试论新疆土地退化对生态环境和国民经济发展的影响

新疆土地退化严重,对生态环境的危害日益加深,其中草地退化导致畜牧业长期不能很快发展,林地萎缩严重危及绿洲灌溉农业,耕地衰退造成粮食单产长期不能很快提高.遏制并逆转土地退化是当前发展农业生产的重大课题,其主要措施是:1.以治水改土为中心,搞好流域规划,建立绿洲生态系统的良性循环,2.以植树种草为基础,建立绿洲林网结构,逆转耕地沙化,3.以农田基本建设为前提,综合治理盐碱地,改造低产田.     

国际资讯

联合国呼吁土地退化零增长 《联合国防治荒漠化公约》秘书处近日发布报告，呼吁国际社会为“土地退化总面积零增长”做出努力。世界范围内有l5亿人口直接受到土地退化的威胁，每年有1200万公顷可耕地由于土地退化和干旱而流失。另一方面，全世界对粮食的需求将在2030年增长50％，为满足不断增长的粮食需求则要增加1．2亿公顷的可耕地。     

青海环境的若干问题与整治对策

青海存在的环境问题较多，随着国家中西部地区经济发展战略的实施，将对表少经济持续发展与环境问题有着十分密切的关系。青海环境问题主要是草地退化、水土流失、土地荒漠化、旱灾、雪灾、风灾、土地次盐渍化和沼泽化、环境污染、气候旱化以及冰川退缩。因此，如何治环境，对青海经济发展和资源开发非常重要。     

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。     

凌海市土地资源保护规划研究

在收集和调查凌海市土地利用现状的基础上,分析土地退化的原因,提出凌海市土地资源保护规划的总体目标、主要任务及保护措施等,以期为凌海生态市建设创造有利条件。     

海南州气候变化对生态环境的影响及对策研究

文章针对青海省海南州气象灾害频繁发生、草场退化、土地荒漠化、湖泊水位下降和河流流量减少等生态环境退化现象日益严重的实际，在广泛收集和整理气候、水资源、草地资源等生态环境因子资料的基础上，对海南州的主要气候要素、地表径流、水资源、植被的演替及其相互间的关系等主要生态环境变化特征进行了分析，为海南州经济社会协调发展提供了科学依据。     

浅议江河源区生态环境现状与保护意见

论述了江河源区的生态环境现状,指出了该地区存在的水源逐年减少、水土流失加剧、草场退化严重、土地沙漠化不断扩大、生态趋于失衡等环境问题,初步分析了生态环境恶化对社会和经济发展所带来的直接影响和潜在危害,简要地提出了保护对策。     

四川黄河流域区生态环境现状、问题及对策

本文根据2001年现场考察与研究获得的信息，结合前人研究的资料，论述了四川黄河流域区生态环境恶化、沼泽退化的状况，其主要表现为：湖沼萎缩，沼泽旱化，沼泽逆向生态演替，区域土地沙化，土壤质量下降，野生动物种类、种群数量减少，草场退化和鼠害猖獗。分析了区域生态环境退化与人类活动干扰、自然因素作用的关系，提出四川黄河流域区生态环境保护的对策与措施。     

新疆阿勒泰地区土地“三化”分析

土地沼泽化、盐渍化和沙漠化是干旱区土地退化的主要表现形式之一，职权勒泰地区土地“三化”具有发展快、危害严重等特点。“三代”形成与地质、地貌、气候、水源和植被等自然因素有关，更受盲目开垦、用水不当、破坏植被等人为因素影响，存在由荒草地→耕地→盐渍地→沼泽地演替等6种过程，宜采取规划土地，合理利用；稳定耕地面积，切勿盲目开垦，因地制宜，发展种植业；完善渠系、灌排配套；井灌井排，降低地下水位；改革灌溉方式，节约用水；保护荒漠植被，营造防风林带；加强“三化”动态监测及防治研究等措施，以保障开的土地永续利用与区域可持续发展。     

典型绿洲农业生态与环境演化中主要问题及对策：以玛纳斯绿洲为例

在阐述了典型绿洲农业生态与环境基本特点的基础上，揭示了其演化规律。具体分析了玛纳斯绿洲农业生态与环境的主要问题，土壤次生盐渍化，土地沙化，草场退化，环境污染加重等，针对问题提出了具体的人工调控对策。     

用机会成本法测算乡镇砖厂的环境经济损益

乡镇砖厂是乡镇企业中的一大财政支柱，目前，绝大多数的砖厂都生产粘土砖，因此，建成 了制砖取土毁地的现象十分严重，而制砖过程排放的大气污染物对农村环境质量的影响也很大，使农村生态环境逐步恶，本文根据机会成本法对佳木斯市乡镇砖厂毁地作环境经济的损益分析。     

德州市耕地资源态势演变的驱动力分析

耕地资源数量与质量动态变化是农区经济与社会的可持续发展的决定性因素,特别是随着农业生态环境的不断恶化,各种不定因素导致耕地数量不断减少,保护和利用好耕地资源显得尤为重要。以地处黄河下游的德州市为背景,分析了其耕地资源现状特点、耕地资源开发利用中存在的问题,采用灰色关联分析方法,找出区域耕地资源态势演变的驱动因素,并对耕地资源供需趋势和保证程度做出预测。     

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。     

Land use and management in the People's Republic of China

Widespread disregard for essential principles of sound environmental management and protection during the three decades of Communist rule prior to 1980 have exacerbated traditional shortages of good arable land and productive forest cover in the People's Republic of China. The government's policies have also drastically reduced valuable freshwater surfaces, caused extensive grassland deterioration and soil erosion, and brought about many local and regional climatic changes. However, new policies put into effect recently are attempting to reverse these trends with a sound ecosystemic approach to land management.     

