荒漠化对新疆绿洲生态环境的危害

新疆荒漠化土地面积大,分布范围广,发展程度高,危害严重.目前,新疆的荒漠化面积为104.4×104km2,占全区总面积的65.25%.在自然因素和人为因素叠加影响下,新疆的荒漠化越来越严重威胁到绿洲生态环境.近几十年来,新疆过度开垦和人口增长过快已经给原本脆弱的生态环境带来巨大压力,加剧了水资源的耗用和土地荒漠化的进程.因此,防治荒漠化,是实现荒漠地区人口,资源与环境协调发展的根本途径.本文简要论述新疆日趋严重的荒漠化对绿洲生态环境的危害.并提出防治对策和见解.     

新疆和田—若羌地区土地荒漠化评价

基于Landsat TM/ETM和OLI卫星遥感数据,应用植被覆盖率法,对新疆和田—若羌地区的土地荒漠化进行了评价,并分析其影响因素。结果表明:1985-2015年,研究区重度荒漠化、中度荒漠化区域面积呈减小趋势;而轻度荒漠化、非荒漠化区域面积则呈增加趋势。研究区荒漠化的趋势变化与沙地戈壁以及耕地面积的变化密切相关,和田—若羌地区沙地戈壁面积在30年间减小4.19×105hm2,总体下降率为23.3%;而耕地面积则增加了1.03×105hm2,增加率为2.6%。     

四川农业生产的自然条件

1土地资源四川省土地资源的特征表现在：①土地总量丰富，但人均量少。四川省总土地面积48．77万km2，耕地面积45．43万ha，但人均土地0．58ha、耕地0．055ha，林地0．08ha、牧草地0．14ha，分别占全国人均水平的58．0％、55．3%、6．7%和52．5%。②耕地和林地比重低。耕地仅占全省土地总面积的9．27％，林地占13．33％，其中林地中有林地比重低。③地域分布不平衡。全省92％的耕地分布在四川盆地内，有林地和牧草地则集中分布在川西北高原山地。④土地质量低。冬水田及坡耕地比重大，多数属重点改造的中低产田地，且山区面积广大，复种指数…     

蓬安县后备土地资源的可持续利用

蓬安县地处四川盆地中部偏北,嘉陵江中游。全县幅员面积1334．02km2,总人口6698万人,人口密度为502人／km2,人均耕地0．07ha,是四川省的农业大县。随着经济的发展和人口的增加,太地矛盾突出,因此必须加强对后备土地资源的开发利用,改善生态环境,缓解人地矛盾。1后备土地资源现状1.1后备土地资源的构成蓬安县后备土地资源主要有本利用地、河滩地和低产地。据调查表明,该县未利用土地2．3万ha、河滩地0．sl万ha、低产地2．22万ha、后备上地资源总量达5．l万ha,占幅员面积的朋．24％。l·2后备土地资源的特点蓬安县后备土地资源的特…     

土地状况

截至2006年10月31日,全国31个省(自治区、直辖市)土地调查面积中,农用地98.58亿亩(占69.1%)、建设用地4.85亿亩(占3.4%)、未利用地39.17亿亩(占27.5%)。人均农用地7.50亩,人均建设用地0.37亩。农用地中,耕地18.27亿亩、园地1.77亿亩、林地35.4亿亩、牧草地39.29亿亩、其他农用地3.83亿亩。建设用地中,居民点及独立工矿用地3.95亿亩、交通运输用地0.36亿亩、水利设施用地0.54亿亩。     

西宁市后备土地资源评价及其开发对策

1后备土地资源现状西宁市后备土地资源量大、类型多样、分布集中。全市后备土地资源主要分布在大通县、城北区和城西区,总面积约5.5万ha（据1992年土地祥查数据）,占全市总土地面积的16％,其中荒草地2．9万ha,占后备土地资源的521％;探岩砾石地2万ha,占36．2％;田坎62863ha,占11．4％;裸土地976ha,占0．2％;沼泽地28．6ha,占of％;沙地1．3ha,盐碱地0．7ha。2后备土地资源评价参照联合国粮农组织（FAO）土地评价’大纲,我们对西宁市后备土地资源进行了土地生产潜力评价,结果表明：西宁市后备土地资源为3～8级,其中3级地1…     

新疆自然资源及其合理开发

一、自然资源基本特点新疆自然资源的基本特点可概括为四个方面:地广人稀,开发潜力很大。新疆土地面积165万km~2,占全国陆地总面积的1/6,是全国最大的省级行政区。新疆现有人口仅1300多万人,占全国总人口的1.3％;每平方公里人口8人,全国平均为106人。这说明     

贵港市未利用土地资源的开发利用前景

贵港市未利用土地资源的开发利用前景潘顺安（广西教育学院．南宁５３００３３）贵港市位于广西东南部，郁江河谷平原中部，土地面积３５．６万ｈａ，人口１５５．１万人，人均土地面积０．２３ｈａ，人地矛盾十分突出。１未利用土地资源特点未利用土地是指未被人们进行过...     

