浅论我国沙漠化防治立法的若干原则和制度

沙漠化防治实行预防为主,生态保护与防治结合原则,防治与经济开发利用相协调促进原则;综合防治与分类控制相结合;公众参与和整治者受益结合;对不同责任主体实行不同责任承担原则,由人为不当活动造成的沙漠化治理责任,实行行为者负担原则;对自然作用造成的沙漠化治理实行政府负担为主,受益者合理负担原则;确立统一规划制度;沙漠化状况调查评估与监测预警制度,休耕限耕和扶贫结合制度,禁限制度,优先区域与紧急行动区域制度。     

对沙漠化成因机制和治理途径的思考

我国土地沙漠化经过近半个世纪的研究与治理,目前沙漠化土面积仍然在以每年２４６０ｋｍ＾２的速度扩展,而且还有加速扩大的趋势。这就要求我们对以往沙漠化的研究治理进行反思,寻找它的症结所在。现代沙漠化主要是由于人的过度经济活动对资源的破坏造成的。其根本原因是由于人口压力过大。本文通过对沙漠成化因机制和当前沙漠化治理症结的分析,提出了沙漠化治理的新思路。     

格尔木市沙漠现状与发展趋势

通过分析沙漠化土地现状及分布情况，探讨了格尔木地区土地沙漠化的形成因素，发展趋势，并提出了防治措施及建议。     

试论绿洲外缘沙漠化的治理

新疆是干旱、半干旱地区，绿洲面积仅占全区总土地面积的３．５％，新老绿洲均处于荒漠包围之中，绿洲外缘是沙漠化的策源地。绿洲外缘沙漠化的治理，是当前新疆治沙工程的重点区域。根据绿洲外缘的生态地位和沙漠化逆转的可能性，阐明了治理目标和主要途径，并建议自治区人民政府和各级职能部门重视绿洲外缘沙漠化的治理。     

辽宁省沙化土地现状及防治措施

辽宁省沙化土地面积54.96×104hm2,潜在沙化土地面积60.66×104hm2.大部分的沙化土地分布在辽西北地区,辽西北是我国北方土地沙漠化最严重的地区之一.近来监测数据表明,辽宁省土地沙化有恶化的趋势,而且这种沙漠化正逐年向辽宁省的腹地扩展.根据辽宁省的沙化特点以及主要的生态环境问题,初步探讨了其有效的防治对策.     

准噶尔盆地油田开发区土地沙漠化防治研究--以石西、莫北油田为例

通过对准噶尔盆地石西油田、石南油田、莫北油田等开发利用区土地沙漠化现状和特点的分析，对油田开发活动引起的水土流失进行了预测，并对产生的新的土地沙漠化现象和水土流失对油田区道路、管线、油区的影响进行了分析，提出了针对钻井井场、道路、输油气管线等的分区防治措施。     

沙漠化不同发育阶段的风沙特征——以科尔沁沙地南部大青沟典型区为例

沙漠化是在特定自然条件下,即干旱、风大且频、旱风同季风和地表沙物质构成,人为强度利用、破坏生态平衡的产物。沙漠化过程是一个植被破坏的过程。地表植被的减少,风蚀增强,风沙活动加剧。地表出现以风沙活动为主要标志的类似沙漠的景观。从而使生物生产量减少,土地资源丧失。由此可见,风沙活动特征,标志着土地沙漠化发育的进程。研究这一主要标志,将可准确的掌握土地沙漠化发育阶段,采取有效地防治对策。     

青海省土地沙漠化及其防治

一、概述青海省是我国土地沙漠化严重地区之一。全省沙漠面积居全国第三位,主要分布于柴达木盆地、共和盆地和青海湖盆地,即大都分布于干旱、半干旱的荒漠和草原地带。青海沙漠化土地与沙漠分布基本上是一致的,主要分布于柴达木盆地、共和盆地和青海湖盆地的东北部,其次是青南高原西部和祁连山西部。青海土地沙漠化过程,可分为两种类型。一是沙漠化的历史过程,即沙漠化的发生发展都是在历史时期内所进行的。据考证,柴达木盆地西南部祁曼塔格山下的大片沙漠,历史上曾是一片草原景观,经     

