首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
华北平原东部淡水资源短缺,旱涝碱成灾害限制了农业生产的可持续发展。海河的治理,解决了排洪排涝排咸出路。春季开发利用地下水包括微咸水和半咸水抗旱灌溉。夏季利用伏雨洗盐排咸,增大降雨入渗,减少径流流失,防治渍涝灾害,把降雨转化为地下水资源。秋冬引蓄河水,回灌地下水补源。以土壤与潜水的地层空间作为调节大气降水、土壤水、地下水、地表水的地下水库,以调控地下水埋深在临界动态为指标,最大限度地把时空分布不均的天然降雨转化为可持续利用的水资源。地表水地下水联合运用,促使水资源采补平衡,降雨灌溉淋洗脱盐强于干旱蒸发积盐过程,地下水淡化强于矿化过程。实现旱涝碱咸综合治理,水土资源可持续利用,经济社会可持续发展,生态环境良性循环。  相似文献   

2.
以发展排水为基础 综合治理旱涝碱咸   总被引:1,自引:0,他引:1  
方生  陈秀玲 《地下水》2008,30(2):1-5
华北平原水资源短缺,旱涝碱成灾害是农业可持续发展的主要制约因素。海河的治理,骨干排水河道的开挖疏浚,解决了排洪排涝排成出路,建成华北平原排洪排涝系统。春季开发地下水包括微成水和半咸水抗旱灌溉,井灌井排降低地下水位,增大地下库容,减少径流流失,增多降雨入渗,淋洗土壤盐碱,防治渍涝灾害,把降雨转化为可利用的水资源。秋冬利用深沟引蓄河水,回灌地下水补源,促使地下咸水淡化。地表水地下水联合运用,保持水资源采补平衡。实现旱涝碱成综合治理,水资源可持续利用,经济社会可持续发展,生态环境良性循环。  相似文献   

3.
南皮县淡水资源严重短缺,制约工农业与经济社会的发展.春季开采浅层地下水包括微咸水和半咸水抗旱灌溉,腾出地下含水层空间;汛期增加降雨入渗,减少径流流失,防渍防涝,把时空分布不均的天然降雨转化为地下水资源;秋冬利用河道沟渠引蓄河水补源,淡化地下水质,增加地下水可采量.地上水地下水联合运用,保持水资源采补平衡.实现旱涝碱咸综合治理、水资源可持续利用与经济社会可持续发展.  相似文献   

4.
水资源合理调控利用发展农业节水灌溉   总被引:3,自引:2,他引:3  
万宝林  肖俊青 《地下水》2005,27(2):81-83
南皮县淡水资源短缺,咸水广布,制约农业生产的可持续发展.解决途径是合理调控利用当地水资源,开发利用浅层地下水包括微咸水和半咸水抗旱灌溉,调蓄雨季降雨径流及汛后河流来水作为补源,地下水地上水联合运用,发展农业节水灌溉,调整农业种植结构,提高水的利用效率.实现水资源可持续利用,农业生产可持续发展,生态环境良性循环,人与自然和谐相处.  相似文献   

5.
华北平原东部水资源可持续利用   总被引:2,自引:0,他引:2  
方生  陈秀玲  Th.M.Boers 《地下水》2003,25(4):207-214
华北平原东部水资源短缺,深层地下水严重超采,生态环境恶化。为水资源的可持续利用.要发展井灌井排渠灌沟排,以开发利用当地浅层地下水包括微成水和成水为基础.以引调可利用的地表水补源。以调控地下水埋深在临界动态为棱心,以土壤及潜水的地层空间作为调节大气降水、土壤水、地下水、地表水的地下水库.最大限度圯犯时空分布不均的天然降雨转化为可持续利用的水资源。  相似文献   

