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河西走廊干旱荒漠区盐碱化土地修复与调控研究--以石羊河灌区为例 总被引:5,自引:0,他引:5
近年来,由于自然因素和人为因素的共同作用,石羊河灌区盐碱化土地面积逐年增加,盐碱化程度不断加深,严重影响到该区国民经济、社会和生态环境的可持续发展。文章分析了造成石羊河灌区盐碱化的自然因素和人为因素.认为自然因素主要是:①.气候干旱,降水稀少,蒸发量强烈;②.水资源量逐年减少;③.地势上位于我国现代地形的第二阶梯,为内陆河流;④.地下水质矿化度高。人为因素是:①.过度开荒,灌区大量超采地下水;②.植被大量减少,加剧了土地盐碱化;③.灌溉技术落后,有灌无排。同时从四个方面探索建立了科学合理的石羊河灌区盐碱化土地综合调控措施:①.水资源合理配置;②.以水盐平衡理论为指导,调控地上水位和盐分的时空分布;③.加强以节水灌溉为核心的灌区配套建设,推广节水防盐的灌水技术;④.扩大牧草种植,逐步实现农业三元结构。 相似文献
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探讨了节水灌溉尺度问题,指出产生节水灌溉尺度现象的原因是由于灌溉过程中回归水的重复利用.结合漳河灌区的实际,讨论了水稻种植区在不同尺度下的水平衡要素及其在节水尺度效应中的作用;说明随尺度的增大,水平衡过程变得复杂化,节水尺度效应现象也更突出.利用漳河灌区田间试验数据和灌区长系列的历史资料,分别从田间、中等、灌溉干渠和灌区共四个尺度,定量地分析了水稻节水灌溉对水分生产率以及水分利用率的影响.结果表明,节水灌溉技术的采用不仅可以提高田间尺度的灌溉水分生产率,也促进了漳河灌区灌溉水分生产率的整体上升. 相似文献
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我国北方地区干旱缺水 ,农田灌溉用水量占总用水量 80 %以上。农业节水的主要潜力在河水灌区。要按农业用水量控制灌溉水量 ,要在河水灌区积极开发利用浅层地下水和微咸水。在河水灌区打井 ,发展井渠结合灌溉 ,地表水地下水联合运用 ,是优化利用水资源 ,防治灌区土壤盐碱化的根本途径。必须统一管理水资源并改革水价。 相似文献
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土壤盐碱化是我国北方地区危害农业增产的主要自然灾害之一。我国盐碱地約有三亿七千万亩,大約有一亿亩分布在耕地內,其中60%是在灌区。近几年来,由于某些人为因素的影响,灌区次生盐碱化有所发展,特别是在华北平原发展規模較大,速度較快。土壤盐碱化是盐分在土壤层富集的結果。促使盐分在土壤层內的富集有其气候、 相似文献
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节水灌溉在盐碱地治理中的作用初探 总被引:1,自引:0,他引:1
土壤和水资源是人类赖以生存和发展的基础,而土壤的盐碱化是人类面临的世界性的生态环境恶化问题。世界各国政府一直非常重视土壤盐碱化带来的危害,并对此开展了一系列研究。通过分析盐碱地的成因和现状以及节水灌溉与盐碱地治理之间的关系,举例论证了通过发展节水灌溉技术可以有效治理土地的盐碱化,并提出了在发展节水灌溉来治理盐碱地的过程中应当注意的问题。 相似文献
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农田土壤盐碱化是农业可持续发展的主要威胁之一,为创建适应现代生态农业发展的农田水盐调控方法,在总结农田盐分来源及其累积动力特征的基础上,从土壤盐分影响土壤供养能力和作物生产能力两大方面,分析土壤盐分对土壤-作物系统功能的影响途径,明确农田水盐高效调控方向。根据不同时代的治盐理念,将水盐调控发展历程分成4个阶段,以抑制盐碱胁迫对土壤和作物的危害为切入点,解析水利措施、化学措施、生物措施和农艺措施的作用特点和调控目标及适用范围。根据现代农业绿色发展与提质增效需求,凝练盐碱胁迫农田控害增效水盐调控理念,提出水盐调控策略,即调控根际水盐传输动力特征,重构农田水盐分布空间格局,提升农业改土促生措施功效;指出农田控害增效水盐调控急需解决的关键技术,总结了创新水盐调控理论有待深入研究的基础科学问题,以期为盐碱胁迫农田绿色、高效和可持续利用提供指导。 相似文献
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分析了在五家子灌区引水工程完成后对镇赉县低平原的环境影响。分析结果表明,该工程可引起研究区内地下水位抬升,减缓当地用水矛盾,改善当前土壤盐渍化严重现象。但是在排水条件不好的周边,如果不加强管理会引起土壤次生盐渍化后果。 相似文献
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渭干河灌区的水土环境及水文地质条件在克孜尔水库建成后发生了一定的变化,本文结合灌区12年来的水盐监测资料,对灌区地下水的埋深变化规律、水质演变趋势、灌区的排水效果及目前存在的问题进行了分析与探讨,并为今后灌区排水措施和保持水土环境的良性发展提出了建议. 相似文献
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Hydro-salinity balance and mobilization in oasis irrigation areas at two different scales 总被引:1,自引:0,他引:1
Decades of intensive irrigation of farmlands in the oasis irrigated areas of Xinjiang, Northwest China has caused secondary
salinization of vast areas of land since the mid-1980s. Based on the systematic analysis of the monitoring data of hydrology,
soil, irrigation and salinity at two different scales in the case of Weigan River Plain Oasis in Xinjiang Province, algorithms
derived from hydrosalinity balance principle were developed to estimate the salt mobilization and characteristics; salt and
water mobilization and distribution were closely examined both in catchment scale and in field scale. The critical ratio of
drainage to irrigation of Weigan River Plain Oasis was estimated to be 9.19%. Furthermore, analysis of the relationship between
the two different scaling issues was illustrated. Finally, corresponding countermeasures for secondary soil salinization were
proposed according to the different developmental stages and salinization status of water and soil resources.The findings
