Rate and historical change of direct recharge from precipitation constrained by unsaturated zone profiles of chloride and oxygen‐18 in dry river bed of North China Plain     

Ruiqiang Yuan  Xianfang Song  Dongmei Han  Yinghua Zhang  Liang Zhang  Bing Zhang  Xiting Long  Yilei Yu 《水文研究》2012,26(9):1291-1301

Quantifying of direct recharge derived from precipitation is crucial for assessing sustainability of well‐irrigated agriculture. In the North China Plain, the land use is dominated by groundwater‐irrigated farmland where the direct recharge derived from precipitation and irrigation. To characterize the mean rate and historical variance of direct recharge derived from precipitation, unsaturated zone profiles of chloride and δ¹⁸O in the dry river bed of the Beiyishui River were employed. The results show that archival time scale of the profile covers the duration from 1980 to 2002 (corresponding to depths from 5 to 2 m) which is indicated by matching the δ¹⁸O peaks in the isotope profile with the aridity indexes gained by instrumental records of annual precipitation and annual potential evaporation. Using the chloride mass balance method, the mean rate of the direct recharge corresponding to the archival time scale is estimated to be 3·8 ± 0·8 mm year^?1, which accounts for about 0·7% of the long‐term average annual precipitation. Further, the direct recharge rates vary from 2·1 to 6·8 mm year^?1 since 1980. Despite the subhumid climate, the estimate of recharge rates is in line with other findings in semiarid regions. The low rate of direct recharge is considered as a result of the relative dry climate in recent decades. In dry river bed, unsaturated zone profiles of chloride and δ¹⁸O combined with instrumental records could offer valuable information about the direct recharge derived from precipitation during droughts. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Characterising deep vadose zone water movement and solute transport under typical irrigated cropland in the North China Plain          下载免费PDF全文

Leilei Min  Yanjun Shen  Hongwei Pei  Bingdan Jing 《水文研究》2017,31(7):1498-1509

Understanding the dynamics and mechanisms of soil water movement and solute transport is essential for accurately estimating recharge rates and evaluating the impacts of agricultural activities on groundwater resources. In a thick vadose zone (0–15 m) under irrigated cropland in the piedmont region of the North China Plain, soil water content, matric potential, and solute concentrations were measured. Based on these data, the dynamics of soil water and solutes were analysed to investigate the mechanisms of soil water and solute transport. The study showed that the 0–15‐m vadose zone can be divided into three layers: an infiltration and evaporation layer (0–2 m), an unsteady infiltration layer (2–6 m), and a quasi‐steady infiltration layer (6–15 m). The chloride, nitrate, and sulphate concentrations all showed greater variations in the upper soil layer (0–1 m) compared to values in the deep vadose zone (below 2 m). The average concentrations of these three anions in the deep vadose zone varied insignificantly with depth and approached values of 125, 242, and 116 mg/L. The accumulated chloride, sulphate, and nitrate were 2,179 ± 113, 1,760 ± 383, and 4,074 ± 421 kg/ha, respectively. The soil water potential and solute concentrations indicated that uniform flow and preferential flow both occurred in the deep vadose zone, and uniform flow was the dominant mechanism of soil water movement in this study. The piston‐like flow velocity of solute transport was 1.14 m per year, and the average value of calculated leached nitrate nitrogen was 107 kg/ha?year below the root zone. The results can be used to better understand recharge processes and improve groundwater resources management.  相似文献   

华北平原下垫面荒漠化和绿化对气候的影响   总被引：4，自引：0，他引：4  

林贤超  尹思明 《地理学报》1993,48(6):552-562

从大气热力学能量方程,水汽守恒方程以及降水与大气水汽含量和相对湿度的经验关系出发,本文假定大尺度环流不受地表下垫面变化的影响,不考虑大气辐射吸收与水汽和温度的反馈作用,对大气和地表能量过程作参数化处理,建立了一个反映区域年平均温度和降水的变化与地表反射率和波恩比变化之间的关系。计算分析表明,对于线性尺度为550km的华北平原来说,如果地表下垫面从目前状态变成沙漠的话,年平均温度将增加2.14°C,年降水量将减少536.1mm。如果华北平原全部绿化、年平均温度变化不大,年降水量可增加21.2mm。  相似文献   

江汉平原农田渍害机理研究^*   总被引：4，自引：0，他引：4  

喻光明 《地理研究》1993,12(3):37-44

本文提出了江汉平原的渍害标准,并从地表水动态,地下水动态、微地貌及垦殖与耕作等主导因子分析入手,探讨了江汉平原渍害的形成原因和形成过程,为渍害的诊断改造和利用提供了理论依据。  相似文献   

