization of lifestyle and low carbonization of institutional policy; the index system of low-carbon community in karst rocky desertification areas was established including target layer, criterion layer and index layer. Five criteria and 35 indices were figured out for evaluating low-carbon community in karst rocky desertification areas.

Abstract: The environmental problems have become global issues. It is a key problem to solve in the near future for human beings to protect the survival environment and to adopt the sustainable development policy. This paper based on property theory analyzes the issues of the current eco-environmental system from the view of property right, points out the limitation of the methods through the property right and the calculation of other fees but not only the price in the market, analyzes the powerful effects when the property right is combined with financial methods from the government, and search some suitable solutions to the advantage of the sustainable development of the society. Finally, the paper analyzes the case of the property right and environmental protection in China.

Abstract: Rubbish rusticated is a pre-structure choice in the process of urbanization. Through intergovernmental conspiracy, it makes the rural land into a communal land where city residents process living rubbish. This kind of behavior encroached on rural land and harmed the environment of farming land. In the process, the separation between benefit circle and suffer circle, the dispersion of benefit circle, the cumulative of its effect and the impotence of struggle of suffer circle make rural land get no corresponding protection in the face of rubbish rusticated. To change this situation, it depends on the struggle of suffer circle, the support of technique and the change of policy.

Abstract: In the study we mapped and analyzed the land use/cover changes Duolun county (one of typical farming-pastoral ecotone of northern China) in previous 20 years by interpreting the multi-temporal TM images received growing season of 1990, 2000 and 2009. The 6 broad types and 12 sub-types of land use/ cover were visually interpreted to get the area of each land use/cover. Our study indicates that the area of grassland displayed stable, but the area of densely and moderate vegetated grassland increased apparently. The forested area also increased 11.51km2 from 46.21km2 in 2009, 34.13km2 in 2000 to 34.70km2 in 1990. In contrast, the area of farmland reduced from 7.82km2 during the 1st (1990-2000) period, and 101.14km2 during the 2nd (2000-2009) period, and desert area declined to 149.07km2. On the whole, the ecosystem improvement is very significant.