2021年3月中旬东亚中部沙尘天气地面起尘量及源区贡献率估算     

柳本立  彭婉月  刘树林  杨婷 《中国沙漠》2022,42(1):79-86

2021年3月中旬,东亚中部包括中国北方大部分地区,爆发了持续性的沙尘天气,引发了人们对于沙尘源区、防风固沙生态建设工程效益的高度关注.提出了一个新的地表起尘量估算方法,使用高精度、大范围的气象数据,计算了这次沙尘天气的地面起沙条件、大风过程中的输沙状况,估算了不同时刻的起尘量,获得了14、15日蒙古和中国北方荒漠地区...  相似文献   

Spatial and temporal variability of the hydrological response in a small Mediterranean research catchment (Vallcebre,Eastern Pyrenees)     

J. Latron  M. Soler  P. Llorens  F. Gallart 《水文研究》2008,22(6):775-787

This paper analyses the spatial and temporal variability of the hydrological response in a small Mediterranean catchment (Cal Rodó). The first part of the analysis focuses on the rainfall–runoff relationship at seasonal and monthly scale, using an 8‐year data set. Then, using storm‐flow volume and coefficient, the temporal variability of the rainfall–runoff relationship and its relationship with several hydrological variables are analysed at the event scale from hydrographs observed over a 3‐year period. Finally, the spatial non‐linearity of the hydrological response is examined by comparing the Cal Rodó hydrological response with the Can Vila sub‐catchment response at the event scale. Results show that, on a seasonal and monthly scale, there is no simple relationship between rainfall and runoff depths, and that evapotranspiration is a factor that introduced some non‐linearity in the rainfall–runoff relationship. The analysis of monthly values also reveals the existence of a threshold in the relationship between rainfall and runoff depths, denoting a more contrasted hydrological response than the one usually observed in humid catchments. At the event scale, the storm‐flow coefficient has a clear seasonal pattern with an alternance between a wet period, when the catchment is hydrologically responsive, and a dry summer period, when the catchment is much less reactive to any rainfall. The relationship between the storm‐flow coefficient and rainfall depth, rainfall maximum intensity and base‐flow shows that observed correlations are the same as those observed for humid conditions, even if correlation coefficients are notably lower. Comparison with the Can Vila sub‐catchment highlights the spatial heterogeneity of the rainfall‐runoff relationship at the small catchment scale. Although interpretation in terms of runoff processes remains delicate, heterogeneities between the two catchments seem to be related to changes in the ratio between infiltration excess and saturation processes in runoff formation. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

A 24 h investigation of the hydrogeochemistry of baseflow and stormwater in an urban area impacted by mining: Butte,Montana     

Christopher H. Gammons  Christopher L. Shope  Terence E. Duaime 《水文研究》2005,19(14):2737-2753

Changes in water quality during a storm event were continuously monitored over a 24 h period at a single location along an urban stormwater drain in Butte, Montana. The Butte Metro Storm Drain (MSD) collects groundwater baseflow and stormwater draining Butte Hill, a densely populated site that has been severely impacted by 130 years of mining, milling, and smelting of copper‐rich, polymetallic mineral deposits. On the afternoon of 26 June 2002, a heavy thunderstorm caused streamflow in the MSD to increase 100‐fold, from 0·2 ft³ s⁻¹ to more than 20 ft³ s⁻¹. Hourly discharge and water quality data were collected before, during, and following the storm. The most significant finding was that the calculated loads (grams per hour) of both dissolved and particulate copper passing down the MSD increased more than 100‐fold in the first hour following the storm, and remained elevated over baseline conditions for the remainder of the study period. Other metals, such as zinc, cadmium, and manganese, showed a decrease in load from pre‐storm to post‐storm conditions. In addition to the large flush of copper, loads of soluble phosphorus increased during the storm, whereas dissolved oxygen dropped to low levels (<2 mg l⁻¹). These results show that infrequent storm events in Butte have the potential to generate large volumes of runoff that exceed Montana water quality standards for acute exposure of aquatic life to copper, as well as depressed levels of dissolved oxygen. This study has important implications to ongoing reclamation activities in the upper Clark Fork Superfund site, particularly with respect to management of storm flow, and may be applicable to other watersheds impacted by mining activities. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

