河岸带土壤磷素空间分布及其对水文过程响应

野外观测太湖地区典型农业河岸带——浯溪荡河岸带土壤总磷（TP）和溶解性总磷（DTP）含量以及当地降雨量、河水水位和地下水水位,探讨了丰水年条件下该河岸带土壤TP和DTP的空间分布特征以及水文过程对其空间分布的影响。结果表明:①在水平方向上,土壤TP和DTP含量从远岸向近岸均呈现先减少后增加的变化趋势;在深度方向上,各断面TP和DTP含量随土层深度的增加均呈减少的变化趋势。②不同月份河水水位均低于地下水水位,地下水补给河水。河水水位和地下水水位随时间的变化规律与降雨量的相似,但具有一定的滞后性。③降雨是土壤水分运动的主要驱动力,降雨、河水水位以及地下水水位对河岸带土壤磷素空间分布的影响显著不同。     

A gis-based distributed parameter hydrologic model for urban areas

A hydrologic model for urban areas has been developed which incorporates distributed parameter modelling concepts and functions in the context of a geographic information system. In the proposed model, the watershed is represented as a cascade of grid cells, whose size can be specified by the user. Preliminary processing includes the determination of overland flow directions for each cell. An automated procedure is used to establish the cell-to-cell connectivity scheme, which is used to order the computations within each time step. Infiltration is computed using the Green-Ampt equation, while runoff rates are computed using a coupling of the continuity equation and Manning's equation for turbulent flow. Storm sewer flows are routed using time-shift routing. The model is capable of simulating flow through streets and offers the possibility of predicting the downstream movement of sewer system overflows. In preliminary testing on a small residential watershed, the model was able to reproduce measured hydrographs.     

西北干旱区水资源的合理开发利用与荒漠化防治

西北干旱区分布的巨大内陆盆地,如准噶尔、塔里木、柴达木盆地和河西走廊等,被认为是典型的戈壁沙漠地区,约占国土总面积的25％。由冰雪融水与降水补给形成的山区河流,流入山前平原,在戈壁带入渗地下,转化为地下水,并在绿洲带溢出地表,成为绿洲耕地的主要灌溉水源。自20世纪50年代以来,由于大规模的水利化建设,导致水资源条件发生巨大变化,生态环境严重恶化,最终导致大片土地荒漠化。因此,重点论述干旱区在人类经济活动影响下,水文系统的演变及其与水环境和生态环境之间的相互影响、相互制约关系。     

通用模型参数率定技术研究

在介绍当前模型参数优选技术的基础上，设计了模型参数同优选方法相耦合的一系列数据接口定义，实现了人工试错和自动优选相耦合、多模型多参数同时自动优选的模型参数率定功能。应用实例表明，通用模型参数率定功能具有简便、快捷、准确的优点，大大提高了参数率定的效率。     

The reliability of an 'off-the-shelf' conceptual rainfall runoff model for use in climate impact assessment: uncertainty quantification using Latin hypercube sampling

Much uncertainty is derived from the application of conceptual rainfall runoff models. In this paper, HYSIM, an 'off-the-shelf' conceptual rainfall runoff model, is applied to a suite of catchments throughout Ireland in preparation for use in climate impact assessment. Parameter uncertainty is assessed using the GLUE methodology. Given the lack of source code available for the model, parameter sampling is carried out using Latin hypercube sampling. Uncertainty bounds are constructed for model output. These bounds will be used to quantify uncertainty in future simulations as they include error derived from data measurement, model structure and parameterization.     

“迭代法”求水文地质参数的原理及应用

在泰斯公式基础上，推导出定流量和变流量非稳定流抽水条件下关于S／T为变量的非线性方程，用“迭代法”解此方程，可方便地求出S、T等水文地质参数。此法可推广到多观测孔、单观测孔或无观测孔抽水试验求参数。     

Inter-annual variation of streamflow,precipitation and evaporation in a small humid watershed (Chengcun Basin,China)

