澳门地区东侧水域夏季余流及通量的时空变化特征

基于澳门地区东侧水域两座河口原型观测试验站夏季15 d的连续观测资料,分析了潮周期垂向平均欧拉余流、拉格朗日余流和斯托克斯余流时空变化特征的同时,将其概念推广到垂向潮汐动力影响下的分层余流分析中.研究显示,夏季澳门地区东侧南、北端水域整体涨落潮流态一致,南侧水域潮动力显著大于北侧;半月时段内,北侧水域潮流物质整体输移方向指向西北,南侧指向东南,拉格朗日余流流速分别为2.2 cm/s和5.1 cm/s,略小于欧拉余流.受海面西南季风影响,南、北侧水域表层欧拉余流、拉格朗日余流和斯托克斯余流流向均为东北向.潮周期垂向平均余流在洪水期指向外海侧,非洪水期北侧水域指向近岸,南侧水域指向伶仃洋河口东侧.海面风主导东南侧水域的斯托克斯漂移强度,对东北侧水域影响不明显,洪水期径流动力增强会削弱海面风引起的漂移作用;但南、北侧水域表层潮流物质输运强度和方向都与海面风密切相关.基于余流流态结合净潮通量分析显示,夏季澳门地区水道出口以下水域存在较为稳定的逆时针余环流,初步分析其原因主要是:珠江河口外海侧强劲的东北向沿岸流引起澳门地区东侧水域形成自东向西的补偿流所致.夏季,该独特的动力结构会截获上游东四口门下泄的部分水沙进入澳门地区水道,导致澳门地区水道滩槽淤积和水体交换不畅.

澳门地区附近水域水文特性及水沙运动特征分析

澳门地区附近水域位于珠江河口伶仃洋西侧,西承磨刀门洪湾水道洪水,东临伶仃洋输水输沙通道,是珠江河口东四口门与西四口门水沙交换的节点水域,水域受洪潮交汇作用,水文情势相当复杂,通过对澳门地区附近水域水文特性及水沙运动特征进行分析研究,为澳门地区附近水域的保护与治理提供技术参考。

澳门地区东侧水域夏季潮流动力时空变化特征

珠江河口澳门地区东侧水域是伶仃洋西滩和澳门地区水道洪季重要水沙通道,基于洪季实测资料分析显示,澳门地区东侧水域为不规则半日潮流,洪季澳门地区东侧水域整体涨潮平均流速21~23 cm/s,落潮平均流速18~29 cm/s,涨潮流态为N—NNW向、落潮流态为S向,流态基本稳定,靠外海侧潮流动力更强。潮周期内水域平均流速主要取决于潮型大小,洪水径流主要对余流和历时有较明显影响,洪水期水域北侧形成滞流区,南侧水沙朝伶仃洋口外净输移。40%水深范围内的水流垂向动力结构受海面风影响显著,且近海面10%水深范围余流流向与海面风向具有较好的跟随性;西南风作用下,最大水平流速梯度出现在潮周期内的第二次涨憩至落憩阶段,与潮周期内的最大含沙量出现时间相对应,由于水域北侧水深浅,床面剪切梯度力整体大于水域南侧,导致水域北侧含沙量显著大于东南侧。综合分析来看,天文潮、洪水径流和海面风是澳门地区东侧水域的主控动力因子,水域北侧浅水摩擦阻力较南侧显著增强,造成垂向涨落潮历时和相位的差异,形成该水域较为特别的“表层汇、中底层散”的垂向动力结构特征,洪水期大量淡水径流下泄进一步加剧了该趋势,导致表层冲淡水朝东侧漂移、底层高盐水向近岸入侵。

临水域软土地区超大深基坑的分区水冲开挖技术初步研究

在软土地区,尤其是在临近水域处,超大深基坑开挖施工可运用水力冲挖法。依次介绍了水冲法的工艺原理、特点、方案、流程,以及设备和人员配置情况。文中以超大深基坑分区后的某单块基坑为例,分析了水冲法和传统机械开挖的效率,测算了经济成本,归纳出可能的技术问题,并提出相应的解决方案。经对比分析可知,水冲法非常适合临近水域的超大基坑的开挖,可应用在诸如大型机场航站楼在内的大型基坑的开挖。

