Applied Mechanics and Materials Vols. 295-298

Abstract: A lot of research about soil erosion similarity have done and obtained rich achievements. However, strictly speaking, it need to do a lot of deep study about to establish the ratio scale model of soil erosion, the problems unsolved include of does not establish the similar equation system about soil erosion and sediment yield entities simulation. we did some experiment, the date shows: the raindrop speed mainly at 0.6-5m/s in 10min, the wave crest was 1m/s and 4.2m/s. At the same times, the 0.125mm grain diameter raindrop speed was about at 0.6-1.4m/s, the 0.25mm grain diameter raindrop speed was about at 1-1.4m/s, the 0.375mm grain diameter raindrop speed was about at 1-1.4m/s, the 0. 5mm grain diameter raindrop speed was about at 1-3.4m/s, the 0.75mm grain diameter raindrop speed was about at 3.4m/s, the 1mm grain diameter raindrop speed was about at 4.2m/s, the 1.25mm grain diameter raindrop speed was about at4.2-5m/s, the 1.5mm grain diameter raindrop speed was about at5m/s.

Abstract: Many drought and flood indices have been developed, the Standardized Precipitation Index (SPI) is one which has various temporal scales together to form an overall judgment of drought and flood and can be applied easily to different locations to identify and monitor drought and flood. Take Nanjing, China in the study as an example to analysis drought and flood variation by computing SPI values of four time scales including 3-months, 6-months, 12-months and 24-months, applying precipitation data from 1946-2000 of the study area. The results demonstrated SPI can be appropriate to analyze drought and flood variation of Nanjing, while the precipitation data were divided into three stages(1946-1963,1964-1981,1982-2000), the frequencies of various drought and flood classes from various time scales are different, particularly 12-months and 24-months. The time series is longer, the frequencies are more reliable and the differences more little.

Abstract: Drought is a recurrent feature of the climate. It occurs in virtually all climatic zones, and its characteristics vary significantly among regions. The precipitation data are obtained from 6 fairly distributed stations across western Jilin province (in China) for the period from 1957 to 2010. The calculated monthly standardized precipitation index (SPI) is used as a drought index. SPI not only nicely reflects drought intensity and duration, but also has a multi-temporal scale application dimension. For the purpose of analyzing multiple meteorological drought time-scales, Morlet wavelet transforms of the station monthly SPI time-series are interpreted. The results show that some stations, such as Chang-Ling and Tong-Yu, have remarkably significant cycles in their respective wavelet power spectrum and variance. However, these significant cycles are not clearly noticeable in the other stations. Irrespective of the trend, time-scale and cycles generally influence drought characteristics in the study area.

Abstract: Water resources are an important influence factor of land remediation in Jilin Province. As support of food production, analysis of water resources supply and demand balance is an important part and technical support of the construction. After forecast of water demand and the calculation of water supply, in major projects areas of the demonstration construction of whole rural land remediation in Jilin province, the average water availability for many years is 736796.1 thousand m3 each year, including surface water availability 543393 thousand m3 and groundwater availability 193403.1 thousand m3.water demand is 463 694.4 thousand m3 in 2015; including water demand for life 49150 thousand m3 and water demand for agricultural irrigation 414544.4 thousand m3. Water supply is more than water demand; the results show that there is a slight surplus of water resources in the region. The basic supply-demand balance can be achieved in conditions of the design of water supply project in every project area.

Abstract: Water resources are an important influence factor of land remediation. As support of food production, analysis of water resources supply and demand balance is an important part and technical support of the construction. According to some relevant calculation formulas on water resources assessment, after forecast of water demand and the calculation of water supply, in the project area of the demonstration construction of whole rural land remediation in Baishan City, the average water availability for many years is 8990.1 thousand m3 each year, in which surface water availability is 7210.6 thousand m3, groundwater availability is 1579.4 thousand m3. Water demand is 5552.4 thousand m3 in 2015, in which water demand for life 4165.2 thousand m3; water demand for agricultural irrigation is 1387.2 thousand m3. Water supply is more than water demand; the results show that there is a slight surplus of water resources in the region. The basic supply-demand balance can be achieved in conditions of the design of water supply project in the project area.

Abstract: A promising and involving interdisciplinary concept-the earth’s critical zone science is introduced in this paper. Within the earth’s Critical Zone, the coupled chemical, physical and biological processes which define Earth’s weathering engine are driven by climatic, anthropogenic, and tectonic forcing. Followed by the concept and specific questions related to the critical zone were given. Finally, current research in order to understand the Critical zone was reviewed.

Abstract: The change of fluctuating rhythm of water level resulted from the construction of the Three Gorges Hydropower Project impacts the composition and structure of riverbank plant communities and plant growth in the reservoir area, which further affects the effects of plant root systems on soil conservation and slope stabilization. The changing trends of riverside ecological environment and vegetation in the reservoir area were analyzed in this paper, so was the study of mechanism on plant root systems in soil conservation and slope stabilization. Some suggestions were put forward finally for the mechanism research of pioneer plant roots in riverbank soil conservation and slope stabilization. It was suggested that the effects and mechanism of plant roots in soil conservation and slope stabilization in the Three Gorges reservoir area could be evaluated and uncovered by studying the temporal and spatial dynamics of root tensile strength, erosion resistance, shear resistance, soil physical and chemical properties, and their relationship with dynamics of the pioneer plant root structure responding to environmental changes induced by the construction of the hydropower project. The study also should include field investigation and simulated experiments in laboratory. The field investigation could reveal the changes of temporal and spatial dynamics of pioneer plant roots’ tensile strength, erosion resistance, shear resistance, and soil physical properties. The simulated experiments could evaluate quantitatively the relationship between plant root structure and their effects on soil conservation and slope stabilization.

Abstract: In order to evaluate the impacts of N and P mobility from agricultural soils on surface water quality, the dissolved N and P concentrations in the runoff, the drainage and stream waters nearby agricultural lands were investigated at the karst hilly regions in central Guizhou Province. The results shown that the concentrations of NO3−, NH4+ and PO43− in the runoff from upland soils were 9.8~22.1 mg L−1, 0.429~0.818 mg L−1 and 0.025~0.052 mg L−1, respectively, and higher concentrations of NO3− (14.5~25.3 mg L−1) in the drainage waters from paddy soils. In karst areas, the concentrations of NO3− in the stream waters nearby agricultural lands was 14.9~28.5 mg L−1, as indicated by high concentration of NO3− compared with the Grade III of Surface Water Quality Standard of China, suggesting a eutrophication problem for surface water nearby agricultural lands with intensive cultivation.

Abstract: China has made great progress in environmental legislation following the Ideal of Ecosystem Approaches since the late of 1970s. With the increasingly serious problems of pollution and ecosystem deterioration which were produced by development of economy, the new generation of the Chinese leaders attaches more importance to environmental protection work than before and carry out various legal measures to practice the Ecosystem Approaches. In the next decades, China would make more brilliant achievements both on central and local level relates to the environmental legal issues.

Abstract: Qinhuangdao City, introduced a National Environmental Protection Model City of the planning area and planning objectives, and focuses on the goal to complete the record mode the main measures taken, including "the implementation of 'Tourism Li City' development strategies to accelerate industrial restructuring and development patterns; optimizing energy structure, depth and energy saving; strengthen pollution reduction, improving environmental quality, "and other aspects. Finally, the analysis of Qinhuangdao City, after completion of the National Environmental Protection Model City, will be in the social, economic and environmental dimensions of the comprehensive benefit.