黄河三角洲滨海盐渍土水盐运移特征与调控技术研究

	黄河三角洲滨海盐渍土水盐运移特征与调控技术研究
	尹春艳1,2
学位类型	硕士
导师	陈小兵 ; 卜凡敏
	2017-05-21
学位授予单位	中国科学院大学
学位授予地点	北京
关键词	黄河三角洲盐碱土淋洗离子迁移蒸发
其他摘要	黄河三角洲地区农业发展中严重缺乏优质的水土资源，规模化开发利用该地区丰富的滨海盐渍土资源是保证农业可持续发展的有效途径，滨海盐渍土开垦过程中的水分高效利用是盐渍土改良的重要内容。本研究以黄河三角洲腹地垦利县为研究区域，通过野外布设监测点，观测县域尺度上土壤和地下水的水盐运移情况，同时布设室内试验，分析不同地下水位对蒸发和土壤表层积盐的影响；分析土壤在不同盐度淋洗水以及不同淋洗方式作用下，盐渍土脱盐规律与可溶离子迁移行为，对改善土壤盐渍化过程中的水盐动态机制进行了初步探究，为今后盐碱地的改良工作提供可靠的科学依据和技术指导。主要研究结果如下：黄河三角洲地区的地下水水位较低，受降雨和潜水蒸发的影响，年内地下水埋深为0.7~2.37 m；农田和荒地的地下水电导率变化范围基本在20.21~29.80 mS/cm和44.79~48.62 mS/cm之间；地下水埋深和电导率二者变化同步。在连续淋洗和间歇淋洗条件下，完全脱盐需淋洗水量分别为550 mm～900 mm和350 mm～700 mm，达到一般农作物（计划湿润层为0~60cm）生长所需淋洗水量分别为472.70 mm和411.60 mm，间歇淋洗比连续淋洗节约用水14.8%。因此为了更高效的利用灌溉淡水资源，选择间歇淋洗的方式进行计划湿润土层脱盐更为适宜。黄河水和微咸水淋洗脱盐水量分别为550 mm～900 mm和460 mm～1125 mm。微咸水达到淋洗终点时，除了土壤总盐量达到植物所需外，并且可溶盐的离子组成也较为合理，并且对植物根系伤害较为显著的Na⁺和Cl^-离子浓度都降到0.03 mol/L和0.05 mol/L以下。因此，微咸水灌溉也可以使土壤达到良好的生境，达到一般农作物（计划湿润层为0~60 cm）生长所需。黄河水和微咸水淋洗脱盐水量分别为472.70 mm和754.20 mm。当地下水埋深为100 cm和140 cm时，蒸发返盐分别需要55 d和116 d达到一般植物生长对土壤盐分的耐盐极限；随着表层盐壳的形成，对蒸发产生了抑制作用，平均蒸发强度分别为11.27 mm/d和7.52 mm/d。不同地下水埋深条件下，Na⁺和Cl^-离子向土柱表层积聚速度最快，且富集的浓度最高。在黄河三角洲地区垦利县主要作物小麦、玉米和棉花的净灌溉需水量为442 mm、133 mm和353 mm，种植面积比例分别为7.59%、9.35%和60.84%。三种主要作物的毛灌溉需水量分别为3384万m³、1033万m³和21664万m³，占用水量的比例分别为12.98%、3.96%和83.06%。 ; Under the background of serious shortage of water and soil resources in the Yellow River Delta, the development and utilization of the rich coastal saline soil resources in the Yellow River Delta was an effective way to ensure sustainable agriculture, The efficient use of water in the process of reclamation of coastal saline soil was an important part of the improvement of salt soil . The Taking Kenli County of the Yellow River Delta as the study area, water and salt transport in soil and groundwater at county scale was researched by field monitoring. At the same time, in order to analyze the relationship between groundwater evaporation and soil surface salt accumulation under different salinities and different leaching methods, a large number of indoor simulation tests were carried out. In this paper, the law of soil desalination and the migration of ions were studied under different salinities and different leaching methods. The dynamic mechanism of water and salt in the process of saturated soil salinization were studied, which can provide reliable scientific basis and technical guidance for the improvement of saline alkali soil in the future. The main results are as follows: The groundwater level in the Yellow River Delta is low and the depth of groundwater depth in many years is 0.07~2.37 m affected by rainfall and phreatic evaporation. The variation range of groundwater conductivity in farmland and wasteland is between 20.21~29.8 mS/cm and 44.79~48.62 mS/cm. The variation of groundwater depth is the same as the conductivity. Under the condition of continuous leaching and interval，the amount of leaching water is 550-900 mm and 350-700 mm，to reach the average crop (planned wetting layer is 0~60cm), the required leaching water was 472.70 mm and 411.60 mm, Intermittent leaching is more water saving than continuous leaching. 14.8%。Therefore, in order to make more efficient use of fresh water resources, we should choose the intermittent leaching method to plan the wet soil. Leaching has played a very positive role in improving the soil environment. The leaching rate of Yellow River water and brackish water was550-900 mm and 450-1125 mm. At the end point of the leaching, the total salt content of soil to plant acceptable and the composition of soluble salt ions was also more reasonable, and the concentration of Na⁺ and Cl^- which more significant plant root damage were respectively reduced to 0.03mol/L and 0.05 mol/L. Therefore, brackish water irrigation can also make the soil meet the requirements of plant growth，in order to reached the average crop (planned wetting layer is 0~60cm),the elution desalting water of Yellow River water and brackish water respectively required 472.70mm and 754.2 mm. The groundwater depth of 100cm and 140cm were 55 days and 116 days, respectively, to reach the limit of general plant growth. With the formation of the surface salt crust, the salt shell has an inhibitory effect on evaporation, and the average evaporation intensity is 11.27 mm/d and 7.52 mm/d. Under different groundwater conditions, Na⁺ and Cl^- ions accumulate fastest to the surface of the soil column, and the concentration is highest. In Kenli County of the Yellow River Delta，the main crops were wheat, corn and cotton, and their net irrigation water requirement is 442 mm, 133 mm and 353 mm respectively. Besides, the proportion of the planting area was 7.59%, 9.35% and 60.84% respectively. The gross irrigation water requirement of the three main crops was 3.384 million m³,1.033million m³ and 21.664 million m³,and the proportion of water consumption was 12.98%, 3.96% and 83.06% respectively.
文献类型	学位论文
条目标识符	http://ir.yic.ac.cn/handle/133337/22006
专题	中国科学院烟台海岸带研究所知识产出_学位论文
作者单位	1.中国科学院烟台海岸带研究所 2.中国科学院大学
第一作者单位	中国科学院烟台海岸带研究所
推荐引用方式 GB/T 7714	尹春艳. 黄河三角洲滨海盐渍土水盐运移特征与调控技术研究[D]. 北京. 中国科学院大学,2017.

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