柴达木盆地盐尘暴及其资源生态环境影响          下载免费PDF全文

张西营  李雯霞  耿鋆  苗卫良  李永寿  唐启亮  陈亮  袁小龙  郭晓宁  王钰  才仁扎西 《盐湖研究》2020,28(1):11-17

在干旱和半干旱地区,盐尘暴是一种常见的极端气象灾害。柴达木盆地频发的沙尘暴实质上就是盐尘暴。柴达木盆地盐尘暴已经对区域大气、土壤、植被、人类健康乃至全球气候变化都产生了不同程度的影响。由于柴达木盆地盐尘暴中可溶盐成分来源复杂,尽管目前对其形成过程和机制还缺乏深刻理解,但人类的资源开发活动对盐尘暴显然具有促进作用。有必要从系统的角度来考虑柴达木盆地盐尘暴对区域乃至全球的影响,这对于区域生态环境的正确评估和后期恢复治理具有重要意义。  相似文献   

风暴潮灾害情景下海岸带暴露指数时空演变研究——以福建省东山湾为例          下载免费PDF全文

王超  黄发明  陈华香  殷飞笺  施荣灿  杨黎静 《海洋科学》2023,47(11):12-23

暴露指数反映了环境在面对极端天气事件时承受灾害的潜在风险程度。研究利用遥感影像数据、数字高程数据(DEM)、海洋水深及风力数据等, 基于暴露指数模型, 以福建省东山湾为案例研究区域, 对风暴潮灾害情景下的海岸带暴露指数及其时空演变进行分析。研究结果显示: (1)近十年来, 东山湾海岸带暴露指数总体呈下降趋势, 潜在风险程度为“中”及以上区域占比由67.14%下降至59.06%, 海岸带在面对风暴潮灾害等极端天气事件时潜在的风险程度总体降低, 海湾地貌类型差异及其形态变化是影响东山湾暴露指数产生波动的主要原因; (2)基于暴露指数评价结果, 结合海岸带开发利用现状, 研究可对东山湾海岸带生态环境的敏感区域进行识别, 并制定具有针对性的开发利用与风险防范对策, 为海岸带空间规划、生态保护修复格局的科学划定提供理论支撑, 在助力海岸带陆海统筹和可持续发展上具有重要意义; (3)研究提出的一种基于时间序列的暴露指数研究技术路线和框架, 可为海岸带脆弱性评估、海岸带韧性评估、海岸带灾害监测预警等相关研究提供新的研究视角, 在基于深度学习的海岸带灾害风险预警与灾害模拟等方面也具有较为广阔的应用前景。  相似文献   

Combined use of spot samples and continuous integrated sampling in a study of storm runoff from a lowland catchment in the south of England     

A. Gkritzalis‐Papadopoulos  M. R. Palmer  M. C. Mowlem 《水文研究》2012,26(2):297-307

We have used two different sampling techniques to study the geochemical response of a small lowland rural catchment to episodic storm runoff. The first method involves traditional daily spot sampling and has been used to develop a standard end‐member mixing analysis (EMMA) of the relative contributions of ground water flow and surface runoff to the total stream flow. The second method utilizes a continuous sampling device, powered by an osmotic pump, to produce an integrated 24‐h sample of the stream flow. When combined with the EMMA results from the spot samples, analyses of the integrated samples reveal the presence of a third component that makes a significant contribution to the dissolved NO₃, Ca and K export from the catchment during the rising limb of the hydrographic profile of a storm event following a prolonged dry period. The storm occurred in the middle of the night, so that the response of the stream chemistry was not captured by the daily samples. We hypothesize that this third component is derived from the flushing of stored soil water that contains the geochemical signature of decaying vegetation. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Developing a building policy for the erosion zone: Solutions to some key (Dutch) questions     