6.
地上水地下水联合运用实现灌区多目标综合治理   总被引:2,自引:0,他引:2  
方生  陈秀玲 《地下水》1999,21(2):79-83
中国北方水资源短缺,实行地上水地下水联合运用是合理开发利用水资源与综合治理旱涝碱咸的基本途径。本文介绍地上水地下水联合运用,关键在于调控地下水理深在适宜的动态,以浅层地下水的地层空间作为调节“四水”(降水、土壤水、地下水、地上水)的地下水库,最大限度地把天然降雨转化为可利用的水资源,使地表径流充分拦蓄利用,增强防涝淋盐和淡化地下水质的作用,达到灌区多目标综合治理。  相似文献   

7.
我国北方主要平原地下水潜力评价   总被引:2,自引:0,他引:2  
陈德华  陈浩  张薇 《地下水》2009,31(2):1-4
通常用地下水开采系数反映地下水资源潜力,只考虑了地下水的持续开采,使地下水资源评价与开发利用相互脱节,不便于地下水资源的管理与利用。地下水潜力系数是综合了地下水可开采盈余量、咸水、微咸水可利用量以及在水资源利用过程中节水量等,对各平原(盆地)地下水潜力进行了评价。指出了不同地区地下水开发利用方向:西北内陆盆地突出要解决地表水、地下水的相互涵养保护和对生态环境保护的问题,应充分利用水资源相互转化和重复循环的规律,扩大地下水开采量,提高水资源的重复利用率。华北及东北地区应从水资源现状、环境和社会经济的特点出发,综合治理,开源节流,保护环境.合理调整开采方案,应加强浅层微咸水综合开发利用研究。  相似文献   

8.
孙振莲 《地下水》2006,28(3):8-10
水是基础性的自然资源和战略性的经济资源,水资源的可持续利用是经济可持续发展极为重要的保证.本文在分析宝坻区自然地理及水利工程和水资源开发利用现状的基础上,对地表水、地下水资源及供需平衡进行了分析计算,提出了水资源优化配置的措施.  相似文献   

9.
通过现状农业—水资源—环境系统分析与诊断发现,黑龙港地区农业结构失调,背离资源条件发展农业,超采地下水,已使该区面临水资源不能永续利用、环境不断恶化的威胁;认为①立足水资源条件发展农业,是建立协调优化的农业—水资源—环境系统,实现农业可持续发展的必要前提;②采用综合措施有效利用土壤水,科学灌溉微咸水,合理开发利用地下水和地表水,是提高水资源对农业贡献的关键;③加强综合科技投入和农村市场经济建设,发展集约化农业,是在有限水资源条件下提高农业生产效率的重要保证;④提高全社会对可持续发展的认识,进行相应的能力建设,是实现黑龙港地区农业—水资源—环境协调可持续发展的社会基础。  相似文献   

10.
方生  陈秀玲 《地下水》1990,12(1):44-50
半干旱地区土壤水盐动态的特征是:盐渍与旱涝相联系;旱季蒸发和盐与雨季淋溶脱盐两种过程交替发生;土壤与地下水水盐运动相互作有。防治土壤盐渍化,不仅要调控土壤根层盐渍度不超过作物耐盐国界值,而且要调控地下水埋深在临界动态;即旱季在防治盐渍化的临界深度(2-3m);雨季前在防涝蓄雨深度(4-6m),雨季在作物抗湿深度(0.5-1.0m)。最大限度地把天然降雨转化为可利用的水资源,使旱涝盐渍得到综合治理。目前海河平原已有大面积盐渍土得到改良,但还存在潜在盐渍化土壤。土壤根层盐渍度已低于作物耐盐度,但有的心底土盐分重,或地下水矿化度高,一旦地下水位升高仍会发生盐渍化。这个地区又是引黄或引江灌区所在,调控地下水埋深在临界动态,是预防灌溉次生盐渍化发生地关键。  相似文献   

