三工河流域冲积洪平原下游灌区盐碱化成因分析与治理对策

对三工河流域冲洪积细土平原灌区土地盐碱化成因及危害发生特征分析,得出灌区土地盐碱化主要与灌区水库供水水源水质以及因灌溉而产生的土壤次生盐渍化有关。 地表积盐严重,土壤次生盐渍化,严重制约团场的发展,为了防治碱灾害,促使团场走可持续发展的道路,分析探讨灌区土地盐碱化成因、提出治理土地盐碱化的对策措施就显得实际和迫切。     

河西走廊干旱荒漠区盐碱化土地修复与调控研究--以石羊河灌区为例

近年来，由于自然因素和人为因素的共同作用，石羊河灌区盐碱化土地面积逐年增加，盐碱化程度不断加深，严重影响到该区国民经济、社会和生态环境的可持续发展。文章分析了造成石羊河灌区盐碱化的自然因素和人为因素．认为自然因素主要是：①．气候干旱，降水稀少，蒸发量强烈；②．水资源量逐年减少；③．地势上位于我国现代地形的第二阶梯，为内陆河流；④．地下水质矿化度高。人为因素是：①．过度开荒，灌区大量超采地下水；②．植被大量减少，加剧了土地盐碱化；③．灌溉技术落后，有灌无排。同时从四个方面探索建立了科学合理的石羊河灌区盐碱化土地综合调控措施：①．水资源合理配置；②．以水盐平衡理论为指导，调控地上水位和盐分的时空分布；③．加强以节水灌溉为核心的灌区配套建设，推广节水防盐的灌水技术；④．扩大牧草种植，逐步实现农业三元结构。     

222团灌区西部土壤盐碱化特征与治理措施

对兵团222团灌区西部为弃耕地和未开发耕地,通过对该区域进行土地盐碱化勘察,得出项目区土壤类型为亚粘土,主要积盐方式为洪积积盐;土壤盐渍化的等级为强盐渍土和盐土;项目区盐碱类型为钠盐型,属碱化-硫酸盐型和碱化-氯化物、硫酸盐混合盐渍化类型存在,针对项目区土壤盐渍化化学性质及其分布特点,提出对项目区土壤盐渍化的改良和治理措施。     

苏打碱化土壤区地下水质的模糊综合评价

运用模糊数学方法,从农业灌溉角度,分别对该地区旱季、雨季的地下水质进行模糊综合评价。结果表明,无论是旱季还是雨季,该区30m深度以内的浅层地下水质均普遍较差,利用其灌溉会产生中等及较高程度的盐碱化危害;而60m深度以下地下水质较优,作为灌溉水源产生盐碱化的程度较低。浅层地下水受地表盐碱性水体和苏打碱化土壤影响,致使水质盐碱性较强;深层地下水由于埋藏较深,不受地表土壤和水体影响,因而水质稳定。     

灾害学定义之下的土壤盐碱化风险评价

为改善灌区中低产地的产量、提高其田间管理及粮食综合生产能力、防止土壤盐碱化灾害的扩展,在土壤盐碱化灾害学研究的基础上,建立了土壤盐碱化灾害风险评价指标体系。选用基于熵权的灰色关联评价方法来构建土壤盐碱化灾害风险评价模型,根据标准自然灾害风险原理,建立土壤盐碱化灾害风险指数计算模型。在松原灌区土壤盐碱化灾害风险评价中的应用表明,灌区各灌片盐碱灾害风险值为0.10～0.36,属于中度风险和重度风险区,风险值由小到大排序为：前郭片、安字片、有字片、龙海片、水字片、大布苏片、潜字片、套浩太片、戎字片、红星片、洪字片。该模型与灌区实情符合较好,客观性较强,表明所建模型可用于土壤盐碱化灾害风险评价。     

地下水开发引起的环境问题与治理

我国北方地下水超采地区，引发了地下水位持续下降、地面沉降、海（咸）水入侵和地下水质污染等问题。而在尚未或很少开发利用地下水的河水灌区，仍然存在着土壤次生盐碱化问题。治理地下水环境问题，要加强对水资源的管理，在井灌区拦蓄降雨径流及汛后河水回补地下水，在河水灌区积极开发利用浅层地下水，利用地下微咸水及经过处理的污水发展灌溉，治理污染源防治地下水污染，提高用水效率，采取农业综合节水技术，控制和减少地正点水开采量，并需跨流域调水补源。     

