荒漠绿洲农田盐渍化过程中土壤环境的演变过程

土壤环境的盐渍化演变过程是盐渍化其它过程研究的基础。采用空间代替时间的方法,在干旱绿洲区选择大麦（Hordeum vulgare L.）作物地不同盐渍化阶段农田为研究对象,并以非盐渍化农田作为对照,探讨农田盐渍化过程中土壤理化特性的演变过程。结果表明,（1）随盐渍化程度的加剧,土壤颗粒组成发生变化,沙粒含量趋于增加,黏粒含量趋于减少,粉粒含量在重度和极重度盐渍化阶段完全消失。表土层土壤容重呈显著增加趋势（P〈0-05）,但土壤温度没有显著性变化（P〉0-05）。（2）土壤有机碳、全氮、全磷和速效氮含量呈波动式降低趋势,而速效磷含量呈波动式增加的趋势。与未盐渍化农田相比,轻度、中度、重度和极重度盐渍化农田土壤表层有机碳和全氮含量分别减少了14.03%、26.26%、42.01%、48.03%;19-08%、35.63%、46.84%、56.88%。（3）随盐渍化程度的加剧,盐分表聚现象明显,除 HCO3-外,Na＋、Cl-、K＋、Mg2＋、SO42-、全盐含量均显著增加（P〈0-05）,且随着深度的增加逐渐下降。与未盐渍化农田相比,轻度、中度、重度、极重度盐渍化农田土壤电导率、全盐,SO42-,Na＋含量分别增加了31.42%、74.42%、203.95%、693.58%,6.56%、96.38%、86.36%、414.86%,5.23%、114.58%、104.00%、430.32%,31.46%、145.22%、345.11%、1797.70%;HCO3-下降了-11-31%、2.02%、3.75%、10.94%。（4）土壤电导率、全盐、SO42-、Ca2＋、Cl-、Mg2＋、K＋、Na＋之间呈极显著正相关（P〈0.01）,但与土壤含水量没有显著正负相关性,与黏粉粒含量呈显著负相关（P〈0-05）;土壤有机碳、全氮、速效氮之间呈极显著正相关（P〈0.01）,但与土壤含水量没有显著正负相关性,与土壤电导率、全盐、SO42-、Ca2＋、Cl-、Mg2＋、K＋、Na＋之间呈极显著负相关（P〈0.01）。这说明,在农田盐渍化过程中,随盐渍?     

水资源短缺条件下绿洲的建设和发展——以卡拉—铁干里克垦区为例

在水资源短缺条件下,垦区农业发展采取了多种经营,发展以棉花、水果和养鹿为主的高效特色农业,同时加强工程建设,进行水资源开源节流,强化管理和对绿洲的保护,这些已成为维持绿洲稳定和促进绿洲农业经济发展的关键措施。     

Exploring effective policies for underground water management in artificial oasis: a system dynamics analysis of a case study of Yaoba Oasis

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我国南疆荒漠喀什-和田地区的畜牧业特点与发展战略

作者在对该地区进行实地考察的基础上,研究了位于新疆南部荒漠最西部两个地区的自然环境和经济条件后,指出该地区畜牧业的 4个基本特点,概括了该地区畜牧业与生态环境以及牧业生产条件之间的关系。地处内陆,极端干旱,周围高山环绕,绿洲经济与绿洲农业发达,对该地区畜牧业的现状与发展有深刻影响。从而作者提出了该地区发展畜牧业的方向与战略。指出今后应以发展集约化的平原绿洲畜牧业为主体。改革饲养方式,加强饲料生产,提高畜群生产水平,近期商品性生产的发展要与自给性生产的发展相结合。使我国这一特殊类型地区的畜牧业得以顺利发展。     

Study on the oasis corridor landcape in the arid regions based on RS and GIS methods—application of Jinta Oasis,China

The study on the oasis corridor landscape is a new hotspot in the ecological environment research in the arid regions.In oasis,main corridor landscape types include river,ditch ,shelterbelt and road.This paper introduces the basic ecological effects of the corridor landscape on the transporting mass and energy and obstructing desert landscape expansion and incursion.Using Geographic Information System(GIS),we have researched the corridor distribution and its spatial relationship with other landscape types in the Jinta Oasis.Based on the dynamically monitoring on the landscape pattern change of the Jinta Oasis during the latter 10 years by using Remote Sensing(RS) and GIS,the driving functions of the corridors on this change have been analyzed in detail.The analysis results showed that all kinds of corridors‘ characteristics can be quantified by the indexes such as length and width ,ratio of perimeter and area,density and non-heterogeneity.The total corridor length of Jinta Oasis is 1838.5km and its density is 2.1km/km^2.The corridor density of the irrigation land.forest and resident area is maximal,which shows that affection degree of the oasis corridors on them is the most.The improvment of the corridors quality is one of the important driving factors on the irrigation land and so on.The organic combination of the RS and GIS technologies and landscape research methods would be an effective means for the corridor landscape research on arid region oasis.     

