Phase Chemistry Study of the Dangxiongcuo Salt Lake Brine:Isothermal Evaporation at 25℃     

NIE Zhen  BU Lingzhong  WU Qian  WANG Yunsheng  ZHENG Mianping 《《地质学报》英文版》2014,(Z1)

正Production of lithium carbonate from brines has become the dominate trend in the world from the beginning of this century.Dangxiongcuo,a carbonate-type salt lake,is located in the interior of the Tibetan Plateau,China.As a salt lake deposit,rich in Li,B,K and other useful trace  相似文献   

蒸发的阻抗模型讨论   总被引：1，自引：0，他引：1  

陈发祖 《地理研究》1991,10(2):1-10

蒸发的阻抗模型,从简单的单层模型到复杂的多层模型,应用日益广泛。目前文献中流行一种看法:单层阻抗模型没有牢固的物理基础,但简单易行;而多层模型才具备可靠的物理基础,不过缺乏实际应用价值。本文对此作了讨论,认为两种模型均有较好的物理基础,但各有自己最适合的应用范围,且两者又都具有共同的难点。  相似文献   

茶卡盐湖湖表卤水摸拟动态蒸发试验研究   总被引：8，自引：3，他引：5  

李海民  徐晓东 《盐湖研究》1998,6(1):11-17

叙述了茶卡盐湖卤水,在模拟湖区温度、风力条件下．蒸发、浓缩、析盐的相化学规律。给出了盐湖卤水的蒸发结晶路线、析出盐类矿物种类。  相似文献   

Development of a new method for efficiently calculating of evaporation from the phreatic aquifer in variably saturated flow modeling          下载免费PDF全文

HAO Qi-chen  SHAO Jing-li  CUI Ya-li  ZHANG Qiu-lan 《地下水科学与工程》2016,4(1):26-34

In this paper, we proposed a new method that has been developed based on the surface soil moisture content (SSMC) to more efficiently calculate the groundwater evaporation in variably saturated flow modeling. In this method, the empirical formula to calculate evaporation was modified and the value of the formula varies from zero to one as a closed interval. In addition, the simulation code for calculating the groundwater evaporation based on the SSMC method was incorporated into the EOS9 module of Tough2, a variably saturated flow modeling code. Finally, two numerical tests and a case simulation were conducted to verify the feasibility and accuracy of the SSMC method. Simulation results indicate that the SSMC method is capable of appropriately simulating the characteristics of water flow in vadose zone and the amount of evaporation with the variable water table. And such results are in coincidence with the value calculated by the logistic function method, and fit well with the measured data globally rather than locally.  相似文献   

西北干旱区夏半年深厚的混合层与干旱气候形成   总被引：8，自引：3，他引：5       下载免费PDF全文

李岩瑛  钱正安  薛新玲  兰晓波  李玲萍 《高原气象》2009,28(1):46-54

为了更好地理解西北干旱区大气混合层(ML)厚度的变化特征及其对当地干旱气候形成的影响,我们利用张掖和民勤站夏季及相关月的实测探空资料及T-log P图解法,首先计算了该两地逐日ML厚度,然后分析并讨论了它的时空间变化特征、与干湿天气气候的关系,以及夏半年的深厚ML,对加剧当地干旱气候的影响.结果表明:(1)河西中东部ML厚度的年变化及地区差异明显.冬季最浅薄,夏半年深厚(特别是5、6月),4月及10月分别是ML急剧增厚及变薄的过渡期;同时,更靠近西北干旱区中心的河西西部及北部的ML更深厚.(2)夏季干(湿)天气通过加强(减弱)地气间的感热交换和干对流,而明显影响当地的ML厚度.平均而言,以高温日最深厚,千日次之,小雨日再次之,而中强雨日最浅薄.千年夏季的ML厚度平均比湿年的对应值增厚300 m左右.夏季典型千日的ML厚度比雨日厚3000 m,典型干日的ML厚度昼宿变化不大.(3)反过来夏半年深厚的ML也通过增加雨滴蒸发损耗,减少了干旱区的降水,加剧了当地干旱的程度,因此夏半年深厚的ML也是形成干旱气候背景的成因之一.  相似文献   

