共查询到19条相似文献，搜索用时 359 毫秒
1.
农业用水是人类开发利用水资源以及影响生态系统的主要扰动因素,科学定量农业用水是合理配置与调控区域水资源的基础工作。传统的农业用水统计只是记录了可测量的用水量,而水足迹则完整刻画了人类活动对水资源系统的压力表现。从水足迹理论出发,采用Cropwat软件计算了新疆1988—2015年近20种农作物生产水足迹总量,并利用Mann-Kendall趋势和突变检验的方法,分析了28年间新疆农作物水足迹的时空变化,探讨了农作物水足迹驱动因素及机制。结果表明：新疆农作物水足迹在28年间总量增加了256%;水足迹序列在2005年前后增长出现了突变,后一阶段增长率是前一阶段的3倍以上;从农作物水足迹中蓝水足迹与绿水足迹的构成看,农作物绿水足迹呈持续增加趋势,但其在农作物水足迹总量中的比例略有下降。进一步分析表明,农业种植规模的快速扩张是新疆农作物水足迹大幅度增加的根本原因,而脱贫致富、扶贫攻坚等经济发展需求下的政策（战略）支持是农业种植规模（灌溉面积）持续快速增长的核心驱动力。通过探究农作物水足迹的变化及原因,揭示了新疆农业用水的时空变化,以及农作物水足迹与国家、地方政策和社会活动之间的关系,可为深入解析新疆农业增长与水资源开发利用及生态环境之间的时空演化关系和相关决策与政策制定提供参考。 相似文献
2.
作物水生产力评估方法研究 总被引：1，自引：1，他引：0
农业用水作为消耗水资源最多的部分, 在全球和区域水资源消耗中占据很大比例. 农业水生产力的评价对于改进区域农业水资源利用方式, 促进农业经济发展具有重要意义, 尤其是在水资源匮乏地区. 首先阐述了作物水生产力的基本概念, 分析了影响作物水生产力的核心要素; 其次总结了作物水生产力的评价方法, 将其分为收获方法、 模型方法和集成遥感或GIS的模型方法, 并分析了这三类方法优缺点; 最后对作物水生产力研究发展趋势进行了展望, 认为将RS或GIS与模型结合用来估算作物水生产力的方法, 将是目前研究的发展方向. 相似文献
3.
效用问题是农业水资源利用的关键和核心.构建科学合理的指标体系评价农业水资源利用效用对于实现农业水资源持续高效利用有着重要的意义.国内外对水资源利用效用评价的理论和方法研究经历了由单一的用水效率评价向以效率和效益有机结合为特征的效用评价的发展历程,其评价尺度也从最初的作物或田间等微观尺度向灌区、流域、国家乃至全球等中观和宏观尺度发展.未来农业水资源利用效用评价研究发展的重点,将集中在建立基于不同尺度水平衡观点上的农业水资源利用效用评价指标体系以及不同尺度指标的尺度效应及转换等方面. 相似文献
4.
新疆塔里木灌区水盐问题研究 总被引：1，自引：0，他引：1
土壤盐碱化和次生盐渍化是威胁塔里木灌区农业生产的主要因素之一。作者主要以水田向水盐平衡为指导分析了塔里木灌区当前水土资源利用方式下的灌区田间尺度的盐分动态、灌区尺度的盐碱化趋势及影响因素以及农田排水的解决对策,估算了地下水临界深度及灌排比,初步探讨了当前节水农业条件下灌区所可能存在的主要问题。文中最后强调:理论上应加强对灌区作物需水研究及水盐运移与聚集规律,特别是节水条件下的根区土壤盐分平衡问题研究;实践中通过完善灌排管理、提高常规灌溉技术的灌溉效率,逐步进行种植业的结构调整,是塔里木灌区灌溉农业持续发展的基础。 相似文献
5.
水是人类生活的重要资源,特别是农业需要大量水进行灌溉。全国大多数城市都呈现地下水资源不足的情况,三河市沟河沿岸地区尤为严重,农作物使用地下水井灌溉从而加剧了地下水短缺的现象,由此考虑到用地表水灌溉农作物的可行性。从洵河水量方面分析,水量是否可以满足灌溉需求;从水质方面分析几种主要污染物的变化规律及对农作物以及环境的影响,提出可行性的地表水灌溉意见。 相似文献
6.
