Advanced Materials Research Vols. 726-731

Abstract: In this paper, we studied the seasonal variation of rainfall and runoff of Yuanjiang-Red River Basin in Yunnan during the last ten years and obtained the seasonal change of rainfall on spring, summer, autumn, winter. But we found some fluctuations in 2002, 2003, 2004, 2010, then analyzed the reasons of fluctuations. In these years, the basin emerged different levels of disasters. Meanwhile, runoff also had the variation, and there were some similarities between rainfall and runoff. The research on seasonal variation is significant for hydrological monitoring.

Abstract: Rainfall, throughfall, stemflow, runoff and outlet flow were studied in a secondary forest during a rain season from April to October in 2009. Some of the chemicals in throughfall, stemflow, runoff and outlet flow were increased in contrast with incident rainfall. The pH value of the water sample was in the order rainfall > throughfall > runoff > outlet flow > stemflow. The concentration of chemicals of rainfall was in the order SO₄^2- > NO₃^- > Na⁺ > Cl^- > K⁺ > Ca²⁺ > NH₄⁺> Mg²⁺ >PO₄^3-. The mean concentrations of nutrients in throughfall, stemflow and runoff were significantly higher than those in incident rainfall except Na⁺ and NH₄⁺. The concentration of chemicals of outlet flow was in the order SO₄^2- > Cl^- > NO₃^- > Ca²⁺ > Mg²⁺ > Na⁺ > K⁺ >NH₄⁺ >PO₄^3-.

Abstract: This article which based on the analysis of the Tibet Linzhi Duobu hydropower stations geological conditions, the review of the permeability coefficient, total water inflow estimation of foundation pit and other foundation researches compares and selects water-lowering schemes when the excavation of underground factory buildings starts. Comparing the impervious curtain and water-lowering scheme with full-well dewatering scheme on applicable conditions, advantages and disadvantages, construction program and cost accounting etc. in detail and the final selection is the "drain openly + the well dewatering program. This article also makes a very detailed discussion on construction management, operation mode, safeguard measures and contingency measures and hopes to have references to the follow-up projects.

Abstract: Natural water cycle is of river-basin characteristic, with obvious river-basin regularity in formation, movement and change. The development and utilization of river-basin water resources are of important significance to solve the shortage of water resources. Dagujia river is the second largest river in Yantai. But with fast development of social economy and population growth of Yantai city, Dagujia river resources have been overexploited, resulting in corresponding environmental effects. Based on the thorough investigation of the current water resources utilization, the paper analyses the production and the change trend of environmental effects and discusses projects and management mode in order to achieve efficient utilization of water resources.

Abstract: In order to ensure availability of water throughout the year in the Tailan River basin of northwestern China, an underground reservoir has been constructed in the basin to augment the groundwater resource and efficiently utilize it. This study investigates the potential impact of future climate change on the reservoir by assessing its influence on sustainability of recharge sources to the reservoir. The methods employed involved using a combined Statistical Downscaling Model (SDSM) and Long Ashton Research Station Weather Generator (LARS-WG) to downscale the climate variations of the basin from a global climate model and applying them through a simple soil water balance to quantify their impact on recharge to the reservoir. The results predict the current mean monthly temperature of the basin to increase by 2.01°C and 2.84°C for the future periods 2040-2069 and 2070-2099, respectively, while the precipitations are to decrease by 25% and 36% over the same periods. Consequently, the water balance analyses project the recharge to the reservoir to decrease by 37% and 49% for the periods 2040-2069 and 2070-2099, respectively. Thus the study provides useful information for sustainable management of the reservoir against potential future climate changes.

Abstract: Filed hydrology and water quality data were collected near the Gezhouba Dam early December of 2012 to analyze the response of Chinese Sturgeon survival condition to water temperature, dissolved oxygen (DO), pH, transparency (SD) and bottom flow-velocity. The results showed that water temperature lag is unconspicuous. The water temperature of Gezhouba Dam Sanjiang (GDS) was lower than that of Gezhouba Dam River (GDR), and it hindered propagation of sturgeon eggs. DO decreased fast in the vertical water column of GDS, pH ranged from 7.5 to 7.71. The hydrology and water quality were suitable for the life condition of sturgeon eggs and fry, except index of bottom flow-velocity.

Abstract: The SWAN model was used to simulate the effect of the coastline change caused by the reclamations on the wave fields in Bohai Bay. The numerical results in the year of 2000 had been compared with that of 2010 to study the influence of the sea reclamations on the wind waves in Caofeidian area. The results show that the significant wave height has a declining trend due to the reclamation and decreased in value of 0.1 to 0.4m in 2010. The magnitude of the decrease of the significant wave height in winter is larger than that in summer. The significant variations of wave fields are occurred in the harbor basin and tide channel.

Abstract: Sunflower is an important oil crop, which is tolerant to water and salt stress and can be planted in vast areas of China. In our studies, four salinity levels of irrigation were used to irrigate one kind of sunflower (TO01244) under two irrigation low limits (65%FC and 75%FC). Plant growth, Soil salinity and leaf water status, yield and quality were researched. The results showed the means of plant heights under 2g/L, 3.5g/L and 5g/L irrigation water were 9.07%, 12.45% and 18.35% lower than the tap water respectively. In soil salinization the means of ECe increased by 271.13%, 173.22%, 132.98% and 4.73% respectively under irrigation water of four salinity levels. It can be found that the seed under 3.5g/L irrigation water had more linoleic acid, which is healthy to human and contribute to address the cardiovascnlar and cerebrovascular diseases as an important part of the sunflower oil. Facing the increasingly serious lack of fresh water resources, development and utilization of underground saline water would play an important role in agricultural production.

Abstract: Combined the grey theory with self-memory theory, a grey self-memory model was set up to predict the low-flow runoff volumes. The Chabagou catchment located in the Loess Plateau was selected to test the model. The least square method was used to determine the memory coefficients; so the prediction equation was obtained to calculate the simulation values. Compared with the grey model (1,1) (GM(1,1)), the grey self-memory model has a better fit between the simulation and measurement data during the fitting period. The pass-rate of the prediction values for two models are 100%, but the grey self-memory model is better than GM (1,1). The fitting and prediction results showed the grey self-memory model is capable of predicting the low-flow runoff volumes in the Loess Plateau.

Abstract: This paper aims to seek a way for improving rainfall prediction accuracy from the perspective of time unit points which are 5 days, 10 days, 15 days, 20 days, 25 days, and 30 days. Based on the daily rainfall data from 2001 to 2010 of Da-dong-yong hydrologic station, the rainfalls are predicted by establishing the model of wavelet neural network. Results show that prediction accuracy and stability of time unit points is 30-day > 25-day > 15-day > 10-day > 20-day > 5-day. The trend of six kinds of rainfall forecast is consistent. When the number of forecast data is fewer and time unit point is longer, the accuracy and stability of rainfall forecast are better.