Effects of water stress on Haloxylon ammodendron seedlings in the desert region of Heihe inland river watershed, Gansu Province, China

The water relation and leaf gas exchange of saxoul (Haloxylon Ammodendron Bge, a C4 shrub) seedlings were studied under water stress in 2001. Saxoul seedlings maintained high transpiration when the soil moisture was above 11%. The seedlings were able to take up water from soil with above 6 % soil water content, which was the threshold level of soil moisture for seedlings. The relationship between transpiration and potential evaporation was linear for well-watered seedlings. The de-crease of soil water availability led to different degrees of down-regulation of stomatal conductance, leaf transpiration and net CO2 assimilation rate. The stomata played a relatively small part in determining the net CO2 assimilation rate for the same seedling. The relationship between net CO2 assimilation rate and transpiration was linear diurnally, and reduction scale of leaf transpiration was much bigger than that of net CO2 assimilation rate by waters tress treatments, therefore intrinsic wa-ter-use-efficiency increased. High evaporative demand increased the leaf transpiration but inhibited net CO2 assimilation rate. Because of the effect of VPD on transpiration in this region, the transpiration of well-watered and mild water stress seedlings becomes responsive to change in stomatal conductance over a wider range.

Nitrate Nitrogen Content Characteristics in Groundwater of Typical Planting Areas in Liao River Basin

The contents of nitrate nitrogen（NO-3-N） in underground water from typical planting areas in Liao river basin were analyzed, so as to provide theoretical basis for rational fertilization and effectively prevent the NO-3-N content from exceeding standard. The results showed that difference of the contents of NO-3-N in groundwater from different typical planting areas was significant. The highest content of NO-3-N in underground water was 37.4 mg/L from flower-growing region, then 22. 3 mg/L from maize-growing region, 21.9 mg/L from vegetable-growing region, and the lowest content of NO-3-N in underground water was 19.2 mg/L from rice-growing region. Except rice-growing region, the contents of NO-3-N in underground water of the samples in all planting areas were exceeding standard limit; potential health risk still existed in rice-growing region. Accordingly 12.5%-87.5%, 9.4%-75.5%, 17.9%-58.9% and 21.4%-96.0% of the samples were exceeding standard limit in maize growing region, rice-growing region, vegetable-growing region and flower-growing region. The contents of NO-3-N in under-groundwater before the rainy season was higher than that of NO-3-N in under-groundwater after the rainy season at the same depth of the well.

上海组合港发展"路线图"

为了将上海港建设成腹地型国际航运中心,就必须整合长江三角洲的腹地经济,建立起以"上海为中心,江浙为两翼"的组合港。这就是组合港的最初概念。上海酝酿组合港的目的是力争超过香港,成为太平洋西岸最大的中转港。上海组合港的范围为:上海市吴淞口以下,江苏省南京长江大桥以下的长江水域以及浙江省宁波、舟山地区水域内已建集装箱泊位及规划建设集装箱泊位的深水岸线。

Regional Division of Production and Development Strategy of Citrus in Hunan Province

[Objective] The aim was to research regional division of citrus production and development strategies in Hunan Province. [Method] According to Rural Statisti- cal Yearbook in Hunan Province during 2002-2011, Citrus in Hunan province were divided into three production regions, namely, superior region, sub-superior and non- superior region. On the base of the divisions, the ecological regionalization and brand strategy, Optimization of regional distribution and developing strategy were proposed, with consideration of avoiding frozen zones, in this paper. [Result] Fresh and processing bases of mandarin orange （C.unshiu Marc）, and specialty industries of seedless ponkan（C.reticulata Blanco）, Bingtang orange （C.sinensis Osbeck Bing- tangcheng）, Dayongjuhuaxinyou （Cgrandis （L.） Osbeck Dayongjuhuaxinyou） and An- jiangxiangyou （C.grandis （L.） Osbeck Anjiangxiangyou） should be constructed, where fresh fruit is dominant, supplemented by canned fruit and juice. Industry belt of sat- suma orange, fresh or processing food, is mainly built, for proportion of early and earlier ripe satsuma orange is over 50% of total yield in Xiangzhong citrus zone; in- dustry belt of excellent fresh navel orange and processing sweet orange should be highlighted in Xiangnan. [Conclusion] The research provides references for decision- making for governments, especially on optimization of citrus production regions and development of citrus industry.