P.R. Winckel  J.K. Vrijling  J. van de Graaff 《Coastal Engineering》2008

In those coastal communities where the most seaward strip of mainland consists of dunes, these dunes often serve as a flexible sea defence. In addition, this strip offers large potential for housing and commercial enterprises. Unfortunately, due to severe storm surges part of this strip (the erosion zone) is subject to erosion, and as a result of which any buildings or infrastructure located here, are destroyed. Therefore, as we will illustrate in this paper, a building policy for this zone should reflect a compromise between two opposite interests: exploitation of the existing potential and, prevention of an unacceptable high risk due to erosion. Accordingly, the authors have developed a framework for such a building policy on the basis of which the desirability of various different types of investments and the location within the erosion zone of such investments can be determined. The examples that are used to illustrate this framework in this paper are limited to experiences in The Netherlands as relevant data and experiences are available and relatively easy accessible here. Nevertheless, the approach as is described is generic and applicable worldwide suggesting that the discovered unused potential for exploitation is not just limited to The Netherlands.  相似文献   

热带风暴热力非对称结构对其运动的影响          下载免费PDF全文

赵凯  沈树勤  王卫芳  王清楼 《海洋科学》2008,32(2):36-41

研究了热力非对称结构对0421号热带风暴"海马(Haima)"的移动和强度变化的影响。通过物理量场诊断分析发现,热带风暴(气旋)的热力结构在垂直、水平方向均呈非对称分布。热力因子对热带风暴的影响,主要体现在低层。热带风暴朝其移向前方的风暴内部的非绝热增温中心偏折,并有向此方向加速的趋势。了解热带风暴的热力结构分布特征及其对热带风暴移动的影响,对短期预报热带风暴的移动有一定的指示意义。  相似文献   

Sensitivity of hurricane surge to morphological parameters of coastal wetlands   总被引：2，自引：0，他引：2  

N.M. Loder  J.L. Irish  M.A. Cialone  T.V. Wamsley 《Estuarine, Coastal and Shelf Science》2009,84(4):625-636

Given the history and future risk of storm surge in the United States, functional storm protection techniques are needed to protect vital sectors of the economy and coastal communities. It is widely hypothesized that coastal wetlands offer protection from storm surge and wave action, though the extent of this protection is unknown due to the complexities of flow through vegetation. Here we present the sensitivity of storm-surge numerical modeling results to various coastal wetlands characteristics. An idealized grid domain and 400-km² marsh feature were used to evaluate the effects of marsh characteristics on hurricane surge, including the effects of bottom friction, elevation, and continuity (the ratio of healthy marsh to open water area within the total wetland area).Through coupled hydrodynamic and wave model simulations, it is confirmed that increased bottom friction reduces storm-surge levels for most storms. However, increases in depth associated with marsh elevation loss generally results in a reduction of surge. As marsh continuity is decreased, coastal surge increases as a result of enhanced surge conveyance into and out of the marsh. Storm surge is parameterized in terms of marsh morphology, namely marsh elevation, frictional characteristics, and degree of segmentation, which will assist in the justification for and optimization of marsh restoration in terms of storm protection.  相似文献   

台风过境期间辽河口滨海湿地水动力特征的数值模拟研究          下载免费PDF全文

王煜嘉  孙振宇  赵学凯  赵梓宇  弓耘  许慧  张明亮 《应用海洋学学报》2024,43(1):020-032

本研究基于FVCOM环流模型，耦合ECMWF背景风场和Jelesnianski台风经验模型形成合成风场，对9711台风“温妮”过境辽河口区域的水动力进行模拟研究。模型通过在动量方程、湍流方程中加入附加源项来表达盐沼植被对水动力的阻碍作用。使用研究区域实测的潮位、流速、流向等数据对水动力模型进行验证，模拟结果与实测数据吻合较好。结果表明：潮滩盐沼植被对台风过境期间的潮位变化无明显影响，但对流速具有显著的衰减作用，且芦苇对潮流的衰减作用大于盐地碱蓬植被，芦苇区的速度最大衰减率达81.43%。此外，台风路径变化对辽河口湿地海域的增减水及流速影响较大，台风强度越强，局部区域造成的风暴潮增水和流速也相应越大。  相似文献