Advanced Materials Research Vols. 356-360

Abstract: The paper analyses the affecting factors of river health points that river channel health is the key and foundation of river health. It proposes the index system for the Lower Yellow River's channel health and sets the appropriate evaluation criteria and indicator weight. It evaluates the Lower Yellow River's channel health using fuzzy comprehensive evaluation method and gets the conclusion that the Lower Yellow River's channel health has deteriorated in 50 years and has not improved until the beginning of this century. Finally, the paper points that river health is closely related to flow-sediment processes and the coordination of flow-sediment relationship is the key to maintaining the health of the Lower Yellow River.

Abstract: photovoltaic system, optimum tilted angle, siphon principle, water treatment Abstract. Based on the recent research at home and abroad and the local meteorological data, this study aims to determine the optimum tilt angle of the solar-cell array surface and the best month on the system to achieve the optimal design of PV system. Full mechanical automatic control system is designed by using lever principle and siphon principle to realize the purpose of all-day and maintenance-free operational situation. It can replace the motor control system and at the same time，enjoys reliability, low cost, long life and energy conservation. The indoor and local river data of the experiment shows that this system has an evident effect on water decontamination. Furthermore， comparing with traditional aeration system. It has many advantages, for instance, it can save more than 20 thousand and carbon emission can be reduced by 683 ton and other aspects.

Abstract: Consideding the current status of the planting of highway’s central segregation area，the article gives suggestions to the design requirements and configuration pattern and Development．

Abstract: This paper is to predict dominant factors influencing temporal sedimentation rates at Loagan Bunut Lake using best-fit model of sedimentation rate and distance from Bunut River. The lake is a flood plain lake located in Sarawak, Malaysia. Twenty two cylindrical traps were installed at the lake from November 2005 until April 2008. Each sample was collected after about four to five months of deployment. Dry sedimentation rates from the traps and the linear distances from Trap 1 located at the confluence of Bunut River were measured. The factors that influence the temporal sedimentation at the lake were both internal and external physical changes of the lake. The factors were net ws (net Stoke’s settling velocity) and water volume in the lake for suspended sediment distribution.

Abstract: Effects of Rhizobium inoculation on plant height (PH), leaf area (LA), leaf net photosynthesis (Pn), leaf transpiration rate (Tr) and water use efficiency (WUE) of stony desertification-grown white clover (Trifolium) by Rhizobium sp. SWFU27, SWFU29 were studied during Spring 2011. Seeds were soaked for 30min in strain SWFU27, SWFU29 cell suspensions respectively, growing individually in autoclaved stony desertification soil under nursery conditions at ambient temperatures. Datum were collected from 90-day-old plants on a sunny day. Rhizobium inoculation by SWFU27 significantly increased PH and LA by 50% and 91.58% separately, and SWFU29 by 129.17% and 158.95. Pn, Tr, WUE for three sets of plants all in turn: SWFU29 > SWFU27 > CK, suggesting that maximum growth of stony desertification-grown plant requires the Rhizobium inoculation to promote the growth, between the two inoculation systems, SWFU29 had a high photosynthesis efficiency, transpiration potential and water use efficiency than SWFU27 and SWFU29 is much light-tolerance species than SWFU27, thereto signify the phenomena that white clover inoculated by Rhizobium sp. SWFU29 is growing better and to be a pioneer dominant in Karst stony desertification area.

Abstract: Abandoning cropland to enable recovery of the natural vegetation has been implemented during the past decade to restore the soil quality in the Loess Plateau, China. However, natural succession on cropland in the different slope aspect is different. The present study aimed at investigating the change in soil chemical and microbial properties abandoned farmland across time, and also to compare the difference of soil chemical and microbial properties in north slope and south slope on the Loess Plateau. The results showed that the slope aspect greatly affected the soil chemical and microbial properties after the cropland was abandoned, this could be attributed to the different precipitation and temperature in the two slopes. Compared with the north slope in which the organic C, total N and available N increased with the increase of abandonment years, that of south slope fluctuated significantly. Microbial biomass C and microbial biomass N in both slopes did not differ significantly in the first 10 years abandoned cropland, then decreased drastically in 15-year sites and thereafter tended to increase. Basal respiration in both slope fluctuated greatly in the sites with different abandonment years. Enzymes activities differed significantly in two slopes.

Abstract: From the holistic perspective, a new dynamic model is proposed in this research to investigate the interaction between vegetation growth and aeolian dust deposition. Three cases of equilibrium distribution can be obtained and the stability of interior equilibriums is determined. When there is a stable interior equilibrium, a critical curve exists and separates the coexistent area where vegetation can survive in the environment of aeolian dust deposition, from the other area where vegetation is to be excluded. Simulation analysis further reveals the variation of the critical curve with the parameters and the anthropic influences. The critical curve and the coexistent equilibrium described by the model may be used as a theoretical basis to evaluate the feasibility of vegetation restoration in the environment of aeolian dust deposition.

Abstract: The evaluation of soil fertility in Zhuxi watershed was studied based on the methods of Geostatistics and GIS. The results showed that the higher soil fertility area was distributed on farmland in the downstream, the lowest soil fertility area was distributed in the central part of the watershed where soil was eroded seriously. The overall of soil fertility was low, the percentage of area was less than 10% in grade 1 and grade 2 which fertility were better, the area of grade 4 taken more than 50%, the area of grade 5 which fertility was lowest still more than 20%. It was indicated that although soil erosion was controlled for years in this watershed, soil fertility was still poor, restoration was a long-term process. The evaluation of soil fertility based on Geostatistics and GIS, which demonstrated that the soil fertility rapidly and intuitive, and give practical application for the results of Geostatistics.

Abstract: The research object is slop near Yingrui highway, we mainly used oven drying method, combined with TDR, carrying out different vegetation types in interchange area and different substrates types in slope area about dynamic monitoring soil moisture in the spring. According to the result, The daily dynamic of the 2 types of slop soil moisture content has no obvious regular pattern, but each time the moisture content in soil slope are higher than rocky slope. We can get the conclusion after variance analysis, the main factors which influencing the discretion of the soil moisture content in slope and interchange area are the slope matrix type and the different vegetation reconstruction mode in interchange area. Meanwhile, according to the data, which we applied to the same experiment with both TDR and oven drying method, and after comparative analysis, we think, it’s completely effective to make TDR applied in deep soil moisture determination in some places such as interchange area, but the data about shallow soil moisture determination which got from the places such as in side slope is inaccurate. We should be more cautious when using it.

Abstract: Taking four types of slopes as test objects this paper measured their, soil nutrient and soil enzyme activity. The results showed that variation of soil nutrients in different slopes is obvious; soil enzyme activity is also a significant difference between different slopes. The soil of A slope (natural secondary forest ) was the highest in activity of urease, invertase, neutral phosphatase and catalase, the lowest in D(wasteland)slope except catalase. There were extremely significant positive correlations among soil urease activity, invertase activity and neutral phosphatase activity. Significant positive correlations were observed between soil urease activity, invertase activity, neutral phosphates activity and organic matter, available N, total N. It suggested that enzymatic activity could be used to indicate and estimate soil fertility of artificial remediation slopes. Combined with and community structure and community characteristics of vegetation on the sanmpled slops, soil enzyme activities could be used to measure the degree of vegetation restoration in the disturbed area.