Revealing Storage-area Relationship of Open Water in Ungauged Subalpine Wetland-Napahai in Northwest Yunnan, China

Mountains and plateaus in Southwest China contain many subalpine and alpine wetlands, with signifieant hydroecological functions. But ungauged or poorly gauged eonditions limit the study and understanding of hydrological regimes of these wetland types. This study selects an ungauged subalpine wetland - Napahai in Northwest Yunnan, China - as a case for developing a practical approach to revealing its storage-area relationship of open water. A Trimble R8 GNSS （Global Navigation Satellites Systems） RTK （Real-time Kinematic system） and sonar fathometer were used to survey fine- resolution elevation data and generate a digital elevation model of the Napahai Wetland. Forty-four Landsat images from 1987 to 2Oll were collected, and the Normalized Difference Water Index was used to classify open water features in the area. The area of open water in Napahai was ealculated for each phase. With these data and a developed conceptual model, the storage of open water for each phase was estimated using ArcGIS tools. Both storage and area of open water showed significant intra-annual and inter-annual variations. In the rainy season, the monthly change of average storage of open water in Napahai showed about 1-2 months lag behind mean monthly rainfall. The storage-area relationship of open water was well fit by a power function equation （R2=0.91, n=44）. This study indicates that if detailedelevations are available for similarly ungauged subalpine wetlands in Southwest China, researchers can use this practical approach to estimate multi- temporal areas and storages and reveal the storage- area relationship of open water in the wetlands. The study provided valuable information of this ease wetland for optimizing its hydro-ecological managements and a new method to wetland researchers and managers for the hydrological study of similarly ungauged wetland complex.

Impact of Land Use Change on Groundwater Recharge in Guishui River Basin,China

It is important to understand how land use change impacts groundwater recharge, especially for regions that are undergoing rapid urbanization and there is limited surface water. In this study, the hydrological processes and re- charge ability of various land use types in Guishui River Basin, China （in Beijing Municipality） were analyzed. The impact of land use change was investigated based on water balance modeling, WetSpass and GIS. The results indicate that groundwater recharge accounts for only 21.16% of the precipitation, while 72.54% is lost in the form of evapotranspiration. The annual-lumped groundwater recharge rate decreases in the order of cropland, grassland, urban land, and forest. Land use change has resulted in a decrease of 4 x 106 m3 of yearly groundwater recharge in the study area, with a spatially averaged rate of 100.48 mm/yr and 98.41 mm/yr in 1980 and 2005, respectively. This variation has primarily come from an increase of urban area and rural settlements, as well as a decrease of cropland.

生态流域水文单元划分方法研究

流域单元划分是进行流域管理、水利普查、水环境污染监测、生态水域规划等的基础,而流域单元划分在地势平坦地区存在各种问题。以烟台市为例,基于DEM数据,提取流域水文单元,根据土地利用类型进行修正,划分生态流域单元。结果表明烟台市一级水文单元23个,二级水文单元93个,三级水文单元550个;采用单纯的DEM数据划分的水文单元,在沿海地区、湖泊、水田等区域直线边界的问题,利用土地利用类型进行修正,得到烟台市三级生态流域水文单元,烟台市生态流域水文单元大概有537个。DEM结合土地利用类型的流域单元划分方法是可行的。

Changes of hydrochemical composition and heavy metals concentration in shallow groundwater from karst hilly areas in Guiyang region,China