加快生态建设步伐扭转江河源头地区生态恶化的趋势

生态环境是人类生存和社会发展的基础。改善生态环境,实施可持续发展战略,是我国各项事业必须坚持的一项基本政策。党的“十五大”报告明确提出“加强种树种草,搞好水土保持,防治沙漠化,改善生态环境”的可持续发展战略。江泽民总书记１９９７年对西北地区的生态环境...     

黄河源区沙漠化现状与防治意见

通过遥感和现地调查资料,记述了黄河源头地区的沙漠化现状,分析了成因和特点,初步揭示了其演化过程,提出了防治意见。     

西气东输工程靖边至宁陕界沙地生态环境保护对策

靖边至宁陕界的西气东输工程段属于毛乌素沙地南缘与陕北黄土高原北缘的过渡地带,项目区生态环境状况不稳定。一旦沙地植被遭到破坏,风吹蚀与沙搬运的荒漠化过程就会迅速发生,从而形成流沙使生态系统退化或破坏。在详细介绍了沙地特征和生态环境特点的基础上,提出了相应的荒漠化防治和治理措施,以将项目区的生态尽可能恢复成原状或将其不良影响降到最低。     

Changes in Soil Properties After Establishment of Artemisia halodendron and Caragana microphylla on Shifting Sand Dunes in Semiarid Horqin Sandy Land, Northern China

In the semiarid Horqin sandy land of northern China, establishment of artificial sand-fixing shrubs on desertified sandy lands is an effective measure to control desertification and improve the regional environment. Caragana microphylla Lam. and Artemisia halodendron Turcz. ex Bess. are two of the dominant native shrub species, which are adapted well to windy and sandy environments, and thus, are widely used in revegetation programs to control desertification in Horqin region. To assess the effects of artificially planting these two shrub species on restoration of desertified sandy land, soil properties and plant colonization were measured 6 years after planting shrubs on shifting sand dunes. Soil samples were taken from two depths (0–5 cm and 5–20 cm) under the shrub canopy, in the mid-row location (alley) between shrub belts, and from nonvegetated shifting sand dune (as a control). Soil fine fractions, soil water holding capacity, soil organic C and total N have significantly increased, and pH and bulk density have declined at the 0–5-cm topsoil in both C. microphylla and A. halodendron. At the 5–20 cm subsurface soil, changes in soil properties are not significant, with exception of bulk density and organic C concentration under the canopy of A. halodendron and total N concentration under the canopy of C. microphylla. Soil amelioration processes are initiated under the shrub canopies, as higher C and N concentrations were found under the canopies compared with alleys. At the same time, the establishment of shrubs facilitates the colonization and development of herbaceous species. A. halodendron proved to have better effects in fixing the sand surface, improving soil properties, and restoring plant species in comparison to C. microphylla.     

川西北高寒草地沙化土壤特征及治理模式探讨——以阿坝州红原县为例

通过对川西北高寒草地不同类型的沙化样地0—10cm,10～20cm和20～30cm土壤有机质、pH和含水量进行分析。结果表明：（1）随着沙化程度加重,土壤有机质含量和土壤含水量明显降低;（2）随着土层深度增加,土壤有机质含量降低;未沙化、轻度沙化样地的土壤含水量随土层深度增加而降低,重度沙化样地则相反;（3）中度和重度沙化样地土壤pH约7．0,未沙化和轻度沙化pH值在6．5左右;沙地土壤有机质与pH值呈显著负相关关系,沙化土壤有机碳与水分损失是一个正反馈。鉴于川西高寒草地特殊环境,探讨了选用适宜的多年生高原药用植物或者其他高价值资源植物作为固沙材料,将治沙与经济发展相结合,建立高寒沙化草地治理模式。     