The Impact of Land Use/Land Cover Changes on Land Degradation Dynamics: A Mediterranean Case Study

In the last decades, due to climate changes, soil deterioration, and Land Use/Land Cover Changes (LULCCs), land degradation risk has become one of the most important ecological issues at the global level. Land degradation involves two interlocking systems: the natural ecosystem and the socio-economic system. The complexity of land degradation processes should be addressed using a multidisciplinary approach. Therefore, the aim of this work is to assess diachronically land degradation dynamics under changing land covers. This paper analyzes LULCCs and the parallel increase in the level of land sensitivity to degradation along the coastal belt of Sardinia (Italy), a typical Mediterranean region where human pressure affects the landscape characteristics through fires, intensive agricultural practices, land abandonment, urban sprawl, and tourism concentration. Results reveal that two factors mainly affect the level of land sensitivity to degradation in the study area: (i) land abandonment and (ii) unsustainable use of rural and peri-urban areas. Taken together, these factors represent the primary cause of the LULCCs observed in coastal Sardinia. By linking the structural features of the Mediterranean landscape with its functional land degradation dynamics over time, these results contribute to orienting policies for sustainable land management in Mediterranean coastal areas.     

山东省城镇空间格局

城镇是人类活动影响地表的最主要形式,是土地利用/土地覆盖变化的主要方面.山东省是中国东部沿海大省,土地利用处于不断地调整过程中.在全省城镇空间分布格局现状的基础上,结合中心地理论,运用数据包络分析(DEA)方法进行了具体分析,对全国土地利用/土地覆盖的深入研究具有重大意义.     

Land Evaluation for Maize Based on Fuzzy Set and Interpolation

The objective of this article is to apply fuzzy set and interpolation techniques for land suitability evaluation for maize in Northern Ghana. Land suitability indices were computed at point observations using the Semantic Import (SI) model, whereas spatial interpolation was carried out by block kriging. Interpolated land suitability shows a high correlation (R2 = 0.87) with observed maize yield at the village level. This indicates that land suitability is closely related to maize yield in the study area. Membership functions were further used to assess the degree of limitation of land characteristics to maize. Sixty percent of the data has membership functions ranging from 0.23 for ECEC to 1.00 for drainage. ECEC, organic C, and clay are the major constraints to maize yield. The use of the fuzzy technique is helpful for land suitability evaluation, especially in applications in which subtle differences in soil quality are of a major interest. Furthermore, the use of kriging that exploits spatial variability of data is useful in producing continuous land suitability maps and in estimating uncertainties associated with predicted land suitability indices.     

Soil erosion and non-point source pollution impacts assessment with the aid of multi-temporal remote sensing images

Soil erosion associated with non-point source pollution is viewed as a process of land degradation in many terrestrial environments. Careful monitoring and assessment of land use variations with different temporal and spatial scales would reveal a fluctuating interface, punctuated by changes in rainfall and runoff, movement of people, perturbation from environmental disasters, and shifts in agricultural activities and cropping patterns. The use of multi-temporal remote sensing images in support of environmental modeling analysis in a geographic information system (GIS) environment leading to identification of a variety of long-term interactions between land, resources, and the built environment has been a highly promising approach in recent years. This paper started with a series of supervised land use classifications, using SPOT satellite imagery as a means, in the Kao-Ping River Basin, South Taiwan. Then, it was designed to differentiate the variations of eight land use patterns in the past decade, including orchard, farmland, sugarcane field, forest, grassland, barren, community, and water body. Final accuracy was confirmed based on interpretation of available aerial photographs and global positioning system (GPS) measurements. Finally, a numerical simulation model (General Watershed Loading Function, GWLF) was used to relate soil erosion to non-point source pollution impacts in the coupled land and river water systems. Research findings indicate that while the decadal increase in orchards poses a significant threat to water quality, the continual decrease in forested land exhibits a potential impact on water quality management. Non-point source pollution, contributing to part of the downstream water quality deterioration of the Kao-Ping River system in the last decade, has resulted in an irreversible impact on land integrity from a long-term perspective.     

Fuzzy decision analysis for integrated environmental vulnerability assessment of the mid-Atlantic Region

A fuzzy decision analysis method for integrating ecological indicators was developed. This was a combination of a fuzzy ranking method and the analytic hierarchy process (AHP). The method was capable of ranking ecosystems in terms of environmental conditions and suggesting cumulative impacts across a large region. Using data on land cover, population, roads, streams, air pollution, and topography of the Mid-Atlantic region, we were able to point out areas that were in relatively poor condition and/or vulnerable to future deterioration. The method offered an easy and comprehensive way to combine the strengths of fuzzy set theory and the AHP for ecological assessment. Furthermore, the suggested method can serve as a building block for the evaluation of environmental policies.