7.
遥感水文应用中的尺度问题 总被引：11，自引：0，他引：11
遥感技术在水文科学中的广泛应用，极大地拓宽了其研究的领域和范围，增加了其研究的深度。但同时也应该看到，遥感信息的空间分辨率和时间分辨率，以及水文科学自身尺度问题的复杂性，一方面对遥感水文的应用产生困难和问题，限制了水文遥感的应用；另一方面又对水文尺度问题提供了新的技术手段，为遥感水文应用增添了新的亮点。从水文机理与空间尺度、遥感信息的空间分辨率、水文参数的空间延拓，以及遥感技术与水文科学的发展等 4个方面探讨了遥感水文的空间尺度问题；从瞬时遥感信息的时间拓展和遥感信息的时间分辨率 2个方面讨论了遥感水文的时间尺度问题。 相似文献
8.
9.
针对日益突出的环境问题,磁学方法依靠自身便捷、经济等一系列优势在环境污染研究方面得到了广泛的应用.文章总结了环境研究中磁性矿物的特征和鉴别方法及主要的环境磁学参数,回顾了磁学方法在地表沉积物污染、水环境污染和大气环境污染方面的应用进展.并指出增进对磁性物质与污染源关系、污染物磁性形成机理的理解,加强从单纯的磁化率测量到多磁性参数的综合运用以及与矿物学、地球化学等方法的结合来查明污染物质的多源性、记录环境信息在时空尺度上的不确定性和不同环境对污染物承载能力的差异性,是提高磁学方法在环境污染研究领域应用效果的关键,有利于使环境污染监测和评价由定性研究向定量化研究发展. 相似文献
10.
河北、河南等地提高某些农作物产量及品质的应用研究朱立新，任天祥，周国华，王徽，张连生（地质矿产部地球物理地球化学勘查研究所，河北廊坊１０２８４９）关键词农业地球化学，农作物产量，农作物品质我们从１９９０年起，先后在河北、河南等地开展农业地球化学研究，... 相似文献
11.
中国农业用水在未来将面临巨大的挑战。根据国际农业用水研究和政策领域近10年出现的范式变迁的核心内容,建立了基于"绿水"、"蓝水"的中国农业用水的新综合分析框架。并利用广义农业水资源量和广义农业水土资源匹配的概念和评估方法,分析了全国1998～2007年10年间4种主要粮食作物(水稻、小麦、玉米和大豆)的农业用水、耗水以及水分生产力变化趋势和现状。结果表明:中国广义农业水资源量中57%来源于耕地有效降水的"绿水",43%来源于耕地灌溉"蓝水"。主要粮食作物水分生产力水平已经接近或达到世界较高水平。未来继续提升水分生产力的任务将会更加艰巨。因此,为保证中国粮食安全,建议国家设立"粮食安全水资源红线"。同时,根据广义农业水资源量的分析计算,主要粮食作物用水安全红线应该划定在大约7800亿m3左右。 相似文献
12.
R. S. Odingo Dr. 《GeoJournal》1981,5(6):521-530
The link between natural resources and economic development is more and more regarded as a fact today even though the whole process of development is only partially understood. The awareness has now spread to the developing countries of the world where resources have yet to be developed to bring about an improvement in standards of living especially for rural populations, as well as a general improvement in the quality of life for the people. Unfortunately many of the resources of these countries are still to be surveyed and development planning is often based on flimsy, inadequate or even unreliable natural resource data. The improvement of data base for resource planning would go a long way to ensure more knowledge about natural resources in developing countries and better use and management of the available resources. There are economic, technological and environmental difficulties to be overcome before more efficient natural resource utilization in these countries could be achieved. The role of population growth in resource realization is still clouded with an inconclusive debate. But even more important is the need for technological assistance and the application of modern technology to food and agriculture and to other resources to ensure a better life for the populations of developing countries. Developments in agriculture will need the greatest attention since it is a primary resource which provides employment for large proportions of the population, food for the rural and urban populations and exportable surpluses required for the purchase of industrial goods for use in the other sectors of the economy. The activities of transnational corporations distort developments in agriculture and mining in many developing countries and many of these countries are today making greater moves to realize full sovereignty over their natural resources as a first step towards more efficient and meaningful planning for economic growth and development. Energy resources, and in particular the development of new and renewable sources of energy, present one of the greatest challenges to developing countries. Examples of the development of rural energy systems in China and India are promising to open the way to alternative forms of energy for the rural masses of other similarly placed developing countries. Finally, new developments in the natural resources debate concerned with the sharing of the resources of the oceans as seen in the Law of the Sea Conference are a pointer to a more equitable approach to the use of global resources for the continued development of the developed as well as the developing countries of the world.The view expressed in this paper are those of the author alone and do not necessarily represent those of the United Nations University. 相似文献
13.
