Prediction of sediment,particulate nutrient and dissolved nutrient concentrations in a dry tropical river to provide input to a mechanistic coastal water quality model

A Generalised Additive Modelling (GAM) approach is applied to prediction of both particulate and dissolved nutrient concentrations in a wet-tropical river (the Fitzroy River, Queensland, Australia). In addition to covariant terms considered in previous work (i.e. flow, discounted flow and a rising-falling limb term), we considered several new potential covariates: meteorological and hydrological variables that are routinely monitored, available in near-real time, and were considered to have potential predictive power. Of the additional terms considered, only flows from three tributaries of the Fitzroy River (namely, the Nogoa, Comet and Isaac Rivers) were found to significantly improve the model. Inclusion of one or more of these additional flow terms greatly improved results for dissolved nitrogen and dissolved phosphorus concentrations, which were not otherwise amenable to prediction. In particular, the Nogoa sub-catchment, dominated by pasture for cattle, was found to be important in determining dissolved inorganic nitrogen and phosphorus concentrations reaching the river mouth. This insight may direct further research, including future refinement of processed-based catchment models. The GAMs described here are used to provide near real-time river boundary conditions for a complex coupled hydrodynamic and biogeochemical model of the Great Barrier Reef Lagoon, and can be coupled with a forecasting hydrological model to allow integrated forecasting simulations of the catchment to coast system.     

基于二元水循环的水量-水质-水效联合调控模型开发与应用

为将我国最严格水资源管理制度的实践与二元水循环理论相结合，提高“三条红线”控制指标的科学性与合理性，本文以SWAT模型为基础，通过改进子流域划分方法、添加经济社会模块和人工用水模块，对其人工侧支循环模拟进行了系统的完善，开发了基于SWAT的水量-水质-水效联合调控模型SWAT_WAQER。以广西南流江流域为例，从国民经济用水量、河道径流与水质等方面对模型进行校验，并在此基础上划分了2030年“三条红线”控制指标。结果表明：该模型性能良好，能够用于不同节水情景下的国民经济用水量、污染物排放量、水功能区水质达标结果分析，可以作为科学制定“三条红线”控制指标的有力支撑工具。     

浅谈东深供水改造工程的设计监理工作

施工图阶段设计监理工作的内容归纳起来主要是对设计质量进行控制.依据<水利建设工程招标、施工图阶段设计监理试行规定>,其具体工作内容仅限于设计成果的合法性和安全性,没有充分发挥设计监理作用,对施工图阶段设计质量的理解是不全面的.施工图阶段的设计质量不仅仅是提交合法和安全的图纸,而且图纸的提交时限性、可实施性及经济性也应是考核设计质量的重要组成部分,为此东深供水改造工程的设计监理工作内容确定为"五项控制"和"两项权利",全面地对施工图阶段的设计质量进行控制.     

悬停直升机的雷达探测技术

首先对直升机旋翼的雷达回波进行建模与分析,在此基础上分析了雷达探测悬停直升机的可能性,提出了一种适用于所有直升机类型的多扫描周期积累检测系统方案,讨论了可能影响其检测性能的因素.     

Engineering Geological Problems of Levee Along Middle and Lower Reaches of Yangtze River

1　ＩｎｔｒｏｄｕｃｔｉｏｎＢｅｃａｕｓｅｏｆｔｈｅｃｏｍｐｌｉｃａｔｅｄｓｕｂｓｏｉｌｐｒｏｆｉｌｅ ,ｔｈｅｌｅｖｅｅａｌｏｎｇｍｉｄｄｌｅａｎｄｌｏｗｅｒｒｅａｃｈｅｓｏｆＹａｎｇｔｚｅ ,ａｂｏｕｔ 36 0 0ｋｍｌｏｎｇ ,ｈａｓｍａｎｙｈｉｄｄｅｎｐｅｒｉｌｓ .Ａｍｏｎｇｔｈｅｄａｎｇｅｒｏｕｓｅｖｅｎｔｓｄｕｒｉｎｇ 1998’ｓｆｌｏｏｄｓｅａｓｏｎｉｎｔｈｅｗｈｏｌｅｖａｌｌｅｙ ,12 .7%ｏｃ ｃｕｒｒｅｄａｌｏｎｇｔｈｅｔｒｕｎｋｓｔｒｅａｍｄｙｋｅｓ,ｏｆｗｈｉｃｈ 6 98ｗｅｒｅｔｈｅｍｏｓｔｄ…     

开关DC—DC变换器并联运行问题的研究

开关直流电源并联运行在许多场合应用。每一路电源输出阻抗的不一致性使每一路输出电流难以均衡，影响了系统的可靠性。本文提出了一种双回路ＤＣ—ＤＣ变换器的控制方案。由于采用电压环（外环）和电流环（内环）两环结构的双回路控制模式，变换器输出电流得到了有效控制，便于多个ＤＣ—ＤＣ变换器输出直接并联，从而实现了模块化，具有一定的实用性     

西藏拉洛水利枢纽及配套灌区工程下泄流量的初步研究

回顾了国内外有关河流生态环境需水的研究进展以及目前较常用的河道内生态环境需水量的计算方法。以西藏拉洛水利枢纽及配套灌区工程为实例,采用多种计算方法对工程拟定的下泄流量方案进行分析比较,并指出工程下泄流量方案存在的问题。分析结果表明,工程拟定的方案在下泄水量方面是满足下游生态环境需水要求的,但下泄流量过程可进一步优化,以减缓引水对下游生态环境的影响。     

泥沙实体模型时间变态问题的研究

运用数学模型对陈家湾~新厂河段实体模型进行数值模拟,采用该河段2002年10月~2004年7月实测水沙资料,对实体模型时间变态有关问题进行了系列研究。分别采用容重为1.38t/m3及1.15t/m3模型沙比较了沿程水位、流量、流速、含沙量等基本参数的变化过程与原型的偏差,以及由此引起模型河道冲淤量与原型河道的偏差,并对这些物理量偏差的原因进行探讨。     

SIMILARITY LAW OF FLUCTUATING PRESSURE WITHIN HYDRAULIC JUMP AREA

Through a series of model tests of five scales for 2-D free hydraulic jump, the da-ta of fluctuating pressure acting on the floor level within the hydraulic jump were obtained. Dur-ing the experiments, Froude number varied from 2.94 to 8.61, and Reynolds number rangedfrom 2×10~4 to 6×10~5. Experiment results indicate that the amplitude scale of fluctuating pres-sure is the length scale of model, i. e. P'=L, which agrees with gravity similarity law: Thefrequency scale of the fluctuating pressure is a unity i. e., f=1, which does not satisfy thegravity similarity law.