四川省土地资源评价及其分区

一、四川土地资源的结构和特征四川省地处长江上游,位于东经97°21′～110°12′和北纬26°03′～34°19′之间,属亚热带区域。全省面积为57万 km~2,约占全国面积的5.(?)%,仅次于新疆、西藏、内蒙、青海,居第五位。四川东部大多数地区水热丰沛,年均温16～18.5℃,(?)10℃积温4500～6500℃,无霜期280～320天,年降水量1000mm 以上,土壤自然肥力高。     

新疆土地资源的开发利用及对环境的影响

新疆土地面积占国土面积1/6，幅员辽阔的地域决定了土地资源自然类型和可利用类型的多样性，近几十年来，新疆土地的开发仍是以农业土地开发为主，其包括开荒扩大耕地面积和广度开发和集约化生产提高单位产量的深度开发，随着西部大开发战略逐渐实施，新疆城市规模不断扩大，工业加速发展，用地需求与日俱增，本文在总结以往的土地开发利用对环境产生的利与弊基础上，为未来土地利用提出了一些趋利避害的建议。     

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.     

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。     

Socio-economic dynamics, local development and desertification in western Lesvos, Greece

The basic aim of this article is to briefly explore the links between socio-economic dynamics and desertification in western Lesvos, Greece. The area is characterised by certain socio-economic and development disadvantages, dependence on few productive sectors (mainly on livestock breeding) and by severe problems of land degradation and desertification. The linkages between socio-economic profile, characteristics and development trajectory with the state of environment in the area are identified through a series of in-depth qualitative interviews with local producers (livestock breeders). Research findings reveal the major socio-economic driving forces towards unsustainable productive practices, which contribute to the persistence of the problems of land degradation and desertification.     

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。     

Book reviews

Abstract

The basic aim of this article is to briefly explore the links between socio-economic dynamics and desertification in western Lesvos, Greece. The area is characterised by certain socio-economic and development disadvantages, dependence on few productive sectors (mainly on livestock breeding) and by severe problems of land degradation and desertification. The linkages between socio-economic profile, characteristics and development trajectory with the state of environment in the area are identified through a series of in-depth qualitative interviews with local producers (livestock breeders). Research findings reveal the major socio-economic driving forces towards unsustainable productive practices, which contribute to the persistence of the problems of land degradation and desertification.     

Building resilience to drought in desertification-prone savannas in Sub-Saharan Africa: The water perspective

Securing sustainable livelihood conditions and reducing the risk of outmigration in savanna ecosystems hosted in the tropical semiarid regions is of fundamental importance for the future of humanity in general. Although precipitation in tropical drylands, or savannas, is generally more significant than one might expect, these regions are subject to considerable rainfall variability which causes frequent periods of water deficiency. This paper addresses the twin problems of “drought and desertification” from a water perspective, focusing on the soil moisture (green water) and plant water uptake deficiencies. It makes a clear distinction between long‐term climate change, meteorological drought, and agricultural droughts and dry spells caused by rainfall variability and land degradation. It then formulates recommendations to better cope with and to build resilience to droughts and dry spells. Coping with desertification requires a new conceptual framework based on green‐blue water resources to identify hydrological opportunities in a sea of constraints. This paper proposes an integrated land/water approach to desertification where ecosystem management supports agricultural development to build social‐ecological resilience to droughts and dry spells. This approach is based on the premise that to combat desertification, focus should shift from reducing trends of land degradation in agricultural systems to water resource management in savannas and to landscape‐wide ecosystem management.     

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。     

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。     

Designing a Public Web-Based Information System to Illustrate and Disseminate the Development and Results of the DESIRE Project to Combat Desertification

Until around 1995 it was challenging to make the scientific results of research projects publicly available except through presentations at meetings or conferences, or as papers in academic journals. Then it began to be clear that the Internet could become the main medium to publish and share new information with a much wider audience. The DESIRE Project (desertification mitigation and remediation of land—a global approach for local solutions) has built on expertise gained in previous projects to develop an innovative online ‘Harmonized Information System’ (HIS). This documents the context, delivery and evaluation of all tasks in the DESIRE Project using non-scientific terminology, with much of it also available in the local languages of the study sites. The DESIRE-HIS makes use of new possibilities for communication, including video clips, interactive tools, and links to social media networks such as Twitter. Dissemination of research results using this approach has required careful planning and design. This paper sets out the steps that have culminated in a complete online Information System about local solutions to global land management problems in desertification-affected areas, including many practical guidelines for responsible land management. As many of those who are affected by desertification do not have Internet access, printable dissemination materials are also available on the DESIRE-HIS.     

Unveiling soil degradation and desertification risk in the Mediterranean basin: a data mining analysis of the relationships between biophysical and socioeconomic factors in agro-forest landscapes

Soil degradation and desertification processes in the Mediterranean basin reflect the interplay between environmental and socioeconomic drivers. An approach to evaluate comparatively the multiple relationships between biophysical variables and socioeconomic factors is illustrated in the present study using the data collected from 586 field sites located in five Mediterranean areas (Spain, Greece, Turkey, Tunisia and Morocco). A total of 47 variables were chosen to illustrate land-use, farm characteristics, population pressure, tourism development, rainfall regime, water availability, soil properties and vegetation cover, among others. A data mining approach incorporating non-parametric inference, principal component analysis and hierarchical clustering was developed to identify candidate syndromes of soil degradation and desertification risk. While field sites in the same study area showed a substantial similarity, the multivariate relationship among variables diverged among study areas. Data mining techniques proved to be a practical tool to identify spatial determinants of soil degradation and desertification risk. Our findings identify the contrasting spatial patterns for biophysical and socioeconomic variables, in turn associated with different responses to land degradation.