Applied Mechanics and Materials Vols. 405-408

Abstract: In order to evaluate quantitatively the hydrology and water resources effects of land use and land cover change (LUCC), a zonal watershed hydrological model considering land use and land cover change (ZWHM-LUCC) was developed. According to the daily rainfall, evaporation and discharge data of Wuding River Basin during 1980~2000, the parameters of the model were calibrated and verified. The results show that coefficient of water balance (R) is 1.004 and the qualified rate of annual runoff depth (DR) is86.67% during calibration period 1986~2000 and the R is 0.938 and the DR is 66.67% during calibration verification 1980~1985. The calculated results indicate that this model has good adaptability in Wuding River Basin. The different scenarios of land use/land cover were analyzed by the model, with 2000 year as base year, 13 scenarios were designed, which be helpful to study water-economy-ecology interactions and natural-social dualistic, and provide the scientific basis for Wuding river basin water and soil conservation planning and water resources planning.

Abstract: Due to the absence of the reasonable allocation and management of flood drainage right, most of the people consider their own interests when the floods occurred, which exacerbated the flood loss and caused water dispute. Taking the midstream of Huaihe River as the example, this study try to solve the flood problems from the reasonable allocation of flood drainage right. We analyzed the drainage conditions, discussed the generalized physical model and dynamic coordination model structure. The dynamic and balanced model for the reasonable allocation of flood drainage right was established with the flood disater losses minimum as the objecetive funciton and flood risk as the important constraint, which will provide the scientific basis to study the reasonable allocation of flood drainage right and serve the project layout, integrated management and flood control.

Abstract: Hydrological models are always related to time and spatial domains, so the model results produced by these models are very large. Microsoft component structured storage can be employed to save the model results, but it is lack of mechanism to reduce the data size. In order to tackle this situation, compressed structured storage method is introduced which based on combining component structured storage and zlib compression library. In this method, standard component rules are complied and containment as most common mechanism for object reuse in COM is applied so as to simplify the usage.

Abstract: The recharge coefficient of karst spring system in Baziling tunnel region of Yiwan railway was studied in this paper, using groundwater regime and daily precipitation data. Tracer test were conducted to confirm the boundary of the S1 karst spring. Attenuation curve of spring was used to calculate the water changes in karst aquifer. The results show that recharge coefficient of one karst spring system is not a constant value, but a variety that influenced by the precipitation intensity and distribution. Thus when water balance model was used, the annual recharge coefficient can only be applied to access normal flow into the tunnel. But if used to access the Maximum flow into the tunnel, the flow will be much less than measured flow into the tunnel, which is a great threat to the tunnel engineering.

Abstract: This paper discusses the conceptual stepped calibration approach (SCA) which has been developed for the Xinanjiang (XAJ) model. Multi-layer and multi-objective functions which can make optimization work simpler and more effective are introduced in this procedure. In all eight parameters were considered, they were divided into four layers according to the structure of XAJ model, and then calibrated layer by layer. The SCA procedure tends to improve the performance of the traditional method of calibration (thus, using a single objective function, such as root mean square error RMSE). The compared results demonstrate that the SCA yield better model performance than RMSE.

Abstract: Multi-object application and water and sediment regulation of the Xiaolangdi Reservoir since 2001 have changed the flow and sediment conditions entering the Lower Reaches of Yellow River and the Estuary. Field flow and sediment data at Lijin Hydrological Station and river cross section elevation data downstream from Lijin Section during 2001~2010 have shown that the Estuary have been in a state of little scouring. The 2D mathematical model has been used to study the flow and sediment conditions for the Yellow River Estuary balance. The conclusions have arrived at that total annual water volume is 196 × 10⁸ m³, total annual sediment volume is 1.40~1.70×10⁸ t, coarse sediment concentration is 3kg/m³.

Abstract: t was carried out to optimize combination scheme experiment of three factors among level-border specifications, irrigation quota and fertilizer methods under the condition of level-border and plastic film irrigation for corn in the sand of soil by cross experiment methods. The result indicates that the main factor affecting corn production is irrigation quota, fertilization methods; a secondary factor is level-border specifications. According to variance analysis of corn physiological characteristics and yield, the optimum combination scheme of the three factors is at level-border specifications 0.133 hm², irrigation quota 1050 m³/hm² and fertilization methods that is one-off hole postponed fertilizer through analysis of physiological properties and yield for corn.

Abstract: This study investigates the association between the sea-land interface moisture flux and reference evapotranspiration during 1971-2010 in Liaohe Delta, Northeast China, which moisture flux is derived from NCAR/NCEP reanalysis I data and reference evapotranspiration is calculated by Penman-Monteith equation. The result shows that the sea-land interface moisture flux presents a seasonal variation with the highest value in summer and the lowest value in winter. The sea-land interface moisture flux and reference evapotranspiration show significantly positive correlation in spring and autumn and significantly negative correlation in summer. Consistent with the past field experiments, the sea-land moisture flux suppresses reference evapotranspiration in summer. The positive correlation reveals that the sea-land moisture flux, especially in surface sublayer, facilitates reference evapotranspiration in spring and autumn. Regressions analysis demonstrate that reference evapotranspiration increases when moisture flux of surface-to-850-hPa sublayer increases until reaches the threshold (67-75 kg/ms), and the opposite trend appears when moisture flux exceeds the threshold.

Abstract: Reservoir regulation make conditions of flow under the dam change greatly after impoundment of the Three Gorges Project. This paper analyzes change trend and abrupt change situation of incoming water and studies characteristics of new flow of Yichang and Hankou Stations after impoundment of the Three Gorges with Mann-Kendall nonparametric rank test method. The result indicates that operation of the Three Gorges Reservoir has leveled runoff process and shortened dry season and extended median water period; After operation of the Three Gorges Reservoir, monthly river runoff of several months in both of Yichang and Hankou Stations changed abruptly. However, so far as time of abrupt change is concerned, sudden change of annual river runoff or monthly river runoff has little to do with operation of the Three Gorges Project.

Abstract: Reservoir regulation make conditions of sediment under the dam change greatly after impoundment of the Three Gorges Project. This paper analyzes change trend and abrupt change situation of incoming sediment and studies characteristics of new sediment of Yichang and Hankou Stations after impoundment of the Three Gorges with Mann-Kendall nonparametric rank test method. The result indicates that after operation of the Three Gorges Reservoir, annual sediment runoff changed suddenly and sediment runoff reduced sharply in Yichang and Hankou Stations; sediment entering the Yichang-Wuhan reach decreases substantially and it almost can be regarded as clean water discharge. Research shows unsaturated degree of the clear water released from reservoirs decreased after obtaining sediment along the river, so the sediment discharge would be partly recovered.