Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Using Nitrate Isotope to Trace the Nitrogen Pollution in Chanhe and Laohe River

XING Meng,LIU Wei-guo,HU Jing,

环境科学 , 2010,
Abstract: 通过分析河水和工业污染水体硝酸盐氮同位素组成,对西安市周边主要河流浐河和涝河的硝酸盐污染源进行了初步研究.结果发现,浐河、涝河从上游至下游,河水硝酸盐氮同位素组成δ15N-NO-3值呈逐渐升高的趋势 (1.3‰~9.0‰和3.3‰~7.4‰),而沿河流域2个工业排污口废水样的δ15N-NO-3值为:11.5‰和11.1‰.不同来源的硝酸盐氮同位素表现出明显的差别,工业排污可能是该河流硝酸盐氮浓度增高主要原因之一.相对于河水硝酸盐浓度变化,河水中硝酸盐氮同位素能够作为示踪水系硝酸盐氮污染来源和过程的可靠手段.同时,本研究大致区分了浐河和涝河流域主要的氮源输入,为研究硝酸盐污染,营养元素流失提供了重要的信息.
Analysis of Runoff Characteristics in the Downstream of Bahe River

勾奎, 莫淑红, 沈冰
Journal of Water Resources Research (JWRR) , 2012, DOI: 10.12677/JWRR.2012.16074
Abstract: 本文以灞河下游马渡王站的实测年径流资料为基础,分析了径流的年际年内变化以及径流的变化趋势、周期和突变点。研究结果表明:灞河下游径流年际变化大,年内分配不均匀;径流序列具有显著的下降趋势;径流序列存在7年、19年和34年的周期,19年的周期最为显著;径流序列突变起始时间发生在1971年。
This article analyses annual runoff variation characteristics, including annual, inter-annual characteristics, tendency and mutation points, based on the runoff data series at Maduwang station in the BaheRiver. The main results are: the runoff has big inter-annual variability and its annual distribution is uneven; the tendency of the runoff is significant decline; the main periods of the runoff are 7 years, 19 years and 34 years, the period of 19 year is the most significant. The mutation of the runoff observed at Maduwang station took place around 1971.
Study on Impacts of Climate Changes on Bahe River Runoff

贾宪, 沈冰
Journal of Water Resources Research (JWRR) , 2013, DOI: 10.12677/JWRR.2013.26060
Abstract: 根据1961~2010年的灞河流域内的逐月水文气象数据,采用Mann-Kendall法对水文气象要素进行变化趋势分析,采用双累积曲线和复回归模型进行径流量的气候变化响应研究。结果表明:流域内年径流量显著减少,年平均气温和年降水量均无显著的变化趋势,仅仅表现为气温略升高、降水稍减少;气温变化和降水变化对径流量的影响各自存在三个突变点,突变点前后径流量增加或减少的变化明显,由回归分析可知,气温升高、降水减少是径流量减少的主要原因。
Based on hydrological data for Bahe River from time series of 1961 to 2010, the trend of hydro- logical and meteorological elements was analyzed by using the Mann-Kendall method. The runoff response to climate change is researched with Double mass curves and multiple regression models. The results showed that: the runoff significantly reduced while the annual mean temperature and annual precipitation have no significant trends, with only slightly elevated temperature and precipitation decreasing slightly; by the regres- sion analysis, runoff reduction is mainly due to rising temperatures and reduced precipitation.
Runoff Change of Bahe River Basin in Qinling Mountains and Its Influencing Factors

MA Xinping,BAI Hongying,HOU Qinlei,YUAN Bo,ZHANG Jie,

资源科学 , 2012,
Abstract: Using runoff data measured by Maduwang station in Bahe River basin during 1959-2010 and combining some mathematical methods such as annual mal-distribution coefficient, wavelet analysis method and M-K mutations point inspection, this paper has analyzed the inter-annual runoff change characteristics and made quantitative analysis of the impacts of climate change and human activities on runoff changes of Bahe River. The results show that: 1) the annual runoff depth distribution in Bahe River basin is extremely uneven, with annual mal-distribution coefficient reaching 0.92; 2) runoff distribution is mainly concentrated in summer and autumn, accounting for 68.15% of annual runoff. The runoff shows an increasing trend from summer to autumn; it is the lowest in spring and winter, highest during mid-July and early August; 3) the annual runoff depth declines on the whole with an average decline rate of 3.0206mm/a; 4) in recent 50 years, Bahe River has different oscillation periods. In the time scale of 20 to 30a, the oscillation is very significant. The annual runoff will continue to increase in the future, and now it tends to be large;the runoff mutation point is 1989, whose primary period of time series is 16 years; 5) Using the relational analysis we have obtained that average annual runoff of Bahe River is closely related to the average annual rainfall. However, human activity is the main factor that causes the runoff decrease and changes of runoff in Bahe River Basin, and precipitation change is the secondary factor. This paper considers only precipitation and temperature factors in climatic analysis, in fact LUCC and evapotranspiration should also be included. Therefore, the specific influencing factors of runoff changes need to be further studied.

