平凉隐伏岩溶水环境同位素研究

地下水资源可持续利用的一个急待解决的重要问题,是对地下水补给和更新能力的评价.利用环境同位素技术研究地下水的补给和可更新性是当前较为新颖的方法之一.在西北干旱、半干旱的隐伏岩溶地区,地下水埋藏条件复杂,常规的地质勘探方法所能提供的水文地质信息有限,环境同位素方法在研究地下水的补给及可更新能力方面发挥了优势,可对传统方法进行补充和验证.其结果表明,研究区隐伏岩溶水形成较早,且有大量现代水的混入,平均混入量为54%.说明区内隐伏岩溶水的补给和更新能力较好.环境同位素分析结果还显示,大岔河隐伏岩溶水为一相对独立、半开放的水文地质单元,其补给来源部分为流域内大气降水、地表水的补给,部分为东南部三道沟岩溶地下水的补给;根据环境同位素EPM模型计算,地下水的滞留时间为36 a.地下水储存量为1.314×108 m3; 储水系数为7.29×10-3.这一结果与传统勘探方法的计算结果基本吻合,说明环境同位素方法的实用性.     

陕西关中盆地中部地下热水H、O同位素交换 及其影响因素

对关中盆地地下热水δ＆18O和8D数据的研究表明：盆地中部西安、咸阳深部的地压地热流体发生明显的δ^18O同位素交换,并出现^2H同位素交换,表明热储流体发生了强烈的水岩反应,盆地周边及中部的非地压地热流体^18O交换则不明显。根据研究区^18O同位素的交换程度（用^2H过量参数d表征）和水化学资料,可将关中盆地热储流体分为循环型和封闭型热储流体2类。地热水埋深越大、滞留时间越长、TDS和温度越高、地质环境越封闭,18^O交换程度就越大。西安和咸阳地下热水分属于不同的地热系统,具有不同的补给来源。     

地震赌博

ＶＡＮ小组自１９８１年以来一直宣称正在进行地震预报，他们对地震两个基本参数，即震级和位置的预报约束非常宽松，大部分ＶＡＮ的震级预报低于Ｍｓ５．７及具有±０．７的容限，预报震级所跨的不确定性有如此的范围，以致这样的预报不能直率地认为是成功的。根据ＶＡＮ对空间解的主张，如果成功的话，可能包含一个震级８．０的震源范围的线性尺度，但并没合适地将震级限制到Ｍｓ７．５那样大。在可以进行的细致判定前，ＶＡＮ不仅     

三江源地区水资源的涵养和保护

分析了三江源区水资源现状,论述了建立水资源三级保护区的意义、作用和划分方案,实施林草植被的保护和恢复的水文生态效益及健全水资源补偿机制的必要性。     

三江源地区水资源的涵养和保护

分析了三江源区水资源现状，论述了建立水资源三级保护区的意义、作用和划分方案，实施林草植被的保护和恢复的水文生态效益及健全水资源补偿机制的必要性。     

对关中盆地腹部深层地下热水δ~(18)O富集主控因素的再认识

开展关中盆地腹部深层地下热水起源成因的研究,对推动研究区地下热水的可持续开发利用意义重大。中国大多数地下热水赋存地区的热水样点与现代循环水的关系密切,多属循环型热水,而关中盆地深层地下热水却远离大气降水线,δ~(18)O漂移显著,对此,国内外学者专家对引起关中盆地地下热水δ~(18)O富集的主要因素有不同的认识。应用同位素水文地球化学方法结合关中盆地地质构造演化,对关中盆地不同构造单元深层地下热水δ~(18)O富集的主控因素进行探索性研究。研究结果表明,影响关中盆地深层地热水δ~(18)O富集的因素是多元的,因热储环境开发度而异,在较封闭的热储条件下,其主控因素是水岩反应。热储蒸发实验的结果表明,深层地热水在进入地层前作为补给水源时,存在一定程度的蒸发作用,入渗后进入较封闭热储环境时则主要受控于水岩作用的影响,且受水岩反应的影响程度为固市凹陷咸礼断阶东咸礼断阶西及西安凹陷。     

Vadose zone-attenuated artificial recharge for input to a ground water model

Accurate representation of artificial recharge is requisite to calibration of a ground water model of an unconfined aquifer for a semiarid or arid site with a vadose zone that imparts significant attenuation of liquid transmission and substantial anthropogenic liquid discharges. Under such circumstances, artificial recharge occurs in response to liquid disposal to the vadose zone in areas that are small relative to the ground water model domain. Natural recharge, in contrast, is spatially variable and occurs over the entire upper boundary of a typical unconfined ground water model. An improved technique for partitioning artificial recharge from simulated total recharge for inclusion in a ground water model is presented. The improved technique is applied using data from the semiarid Hanford Site. From 1944 until the late 1980s, when Hanford's mission was the production of nuclear materials, the quantities of liquid discharged from production facilities to the ground vastly exceeded natural recharge. Nearly all hydraulic head data available for use in calibrating a ground water model at this site were collected during this period or later, when the aquifer was under the diminishing influence of the massive water disposals. The vadose zone is typically 80 to 90 m thick at the Central Plateau where most production facilities were located at this semiarid site, and its attenuation of liquid transmission to the aquifer can be significant. The new technique is shown to improve the representation of artificial recharge and thereby contribute to improvement in the calibration of a site-wide ground water model.     

Estimating nutrient budgets in tropical estuaries subject to episodic flows

Most Australian estuaries are subject to riverine discharge regimes that are highly episodic. This characteristic poses difficulties for estimating nutrient budgets of such systems based on sampling regimes that do not resolve the discharge variation and the changes in nutrient distributions that they cause. This paper presents a method for calculating nutrient budgets in estuaries having episodic hydrology. The method utilises a simple hydrodynamic transport model that is calibrated using measured salinities and which is used to describe the transport properties of the estuary as they respond to river discharge. Using this transport model, the temporal variation in nutrient concentrations within the estuary can be resolved between sampling surveys even when the discharge events are of short duration. An inverse method is then applied to calculate internal fluxes of nutrients from measurements obtained on successive sampling surveys. The approach is demonstrated through an application to the Fitzroy Estuary in Queensland, Australia.