Dr. A. K. Biswas 《GeoJournal》1979,3(5):445-456
Important as water is to man's manifold activities, a significant percentage of mankind still do not have access to clean water for drinking and personal hygiene. According to a WHO survey of facilities available in developing countries to the end of 1975, 75 % of urban population and 20 % of rural population have access to potable water. Studies carried out by the UN system estimate that investment necessary to provide clean water and sanitation by 1990 to both rural and urban areas is on the order of $ 132,940 million in constant 1977 dollors. Furthermore, provision of clean water alone is unlikely to eliminate all water-borne diseases, since it is only one of several complex factors affecting human health.The situation in developing countries on water requirements for agriculture, industry and generation of hydroelectric power also requires attention because of large amounts of water involved. Effectiveness and efficiency of the supply and distribution systems must be given top priority. There is a considerable potential for improving the efficiency of water use in virtually every developing country and in every sector. 相似文献
14.
我国农田土壤碳库演变研究:全球变化和国家粮食安全 总被引：99，自引：0，他引：99
《京都议定书》已于2005年生效,我国面临着CO2减排的巨大压力。分析了我国农业土壤有机碳库及其演变研究的现状,认为当前我国农业在耕地资源严重短缺、耕地地力趋于下降的背景下面临着2个巨大挑战：提高和稳定粮食生产能力与补偿日益增加的工业CO2排放。有机碳贫乏作为我国耕地土壤的基本特点,这一方面提供了我国较大的固碳空间,另一方面也体现了我国实施固碳农业的必要性和紧迫性。目前迫切需要了解我国农业土壤在最近20年来的碳库演变态势与规模,明确我国农业土壤的固碳潜力与容量,在国家层面上实施农业固碳稳产工程,以在农业可持续发展和争取国家CO2排放的较大配额上实现双嬴。 相似文献
15.
Salah Abdesselam Amor Halitim Anthony Jan Fabienne Trolard Guilhem Bourrié 《Environmental Earth Sciences》2013,70(5):2129-2141
In southern Hodna, an arid region of Algeria, the extension of irrigated agriculture and overexploitation of groundwaters have led to a rupture with traditional land use by pastoralism. Due to the arid conditions, groundwaters are the only water resources for man and irrigation. This study focuses on nitrate contamination of groundwaters and its increase since the last 40 years, on the basis of two archives and recent analyses. The chemical facies of waters is sulphate-chloride, the risk of salinity is moderate to large. The sodicity risk, as estimated by the SAR, is low due to the large salinity and the sandy soil texture. Nitrate contamination of deep groundwater is a clear evidence when recent data are compared to the historical data. From 1996 to 2008, the proportion of samples with NO 3 ? concentrations larger than 50 mg/L increases from 24 to 61 %, the proportion of samples with NO 3 ? concentrations larger than 100 mg/L increases from 12 to 27 %. The study points at a general contamination of aquifers from anthropic origin: phreatic water was already contaminated when pastoralism was dominant (1967); as population increased and irrigation agriculture developed with large use of N-fertilizers and organic amendments, contamination extended spatially and vertically to deep aquifer. To remediate this contamination, fertilizers should be fractionated and limited to plant requirements on the basis of soil and plant analyses. Excess of irrigation should be avoided. Soil surface should be continuously covered to prevent nitrate leaching. Secondly, more efficient irrigation techniques, such as localized irrigation, should be implemented, with adaptation of crop systems and fertilizer inputs to arid conditions. Farmers should then be trained; simultaneously, local agronomic references that are presently lacking should be acquired. 相似文献
16.
