KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 近30a干旱区典型灌区盐渍化过程分析——以玛纳斯灌区为例 | |
| 李夏 | |
| Subtype | 硕士 |
| Thesis Advisor | 乔木 |
| 2016 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 环境科学 |
| Keyword | 土壤盐渍化 时空演变 3s技术 驱动力 改良分区 玛纳斯灌区 |
| Abstract | 玛纳斯灌区为新疆典型的绿洲农业区，其干旱的气候条件导致土壤盐渍化现象突出，严重影响了农业社会经济发展和生态环境的稳定。本文选择玛纳斯灌区为研究区（范围为玛纳斯县），利用相关性分析方法和地统计学方法分析了灌区土壤盐分特征，运用“3S”（RS、GIS和GPS）技术以及动态度模型与转移矩阵定量研究土壤盐渍化在时间和空间尺度上的变化，同时分析了灌区土壤盐渍化的驱动因素，在此基础上对研究区进行分区，针对不同的区域特点提出相应的改良治理对策。研究成果为玛纳斯灌区农业的可持续发展以及土壤盐渍化的改良治理提供科学依据和技术参考。主要结论如下： 1. 玛纳斯灌区0~30 cm土层土壤盐分组成：阳离子以Na+、Ca2+为主，阴离子以Cl-、SO42-为主。不同盐分指标的空间变异性变化较大：总盐、Na+、Cl-和SO42-属强变异性，HCO3-、Ca2+、Mg2+和K+属于中等变异性，而pH变异程度最小，属于弱变异性。通过相关性分析发现：SO42-与Na+、Ca2+、K+、Mg+呈极显著正相关（P<0.01），其中与Ca2+的相关性最高，相关系数高达0.914；Cl-与K+、Na+呈极显著正相关（P<0.01），其中与Na+的相关系数达到0.912；HCO3-与其它盐分离子无显著相关性。 2. 玛纳斯灌区土壤盐渍化类型主要以硫酸盐和氯化物—硫酸盐为主，其中冲洪积扇地区以硫酸盐为主，干三角洲地带以及冲积平原以氯化物—硫酸盐为主。Kriging插值结果表明：洪冲积扇地区的含盐量最低，基本上属于非盐渍化土壤；冲积平原上部和东南部以及干三角洲地区以轻度盐渍化为主。通过半方差函数分析可以看出，总盐、Na+、K+、Ca2+和SO42-符合指数模型，Mg2+和HCO3-符合球状模型，Cl-符合高斯模型；除了Na+、Ca2+、Cl-外，盐分和其他离子表现出强烈的空间相关性，盐分离子的相关距离在3~374m之间，这是结构性因素作用的结果。 3. 近30a间，玛纳斯灌区非盐渍化耕地和轻度盐渍化耕地变化剧烈，面积呈不断增加态势；中度盐渍化耕地总体上面积减少，主要向轻度盐渍耕地和非盐渍化耕地转化；盐土面积持续减少，主要转化为轻度盐渍耕地和中度盐渍化耕地。通过转移矩阵还发现，研究期间耕地（非盐渍化耕地、盐渍化耕地）和盐土这两种类型转移量较大，成为主要的转换方式。 4. 玛纳斯灌区土壤盐渍化现象普遍，且表现出了很强的空间变异性，主要分布在冲积平原上部、地势平缓低洼、扇缘溢出带地下水位高以及平原水库周边等地区。研究时间段内前13年间（1985~1998年）灌区内部和绿洲外围的土壤盐渍化类型均发生了较明显的变化；中间时间段内（1998~2006年）灌区内部如西南和东南部土壤盐渍化类型变化较大，外围变化较小；最后8年（2006~2014年）灌区土壤盐渍化类型总体变化不大。 5. 玛纳斯灌区土壤盐渍化发生发展的驱动因素包括自然因素和人为因素。自然因素如气候条件、土壤母质等是内因，促进了土壤盐渍化的发生，而人类进行的大规模的土地开发利用、水库渠系渗漏、滴灌的影响以及不完善的排灌体系，是土壤盐渍化发展演变的外在因素。 6. 依据研究区土壤盐渍化的空间特征、积盐特点、地形地貌、地下水埋深、地下水矿化度，将玛纳斯灌区划分为5个改良区，针对不同的区域特点提出相应的建议和改良治理对策。 |
| Other Abstract | Manasi irrigation area is typical oasis agriculture of Xinjiang. The serious soil salinization phenomenon, which is caused by the drought climate conditions, is having a serious influence on the stability of the agricultural development of social economy and ecological environment. This paper chooses the Manasi irrigation area as the research area, analyses the characteristic of regional soil salt with the method of correlation analysis and statistical analysis, analyses the spatial-temporal change of soil salinization with "3S"(include GPS, GIS and RS) technology and the dynamic model of quantitative and the transfer matrix. Besides, it analyzes the driving factors of soil salinization in the irrigation area, on the basis of the partition in the studied area, and raises some countermeasures which can improve that kind of situation according to the characteristics of the different regions. Research results provide scientific basis and technical reference to the sustainable development and improvement of land utilization of Manasi irrigation area. The main conclusions of this paper include the following: 1. The mainly cation was Na+ and Ca2+, while Cl- and SO42- was main anion in 0~30 cm soil layer in the study area. The spatial variability of different salinity indexes changed greatly. Total salts, Na+, Cl- and SO42- was a strong variability, HCO3-, Ca2+, Mg2+ and K+ in the medium variant, while pH belonged to the weak variation. The correlation analysis showed that SO42- and Na+, Ca2+, Mg+, K+ positive correlation were significant (P<0.01), which had the highest correlation with Ca2+ and the correlation coefficient reached 0.914, and Cl- was significantly positively correlated with K+ and Na+ (P<0.01) and the correlation coefficient of Na+ was 0.912. However, HCO3- and other ions had no significant correlation. 