黄河下游河道萎缩的特点及其水文学背景

通过分析黄河下游1986年以来实测资料，探讨了黄河下游1986—1999年水文系列的特点和河道萎缩的特点，指出了上世纪80年代后期以来河道萎缩使河道泄流排沙能力降低，洪水位抬高，威胁堤防安全，河道萎缩还关系到流域的开发和水资源的利用。本文还分析了河道萎缩与水沙特征的关系及河道萎缩的形成条件，并提出了判别形成河道萎缩的水沙关系。     

Hydrology research priorities for Dryland Agriculture in India

A conceptual approach was described and used to identify priorities for the cooperating centres of the All India Coordinated Research Project for Dryland Agriculture (AICRPDA). The approach was based on AICRPDA centre information, soil available water, runoff estimates, and rainfall at each centre. Lines of equal runoff were derived from the runoff-rainfall curves of the major dryland soils. Two scenarios were described, one where vertisols are cropped during the rainy season and the second where they are left under fallowed conditions during the rainy season. Three water management zones were identified for each scenario: less than 100 mm of runoff, 100 to 260 mm of runoff and greater than 260 mm of runoff. Depending on the scenario, each AICRPDA centre was incorporated into one of the three water management zones. Research orientation and priorites were set for each zone. Research efforts in the low rainfall zone can be based on small areas and in-situ water conservation. In the medium runoff zone, research can be based on areas ranging in size from 10 to 100 ha and water harvesting techniques. For the high runoff zone, greater efforts have to be put on runoff and erosion control and also on drainage response alleviating the problems created by waterlogging over large areas of 100 to 10 000 ha. Secondary priorities were also identified for each zone.     

On some apparent paradoxes in water spreading,hydrology and seepage

In water spreading and underground hydrology, one should beware of pitfalls. This is illustrated by several examples of vertical downflow and upflow. Drainage by overcharging: When a fine-grained soil overlies a coarse-grained soil, a certain amount of water can be suspended in the interzone. Adding water may cause excessive drainage. Cavitation in soils: When water flows from an upper less pervious layer to a more pervious layer, the pressure head in the interzone may become negative, the gases dissolved are released in the form of bubbles which render the soil temporarily impervious. At the initial instant of seepage of water from a pond into a dry soil, inertial forces and kinetic energy cannot be neglected. At the interface of two anisotropic media, the angle of refraction of a streamline depends on the tangential hydraulic conductivity only, whereas that of a gradient line depends on the normal component only. Impossibility of steady-state evaporation from a deep water table: It is shown that the water concentration may become negative, which is physically impossible. Two modes of downflow: In insaturated downflow there exists a critical water concentration c such that the corresponding hydraulic conductivity K(c) is equal to the descending specific flux. The moisture distribution is radically different in the subcritical and supercritical zones.     

鸡冠嘴与桃花嘴矿床水文地质新认识

对湖北三鑫金铜股份有限公司自1988年以来所开发的鸡冠嘴与桃花嘴矿床深达600m,东西长约1 000m,南北宽500m,共计11个生产中段,虽然早期曾发生过岩溶突水与突泥事件,但以后所揭露的矿岩体其水力联系微弱,今后不大可能发生自然的突水可能性,并形成对该矿床水文地质新认识。     

Application of an evolutionary algorithm for parameter optimization in a gully erosion model

Herein we demonstrate how to use model optimization to determine a set of best-fit parameters for a landform model simulating gully incision and headcut retreat. To achieve this result we employed the Covariance Matrix Adaptation Evolution Strategy (CMA-ES), an iterative process in which samples are created based on a distribution of parameter values that evolve over time to better fit an objective function. CMA-ES efficiently finds optimal parameters, even with high-dimensional objective functions that are non-convex, multimodal, and non-separable. We ran model instances in parallel on a high-performance cluster, and from hundreds of model runs we obtained the best parameter choices. This method is far superior to brute-force search algorithms, and has great potential for many applications in earth science modeling. We found that parameters representing boundary conditions tended to converge toward an optimal single value, whereas parameters controlling geomorphic processes are defined by a range of optimal values.     

Effect of Roof Surface Type on Storm-Water Runoff from Full-Scale Roofs in a Temperate Climate

Roof surfaces represent a significant portion of the impervious area associated with urban development. Storm-water runoff from those surfaces causes stream degradation in receiving waters attributable to excess volume of water runoff. This paper investigates the influence of roof surface type on storm-water runoff and specifically considers the benefits of a vegetated roof, or green roof, as a storm-water best management practice (BMP). Runoff data were collected over a 6-month period from three full-scale roofs, which were retrofitted with flow meters and automated water-quality samplers. The roof surfaces included an asphalt roof (for control purposes), a vegetated extensive green roof, and a stone ballasted roof. Both the green roof and stone roof were effective at reducing runoff volume and attenuating peak discharge, with the green roof being more efficient for rainfall events less than 2.54?cm. Overall, the green roof retained 68.25% of rainfall volume and reduced peak discharge by an average of 88.86%. Water-quality results were inconclusive, but did provide some indication that green roof systems could reduce nutrient loadings.     

鄱阳湖环湖区水文站网合理分布和设置

评价、检验鄱阳湖环湖区现有水文站网.根据防汛抗旱、水资源开发利用、水环境保护、湖泊科学研究等国民经济持续发展的需要,科学、合理地布设水文站网。     

中子活化分析在大气环境及水环境研究中的应用

利用中子活化分析方法测试了成都市的大气环境及水环境样品。研究了有害污染元素分析的特征。     

水文部门水质监测站(点)设置的几点思考

对水文部门水质监测站(点)的设置提出了几点思考．