Applied Mechanics and Materials Vol. 707

Abstract: Douhe Reservoir (DR) is the most important water source for the city of Tangshan, China. In this paper, a new online monitoring and management system is developed for the purposes of water quality management and human health protection. The system includes two parts: an online monitoring system, consisting of a biological early warning system (BEWS) and a physical factor monitoring system (PFMS), and an environmental management system. Once BEWS warns of changes in water quality, PFMS is used to determine whether there has been a water pollution accident. If an accident has occurred, then optimal allocation of source water in DR is initiated on the basis of the results of the online monitoring and management system. Meanwhile, an emergency treatment procedure for accidental pollution of DR, which includes laboratory testing of water quality and the treatment of polluted water, is carried out. Therefore, the online monitoring and management system will provide an effective approach to make water management and human health protection.

Abstract: With the rapid development of social and economy, land use/cover change (LUCC) has been regard as a critical effect of global environment change. Researches on LUCC convert from single factor influence to overall research on the effects of regional ecological environment. Research Scope of study area gradually changes from the ecological fragile areas in the western to developed areas. This paper summarized the main methods of effect of land use change on the evaluate of eco-environment research. The results show that: environmental effects of land use/cover change improved in the long term; the rapid progress of remote sensing technology and geographic information system make environmental effects of land use/cover change more convenient.

Abstract: In this paper, Lixian County 2001-2010 dynamic changes of cultivated land resources were studied. Studies have shown that: the past 10 years the average annual reduction rate of 0.72% Lixian County arable land, and the reduction since 2002, much faster, In the spatial region, most dramatic change is more economically developed society Liwu Town, Dabaichi Town, Xinxing Town and Liushi Town. According to the statistical Yearbook 2001-2010 review, we select factor and use principal component analysis. The main driving factors of impacting Lixian County arable land resources change are economic factor, demographic factor and progress in agricultural technology factor.

Abstract: Urbanization in high-speed nowadays is changing soil carbon dynamic. Soil carbon mineralization (C_m) and microbial biomass carbon (MBC) of in situ and exchange-location incubation was characterized along urban-rural gradient in Nanchang, China. As a result, soil C_m and MBC of in situ incubation were higher in urban than in suburban, which were significantly higher than those in rural area (P<0.05), at the same time, urban soils incubating in rural area mineralized about 1.8 times the amount of carbon than rural soils incubating in rural area; MBC in soils of exchange-location incubation exhibited a significant decrease tendency with area farther away from urban as well (P<0.05), while there was no significant difference observed in C_m of soils from the same origin incubating in different area between urban, suburban and rural (P>0.05). The result indicated that urban soils have potential for higher losses of carbon than rural soils.

Abstract: There are rich forestry resources, good climatic conditions, rainfall abundant, so lush plants, a good ecological environment in Dandong area, and rich mineral resources, mining economy vigorous development, but the development and utilization of resources is bound to adversely affect the ecological environment. This paper mainly Analysis on the influence of mining development on the ecological environment in Dandong area, and provides the decision basis for development of Castle Peak protection and the control work further.

Abstract: In this study, three kinds of natural clay minerals (kaolin clay, montmorillonite and diatomaceous earth) were used to treat the raw water containing humic acid (HA) by adsorption/sedimentation. The results indicated that natural kaolin clay had no obvious effect on removing HA in water. Using chitosan to modify montmorillonite and diatomaceous earth, the removal effect of the modified diatomaceous earth for HA was better than modified montmorillonite, and the optimal ratio between chitosan and diatomaceous earth was 1:30. Compared with natural diatomaceous earth, the modified clay had better adsorption property for HA at the same dosage. Using modified diatomaceous earth, the maximal removing rates for TOC and turbidity could respectively reach 85.9% and 64.6% with 60 mg/L dosage and 50 min.

Abstract: Biochar has been applied in soil amelioration due to its multiple agricultural and environmental benefits. Biochar sample (BC) and biochar-based amendment (AD) were added into a poor quality soil (light sierozem) collected from Ningxia Hui Autonomous Region at the rates of 0%, 1.5%, 3% and 5% (w/w), respectively. Maize (Zea mays) was chosen as a test plant, and the effect of BC and AD on its growth was investigated. The results indicated that the maize biomass increased by 44.4-96.2% and 113.8-187.3% in the soils amended with BC and AD, respectively. Therefore, BC and AD may be used as the poor quality soil amendments.

Abstract: Salt stress, with nutrient deficiency, has been threatening plant growth in coastal saline soil. This study is to address the potential of using biochar treated with 1.69 mol/L HNO₃ (BCH) as a soil amendment to ameliorate coastal saline soil. Both BCH and BCH with fertilizer treatments increased plant height and biomass of sesbania (Sesbania cannabina) and seashore mallow (Kosteletzkya virginica), especially at the adding rate of 1.5% (w/w). The maximal biomass of sesbania and mallow was increased by 158%, and 214%, respectively. However, with the increasing adding rate, the value of biomass and height for both plant decreased, but not lower than those of the control. It suggested that the biochar treated by HNO₃ is a good way to overcome biochar’s inherent nutrient deficiency and ameliorate the soils with salt stress.

Abstract: Algae and bacteria blooms in eutrophication in summer have made the quality of landscape water degradation. Treatment efficiency of potassium monopersulfate compound, a new kind of oxidation reagent, on killing algae and bacteria has been valued and the effect of influence factors, such as dosage, contact time and temperature are also discussed. The results indicated that potassium monopersulfate is appropriate for killing algae and bacteria in landscape water, dosage and contact time are the major influence factors. The contact time should be longer than 20min and the algicidal rate is higher when the temperature is above 20°C.

Abstract: Striped vegetation pattern formation in arid and semiarid regions has attracted many researchers in ecological field. In this research, we modify the classical Klausmeier model and study nonlinear mechanism of oscillatory instability which can also possibly lead to pattern formation in ecological systems. Via simulation, irregular striped vegetation patterns are numerically obtained for the modified model. From the mechanism of oscillatory instability, this research provides a theoretical explanation for the formation of irregular striped vegetation patterns in nature.