考虑空间变异性的统计产流模型研究

针对控制产流过程的降雨等主要因素在空间分布不均匀的特征,提出了考虑空间变异性的统计产流模型．引入一个新的概率密度函数描述每个时段降雨的空间变化,采用土壤下渗容量曲线描述流域土壤下渗能力的空间变化,利用土壤水蓄水容量曲线表征土壤蓄水容量空间分布不均匀性．采用超渗产流模式根据降雨与下渗能力的联合概率分布计算地表径流的空间统计分布,通过推导得到计算地表产流量的准解析表达式;采用蓄满产流模式根据下渗与土壤蓄水容量曲线计算地下径流．选用黄河支流伊河东湾流域的资料对模型进行了验证,并将其结果与新安江模型产流结果进行对比,表明模型在该半湿润地区具有一定的适用性．     

五道沟试验场降雨径流中的氢氧稳定同位素特征分析

在淮北平原区五道沟水文水资源试验场,对降雨径流中的氢氧稳定同位素组成变化的特点及控制平原区河道径流组分划分的一些流域水文因素进行了同位素示踪实验研究.结果表明,实验期间降雨中的δ(18O)(-0.918%～-0.518%)及δ(2H)(-5.064%～-2.310%)的变幅较大,并随雨强的降低而增大;1,3,6号测井地下水的δ(18O)(或δ(2H))主要与补给区水源及降雨的δ(18O)(或δ(2H))有关,其对降雨入渗补给的响应较慢,有明显的滞后效应;IR自记井及S4抽水井由于受抽水灌溉等人类活动的持续影响,δ(18O)(或δ(2H))明显偏负,表明有来自深部潜水的补给.此外,流域出口断面河水的δ(18O)(或δ(2H))受平原型流域较强均化作用的影响,其变幅远远小于降雨的δ(18O)(或δ(2H))变幅,在使用同位素方法划分河道径流组分时,需要考虑降雨到形成河道径流的传输时间.     

幼发拉底河生态径流计算

根据生态径流的概念和计算方法,利用幼发拉底河流域上的3个代表水文站在流域大规模建坝前的流量资料,计算了各个站点的最小生态径流和适宜生态径流,提出了幼发拉底河维持河流生态健康所需的生态径流量.     

不同土地利用类型水土保持特征研究

在富阳、安吉、平江和沐川连续两年对集约经营型竹林、粗放经营型竹林、天然次生林、针叶林、经济林、农耕地等6种植被类型试验样地进行地表径流和侵蚀产沙观测研究。结果表明：(1)不同土地利用类型/植被类型地表径流差异显著,天然次生林年地表径流量和径流系数最小,其次是针叶林、集约经营型竹林和经济林,粗放经营型竹林年地表径流量、径流系数较大。农耕地年地表径流量、径流系数最大,是天然次生林的3~8倍。(2)不同土地利用类型/植被类型土壤侵蚀模数差异也表现出相似规律。天然次生林土壤侵蚀模数最小,其次是针叶林,粗放经营型竹林、集约经营型竹林和经济林较大。农耕地土壤侵蚀模数最大,是天然次生林的3~9倍。(3)我国东部-西部梯度上不同土地利用类型的水土保持特征差异显著。东部地区的地表径流系数和土壤侵蚀模数均显著低于中西部地区。这与我国东部、西部不同的自然条件、经济社会发展水平和水土保持生态建设现状相关。 关键词：土地利用类型;水土保持;地表径流;径流系数;土壤侵蚀模数;东-西部梯度     

黄河流域天然径流量分区评价

分析了控制站法和分区评价法2种流域天然径流量计算方法的差别与关系.利用相关延长法得到黄河流域干流区间1951-1998年天然径流量系列,并对黄河流域进行水资源分区评价.结果表明,各分区天然径流量代际变化趋势类似,且近20年来,黄河流域大多数分区的天然径流量都有不同程度的减少,同时干流河道水量输移中的净损失逐渐增大.分区天然径流量与干流河道水量净损失综合影响导致黄河流域控制站天然径流量大幅度下降,而且分区天然径流量衰减是黄河流域控制站天然径流量剧减的根本原因.     

城市饮用水源地周边城区不同类型地表径流污染特征

城市饮用水源地水质保障是影响城市供水安全和供水系统处理效能的重要因素,其周边城区的径流污染是威胁饮用水源安全的因素之一。为研究城市饮用水源地周边城区不同类型地表径流污染特征及对饮用水源地的潜在影响,以常州应急备用水源地德胜河周边城区的城市主路、快速路和建筑小区三处不同类型地表径流进行了现场监测,分析了不同地表径流的典型常规污染物、重金属和有机物污染特征。研究结果表明：城市主路、快速路、建筑小区的地表径流中COD（chemical oxygen demand）、TP（total phosphorus）、Pb、Cr、Zn的事件平均浓度超过《地表水环境质量标准》（GB3838—2002）中Ⅴ类水标准,地表径流直接排放将严重威胁饮用水源地安全;典型有机污染物石油类、苯酚、苯污染水平总体相对较低,对饮用水源地可能造成的潜在威胁相对有限。降雨量和降雨强度等降雨特征,地表类型、坡度等下垫面特征都会影响径流污染物初期冲刷的程度,且重金属与SS（suspended solids）呈现较为一致的初期冲刷规律。城市主路、快速路和建筑小区径流中常规污染物SS、COD、TN（total nitrogen）、TP的年污染负荷与其他城市同类型下垫面的年污染负荷基本一致,但Pb、Cu、Cr、Zn、Mn的污染负荷较高,将对应急备用饮用水源地德胜河的水环境质量造成严重威胁,迫切需要采取径流污染控制工程与管理措施,以保障饮用水源地水环境质量和城市供水系统安全。     

