Advanced Materials Research Vol. 709

Abstract: This paper took Guangdong province as an example, using the statistical data of twenty times storm surges from 2003 to 2010 to evaluate the disasters and predict the economic losses. We expected it to supply with sound references and proof for the decision-makers to prevent storm surges. With economic indices of direct economic losses, collapsed houses, damaged farmland area, et al., this paper used entropy method and factor analysis method to grade the storm surges into separate levels, which are the mild disaster, the moderate disaster, the serious disaster and the extra serious disaster. By BP neural networks and gray prediction method, we established the evaluation and prediction models of direct economic losses. Comparing the results of both methods, it found that neural network is more applicable and accurate to predict the economic losses of storm surges.

Abstract: Rainfall infiltration can induce landslides and influence engineering treatment effects. With a landslide uncounted in expressway construction in Shanxi province as an example, the bad effect of water was analyzed. Based on changes in soil strength caused by rainfall infiltration and shear experiments of undisturbed and water-saturated sliding zone soil under several conditions, the calculation parameters of soil were determined. Distribution of the maximum principal stress and shear stress inside the supported landslide before and after the rain was calculated through FEM numerical simulation and then deformation and failure mechanism of landslide was analyzed; the results reveal that for the supported landslide, the principal stress is mainly caused by gravity before and after the rain, meanwhile infiltration can induce increase in instantaneous strain and dramatic change in maximum shearing stress which is focused on the sliding surface adjacent to the bedding plane. As mentioned above, the drainage of surface water and groundwater in landslide treatment can delay landslide deformation effectively.

Abstract: It is a kind of low cost and also low power sewage treatment pathway for using sewage in irrigation, one of effective action to protect the water resources sustainable utilization in town. Using sewage in irrigation is a way of reducing operating costs at Malong County. As the yellow soil permeability is low at Malone County and the penetration rate is 1m/d. What’s more, the quality sewage used in irrigation can meet the class A demands, so this article predicted that sewage irrigation will has less impact on the groundwater at Malone County. We can get analogy method and drew experimental plan according to different influence results of water quality, soil and groundwater of Malone County.

Abstract: The study wetland vegetation restoration technology system and representative beach wetland restoration projects at home and abroad are summarized. Technology system of wetland vegetation restoration mainly includes engineering technology and biological technology. Ecological restoration research of coastal wetland in China mainly concentrated in the Yellow River Delta, the southeast coastal mangrove wetlands, coastal beaches of Jiangsu and the coastal wetlands in Shanghai Fengxian District. Finally, the issues existed in current research field were pointed out. The research fields need to be strengthened for the detailed field investigation and laboratory analysis of soil, vegetation, hydrology, meteorology, etc. According to the actual situation of wetland beaches, wetland site type will be divided. Suitable salt-tolerant plant varieties should be filtered and the mudflat wetland vegetation recovery key technologies should be explored.

Abstract: With the implementation of new rural development policy and development of rural economic in China, water pollution becomes a serious problem in rural areas, which has been the major factor that leads to watershed quality deterioration and ground water pollution. It should adjust measures to local condition to use decentralized wastewater treatment mode in rural area in China. Basing on current situation and characterization of wastewater discharge in rural areas, the characterization, application and development of decentralized wastewater treatment in the worldwide were reviewed. Major problems encountered in its design and operation processes were discussed, solution measures were also given combining the actual condition in rural areas.