干旱区凝结水研究进展 总被引：5，自引：0，他引：5
凝结水是维系干旱、半干旱地区主要食物链的水分来源之一,具有重要的生态意义。较详细地列举了目前国内外在干旱区测定凝结量及其持续时间所采用的研究方法,从凝结水的数量特征以及时间格局两方面阐述了不同地域凝结水的时空差异性,并从气象因素、凝结面的类型及其位置、周边植被对其作用等方面综合分析了影响凝结水发生的主要因素,探讨了干旱区凝结水的生态作用及其意义,展望了干旱区凝结水未来的研究趋势。提出在未来的干旱区凝结水研究中应加强与气象学、生态学等多学科的交叉,从能量平衡角度加强对凝结水量的研究;同时,改进和规范凝结水的测量方法,开展荒漠植被对凝结水的生理响应研究以及凝结水对极端干旱胁迫植物的作用研究。 相似文献
17.
Hydrogeology and sustainable agriculture 总被引：3，自引：0，他引：3
C. R. Aldwell 《Environmental Geology》1997,32(2):93-99
The world's population continues to grow and to require more and more food. Attempts by modern high output agriculture to
meet this need have led to serious environmental problems. A more sustainable balance is now required and is being sought
in a variety of ways. Hydrogeologists should continue to highlight the threat posed by agriculture to groundwater, particularly
since groundwater is a hidden resource and its degradation and rehabilitation often take place slowly. But the time has come
for groundwater specialists to go further and become actively involved in helping to provide practical and sustainable solutions.
The agriculture of the future requires a holistic approach which balances the essential economics of food production with
equally valid environmental needs, including those of groundwater. Such an approach demands cross-sectoral collaboration involving
multidisciplinary research and action within an integrated policy framework. This paper reviews the current groundwater/agriculture
interface and some of the attempts being made to achieve a more truly sustainable agriculture with particular emphasis on
European experience. It aims to stimulate greater interest and involvement by hydrogeologists in helping to bring about realistic
solutions that will enable future generations to enjoy adequate good quality food and water.
Received: 9 August 1996 / Accepted: 11 November 1996 相似文献
18.
近50年来重庆南川市三泉镇喀斯特区农田生态系统的演替分析 总被引：1，自引：1，他引：0
农田生态系统是受人类生产活动影响显著的一种半自然人工生态系统,其演化过程是自然与人类活动共同作用的结果。喀斯特区农田生态系统具有空间分布上的破碎性、受水分限制明显、对外界影响既敏感又脆弱、人口压力巨大等特征。近50年来,南川市三泉镇农田生态系统由单纯的粮食生产系统向多种经营生态系统发展,复种指数不断上升,水田比例不断提高。随着农田生态系统组分的增多,其结构日趋复杂,农田生态环境逐步改善,农田生态系统正向良性方向发展。该区今后应因地制宜发展农业生产,加强农田基本建设,实施农业综合开发,促进农田生态系统稳定持续发展。 相似文献
19.
Application of a Weighted-Averaging Method for Determining Paleosalinity: A Tool for Restoration of South Florida’s Estuaries 总被引：1，自引：0，他引：1
A molluscan analogue dataset is presented in conjunction with a weighted-averaging technique as a tool for estimating past
salinity patterns in south Florida’s estuaries and developing targets for restoration based on these reconstructions. The
method, here referred to as cumulative weighted percent (CWP), was tested using modern surficial samples collected in Florida
Bay from sites located near fixed water monitoring stations that record salinity. The results were calibrated using species
weighting factors derived from examining species occurrence patterns. A comparison of the resulting calibrated species-weighted
CWP (SW-CWP) to the observed salinity at the water monitoring stations averaged over a 3-year time period indicates, on average,
the SW-CWP comes within less than two salinity units of estimating the observed salinity. The SW-CWP reconstructions were
conducted on a core from near the mouth of Taylor Slough to illustrate the application of the method. 相似文献