内蒙古扎鲁特旗土地利用方式及强度对草原群落的影响

内蒙古扎鲁特旗位于北方农牧交错带区域，近期对其草原植被的调查分析表明：人类不合理的土地利用方式及过大的土地利用强度对该地草原植被造成严重影响，草原面积缩小、植被退化严重，草场质量下降。人口激增引发的土地利用方式由牧向农的转化（垦草为粮）以及草地利用强度的加大（超载过牧）是造成该区草原植被退化的主要原因。改变土地利用方式、围栏禁牧是实现退化草原植被恢复演替的有效措施。     

《地下水》编委简介

方生—河北省水利科学研究院教授级高级工程师。水资源与灌溉排水专家,《地下水》杂志编委。1928年1月出生于山东青岛市。1945、1947肄业于天津工商学院建筑工程系、河北工学院水利工程系。水利部地下水专家组成员、世界银行国际灌溉排水技术研究计划(IPTRID)专家组成员、全国地下水信息网顾问。曾任水利部土壤调查总队副总队长,河北省水利厅勘测设计院试验室、综合设计室、科研室主任,河北省水利科学研究所所长,中国水利学会农田水利专业委员会委员、中国土壤学会盐碱土专业委员会副主任、河北省农业系统工程学会副理事长等。上世纪50年代参与水利部与中国科学院合作组织华北平原、内蒙古河套、宁夏青铜峡引黄灌区及山西河谷盆地土壤地下水调查。为黄河中下游灌区开发、根治海河、旱涝盐碱综合治理提供科学依据。参加编著《华北平原土壤》,获全国科学大会奖。60年代组织海滦河平原防治土壤盐碱化调查与科学实验。在河北深县组建后营旱涝盐碱综合治理试区,解决了灌区次生盐碱化防治问题。十年实现人均千斤粮,二十年粮食总产翻两番。后营试区获河北省科技工作先进集体先进个人代表会议奖。70年代主持国家河北黑龙港地区地下水合理开发利用的研究,《综合治理旱涝碱咸》...     

河套灌区井渠联合运用优化灌溉模型

针对河套灌区的地面水与地下水联合运用问题,提出了井渠结合优化灌溉模型,以最佳种植模式和最优工程运行策略,达到控制地下水位、防治土壤盐碱化、获得农作物稳产高产的目的.模型有调蓄地面水源、土壤贮水层、地下含水层的能力.优化计算成果与266.7hm2试验示范区的实际运行结果相吻合,节水、节能、增产及控制地下水位、改良盐碱地等效果十分显著,这对发展节水型灌溉农业具有重要的现实意义.     

黑河下游水土理化性质变化及生态环境意义

对黑河下游不同类型沙漠化土地土壤的盐分进行了调查和分析. 结果表明: 潜在沙漠化土地土壤水化学类型为Cl--SO2--4-Na -Mg2 离子型土,正在发展的沙漠化土地为SO2--4-Cl--Mg2 -Na 离子型土, 强烈发展的沙漠化土地为HCO--3-Cl--Ca2 -Na 离子型土, 严重沙漠化土地为Cl--SO2--4-Mg2 -Na 离子型土. 不同土壤中全N、全P、全K、 PH值和有机质含量差异较小, 而速效N、速效P和速效K养分含量差异较大;主成分分析显示, 全N、全P、 有机质和速效N含量总贡献累计达76.24%. 黑河下游地区随着上中游水量的减少, 在强蒸发作用下, 地表水与浅层地下水的矿化度显著升高. 水文过程的改变, 使维系绿洲的水资源由平衡到失衡, 在水环境的恶化过程中, 周期性积盐作用, 使绿洲内的非盐渍化土壤向轻盐土发展、 轻盐土向重盐土方向发展, 盐碱化土地不断扩展导致土地沙漠化程度增加. 上述各过程共同构成绿洲沙漠化复杂的地表动力学过程.     