11.
Most sulfide-rich magmatic Ni-Cu-(PGE) deposits form in dynamic magmatic systems by partial melting S-bearing wall rocks with variable degrees of assimilation of miscible silicate and volatile components, and generation of barren to weakly-mineralized immiscible Fe sulfide xenomelts into which Ni-Cu-Co-PGE partition from the magma. Some exceptionally-thick magmatic Cr deposits may form by partial melting oxide-bearing wall rocks with variable degrees of assimilation of the miscible silicate and volatile components, and generation of barren Fe ± Ti oxide xenocrysts into which Cr-Mg-V ± Ti partition from the magma. The products of these processes are variably preserved as skarns, residues, xenoliths, xenocrysts, xenomelts, and xenovolatiles, which play important to critical roles in ore genesis, transport, localization, and/or modification. Incorporation of barren xenoliths/autoliths may induce small amounts of sulfide/chromite to segregate, but incorporation of sulfide xenomelts or oxide xenocrysts with dynamic upgrading of metal tenors (PGE > Cu > Ni > Co and Cr > V > Ti, respectively) is required to make significant ore deposits. Silicate xenomelts are only rarely preserved, but will be variably depleted in chalcophile and ferrous metals. Less dense felsic xenoliths may aid upward sulfide transport by increasing the effective viscosity and decreasing the bulk density of the magma. Denser mafic or metamorphosed xenoliths may also increase the effective viscosity of the magma, but may aid downward sulfide transport by increasing the bulk density of the magma. Sulfide wets olivine, so olivine xenocrysts may act as filter beds to collect advected finely dispersed sulfide droplets, but other silicates and xenoliths may not be wetted by sulfides. Xenovolatiles may retard settling of – or in some cases float – dense sulfide droplets. Reactions of sulfide melts with felsic country rocks may generate Fe-rich skarns that may allow sulfide melts to fractionate to more extreme Cu-Ni-rich compositions. Xenoliths, xenocrysts, xenomelts, and xenovolatiles are more likely to be preserved in cooler basaltic magmas than in hotter komatiitic magmas, and are more likely to be preserved in less dynamic (less turbulent) systems/domain/phases than in more dynamic (more turbulent) systems/domains/phases. Massive to semi-massive Ni-Cu-PGE and Cr mineralization and xenoliths are often localized within footwall embayments, dilations/jogs in dikes, throats of magma conduits, and the horizontal segments of dike-chonolith and dike-sill complexes, which represent fluid dynamic traps for both ascending and descending sulfides/oxides. If skarns, residues, xenoliths, xenocrysts, xenomelts, and/or xenovolatiles are present, they provide important constraints on ore genesis and they are valuable exploration indicators, but they must be included in elemental and isotopic mass balance calculations.  相似文献   

12.
Partition coefficients of Hf,Zr, and REE between zircon,apatite, and liquid   总被引:25,自引:2,他引:25  
Concentration ratios of Hf, Zr, and REE between zircon, apatite, and liquid were determined for three igneous compositions: two andesites and a diorite. The concentration ratios of these elements between zircon and corresponding liquid can approximate the partition coefficient. Although the concentration ratios between apatite and andesite groundmass can be considered as partition coefficients, those for the apatite in the diorite may deviate from the partition coefficients. The HREE partition coefficients between zircon and liquid are very large (100 for Er to 500 for Lu), and the Hf partition coefficient is even larger. The REE partition coefficients between apatite and liquid are convex upward, and large (D=10–100), whereas the Hf and Zr partition coefficients are less than 1. The large differences between partition coefficients of Lu and Hf for zircon-liquid and for apatite-liquid are confirmed. These partition coefficients are useful for petrogenetic models involving zircon and apatite.  相似文献   