2. The main types of soil salinization were sulfate and chloride- sulfate in Manasi irrigation area, which the alluvial fan area dominated by sulfate, dry delta and alluvial plain with chloride-sulfate. The Kriging interpolation results showed that the salt content in the alluvial fan area was the lowest, which basically belonged to non-salinization soil; the upper part and the southeast part of the alluvial plain as well as the dry delta area were mainly dominated by mild salinization. Semivariance analysis also found that total salt, Na+, K+, Ca2+ and SO42- could be best described by exponential model; Mg2+ and HCO3- conformed to the spherical model; and Cl- accord with Gauss model. In addition to Na+, Ca2+ and Cl-, salt and other ions showed a strong spatial correlation, and the ranges of salt ions varied from 3 m to 374 m, which was the result of structural factors. 3. In nearly 30 years, Manasi irrigation area of non-salinization of arable land and slight salinization of arable land changed dramatically, the area was constantly increasing trend. Moderate salinization of cultivated land total area reduced, mainly to slightly salinized cultivated and non-salinization of cultivated land conversion. Saline soil area continues to decline, mainly transformed slightly salinized cultivated land and moderate salinization of cultivated land. The transfer matrix analysis also showed that the transfer between cultivated land (include non-saline cultivated land and saline cultivated land) and solonchaks were larger and become the main conversion. 4. The phenomenon of soil salinity in Manasi irrigation area was widespread and showed a strong spatial variability, which was mainly distributed in the upper part of alluvial plain, the gently low-lying topography, the high groundwater levels in fan-shaped overflow belt and the surrounding areas distributing in plain reservoir. Grate changes had taken place in the soil salinity of the internal and external researched region from 1985 year to 1998 year. The internal researched region such as the southwest and southeast underwent the biggest changes, but the external change was smaller. The overall change was small from 2006 year to 2014 year. 5. The natural and artificial factors had an influence on the development processes of soil salinity. The natural factors such as climate condition, organic salt and so on were the internal cause, which promoted the occurrence of soil salinity. However, the extensive development and utilization of the land, the leaky reservoir systems, the effect of drip irrigation and the imperfect system of irrigation and drainage project were external. 6. On the basic of the spatial characteristics soil salinization, salt accumulation characteristics, landform, groundwater depth, groundwater salinity, the Manasi irrigation was divided into five improvement areas. Improved governance zones for different soil salinization, proposed the improvement of the corresponding propositions and countermeasures. |
| Subject Area | 环境科学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/14714 |
| Collection | 研究系统_荒漠环境研究室 |
| Affiliation | 中科院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 李夏. 近30a干旱区典型灌区盐渍化过程分析——以玛纳斯灌区为例[D]. 北京. 中国科学院大学,2016. |
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