平原地区活断层研究   总被引：3，自引：0，他引：3  

王华林  李家灵 《地震研究》1991,14(2):132-140

本文归纳、总结了近几年来山东省地震局在工程地震工作中采用的平原地区活断层研究的方法。几个典型实例证明,这一方法在平原地区活断层研究中是行之有效的,获得了良好的、具有科学价值的结果,同时讨论了与这一方法有关的几个问题。  相似文献   

The　abnormal　mantle　and　deep　tectonic　process　in　the　southern　region　of　North　China　Plain     

高世玉  胡鸿翔  丁山 《地震学报(英文版)》1994,(Z1)

ＴｈｅａｂｎｏｒｍａｌｍａｎｔｌｅａｎｄｄｅｅｐｔｅｃｔｏｎｉｃｐｒｏｃｅｓｓｉｎｔｈｅｓｏｕｔｈｅｒｎｒｅｇｉｏｎｏｆＮｏｒｔｈＣｈｉｎａＰｌａｉｎＳｈｉ－ＹｕＧＡＯ（高世玉），Ｈｏｎｇ－ＸｉａｎｇＨＵ（胡鸿翔）ａｎｄＳｈａｎＤＩＮＧ（丁山）（Ｉｎ...  相似文献   

松嫩平原晚第三纪—更新世孢粉组合及古植被与古气候的研究   总被引：9，自引：0，他引：9  

夏玉梅  汪佩芳 《地理学报》1987,(2)

本文通过大庆、乾安、长春、哈尔滨等地所揭示孢粉资料,试将松嫩平原晚第三纪到更新世时期划出13个孢粉带。根据孢粉组合系列变化和磁性地层测定,论述古植被与古气候演化过程,为研究东北平原第四纪自然环境变迁提供科学依据。  相似文献   

海河平原地下水资源可持续利用前景评价   总被引：7，自引：0，他引：7  

王金哲  费宇红  张光辉  申建梅  聂振龙 《水文地质工程地质》2005,32(4):56-59

本文通过综合分析海河平原地下水资源盈余量以及建立典型三级区平原开采系数与地下水水位下降速率、地面沉降速率的关系,分析了各三级区平原依靠环境容量可扩大开采量,根据疏干时限性评价指标对海河平原地下水的开采潜力进行了评价,客观展现了维持现状开采条件下研究区地下水资源可持续利用的暗淡前景。  相似文献   

Factors affecting arsenic concentration in groundwaters from Northwestern Chaco-Pampean Plain,Argentina     

María Gabriela García  Ondra Sracek  Diego Sebastián Fernández  Margarita del Valle Hidalgo 《Environmental Geology》2007,52(7):1261-1275

The concentration of arsenic measured in groundwater from three aquifers in the study area located in the Eastern Tucuman province, Argentina, mostly depends on the lithology, but the spatial and temporal variations of concentrations seem to be also controlled by pH changes, climatic factors, and human perturbations. The highest concentrations of As (more than 1,000 μg L⁻¹) were found in the shallow aquifer, made of As-rich loess, while the lowest concentrations were measured in the deep confined aquifer, consisting of alternating layers of alluvial sands/gravels and clays. Intermediate values were measured in the semiconfined aquifer made of the fluvial sediments deposited in the Salí River valley, that alternate in the upper part of the sedimentary sequence with layers of loess. Because most of As in the loess is considered to be adsorbed onto Fe-oxyhydroxide coatings, the increase of pH in the flow direction (west-east) leads to increasing arsenic concentrations towards the eastern border of the study area. The decomposition of organic wastes poured into the Salí River or associated with local and diffuse sources of contamination in the eastern part of the study area depletes dissolved oxygen, which leads to the reductive dissolution of Fe and Mn oxyhydroxides, and to the subsequent release of the adsorbed and co-precipitated As. This process mainly affects shallow groundwater and the upper part of the semiconfined aquifer. Geochemical and hydrological data also suggest that rising water table levels at the end of the wet season may also lead to reductive dissolution of As-rich Fe oxyhydroxides in the shallow aquifer.  相似文献   

中原城市群公路网络建设与城市化水平相关性研究   总被引：6，自引：0，他引：6  

梁留科  牛智慧 《地域研究与开发》2007,26(2):48-51,96

分析了中原城市群地区1994～2004年公路交通网络和城市化的发展及现状,寻求区域内公路网络发展和城市化水平相关性,得出二者无论是在时间序列还是在空间系列上都具有显著的线性相关性.证明陈彦光提出的线性相关模型不仅可应用于铁路交通网络分析,而且还能适用于公路交通网络分析.在市场经济条件下,交通网络与城市化是同步发展、相互促进的,且相关性更强.  相似文献