13.
《Chemical Geology》2007,236(1-2):13-26
We examined the coprecipitation behavior of Ti, Mo, Sn and Sb in Ca–Al–Mg fluorides under two different fluoride forming conditions: at < 70 °C in an ultrasonic bath (denoted as the ultrasonic method) and at 245 °C using a Teflon bomb (denoted as the bomb method). In the ultrasonic method, small amounts of Ti, Mo and Sn coprecipitation were observed with 100% Ca and 100% Mg fluorides. No coprecipitation of Ti, Mo, Sn and Sb in Ca–Al–Mg fluorides occurred when the sample was decomposed by the bomb method except for 100% Ca fluoride. Based on our coprecipitation observations, we have developed a simultaneous determination method for B, Ti, Zr, Nb, Mo, Sn, Sb, Hf and Ta by Q-pole type ICP-MS (ICP-QMS) and sector field type ICP-MS (ICP-SFMS). 9–50 mg of samples with Zr–Mo–Sn–Sb–Hf spikes were decomposed by HF using the bomb method and the ultrasonic method with B spike. The sample was then evaporated and re-dissolved into 0.5 mol l 1 HF, followed by the removal of fluorides by centrifuging. B, Zr, Mo, Sn, Sb and Hf were measured by ID method. Nb and Ta were measured by the ID-internal standardization method, based on Nb/Mo and Ta/Mo ratios using ICP-QMS, for which pseudo-FI was developed and applied. When 100% recovery yields of Zr and Hf are expected, Nb/Zr and Ta/Hf ratios may also be used. Ti was determined by the ID-internal standardization method, based on the Ti/Nb ratio from ICP-SFMS. Only 0.053 ml sample solution was required for measurement of all 9 elements. Dilution factors of ≤ 340 were aspirated without matrix effects. To demonstrate the applicability of our method, 4 carbonaceous chondrites (Ivuna, Orgueil, Cold Bokkeveld and Allende) as well as GSJ and USGS silicate reference materials of basalts, andesites and peridotites were analyzed. Our analytical results are consistent with previous studies, and the mean reproducibility of each element is 1.0–4.6% for basalts and andesites, and 6.7–11% for peridotites except for TiO2.  相似文献   

14.
针对兖州煤田下组煤深部开采受奥灰高承压水威胁以及当地大型煤化工企业生产用水量大的现状,在已进行的水文地质勘探及放水试验基础上,评价奥灰富水性,并采用有限差分法进行奥灰疏水降压数值模拟研究,提出水煤共采观点。研究结果表明:兖州煤田深部奥灰水压高,合理布置水煤共采孔,可以实现奥灰水位的有效疏降,疏降中心区水位最大降深可达110 m,突水系数显著下降,提高了下组煤开采的安全性;同时可提供煤化工43200 m3/d的供水量,能达到可持续的、水资源保护性的供水效果,实现下组煤的水煤共采。  相似文献   

15.
16.
17.
The distribution of Cu, Co, As and Fe was studied downstream from mines and deposits in the Idaho Cobalt Belt (ICB), the largest Co resource in the USA. To evaluate potential contamination in ecosystems in the ICB, mine waste, stream sediment, soil, and water were collected and analyzed for Cu, Co, As and Fe in this area. Concentrations of Cu in mine waste and stream sediment collected proximal to mines in the ICB ranged from 390 to 19,000 μg/g, exceeding the USEPA target clean-up level and the probable effect concentration (PEC) for Cu of 149 μg/g in sediment; PEC is the concentration above which harmful effects are likely in sediment dwelling organisms. In addition concentrations of Cu in mine runoff and stream water collected proximal to mines were highly elevated in the ICB and exceeded the USEPA chronic criterion for aquatic organisms of 6.3 μg/L (at a water hardness of 50 mg/L) and an LC50 concentration for rainbow trout of 14 μg/L for Cu in water. Concentrations of Co in mine waste and stream sediment collected proximal to mines varied from 14 to 7400 μg/g and were highly elevated above regional background concentrations, and generally exceeded the USEPA target clean-up level of 80 μg/g for Co in sediment. Concentrations of Co in water were as high as in 75,000 μg/L in the ICB, exceeding an LC50 of 346 μg/L for rainbow trout for Co in water by as much as two orders of magnitude, likely indicating an adverse effect on trout. Mine waste and stream sediment collected in the ICB also contained highly elevated As concentrations that varied from 26 to 17,000 μg/g, most of which exceeded the PEC of 33 μg/g and the USEPA target clean-up level of 35 μg/g for As in sediment. Conversely, most water samples had As concentrations that were below the 150 μg/L chronic criterion for protection of aquatic organisms and the USEPA target clean-up level of 14 μg/L. There is abundant Fe oxide in streams in the ICB and several samples of mine runoff and stream water exceeded the chronic criterion for protection of aquatic organisms of 1000 μg/L for Fe. There has been extensive remediation of mined areas in the ICB, but because some mine waste remaining in the area contains highly elevated Cu, Co, As and Fe, inhalation or ingestion of mine waste particulates may lead to human exposure to these elements.  相似文献   