乾安县浅层高氟地下水的分布规律及成因的初步探讨     

诚俊华 《吉林地质》1991,10(1):71-74

本文主要阐述了乾安县浅层高氟地下水的分布规律;探讨了浅层高氟地下水的成因与构造、地貌、古气候、地层岩性和水文地质条件的关系,从而闸明了广泛分布的湖沼相松散沉积物的组成和水文地质条件是本区浅层高氟地下水的主要原因。  相似文献   

Geochemical and isotopic investigation of the aquifer system in the Djerid-Nefzaoua basin, southern Tunisia   总被引：2，自引：0，他引：2  

Samir Kamel  Lassaad Dassi  Kamel Zouari  Brahim Abidi 《Environmental Geology》2005,49(1):159-170

In the Djerid-Nefzaoua region, southern Tunisia, about 80% of agricultural and domestic water supply is provided by the complex terminal (CT) aquifer. However, 20% of this demand is provided by other hydraulically connected aquifers, namely the continental intercalaire (CI) and the Plio-Quaternary (PQ). Overexploitation of the CT aquifer for agricultural practices has contributed to the loss of the artesian condition and the decline of groundwater level which largely increased the downward leakage from the shallow PQ aquifer. Excess irrigation water concentrates at different rates in the irrigation channels and in the PQ aquifer itself. Then, it returns to the CT aquifer and mixes with water from the regional flow system, which contributes to the salinization of the CT groundwater. A geochemical and isotopic study had been undertaken over a 2-years period in order to investigate the origin of waters pumped from the CT aquifer with an emphasis on its hydraulic relationships with the underlying and the overlying CI and PQ aquifers. Geochemistry indicates that groundwater samples collected from different wells show an evolution of the water types from Na-Cl to Ca-SO₄-Cl. Dissolution of halite, gypsum and anhydrite-bearing rocks is the main mechanism that leads to the salinization of the groundwater. Isotopic data indicate the old origin of all groundwater in the aquifer system. Mixing and evaporation effects characterizing the CT and the PQ aquifers were identified using δ²H and δ¹⁸O relationship and confirmed by the conjunction of δ²H with chloride concentration.  相似文献   

Determination of Area-Averaged Water Vapour Fluxes with Large Aperture and Radio Wave Scintillometers over a Heterogeneous Surface – Flevoland Field Experiment     

W. M. L. Meijninger  A. E. Green  O. K. Hartogensis  W. Kohsiek  J. C. B. Hoedjes  R. M. Zuurbier  H. A. R. De Bruin 《Boundary-Layer Meteorology》2002,105(1):63-83

A large aperture scintillometer (LAS) andradio wave scintillometer (RWS)were installed over a heterogeneous areato test the applicability of the scintillation method.The heterogeneity in the area, whichconsisted of many plots, was mainly caused bydifferences in thermal properties ofthe crops; the variations in theaerodynamic roughness lengthwere small. The water vapour fluxesderived from the combined LAS-RWSsystem, also known as the two-wavelengthmethod, agreed fairly well with the aggregatedwater vapour fluxes derived from in-situeddy covariance measurements. The water vapourfluxes derived from a stand-alone LASare also presented. It was found that a single LASand an estimate of the area averagedavailable energy (using a simple parameterisationscheme) can provide also reasonablearea-averaged water vapour fluxes.  相似文献   

作物叶面蒸腾与棵间蒸发分摊系数的计算方法   总被引：13，自引：2，他引：13       下载免费PDF全文

康绍忠  张富仓 《水科学进展》1995,6(4):285-289

依据在冬小麦和玉米冠层表面及冠层内部下方土壤表面的净辐射观测资料,建立了一个能较准确地反映叶面蒸腾与棵间土壤蒸发分摊系数物理变化规律的较实用的计算模式,结果表明,分摊系数(α)随叶面积指数(LAI)增加而增加,且具有明显的日变化,α在中午最小、早、晚稍大,这种日变化受叶气孔调节的影响。  相似文献   

山地蒸发的计算   总被引：8，自引：0，他引：8  

傅抱璞 《气象科学》1996,16(4):328-335

本文研讨了山地下垫面蒸发的计算，提出了根据迳流系数和降水强度确定计算蒸发公式中与地形、植被、土壤等下垫面特性降水性质有关的参数的方法，经实际检验，结果令人满意。  相似文献