The quality changes of shallow groundwater from karst hilly areas in Guiyang region of China impacted by the urbanization were investigated. The results show that the major ions in shallow groundwater from the karst hilly areas are mainly composed of HCO3^-, SO4^2-, Ca^2＋ and Mg^2＋, and the concentrations scopes of NO3^-, Cl^-, K^＋ and Na^＋ of the groundwater in agricultural, residential and industrial areas are 4.5-9.6, 2.8-7.1, 3.9-6.3 and 2.5-4.9 times higher than those in the forest areas, respectively. The concentrations of As, Pb and Cd of shallow groundwater in the industrial areas are also significantly enhanced, followed by those in the residential areas and the agricultural areas. The concentrations of NO3^-, SO4^2- , As, Pb and Cd of the groundwater in the industrial areas and those of NO3^- , SO4^2-, As and Cd of shallow groundwater in the residential areas reach grade Ⅲ of the Groundwater Quality Standard of China （GB/T 14848-93）, while the concentration of NO3^- in the groundwater from the industrial areas exceeds grade V. With the process of urbanization, NO3^- is the key factor to influence the groundwater quality in karst hilly areas, followed by SO4^2-, As, Pb and Cd.

Identification and Evolution of Groundwater Chemistry in the Ejin Sub-Basin of the Heihe River, Northwest China

Hydro-chemical characteristics of groundwater and their changes as affected by human activities were studied in the Ejin Sub-Basin of the Inner Mongolia Autonomous Region, China, to understand the groundwater evolution, to identify the predominant geochemical processes taking place along the horizontal groundwater flow path, and to characterize anthropogenic factors affecting the groundwater environment based on previous data. The concentrations of major ions and total dissolved solids （TDS） in the groundwater showed a great variation, with 62.5% of the samples being brackish （TDS ≥ 1 000 mg L^-l）. The groundwater system showed a gradual hydro-chemical zonation composed of Na^＋ -HCO3^-, Na^＋ -Mg^2＋ -SO4 ^2 -Cl^-, and Na^＋ -Cl^-. The relationships among the dissolved species allowed identification of the origin of solutes and the processes that generated the observed water compositions. The dissolution of halite, dolomite, and 2- gypsum explained, in part, the presence of Na^＋, K^＋, Cl^-, SO^4 , and Ca^2＋, but other processes, such as mixing, Na^＋ exchange for Ca^2＋ and Mg^2＋, and calcite precipitation also contributed to the composition of water. Human activity, in particular large-scale water resources development associated with dramatic population growth in the last 50 years, has led to tremendous changes in the groundwater regime, which reflected in surface water runoff change, decline of groundwater table and degeneration of surface water and groundwater quality. Solving these largely anthropogenic problems requires concerted, massive and long-term efforts.

A Different Light in Predicting Ungauged Basins： Regionalization Approach Based on Eastern USA Catchments

This paper reviewed the existing methods in regionalization studies to predict ungauged catchments and considering all the aspects a different methodology is developed, which is named as RDS method. ROPE （robust parameter estimation）-D （data depth）-S （spatial proximity） together gets this name RDS. Catchment properties and hydrological model parameters are used consistently to predict ungauged basin. This study explores the potential of the regionalization process to predict ungauged basins using the data of the Eastern USA catchments. Two conceptual rainfall-runoff hydrological models： HYMOD and HBV are used in this study. Analysis shows 95% success in predicting ungauged basins with HBV and 90% success with HYMOD. It is undoubtedly perceptible that RDS method is very effective in predicting ungauged basin and regionalization is independent of the conceptual rainfall-runoff model.

Suspended sediment concentration mapping based on the MODIS satellite imagery in the East China inland, estuarine, and coastal waters

The purpose of this research is to improve the retrieval accuracy for the suspended sediment concentration(SSC) from in situ and satellite remote sensing measurements in turbid East China estuarine and coastal waters. For this aim, three important tasks are formulated and solved: 1) an estimation of remote-sensing reflectance spectra R_(rs)(λ) after atmospheric correction; 2) an estimation of R_(rs)(λ) from the radiometric signals above the air-water surface; and 3) an estimation of SSC from R_(rs)(λ). Six different models for radiometric R_(rs)(λ) determination and 28 models for SSC versus R_(rs)(λ) are analyzed based on the field observations made in the Changjiang River estuary and its adjacent coastal area. The SSC images based on the above-mentioned analysis are generated for the area.