A distributed surface energy and mass balance model and its application to a mountain glacier in China

Based on the field observations on Qiyi Glacier during the warm season of 2007, using a digital elevation model (DEM, 15 m resolution), we developed a distributed surface energy- and mass-balance model with an hourly resolution. The model described the effect of topography on shortwave solar radiation, and used a new parameterization for glacier albedo. The model was applied to Qiyi Glacier in the Qilian Mountain, China, for the period 20 : 00 30 June to 12 : 00 10 October 2007, to simulate the firn-line changes, the temporal and spatial variations of mass balance, and the glacial meltwater runoff. The results indicated that the patterns of altitudinal profile of glacier mass-balance were affected mainly by the altitudinal profile of albedo, and the status of the glacier mass balance was influenced directly by the values of albedo. The parameter sensitivity test showed that the model was sensitive to the air temperature lapse rate and precipitation gradient, and also sensitive to the threshold temperature for solid/liquid precipitation. Furthermore, the climate sensitivity test showed that the mass balance was more sensitive to air temperature than precipitation, and the response of mass balance to air temperature change was nonlinear while the response to precipitation change linearly. The negative mass balance trend of the glacier can not be reversed when precipitation increases by 20% and meanwhile air temperature rises by 1°C.     

辽河流域水资源状况分析

水资源是指陆地表面及表层短中期（一年或数年内）可由降水补给更新的淡水资源,它的丰欠与大气降水量和地表径流量有密切关系。利用1960—2000年我国辽河流域地区30个水文站的月径流资料,采用EOF分析、旋转EOF分析、MK突变检验法,重点分析了辽河流域径流量的变化规律及变化趋势。结果表明：辽河流域的径流量总体呈下降趋势,不同站点的径流量之间的变化趋势和幅度值有所差异,而且径流量也存在时间差异性。     

前缘反倾式锁固型滑坡变形破坏模式及失稳机理

了解滑坡的失稳机理和破坏模式是对其进行预防预报的前提。采用物理模型试验方法,以降雨为触发条件,进行多次模型试验,记录前缘反倾式锁固型边坡在不同坡面形态时的变形破坏现象,研究该类边坡的失稳机理及破坏模式。研究结果表明:前缘反倾式锁固型边坡为后缘推移式滑动破坏,该类边坡失稳始于边坡后缘,其破坏模式为开始降雨→雨水从坡面入渗,边坡土体强度降低→后缘土体发生沉降→前缘土体发生垮塌→坡体后缘持续下沉,推动边坡底部土体向前滑动-坡体前缘出现推挤隆升现象-边坡整体失稳破坏;前缘反倾式锁固型边坡发生整体失稳的根本原因是边坡前缘土体强度降低及垮塌,致其无法提供足够的抗滑力,边坡发生整体失稳。研究成果对此类滑坡的预防预报具有一定的指导意义。     

A test of Snowmelt Runoff Model （SRM） for the Gongnaisi River basin in the western Tianshan Mountains, China

The Snowmelt Runoff Model (SRM) is one of a very few models in the world today that requires remote sensing derived snow cover as model input. Owing to its simple data requirements and use of remote sensing to provide snow cover information, SRM is ideal for use in data sparse regions, particularly in remote and inaccessible high mountain watersheds. In order to verify the applicability of SRM in an environment of continental climate, a test of SRM is performed for the Gongnaisi River basin in the western Tianshan Mountains, the results show that two SRM average goodness-of-fit statistics for simulations, Nash-Sutcliff coeffident (R2) and volume difference (Dv), are 0.87 and 0.90%,respectively. As compared with the application results over 80 basins in 25 different countries around the world, SRM performs well in the Gongnaisi River basin. The results also show that SRM can be a validated snowmelt runoff model capable of being applied in the western Tianshan Mountains.On the basis of snowmelt runoff simulation, together with a set of simplified hypothetical climate scenarios, SRM is also used to simulate the effects of climate change on snow cover and the consecutive snowmelt runoff. For a given hypothetical temperature increase of 4℃, the snow coverage and snowmelt season shift towards earlier dates, and the snowmelt runoff, as a result, is changed significantly at the same time. The simulation results show that the snow cover is sensitive to changes of climate, especially to the increase of temperature, the major effect of climate change will be a time shifting of snowmelt runoff to early spring months, resulting in a redistribution of seasonally runoff throughout the whole snowmelt season.