Combating desertification in Iran over the last 50 years: An overview of changing approaches

Desertification in Iran was recognized between the 1930s and 1960s. This paper traces Iran’s attempts to reclaim desertified areas, evaluates the anti-desertification approaches adopted, and identifies continuing challenges. Iran has areas vulnerable to desertification due to extensive areas of drylands and increasing population pressure on land and water resources. Over-grazing of rangelands is a particular problem. Initially desertification was combated mainly at the local level and involved dune stabilization measures, especially the use of oil mulch, re-vegetation and windbreaks. Insufficient technical planning in the early years has led to changed approaches to plant densities and species diversity in plantations, and increased on-going management of existing plantations. Since the late 1980s forage and crop production has increased in areas where runoff control techniques are practiced. The social and economic aspects of anti-desertification programs have assisted in poverty reduction by providing off-season employment in rural areas. In 2004 a national plan to combat desertification was ratified and this placed an emphasis on community participation. Continuing challenges include managing existing desertified areas as well as taking into account potential future problems associated with rapidly depleting groundwater supplies and a predicted reduction in the plant growth period accompanying climate change.     

艾比湖湖周生境恶化及其恢复对策

艾比湖是新疆第二大咸水湖，湿地内分布着多种植被类型。自20世纪60年代开始，湖水水位急剧下降，造成湖盆大面积裸露，在当地强风作用下成为巨大风沙之源，从而成为困扰新疆地区的严重生态问题。通过有关资料对艾比湖及其毗邻地区环境恶化的现象进行剖析，提出保护、恢复的相关对策。     

新疆玛纳斯河流域的土地利用与退化问题

玛纳斯河流域山地、平原、沙漠、湖泊俱全，土地利用类型有8个一级类型及40个二级类。20世纪50年代以来，在山前水、土、光热组合优良地区开展大规模水土开发建设，使区内的土地资源得以充分利用，土地开发利用率达40％以上。然而，不合理的土地利用已经导致土地退化，其主要类型有土地荒漠化、耕地土壤贫瘠化、土壤次生盐渍化、土地沙漠化、水土流失、土地污染等6种。据区域土地利用特点与退化类型及原因，提出了合理利用土地与防止土地退化的5条措施，以确保玛河流域土地永续利用与持续发展。     

Effects of sandy desertified land rehabilitation on soil carbon sequestration and aggregation in an arid region in China

The rehabilitation of sandy desertified land in semi-arid and arid regions has a great potential to increase carbon sequestration and improve soil quality. Our objective was to investigate the changes in the soil carbon pool and soil properties of surface soil (0–15 cm) under different types of rehabilitation management. Our study was done in the short-term (7 years) and long-term (32 years) desertification control sites in a marginal oasis of northwest China. The different management treatments were: (1) untreated shifting sand land as control; (2) sand-fixing shrubs with straw checkerboards; (3) poplar (Populus gansuensis) shelter forest; and (4) irrigated cropland after leveling sand dune. The results showed that the rehabilitation of severe sandy desertified land resulted in significant increases in soil organic C (SOC), inorganic C, and total N concentrations, as well as enhanced soil aggregation. Over a 7-year period of revegetation and cultivation, SOC concentration in the recovered shrub land, forest land and irrigated cropland increased by 4.1, 14.6 and 11.9 times compared to the control site (shifting sand land), and increased by 11.2, 17.0 and 23.0 times over the 32-year recovery period. Total N, labile C (KMnO₄–oxidation C), C management index (CMI) and inorganic C (CaCO₃–C) showed a similar increasing trend as SOC. The increased soil C and N was positively related to the accumulation of fine particle fractions. The accumulation of silt and clay, soil C and CaCO₃ enhanced the formation of aggregates, which was beneficial to mitigate wind erosion. The percentage of >0.25 mm dry aggregates increased from 18.0% in the control site to 20.0–87.2% in the recovery sites, and the mean weight diameter (MWD) of water-stable aggregates significantly increased, with a range of 0.09–0.30 mm at the recovery sites. Long-term irrigation and fertilization led to a greater soil C and N accumulation in cropland than in shrub and forest lands. The amount of soil C sequestration reached up to 1.8–9.4 and 7.5–17.3 Mg ha^?1 at the 0–15 cm layer over a 7- and 32-year rehabilitation period compared to the control site, suggesting that desertification control has a great potential for sequestering soil C and improving soil quality in northwest China.     

