Advanced Materials Research Vols. 864-867

Abstract: There is a correlation between sea surface temperature of the upper boundary waters and the intensity of typhoon. This paper analyzes the use of Argo float data and using inverse distance weighted interpolation method to calculate its internal regional sea surface temperature, when typhoon and other data were compared and error analysis. The results showed that: the method is reliable. When you select a point closer distance calculation and spatial distribution of Argo floats as closely as possible, the weight coefficients taken 2, known buoy number is 4-6, the relative error of calculated is less than 0.4%, RMSE error is less than 1.2 in the 0-600m depth layer

Abstract: With the growth of population and the increasing scarcity of water resource, making a good water strategy is more and more important. Seawater desalination is the technology to get fresh water from seawater. We construct a model to estimate the cost of desalinization in 2025 and give some advises about the desalination project.

Abstract: Irrigation water use efficiency is an important index to evaluate agricultural water use efficiency of irrigation districts, and is a basic parameter of hydraulic engineering construction and water management. However, there are many problems in practical applications of the traditional irrigation water use efficiency which is based on sufficient irrigation theory. This paper puts forward a new concept and determination method of irrigation water use efficiency based on the theories of deficit irrigation. Finally, we discussed the connotations from the project characteristics, benefit characteristics, spatial scale and time scale characteristics.

Abstract: In order to study the aerated cavity length and negative pressure on stepped spillway which combined with Y-shape asymmetric flaring gate pier body type, this paper applied RNG turbulence model,VOF model of water vapor two-phase, iterative solution of geometry reconstruction format of unsteady flow to generate free surface. Numerically simulated the length of aerated cavity and negative pressure of stepped spillway which combined with asymmetrical Y-shape flaring gate pier that with the contraction ratio respectively of 598, 0.497 and 0.445, the range from the upstream reservoir to downstream stilling basin. And compared the simulation results with experimental results, found that the aerated cavity length on steps basically consistent with the measured cavity length, the maximum error is 9.7%. The simulation results shows that the aeration cavity length on steps increases with asymmetric flaring gate pier contraction ratio decreases, and the aerated cavity length of lateral side with smaller contraction angle is larger 4 to 5 times than lateral side with larger contraction angle.

Abstract: Contrasts between TRMM 3B43 monthly data and rainfall observations of 720 stations in China are conducted based on a linear regression model. During January 1999 and December 2007, there is a significant correlation between TRMM data and the observed ones with an average r² 0.834. TRMM data performs better in the South and North, especially for flat regions. Limited by radar signal degradation due to heavy rain and low resolution of monitoring, TRMM data have better results in low-flow season than that in flood season. TRMM data cover all the places in middle and low latitudes. It is useful for long-term water resources planning, drought analysis in ungauged basins (PUB), and will be helpful for flood warning. Spatiotemporal data with higher resolution will greatly promote the development of hydrology in the future.

Abstract: The energy dissipater of stepped spillway combined with flaring gate pier is widely used in china's hydraulic engineering. The finite volume method is applied to discrete analysis, with the RNG turbulence model and VOF model of water vapor two-phase, iterative solution of geometry reconstruction format unsteady flow to generate free surface. Adopting structured grid for geometric shape, numerically simulated the water vapor two-phase flow from the reservoir to stilling basin. The parabolic water-vapor interface , overall flow pattern, water wings, section depth and other hydraulic characteristics was produced by simulating the three-dimensional flow field.Compared the simulated results of water depth, flow velocity in stilling pool, the board pressure with experiment data, the average error is: the left side depth of 3 # table hole of 7.1%, and the right of 7.4%; the underside flow velocity of 3 # table hole of 5%;1 # table hole stilling pool board pressure of 7.6%,3 # table hole stilling pool board pressure of 6.6%.

Abstract: In the middle and downstream area of the Yangtze River, low water levels had occurred at post-flood season or before the flood season in recent years, since the trial impoundment of the Three Gorges Reservoir (TGR) in 2008. Based on the analysis of the low water levels, both rating curve of main stations in the middle and lower reaches of the Yangtze River and the operation of TGR in the dry season were analyzed in study to reveal the effects of the impoundment of TGR on water level of downstream areas. The research results show that the water supplement of the TGR could raise the downstream water level, which has positive effect on water supplement and navigation in this area.

Abstract: Due to long-term excessive exploitation of groundwater, serious land subsidence has been caused in Cangzhou City, Hebei Province, China. With GIS spatial analysis method, this paper conducted an analysis of the quantitative relationship between deep groundwater exploitation and the land subsidence in this area. This quantitative relation was analyzed by using data of both long-term and short-term time series. The long-term time series analysis indicates that the land subsidence volume accounts for 57.6% of the amount of deep groundwater exploitation, indirectly showing the proportion of released water from compressibility of the aquifers and the aquitards in deep groundwater exploitation. Some factors such as hysteresis effects of subsidence may be ignored in the short-term time series analysis, thus the calculated ratio becomes significantly large. From perspective of water resources evaluation, the long-term time series analysis is better to analyze the relation between land subsidence and deep groundwater exploitation.

Abstract: The purpose of this research is to study the temporal variability of precipitation time series of Tianchang County in Anhui Province, China to aid in the understanding of the state of the hydrology of the catchment. Trend analysis of one of the main component of the water balance of a catchment and a climate variable, precipitation was conducted with the aim of detecting a possible trend in the precipitation time series of Tianchang County, the non-parametric Mann-Kendall test was applied to precipitation series from 1951-2010 of Tianchang County. It was performed using Trend (version 1.0.2) to identify the significant positive or negative trends in the precipitation data if any. The 59 years period of precipitation data for the different towns in whole area showed, on the whole, some significant trend at an alpha level of 0.01 and 0.05 when grouped into the four seasons present in the area. The trend analysis revealed an overall upward and significant trend in five towns namely Datong, Xinjie, Shiliang, Qinlan and Tongcheng with downward statistically non-significant trend in the other ten areas .Using hypothesis testing, the null hypothesis states that there is no trend and alternative state there is a trend. From the results we reject the null hypothesis within the level of confidence 0.05 and 0.01. The rising rate of precipitation in some months and decreasing in others signifies an overall random pattern in the time series. This result is a part contribution to the effect of Climate change on hydrology and indicates that there is still room for research on the impact of climate change to ensure sustainable development in future.

Abstract: In order to reveal the ecological mechanism of rainfall redistribution and lag effects on precipitation of evergreen broad leaved forest in eastern coastal China, 25 m×25 m permanent plot studies were carried in C. fargesii stand and S. Superba stand in Forest Ecosystem Observation and Research station in Tiantong, Zhejiang Province. The results indicated that the total rainfall outside the forest was 5114.0 mm, the average rates of canopy interception, throuhfall, and stemflow were 24.5%, 6.1%, and 69.4% respectively in C. fargesii stand, which were 30.7%, 7.7%, and 61.6% respectively in S. Superba stand. Rainfall redistribution function of C. fargesii stand was better than that of C. fargesii stand. Throughfall and stemflow were increased with rainfall class increasing while canopy interception decreased as rainfall class increasing, especially during typhoon storm period. throughfall was observed after 67.6min when rainfall classes<5 mm happened, while throughfall was observed after 11.8 min when special heavy storm happened in C. fargesii stand, 6 times shorter than little rainfall event. The lag time of throughfall in S. Superba stand was longer than that in the C. fargesii stand. The time lag shortened gradually as rainfall class increased. Lag time of stemflow was about 2 times than that of throughfall.