of this paper is helpful in controlling the local hydrology, in limiting or diminishing salinization trends, as well as in
providing academic and instructive meaning for the sustainable development of agriculture in oasis irrigation areas. 相似文献
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塔里木河流域土地盐渍化改良与竖井排灌工程 总被引:10,自引:0,他引:10
塔里木流域是我国第一大内陆河流域,由于人类活动和自然因素,流域生态地质环境恶化,土壤盐渍化日趋严重。本文在系统分析土壤盐渍化的控制因素的基础上,论述了竖井排灌的作用和综合效应,并提出土壤改良的最优化模式。 相似文献
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Evaluation on Groundwater Resources of Medium Salinity in Tarim Basin and Development and Demonstration of Under-mulch-drip Irrigation Technology for Cotton
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The groundwater of medium salinity refers to the groundwater with a mineralization degree of 2-7 g/L that can be directly or indirectly used for irrigation. This paper determined the distribution area of the groundwater with medium salinity in Tarim Basin, estimated the total amount of recharge resources and exploitable quantity of the groundwater of medium salinity. The irrigation water quality assessment was conducted on the groundwater of medium salinity by using multiple factors and methods. The salt tolerance parameters and irrigation water mineralization control parameters of the cotton in under-mulch-drip irrigation were determined. The under-mulch-drip irritation technology for cotton in groundwater of medium salinity was developed and applied successfully to the demonstration area. The social, economic and ecological effects of this technology as well as the application prospect were analysed. This paper also puts forward two questions that need to be further studied 相似文献
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土壤盐渍化与竖井排灌关系研究 总被引:8,自引:0,他引:8
以新疆地区为例,分析了该区土壤盐溃化的形成过程、类型及土壤盐渍化的原因。气候、土壤类型以及人为因素是土壤盐渍化形成的主要原因。以塔里木河流域实施竖井排灌工程的成功实例,证明竖井排灌效果。通过对竖井排灌作用机理分析及其与土壤盐渍化的关系研究,论证了在新疆地区采取竖井排灌工程的可行性和必要性。提出竖井排灌和明渠排水相结合的灌溉方式,作到合理开发利用水资源,改善生态环境。 相似文献
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Efforts are being made to improve the irrigation efficiency in the Murray-Darling River Basin, Australia, to deal with predicted rainfall decline and to reduce the incidence of secondary soil and water salinization. The latter commonly occurs as a result of locating water reservoirs upon relic drainage channels. To better manage irrigation, information is required about the spatial distribution of soil type and the stratigraphic features capable of redistributing deep-draining water. In previous research, electromagnetic (EM) induction instruments (e.g. EM38 and EM34) have been used to map the distribution of soil type, hydrological processes (e.g. deep drainage) and vadose-zone features. The aim of this research is to demonstrate how a joint inversion of EM38 and EM34 data, using a one-dimensional spatially constrained algorithm for quasi three-dimensional (quasi-3D) electrical conductivity imaging, can be used to infer the areal distribution of soil types and physiographic and hydrogeological units. The quasi-3D modeling of true electrical conductivity provides a framework for future environmental monitoring and management to mitigate the hydrological processes that drive localized secondary salinization in the study area. 相似文献