羌塘赤布张错地区新生代火山岩研究

根据K-Ar同位素年代学研究成果，将赤布张错新生代火山活动划分为3期：第Ⅰ期(40．1～35．1Ma)火山喷发较弱，形成小范围分布的细粒安粗岩和斑状粗面岩；第Ⅱ期(26．5～17．6Ma)火山喷溢最为强烈，形成大面积厚层黑色气孔状安粗岩；第Ⅲ期(5．5～4．61Ma)由潜火山作用形成球粒状、斑状粗面岩岩丘。新生代火山岩系包括高钾钙碱性系列和钾玄岩系列，高钾钙碱性火山岩形成于始新世，属于壳源岩浆系列；钾玄岩系火山岩形成于中新世一上新世，属于幔源岩浆系列。由老到新，岩石系列由高钾钙碱性系列一钾玄岩系列演化，岩性由安粗岩一粗面岩演化。     

Catastrophic earthquakes in the European area

A general review of relevant data on the conditions for and the occurrence and distribution of catastrophic earthquakes in Europe is presented. A table of some important events is included.     

Industrial location in the Nairobi area

The paper opens with a brief examination of the Nairobi City pattern of industrial location (especially in terms of industrial areas), including the enumeration of some of the industries involve (a number of them located outside the city boundary). Industrial structure (cum-location) aspects, both in the city and in the neighbouring districts of Kiambu, Machakos and Kajiado (which together constitute the Nairobi Area), are next discussed in detail. The data used are those from the 1965 and 1975 research surveys, and are presented on a national basis so as to demonstrate the significance or otherwise of the Nairobi Area as the industrial core of Kenya. The discussion of the location factors in the Nairobi Area brings the paper to a close. Incorporated are seven tables and four maps.     

Seismic faults in the Aegean area

Reliable fault plane solutions of shallow earthquakes and information on surface fault traces in combination with other seismic, geomorphological and geological information have been used to determine the orientation and other properties of the seismic faults in the Aegean and surrounding area.Thrust faults having an about NW-SE strike occur in the outer seismic zone along western Albania-westernmost part of mainland of Greece-Ionian Sea-south of Crete-south of Rhodes.The inner part of the area is dominated by strike-slip and normal faulting. Strike-slip with an about NE-SW slip direction occurs in the inner part of the Hellenic arc along the line Peloponnesus-Cyclades-Dodecanese-southwest Turkey as well as along a zone which is associated with the northern Aegean trough and the northwesternmost part of Anatolia. All other regions in the inner part of the area are characterized by normal faulting. The slip direction of the normal faults has an about SW-NE direction in Crete (N38°E) and an about E-W direction (N81°E) in a zone which trends N-S in eastern Albania and its extension to western mainland of Greece. In all other regions (central Greece-southern Yugoslavia and Bulgaria, western Turkey) the slip of the normal faults has an about N-S direction.     

朱溪矿集区横路矿区成矿条件与找矿潜力分析

横路矿区位于朱溪矿集区内,其成矿条件与世界最大钨矿床--朱溪矿床类似,目前已发现了多处找矿线索,但前期工作主要聚焦于500 m以浅,亟待探索该区深部找矿前景。本文从矿区地质、地球物理、地球化学、遥感特征及钻探验证等方面综合分析,并与朱溪矿区进行对比,发现二者在成矿地层层位、控岩控矿构造以及岩浆岩所处成岩-成矿事件等重要成矿条件上极为相似。此外,横路矿区的浅表矿化蚀变分布情况与岩脉密切相关,物化探异常及岩脉分布特征显示深部存在隐伏岩体。综合分析认为横路矿区深部找矿潜力巨大,具有找寻破碎带(热液脉)型、矽卡岩型及斑岩型铜钼金多金属矿床的良好前景。     

青田县石平川钼矿区外围成矿远景分析

石平川钼矿位于浙江省青田县黄垟乡石平川村―底黄垟村一带,经过几十年的开发资源储量已经不多。通过对石平川地区地质、地球物理、地球化学等方面研究表明:矿床受石平川火山穹窿控制,在其外围还有多个火山机构存在迹象;地球重力异常表明石平川外围地区存在与石平川岩体相似的隆起区,有相应的地球化学组合异常区。这三者之间构成了有机整体,表明本区具有良好的成矿远景。     