18.
The dielectric constants and dielectric loss values of 4 Ca-containing minerals were determined at 1 MHz using a two-terminal method and empirically determined edge corrections. The results are: vesuvianitel κ′ a=9.93 tan δ=0.006 κ′ c=9.79 tan δ=0.005 vesuvianitel κ′ a=10.02 tan δ=0.002 κ′ c=9.85 tan δ=0.003 zoisite1 κ′ a =10.49 tan δ=0.0006 κ′ b =15.31 tan δ=0.0008 κ′ c=9.51 tan δ=0.0008 zoisite2 κ′ a =10.55 tan δ=0.0011 κ′ b =15.45 tan δ=0.0013 κ′ c=9.39 tan δ=0.0008 epidote κ′ 11= 9.52 tan δ=0.0008 κ′ 22=17.1 tan δ=0.0009 κ′ 33= 9.37 tan δ=0.0006 fluorapatite1 κ′ a =10.48 tan δ=0.0008 κ′ c = 8.72 tan δ=0.0114 fluorapatite2 κ′ a =10.40 tan δ=0.0010 κ′ c=8.26 tan δ=0.0178 The deviation (δ) between measured dielectric polarizabilities as determined from the Clausius-Mosotti equation and those calculated from the sum of oxide polarizabilities according to α D (mineral)=∑ α D (oxides) for vesuvianite is ~ 0.5%. The large deviations of epidote and zoisite from the additivity rule with Δ=+ 10.1 and + 11.7%, respectively, are attributed to “rattling” Ca ions. The combined effects of both a large F thermal parameter and possible F-ion conductivity in fluorapatite are believed to be responsible for Δ=+2–3%. Although variation of oxygen polarizability with oxygen molar volume (Vo) is believed to affect the total polarizabilities, the variation of Vo in these Ca minerals is too small to observe the effect.  相似文献   

19.
The contents of As, Cd, Cu, Cr, Mg, Mn, Ni, Pb and Zn have been determined in sediment and water samples from Valle de las Garzas estuary and Port Manzanillo (Colima, Mexico) using ICP-AES. The concentrations of these elements were used for a comparative study to determine the distribution of heavy metals and to evaluate which elements reflect natural or anthropogenic backgrounds. For this purpose, seven sampling points were selected: Four of them correspond to the lagoon, and three were situated in the port. Statistical analysis of the mineral content was assessed. Initially, data comparison was assessed by statistical tests for each variable. Principal component analysis was then applied considering the influence of all variables at the same time by obtaining the distribution of samples according to their scores in the principal component space. In this way, four studies were carried out: (1) study of sediments collected during the dry season; (2) study of sediments collected during the rainy season; (3) comparative study between sediments from rainy and dry season; and (4) study of water composition collected during rainy season. From the results of the performed analyses, it can be concluded that metals distribution pattern reflected natural and anthropogenic backgrounds (e.g., sediments from the lagoon, situated at the beginning of the rain channel, presented high contents of Zn and Cu, perhaps related to anthropogenic activities or the influence of igneous sediments).  相似文献   

20.
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号