中国西北地区人工绿洲的开发与可持续发展

中国西北地区的人工绿洲是当地人类赖以生存的物质基础和未来文明建设的主要依托，也是本地区独有的人工生态景观。中国西北属干旱、半干旱地区，于是蒸发量大、降雨量小。光热资源充足为当地的主要气候特征，为人工绿洲的开发与发展准备了前提。通过人为作用于干旱、半干旱地区，把地下水或者河流水引入进行灌溉，增加土壤水份，改善土壤成分，形成了可供人类生存的绿洲。西北地区的人工绿洲经过2000多年的曲折道路，有的已消失，有的正在衰退中，有的取得了良好的生态、社会和经济效益。分析中国西北地区的水土源与引水开垦条件及人工绿洲的发展趋势和现存的生态问题。从而得出，人类对水资源的不合理利用是导致人工绿洲生态失衡的主要原因，总结人工绿洲衰退的原因，提出西北地区人工绿洲可持续发展的模式。     

黑河流域地域系统的下游绿洲带资源-环境安全

额济纳绿洲是我国西北干旱区中心的一道生态防线。20世纪后半叶绿洲生态系统严重受损,景观结构急剧恶化,黑河的供水量逐年下降,由50年代的12.25×108m3下降到90年代的7.24×108m3。地下水位也相应降低,土地盐化也在加剧。各种禾草草甸严重退化,并多已演替成为苦豆子群落。为了维护我国西北的这一生态屏障,论文认为必须坚持以恢复与保护自然绿洲为主,恢复胡杨林、沙枣林、红柳灌丛与梭梭林的覆盖率;建立人工草地,改善土地覆盖,建设自然-人工复合绿洲。在绿洲建设与保育工程中必须保证供水,保持地下水位的临界高度,调控水盐动态,发挥生物-景观多样性的系统耦合效应,实现绿洲生态系统健康与资源-环境安全。     

绿洲浅层地下水位与水质变化对人为驱动LUCC的响应——以三工河流域为例

以新疆三工河流域绿洲为例,应用遥感、地理信息系统、空间插值和统计分析的方法,初步分析干旱区绿洲土地利用/土地覆被变化对绿洲浅层地下水位水质变化的影响。研究数据包括1978、1987和1998年三期遥感数据和近25年8口常年观测井水位数据及1987和1998年两期20口观测井水质数据。结果表明,绿洲随着城市、工矿用地为主的非农业用地和以耕地为主的农业用地的持续增加,浅层地下水水位与水质发生了显著性的时空变化。冲洪积扇绿洲主要城镇聚居区地下水位以年均45cm的速率下降,冲积平原下部绿洲地下水位以年均7cm的速率呈现缓慢的上升趋势;绿洲地下水水质趋于恶化,矿化度总体呈现上升的态势,且冲积平原绿洲地下水矿化度上升的幅度普遍大于冲洪积扇绿洲,这与地形、水文地质条件、土地资源开发、灌排强度、地表蒸发、化学肥料和农药的使用密切相关。     

阿拉善地区生态环境问题及探讨

阿拉善荒漠地处我国西北内陆，亚洲荒漠区最东部，总面积27万平方公里。由于所处的特殊地理位置，阿拉善荒漠植被，历来成为甘肃河西走廊、宁夏平原和内蒙古河套平原三大绿洲的天然保护屏障。然而，阿拉善地区的生态环境日趋恶化，气候干旱、沙尘暴频繁、黑河下泻水量锐减，水资源危机，造成湖泊干涸，地下水位下降，水质恶化，土地盐渍化加重。成为我国沙尘暴主要尘源地区之一。植被严重衰退，生物多样性减少。草地面积缩小，保护功能强大的乔、灌、草植被，每年以2万亩的速度减少消失。绿洲萎缩，濒临消亡，濒危物种亟待抢救。沙漠化面积扩大，吞并草场，埋没农田。每年以1000平方公里速度扩张，沙进人退现象加重，生态难民增多。著名的巴丹吉林，腾格里，乌兰布和三大沙漠向前推进，倾入黄河，阻断公路、铁路、吞食盐场，直接经济损失巨大。阿拉善的生态危机和居延绿洲的严重衰退，直接影响到国防和航天建设。也威胁到了相邻省区以及黄土高原的工农业生产，甚至波及到华北、西北，以及更远的江淮地区。本地区的生态环境问题，已不是区域性的环境问题。是全社会、全民族的问题，已引起国家及各部门的高度重视。     

Emission Patterns under Alternative Congestion and Motor Vehicle Pollution Mitigation Policies in Shanghai

Abstract

Minqin Oasis is located in the lower reaches of the Shiyanghe River Basin, northeast of the Heixi Corridor, at the middle of the Silk Road. Because of the its existence, Badain Jaran Desert and Tengger Desert cannot converge and develop in the south. It has always been an important green barrier to guarantee the eco-security of Hexi Corridor and the Silk Road for thousands of years. But in recent decades, Minqin Oasis is becoming smaller and the desert is becoming larger. Many people, especially the governmental officials in the lower reaches think that the upper and middle reaches have robbed the lower reaches of water resources, and caused insufficient water usage and the deteriorated eco-environment, in the lower reaches, However, the governmental officials in the upper and middle reaches claim that the whole river basin should take the upper and middle reaches as the key regions to develop economy. To address the above argument, we analyze the reasons why Minqin Oasis is disappearing, and find that there are two main factors. One is the quick development of population and economy in the upper and middle reaches; the other is the rapid development of population and economy in the lower reaches. The two factors both have great effect on the water utilization for eco-environment in the lower reaches. So Minqin Oasis is disappearing not only because of the upper and middle reaches but also because of the growth of population and economy itself. The lower reaches should not completely blame the upper and middle reaches. The upper and middle reaches should also pay more attention to the eco-environment in the lower reaches. The whole river basin should develop a harmonious and sustainable relationship among the upper, middle and lower reaches.