Perceptible earthquakes in the broad Aegean area

A probabilistic estimate of seismic hazard can be obtained from the spatial distribution, of earthquake sources, their frequency–magnitude distribution and the rate of attenuation of strong ground motion with distance. We calculate the earthquake perceptibility, i.e. the annual probability that a particular level of ground shaking will be generated by earthquakes of particular magnitude, by weighting frequency–magnitude data with the predicted felt area for a given level of ground shaking at a particular magnitude. This provides an earthquake selection criterion that can be used in the anti-seismic design of non-critical structures. We calculate the perceptibility, at a particular value of isoseismal intensity, peak ground acceleration and velocity, as a function of source magnitude and frequency for the broad Aegean area using local attenuation laws. We use frequency–magnitude distributions that were previously obtained by combining short-term catalogue data with tectonic moment rate data for 14 tectonic zones in Greece with sufficient earthquake data, and where contemporary strain rates are available from satellite data. Many of the zones show a ‘characteristic earthquake’ distribution with the most perceptible earthquake equal to the maximum magnitude earthquake, but a relatively flat perceptibility between magnitudes 6 and 7. The maximum perceptible magnitude is in the fastest-deforming region in the middle of the Aegean sea, and tends to be systematically low on the west in comparison to the east of the Aegean sea. The tectonic data strongly constrain the long-term recurrence rates and lead to low error estimates (±0.2) in the most perceptible magnitudes.     

Variscan plate dynamics in the circum-carpathian area

Abstract

Magmatic and metamorphic events, imprinted in the crystalline rocks of the so-called core mountains inside the Alpine structure of the Inner Carpathians, allow the re-construction of the history of the Rheic Ocean opening, its development and its final closure. Intra-Carpathian core-mountains are the remnants of the continents that drifted away from Gondwana and docked, initially, with Baltica as part of Avalonia and later on as parts of the Gondwana-derived Armorica Terrane Group or as a separate micro-continent.

All magmatic suites, mafic and felsic, present in the Carpathians core mountains, show similarities to those found in the European Variscan Belt. All described- and dated metamorphic and magmatic events also have equivalents in the evolution of the Caledonian-Variscan Belts of Europe. The most pronounced feature of all Carpathian core mountains is the syn-collisional, multistage I/S granitoid magmatism (370-340 Ma) related to subduction, mafic-magma influx, extensional decompression and slab melting. That episode marked the Laurussia - Gondwana collision and closure of the Rheic Ocean, as in the whole of Central and Western Europe.

The Carpathian core-mountains, currently dispersed inside the Alpine mountain chain, can be considered the broken fragments of the eastern prolongation of the Variscan orogenic belts – possibly part of the Moldanubian Unit.     

GPS Measurements in the Neapolitan volcanic area

The surveillance of the Neapolitan volcanic area (Mt. Vesuvius, the Phlegrean Fields and the island of Ischia) represents the principal activity of the Osservatorio Vesuviano. Such an activity is carried out also through the study of ground deformations. This study deals with the use of the GPS as a powerful topographic technique. In the last two years, three GPS networks in the above mentioned area were established, with 8 vertices at Mt. Vesuvius, 20 vertices in the Island of Ischia and 30 vertices in the Phlegrean Fields. In Mt. Vesuvius area a GPS test was carried out, in order to verify the possibility of the installation of a network of GPS permanent stations. In the island of Ischia, three different GPS techniques (Static, Fast Static and RTK-Real Time Kinematics) have been used to get a first set of coordinates and to carry out a comparison between these in small extension areas. GPS data of the Phlegrean Fields are still in processing. The results for Mt. Vesuvius area and the island of Ischia are hereby presented and discussed.     

柴达木盆地北缘德令哈地区基性麻粒岩的发现

近年来，对柴达木北缘达肯达坂群的研究取得一系列重要进展。如在绿梁山—锡铁山—都兰带原定的达肯达坂群中厘定出一条长350km的加里东期榴辉岩带，其地质意义已进行过广泛的讨论［1～3］。最近，在这个带的北部乌兰地区进行的1∶5万地质填图中，又有基性麻粒岩出露的报道；我们在1999年的野外工作中，在青海省德令哈市附近原定为古元古代（？）达肯达坂群的长英质片麻岩中发现有基性麻粒岩存在，从区域走向及岩石的基本特征来看，它们与乌兰地区发现的基性麻粒岩相似，可构成一条NWW—SEE走向的麻粒岩带，这一麻粒岩带的厘定及形成时代…