Zhan Jingbo,Zhan Jingbo,Zhan Jingbo,Yuan Daoxian,Yuan Daoxian Null,

第四纪研究 , 2000,
Abstract: On the basis of one yea's observation of pH, the content of CO2, HCO3, Ca2+, Mg2+ in the water of the river, the ground water in loess, and the rain of Bahe River catchment area in Xi'an, this paper discusses the characteristics of modem karst processes and puts forward a method to calculate the absorbed amount of CO2 in the karst processes. The observation results are as follows. The indexes of the rain show that pH is from 6.30 to 6.46, the content of HCO3 is from 10.66 to 25.38mg/L, the content of Ca2+ and Mg2+ is very low, the content of free CO2 is from 3.46 to 34.12mg/L, and sometimes there is aggressive CO2. And the characteristics of chemical composition shows that the rain has obvious acidity and strong corrosion ability. The indexes of the river show that pH is higher than 8.30, the content of HCO3 is from 87.8 to 237.9mg/L, the content of Mg2+ and Ca2+ is high, and there is a little free CO2 only within three days after raining. As compared with the rainwarer, the pH and the content of HCO3 of the river water are higher than that of the rain water, which shows that the rainwater undergoes obvious karst processes and most of CO2 is consumed on the course of converging into the river. However, within three days after raining, the content of CO2 in the river reaches 1.8mg/L, which shows that CO2 has not been used up and about 18 percent has run off with the river. The chemical composition of the river water expresses seasonal changes. In the rainfall summer and autumn, pH is low, and the content of HCO3 is high. But this situation in winter and spring is opposite. The results show the karst processes are strong in summer and autumn, and weak in winter and spring. The reason is that there is free CO2 in the karst wader in summer and autumn. The indexes of the ground warer in the loess containing rich CaCO3 show that pH is from 7.46 to 7.76, the content of HCO3 is from 120.1 to 137.6mg / L, the contents of Ca2+ and Mg2+ are 32.6-38.5mg / L and from 4.8 to 6.2mg/L, there is no free CO2. Its chemical composition is similar to that of the river water, and as same as that of the karst water in the limestone area in the southern part of north China. The results show that the loess has obvious karst processes and absorbs CO2 constantly. The rate of the karst processes is high because the calcite in the loess is small and scattered, and the loess is loose and porous. The strong alkalinity and high degree of mineralization of the ground water in the other areas in the Loess Plateau show that the widely distributed loess has strong effect on the global CO2 cycle and it should be regarded as one of the most impohant areas for researching the subject. This paper gives a method to calculate the absorbed amount of CO2 in the karst processes in a catehment area. The free CO2 in the rainwater minus the free CO2 left after the karst processes is the absorbed CO2. It is hard to get the result by the denudation test of limestone tablets because there is not
Multiple scale protection planning of waterbird habitats in Xi′an Chanba River wetland

ZHAO Zhen-Bin,ZHAO Hong-Feng,TIAN Xian-Hua,YAN Jun-Ping,

生态学报 , 2008,
Abstract: Urban wetland and wildlife diversity protection is the important task of urban ecological construction. With the case study of Chan-ba River wetland in Xian City, the issues of urban waterbird habitat protection planning are discussed in this paper. By field investigation, the study area is found feeding 20 species, belonging to 8 orders and 12 families, showing a high birds diversity level. Some indigenous plant species and different habitat types are also found in the study area, with high value in sight of urban nature protection. The protection of the waterbird habitats in Chanba river wetland should be based on the relating theories of landscape ecology, conservation biology, and metapopulation, and carried on from different spatial scale. The main approaches include: habitat network construction, small habitat design, water depth control, and land use pattern optimization in riparian zone, plant community organization.
Production dynamics and trophic basis of three dominant mayflies in the continuum of Shenglihe Stream in the Bahe River Basin

