VARIATION OF WATER DEPTH AND MANNING''''S ROUGHNESS n DUE TO RIVER MEANDERING IN SUBCRITICAL FLOW REGIME

I INTRODUCTIONThe flow in a channel will be retarded by several factors, including surface roughness, vegetation,channel irregUlarity, channel alignment, and obstrUctions. The surface roughness is often only consideredin selecting the roughness coefficient, such as Manning's n. However, in case of a meandering channel,the channe1 alignment is sometimes more dominant than the surface roughness. The meandering ofnatural streams may increase the Manning's n as high as 30% (Chow, l969). Sc…     

黄淮海平原水土资源利用的可持续性评价、开发潜力及对策

黄淮海平原耕地顷均水资源量仅及全国平均水平的1／4，目前缺水率为19．3％，水资源利用可持续性综合评价指标属于中等偏下水平，为我国较为严重的缺水区，尤其是海河低平原区。土地资源利用对种植业而言，属于临界可持续状态，山前平原区指数值最低，有使耕地进一步向非农用方面转化的可能。2010年，本区水资源可供水量将比2000年增长22．4％，耕地面积仍能维持1998年水平。本区水土资源的区域匹配有明显的地区差异：山前平原区与海河低平原区水资源开发潜力不大，土地利用受缺水制约，水资源利用率已超过86％，平均可利用水资源量不足2500m^3/hm^2；但黄淮平原区和滨海低平原区水土资源均有较大的开发潜力，水资源利用率低于50％，平均可利用水资源量分别为3330m^3/hm^2和7020m^3/hm^2。本区水土资源利用的对策应为：积极开辟灌溉新水源（2010年外流域调水量和污水处理回用与微咸水利用量分别占可供水量的20．2％和4．9％），积极发展节水灌溉新技术，加快中低产地改造与高产农田的建设（中低产地改造后每公顷可增产粮食1950kg）以及实施稳定北部、提高中部、发展南部粮食生产的重点区域发展布局，以促进其农业和农村的可持续发展。     

Gewässergütebewertung und Bewertung von Abwasserfahnen in Rhein und Main auf der Basis mikrobieller Enzymaktivitäten

Quality Mapping of Surface Water and Assessment of Treated and Untreated Waste-water Inputs into the Rhine and Main River Based on Microbial Enzyme Activities Microbial enzyme activities are used for an extension of the traditional quality mapping of surface water. In the following study, the enzymatic parameters were proved and validated on samples from various creeks and rivers in Baden-Württemberg and on samples gathered from the Rhine and Main Rivers (Germany). The test parameters should also be used for the control and the preservation of the capacity of the biological self-purification, which is the only natural and essential process in drinking-water conditioning of surface water. Main subject of the surveys was the development of criteria for an assessment of the measured enzymatical inhibition effects. Therefore, classes of inhibition and indices of inhibition are defined.     

香港缺水问题与东江水资源开发

本文讨论了香港的缺水情况，东江水供香港的作用，以及在近年经济、社会迅速发展的新形势下东江流域水资源开发利用出现的新问题。     

黄土高原水资源特征与利用对策

本文在简述黄土高原气候干旱、降水稀少、地面破碎、植被缺乏、水土流失严重等自然条件的基础上。分析了黄土高原水资源短缺、时空分布不均、变化很大,河流含沙量极高,水质污染日趋严重等特征。提出了蓄水保土,建立“土壤蓄水库”,抑制土壤蒸发,发展节水型工农业体系,提倡节约用水、科学用水,加强水资源管理与保护等措施,力求最充分合理地开发利用黄土高原地区有限的水资源。     

Premonsoonal water characteristics and circulation in the east central Arabian Sea

The hydrographic structure in the east central Arabian Sea during premonsoon period undergoes significant temporal change in the thermal field of upper 100 m, wherein temperature rises by about 0–5°C on an average from May to June. The major contribution in increasing the surface layer temperature comes from surface heat exchange processes, while the horizontal advective process tends to remove the heat from the upper layer. The geostrophic flow patterns are similar from May to June in the major part of the study area while in the coastal areas off Goa a southerly current sets in June in response to coastal upwelling.     

Elektrochemische Einschätzung des Oberflächenzustandes von Wasserreinigungskohlen

Electrochemical Characterization of the Surface of Activated Carbon Used in Water Treatment Plants. We tried to measure electrochemically those properties of activated carbons which are important for using them for water purification. A success was achieved with the electrochemical immersion potential U_i which is found to be a function of concentration of functional surface groups on the carbon surface. However, the expected direct proportionality for inert surfaces between BET surface area and amount of charge measured in recharge processes has not been observed.     

利用NOAA－AVHRR资料提取水体信息的初步研究

本文讨论了应用NOAA-AVHRR资料来提取水体信息的方法。采用AVHRR一、二通道(下面简写为CH1、CH2)获得的地面反射率数据构成的归一化植被指数(NDVI)来识别水体,并初步提出了应用模糊数学的方法提取混合像元中的水体面积信息的技术思路。     

The influence of karst features on environmental studies in Turkey

 The carbonate rocks of Turkey, which underlie about one third of the country, possess major water resources with great potential for electricity generation and water supplies. The ongoing development of karst features, especially in the southern part of Turkey, demonstrates specific environmental problems that occur in many karst water supply projects. Karst aquifers, springs, sinkholes, dolines, poljes and other karst features are of great importance from the standpoint of karst water resources and environmental research studies. In karst regions, conservation and protection of groundwater resources for both qualitative and quantitative evaluations is possible only when the catchment area is determined accurately. Since the catchment area in karst terrains is not limited by the surface drainage boundaries and the groundwater flows through well-developed coduits or fissures, the equations used in non-karstic areas cannot be applied to such karstic regions. Studies on the development of karst features and its environmental impacts in Turkey are of recent origin. Therefore, many unreliable methods are being applied in karstic areas. For example, the use of "shallow holes or sinkholes and fault zones" for septic water waste disposal or as sewage by those who are not familiar with karst, sometimes causes very serious problems of extensive groundwater pollution. This paper discusses the development of different karstic features in Turkey and case studies on its environmental impacts. Received: 27 December 1995 · Accepted: 10 July 1996     

Water policy,trust and governance in the Murray-Darling Basin

Concerns for river health in the Murray-Darling Basin (MDB) area and shifting priorities for water use have led to a significant process of water reform over the last decade. The MDB area, also known as the food bowl of Australia, produces much of the country's food and is home to a significant portion of the population. A long-term drought, historical over-allocation of water for irrigation and climate variability have led to mounting concerns about the long-term viability of the rivers. While the reform process has resulted in the Commonwealth government taking control of the rivers from the States, it has also been influenced by changes in governments and consequent shifts in water allocation priorities from a privileging of agriculture to a broader approach encompassing economic, environmental and social concerns. This had led to uncertainty for the people and communities in the Basin and some confusion between the various layers of governance structures. This paper presents the results of exploratory research conducted with key, high-level stakeholders involved in water reform to examine their perceptions of the evolving water policy process. Despite agreement amongst stakeholders that returning water to the environment to ensure river health is critical, our research reveals significant tensions between stakeholders concerning the evolving process, particularly centred on the potential social outcomes and fairness and equity. This suggests the need for more integrated and transparent governance structures, attention to levels of trust between partners and a common vision that incorporates environmental, economic and social goals.