Population crisis and desertification in the Sudano-Sahelian region

People living in the area just south of the Sahara Desert in Africa face their 3rd major drought since 1900. This drought brings about famine. Drought and famine are only manifestations of more profound problems: soil erosion and degradation. They diminish land productivity which aggravates the population's poverty. Yet soil erosion and degradation occur due to an expanding population. Continued pressures on the land and soil degradation results in desertification. The UN Environment Programme's Assessment of the Status and Trend of Desertification shows that between 1978-84 desertification spread. Expanding deserts now endanger 35% of the world's land and 20% of the population. In the thorn bush savanna zone, most people are subsistence farmers or herdsmen and rely on the soils, forests, and rangelands. Even though the mean population density in the Sahel is low, it is overpopulated since people concentrate in areas where water is available. These areas tend to be cities where near or total deforestation has already occurred. Between 1959-84, the population in the Sahel doubled so farmers have extended cultivation into marginal areas which are vulnerable to desertification. The livestock populations have also grown tremendously resulting in overgrazing and deforestation. People must cook their food which involves cutting down trees for fuelwood. Mismanagement of the land is the key cause for desertification, but the growing poor populations have no choice but to eke out an existence on increasingly marginal lands. Long fallow periods would allow the land to regain its fertility, but with the ever-increasing population this is almost impossible. Humans caused desertification. We can improve land use and farming methods to stop it.     

Evaluation of alternative landfill cover soils for attenuating hydrogen sulfide from construction and demolition (C&D) debris landfills

Hydrogen sulfide (H(2)S) generated from C&D debris landfills has emerged as a major environmental concern due to odor problems and possible health impacts to landfill employees and surrounding residents. Research was performed to evaluate the performance of various cover materials as control measures for H(2)S emissions from C&D debris landfills. Twelve laboratory-scale simulated landfill columns containing gypsum drywall were operated under anaerobic conditions to promote H(2)S production. Five different cover materials were placed on top of the waste inside duplicate columns: (1) sandy soil, (2) sandy soil amended with lime, (3) clayey soil, (4) fine concrete (particle size less than 2.5 cm), and (5) coarse concrete (particle size greater than 2.5 cm). No cover was placed on two of the columns, which were used as controls. H(2)S concentrations measured from the middle of the waste layer ranged from 50,000 to 150,000 ppm. The different cover materials demonstrated varying H(2)S removal efficiencies. The sandy soil amended with lime and the fine concrete were the most effective for the control of H(2)S emissions. Both materials exhibited reduction efficiencies greater than 99%. The clayey and sandy soils exhibited lower reduction efficiencies, with average removal efficiencies of 65% and 30%, respectively. The coarse concrete was found to be the least efficient material as a result of its large particle size.     

新疆土地退化的成因分析与防治对策--着重于土地的荒漠化

新疆地处亚欧大陆腹地,远离海洋,四周环山,幅员辽阔,土地面积居全国各省（区）之首,约占全国土地面积的1／6,但是人类赖以生存的绿洲面积仅占总面积的2．39％,人均耕地面积0．19hm^2,虽然高于全国人均水平,但耕地质量差,复种指数低,产出率低,同时还受到荒漠化的影响。文章通过对新疆荒漠化土地的分布与现状,以及其对农、牧、林、交通运输线路、居民建筑等的危害的综述,探讨了新疆土地荒漠化的主要原因,并为进一步更好的利用、保护土地提出了几点建议。