For sustainable water resource management,it is important to determine the relationship between streamfl ow and other variables that infl uence availability of water resources.However,many catchments do not have suffi cient data to allow for a more detailed study of these relationships.We faced a similar challenge in the Chengcun Basin(limited historical data: from 1986–1999); and therefore we used a new approach to overcome this.We found that,using nonparametric trend methods in conjunction with the climate elasticity analyses and the 2D visualization of hydrologic data,it is possible to assess the relationships between streamfl ow and other hydro-climatic variables.In the past,streamfl ow trends in the basin were more correlated with precipitation than with potential evapotranspiration(PET).In addition,there is a gradual shift in the hydrological regime of the catchment,which may affect the occurrence of available water resources and activities that depend on them.In addition,based on our climate sensitivity analyses,the streamfl ow is dependent and more sensitive to variations in precipitation than to PET(δQ=0.79δP+0.42δE; precipitation elasticity,ε P=1.32; PET elasticity,ε E=-2.10).Therefore pending more detailed studies,the use of our approach will provide a rapid means to assess the variation of water resources(streamfl ow)in a watershed.In the future,we hope to carry out related research in other watersheds and also perform a more detailed studies to improve upon the results of this study.     

A total water management analysis of the Las Vegas Wash watershed,Nevada

Climate change, land-use change, and population growth are fundamental factors affecting future hydrologic conditions in streams, especially in arid regions with scarce water resources. Located in the arid southwest within the Las Vegas Wash watershed, Las Vegas is one of the fastest growing metropolitan areas of the country. In the past 30?years, because of climate and land-use changes, it has experienced a decrease in clean water supply but an increase in water demand. To alleviate some of these problems, large amounts of water have been pumped into the city from different sources, such as Lake Mead, and the urban wastewater is treated and returned back to the reservoir for water augmentation. However, in the face of continual global climate change and urbanization in the watershed, long-term planning for sustainable water management is critical. This research was designed to provide a comprehensive analysis incorporating hydrologic modeling, population projection, land-use change modeling, and water management policies to examine the total water balance and management options in this arid and rapidly urbanizing watershed under various scenarios of climate regime, population growth, land-use change, and total water management programs for the year 2050.     

Rising and falling river flows: contrasting signals of climate change and glacier mass balance from the eastern and western Karakoram

Abstract

Field observations and geodetic measurements suggest that in the Karakoram Mountains, glaciers are either stable or have expanded since 1990, in sharp contrast to glacier retreats that are prevalently observed in the Himalayas and adjoining high-altitude terrains of central Asia. Decreased discharge in the rivers originating from this region is cited as a supporting evidence for this somewhat anomalous phenomenon. Here, we show that river discharge during the melting season of the glaciers in the eastern and western Karakoram, respectively, exhibits rising and falling trends. We have implemented a statistical procedure involving non-parametric tests combined with a benchmark smoothing technique that has proven to be a powerful method for separating the stochastic component from the trend component in a time series. Precipitation patterns determined from ERA-40 and GPCP data indicate that summer-monsoonal precipitation has increased over the Karakoram Mountains in recent decades. Increasing flows in June and July in the eastern Karakoram are due to an increase in summer-monsoonal precipitation. The rising trend of August discharge is due to an increase in the loss of glacier storage at an approximate average rate of 0.186–0.217 mm d^-1 year^-1 during the period 1973–2010. Moreover, this rate is higher than the rate of increase in monsoonal snowfall during the months of August and September. Therefore, most plausibly, glacier mass balance in the eastern Karakoram is negative. In the western Karakoram, river flows show declining trends for all summer months for the period 1966–2010, corresponding to a rate of increase of glacier storage by approximately 0.552–0.644 mm d^-1 year^-1, which is also higher than the rate of increase in summer-monsoonal precipitation. The gain of the cryospheric mass in the western Karakoram is in the form of increased thickness of the glaciers and perennial snowpacks instead of areal expansion. This investigation shows two contrasting patterns of trends of river flows that signify both negative and positive mass balance of the Karakoram glaciers. Trends of river flows are spatially and temporally integrated responses of a watershed to changing climate and thereby are important signals of the conditions of the cryospheric component of a watershed where it is highly significant. However, they cannot unequivocally provide indications of the state and fate of the glaciers in the complex hydrometeorological setting of the Karakoram. Extreme caution and care must be exercised in interpreting trends of river discharge in conjunction with climatic data.