DENG Shan,YE Caiwei,WANG Lixiao,LI Xiaoyu,YAN Yunjun,

生态学报 , 2012,
Abstract: 大型底栖动物在河流生态系统中发挥着重要作用, 2009 年3月至2010 年3月间对长江中游支流巴河流域的胜利河大型底栖动物群落优势种类的生产力进行为期1 周年的调查研究, 结果表明, 主要蜉蝣优势种扁蜉、等蜉和红斑蜉的生活史为3代/年、3代/年和 2代/年。现存量呈现出1-3级河流增加,而4级又较3级有所下降的趋势。采用龄期频率法( instar-frequency method) 测算的平均周年生产量分别为扁蜉, 200.13 g/(m2.a) , P/B 为23.69; 等蜉, 82.06 g/(m2.a), P/B 为18.12;红斑蜉, 12.30 g/(m2.a), P/B 为8.78。三种蜉蝣的生产量动态在时间上与现存量动态较一致,但彼此各不相同。扁蜉的日均产量于2009年3月在二级河流中达到最大(363.56 mg/m2.d),等蜉于2010年3月在三级河流中到达最大(282.76 mg/m2.d),而红斑蜉于2009年3月在一级河流中到达最大(33.36 mg/m2.d)。生产量的营养基础分析结果表明,扁蜉前肠内含物中无形态碎屑、动物组织、植物纤维、丝状藻类、硅藻所占平均比例为74.37%,4.19%,17.11%,4.29%,0.04%,对生产量的贡献率分别为77.15%,11.27%,6.57%,4.95% ,0.04%;等蜉前肠内含物中无形态碎屑、动物组织、植物纤维、真菌、丝状藻类和硅藻所占平均比例为65.64%,6.17%,23.04%,0.54%,4.53%,对生产量的贡献率分别为: 68.16%,16.61%,8.86%,1.03%,5.23%,0.09%,0.10%;红斑蜉前肠内含物中,无形态碎屑、动物组织、植物纤维、真菌、丝状藻类和硅藻所占平均比例为41.14%,5.96%,38.04%,1.34%,11.21%,2.31%,对生产量的贡献率分别为46.67%,17.52%,15.98%,2.81%,14.13%,2.91%。这与我们在黑竹冲和叹气沟的研究结果存在一定差异,可能与这些溪流自身环境和地区分布有关。
基于流域不同特征的浐灞河生态系统健康评价  [PDF]
徐志嫱?,刘 维?,张建丰?
西北农林科技大学学报(自然科学版) , 2011,
Abstract: 【目的】根据流域不同特征,构建浐灞河流域生态系统健康评价指标体系,并对其生态系统健康状况进行评价,为河流综合治理提供科学依据。【方法】基于浐灞河流域的水资源开发利用程度、水功能定位和生态环境保护的不同特点,构建了由生态结构与功能、水文特征、水环境状况、社会经济和生态服务功能5个方面要素,11个单项指标组成的流域生态系统健康评价指标体系,并采用模糊综合评价法与层次分析法相结合的方法对浐灞河流域生态系统健康状况进行评价。【结果】影响浐灞河流域上中游区域生态系统健康的主要问题有水土流失、植被破坏以及人口增加对环境的压力,影响浐灞河下游城市段生态系统健康的主要问题有水资源过度开发和河流水质污染。浐灞河上中游区域和下游城市段生态系统健康综合评价度分别为0.8037和0.7609,可知浐灞河流域上中游区域生态系统处于亚健康状态,下游城市段为临界状态。【结论】浐灞河流域上中游区域生态结构与功能欠缺,下游区域受水文特征和水环境状况的影响较大,是浐灞河进行流域治理和水生态保护与修复应重点关注的问题。
多尺度结合的西安市浐灞河湿地水鸟生境保护规划  [PDF]
生态学报 , 2008,
Abstract: 城市湿地及其物种多样性的保护是城市生态建设的重要内容。结合西安市浐灞河湿地,对城市湿地水鸟生境的保护规划问题进行了探讨。经调查,西安市浐灞河段共发现水鸟20种,分属8目12科,孕育了丰富的水鸟多样性资源。同时保留有本地湿地植物种类,生境类型多样,具有很高的保护价值。浐灞河湿地水鸟生境的保护规划应以景观生态学、保护生物学、复合种群等相关理论为指导,区域/景观-局地-群落多尺度结合,保护与开发结合进行规划,具体从以下方面着手:生境网络的构建;小生境的设计,滨水地带土地利用格局优化及生境水深的控制;生境植物群落的构建。
浐河、涝河河水硝酸盐氮污染来源的氮同位素示踪  [PDF]
环境科学 , 2010,
Abstract: 通过分析河水和工业污染水体硝酸盐氮同位素组成,对西安市周边主要河流浐河和涝河的硝酸盐污染源进行了初步研究.结果发现,浐河、涝河从上游至下游,河水硝酸盐氮同位素组成δ15N-NO-3值呈逐渐升高的趋势(1.3‰~9.0‰和3.3‰~7.4‰),而沿河流域2个工业排污口废水样的δ15N-NO-3值为:11.5‰和11.1‰.不同来源的硝酸盐氮同位素表现出明显的差别,工业排污可能是该河流硝酸盐氮浓度增高主要原因之一.相对于河水硝酸盐浓度变化,河水中硝酸盐氮同位素能够作为示踪水系硝酸盐氮污染来源和过程的可靠手段.同时,本研究大致区分了浐河和涝河流域主要的氮源输入,为研究硝酸盐污染,营养元素流失提供了重要的信息.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.