ISWC OpenIR  > 水保所知识产出(1956---)
干旱区膜下滴灌水盐运移规律的模拟及预测的研究
单鱼洋
Subtype博士
Thesis Advisor王全九
2012-05
Degree Grantor中国科学院研究生院
Place of Conferral北京
Keyword水盐运移 膜下滴灌 Hydrus-3d 模型 Saltmodel 模型
Abstract

淡水资源的日益缺乏和盐分的不断增加严重影响着农业的发展,特别是干旱半干
旱地区。新疆属于典型的干旱半干旱地区,水盐问题也严重影响该地区的农业发展。
为了解决这些问题,许多措施被广泛应用。滴灌被认为是最有效的一种方法,它能够
提高产量、节约用水、抑制盐分和减少深层渗漏。另外,在田间经常发生交汇现象,
并形成交汇区。对于种植间距较小的作物,经常会被种植在交汇区,交汇区内水盐的
分布对作物的产量有着重要的影响,因此了解交汇情况下的水盐运移是十分重要的。
随着滴灌技术的逐年实施,盐分呈现增加的趋势,掌握盐分的累积情况显得十分重要。
为了更好的了解滴灌条件下的水盐运移,通过试验和模型相结合的方式进行分析研
究,得到了以下的结论:
1. 通过对不同滴头流量、灌水量、滴头间距交汇条件下湿润锋运移规律的研究,以
Schwartzman 提出的经验公式为基础,建立了一种新的经验公式,模拟交汇条件下的
湿润锋的距离。公式如下:
W 和W1 分别表示滴头下方和交汇区湿润锋宽度。
2. 证明了HYDRUS3-D 模型能够很好的模拟田间点源交汇条件下的水盐分布。并利
用模型对不同灌水量、滴头流量和不同土壤质地点源交汇条件下,交汇区水盐分布评
价分析。结果发现1. 灌水量和脱盐区范围也符合幂函数的关系。2. 滴头流量和湿润
范围存在幂函数关系,与脱盐范围则符合指数函数关系。3. 不同质地条件下,质地
较细的土壤水平和垂直湿润锋基本相同,质地较粗的土壤垂直湿润锋远远大于水平湿
润锋,脱盐区的范围遵循这一规律。
3. 通过模型确定了“干播湿出”条件下,棉花出苗水的灌水量。通过棉花的出苗率
很好的证明了模型的准确性。说明模型可以作为一种有效的工具设计合理的灌水量。
4. 生育期灌水频率越高土壤的含盐量越少,冬灌频率与土壤中的含盐量成正比。
5. 通过实测值和模拟值的对比,证明了SaltModel 模型能够比较准确的模拟盐分的
累积过程。6. 根据SaltModel 模型模拟的结果,确定了合理的灌溉制度应是:灌水的矿化度1g/L、
生育期灌水量:4500 m3/ha、冬灌水量应为3000m3/ha。地下水位应控制在1.8 米。并
且根据模拟结果发现,该灌溉制度条件下,达到水盐平衡的年限为9 年。
关键词:水盐运移;膜下滴灌;HYDRUS-3D 模型;SaltModel 模型

Other Abstract

Freshwater scarcity and soil salinity increases are frustrating the sustainable development
of agriculture worldwide, particularly in arid and semi-arid regions. Xinjiang in northwest
China is typical of arid and semi-arid region which is serious affected by two factors. To
address the problems, some measures have been applied. Drip irrigation is considered as
one of the best methods which can increase crop yields; reduced water application;
decreased salinity; and deep percolation. Under drip irrigation, confluence occurs between
pairs of emitters and the area of confluence is termed the ‘overlap zone’, as well as plants
(e.g., cotton) are always grown in the overlap zone between neighboring emitters in a field,
hence knowledge of salinity distributions in the zone is very important for achieving high
crop yields. Salinity increases with times under drip irrigation, it is very important to
understand salt accumulation. In order to understanding water and salinity transport with
drip irrigation, we analysis the problem by combination experiments with simulations. The
conclusions as follows:
1. Research on wetting front dimension with different emitter discharge、different irrigation
volume、different emitter spacing, using the model developed by Schwartzman and Zur
(1986) as a starting point and developed a new empirical model for wetting front
dimension with double-point-source drip irrigation. The following relationship:
where W and W1 denote the widths of the wetting fronts below the dripper and in the
overlap zone, respectively.
2. HYDRUS3-D can successfully simulate both temporal and spatial soil water content
distributions, as well as the salinity distributions with double-point-source drip irrigation  under field conditions. Additional simulations with HYDRUS-3D were used to evaluate
the effects of various design parameters on desalinization zone pattern around the overlap
zone. The additional simulation results showed that the area of the desalination zone was:
(1) positively correlated with irrigation volume, following a power function; (2) positively
correlated with discharge rate, following an exponential function; (3) the simulation results
also showed that, for the fine soil type, the horizontal and vertical distances were nearly
uniform, for the coarser soil type, the extent of diatance was far greater vertically than it
was horizontally, as well as desalination also follows.
3. Employed the HYDRUS-3D to determining optimal drip irrigation volumes with the
HYDRUS-3D model for cotton established by dry seeding and planting after
pre-germination under mulch and confirmed by cotton emergency.
4. The lower salt content in high frequency irrigation during the growth period. The
relationship between the frequency winter irrigation and soil salt content has a positive
relation.
5. Compared between observed and simulated, the result showed that the SaltModel can
accuracy predict salt accumulate for the regional.
6. Based on the simulation results, we determined the suitable irrigation schedule including:
irrigation water mineralization 1g/L、irrigation volume 4500m3/ha in growth periods、
winter irrigation 3000m3/ha、water table level is 1.8m. Predict attained the water-salt
balance in 9 year under the irrigation schedule.
Keywords: water and solute transport; drip irrigation with mulch; HYDRUS-3D software;
SaltModel software.

Language中文
Document Type学位论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/8932
Collection水保所知识产出(1956---)
Recommended Citation
GB/T 7714
单鱼洋. 干旱区膜下滴灌水盐运移规律的模拟及预测的研究[D]. 北京. 中国科学院研究生院,2012.
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