Changes of Terrestrial Water Storage in River Basins of China Projected by RegCM4

In this study, a historic simulation covering the period from 1951 to 2000 and three projected scenario simulations covering 2001-2050 were conducted em- ploying the regional climate model RegCM4 to detect the changes of terrestrial water storage （TWS） in major river basins of China, using the Intergovernmental Panel on Climate Change （IPCC） Special Report on Emissions Scenarios （SRES）： A1B, A2, and B1. The historic simula- tion revealed that the variations of TWS, which are dominated by precipitation in the basins, rely highly on their climatic features. Compared with the historic simu- lation, the changes of TWS in the scenario simulations showed strong regional differences. However, for all sce- narios, TWS was found to increase most in Northeast China and surrounding mountains around the Tibetan Plateau, and decrease most in eastern regions of China. Unlike the low seasonal variations of TWS in arid areas, the TWS showed strong seasonal variations in eastern monsoon areas, with the maximum changes usually oc- curring in summer, when TWS increases most in a year. Among the three scenario simulations, TWS increased most in Songhua River Basin of B1 scenario, and de- creased most in Pearl River Basin of A2 scenario and Hal River Basin of A1B scenario, accompanied by different annual trends and seasonal variations.

Quantitative Assessment of Impacts of Regional Climate and Human Activities on Saline-alkali Land Changes:A Case Study of Qian'an County,Jilin Province

Interdecadal and interannuat variations of saline-alkali land area in Qian＇an County, Jilin Province, China were comprehensively analyzed in this paper by means of satellite remote sensing interpretation, field flux observations and regional climate diagnosis. The results show that on the interannual scale, the impact of climate factors accounts for 71.6% of the total variation of the saline-alkali land area, and that of human activities accounts for 28.4%. Therefore the impact of climate factors is obviously greater than that of human activities. On the interdecadal scale, the impact of climate factors on the increase of the saline-alkali land area accounts for 43.2%, and that of human activities accounts for 56.8%. The impact of human activities on the variation of saline-alkali land area is very clear on the interdecadal scale, and the negative impact of human activities on the environment should not be negligible. Besides, changes in the area of heavy saline-alkali land have some indication for development of saline-alkali land in Qian＇an County.

Trends of Extreme Flood Events in the Pearl River Basin during 1951-2010

The study investigated the trend of extreme flood events in the Pearl River basin during 1951-2010. Stream flow data at 23 gauging stations were used for the study. The Pearson type III distribution was selected for the flood frequency analysis. Results indicate that extreme flood events increase significantly in the Pearl River Basin since 1980. At the 23 gauging stations, there are 16 (70%) stations show positive (increasing) trends in 1981-2010. Most of the 16 stations are located along the West River and North River. While 7 (30%) stations show negative (decreasing) trends, and are found in the East River and the southeast region of the West River Basin.

Groundwater in Thailand

This article offers a brief description of the water resources situation of the Kingdom of Thailand, a country with a population of over 65 million people and a surface area of 513,120 km^2. The average annual rainfall is 1,430 mm and the total water resources are estimated at 215,000 Mm^3 （million of m^3）-year^-1. The hydric demand in the country is 70,000 Mm^3.year^-1, 6% of which is groundwater in origin. Over 70% of the water is used for agriculture. Thailand is the world＇s leading exporter of rice. The main problems faced by the Water Authority in Thailand are pollution, floods and droughts, depending on the geographical zone. From the hydrogeological point of view, the Central Plain is the main groundwater reservoir in the nation. Intensive extraction of groundwater over a long period of time has caused three main problems： a decline in groundwater levels, land subsidence, and seawater intrusion. These problems have been especially pressing in the area known as Greater Bangkok.