塔里木河下游沿河淡化带及其与植被关系研究

发布时间：2018-06-09 06:12

本文选题：沿河淡化带 + 生态输水工程　；参考：《聊城大学》2017年硕士论文

【摘要】：干旱内陆河在丰水期,河道水在侧渗补给作用下,向河道两侧延伸,沿途接纳了土壤中的可溶性盐分,盐分随水一起被推向水头所能及之地,从而在河道两侧形成一定宽度的地下水质和盐分适宜,地下水埋深和土壤水分适中,适合多种荒漠植被生长的区域,称为沿河淡化带。塔里木河下游在生态工程的影响下形成了具有响应输水特征的沿河淡化带。本文在多年实地监测资料的基础上,结合植被与土壤数据,以面上分析与典型分析相结合,运用排序分类及时间序列等方法,探讨了塔里木河下游沿河淡化带的形成特征及对输水的响应规律;分析了沿河淡化带水土环境与植被分布特征,阐明了沿河淡化带植被类群及其对水盐因子的多年响应变化。研究结果表明:(1)沿河淡化带形成与响应规律。在博斯腾湖淡水水源的影响下,英苏断面多年资料表明,距河道450m范围内矿化度含量较低,而750m处接纳了随水而来的沿途可溶性盐分,矿化度剧增。由此形成该断面750m宽度的淡化带;同样,喀尔达依断面形成了850 m的淡化带范围。沿河淡化带的形成是循序渐进的过程,且有一定规律。运动水体受可溶性盐分溶解作用,所到达处的地下水矿化度会有升高的波动,随着输水的继续进行,矿化度会有所下降,但在淡化带边界会形成较高的矿化度值而不会下降。典型断面英苏,是在第5次输水后初步形成沿河淡化带范围。(2)沿河淡化带水土特征。生态输水影响下,英苏断面的淡化带内,距河道50m、250m、350m、450m地下水埋深分别为3.39m、5.10m、5.11m、5.17m,输水间歇,地下水埋深分别增至5.21m、5.91m、6.27m、6.13m,距河道50m处的水位变化最大。而淡化带外距河道750m、1050m的地下水埋深,输水期为5.61m、6.26m;输水间歇为6.74m和6.72m,1050m处的地下水位变化甚微。淡化带内地下水质在输水稀释作用下,各离子含量值明显小于淡化带外,其中淡化带外矿化度值是淡化带内平均值的11.4倍,差异较大。受降水少、蒸发强的极端干旱气候影响,土壤中可溶性离子在强烈的“上行”蒸发作用下,近河道处土壤含水量高的生境,土壤盐分含量也相对较高,而淡化带外的高埋深低含水量的环境土壤盐分含量相对要低;受多种植物间的残体及根系分解作用影响,淡化带内土壤养分高于淡化带外。(3)沿河淡化带植被分布。在英苏断面,淡化带内共有植物7种,分属于5科6属。群落垂直结构可分为乔木层、灌木层和草本植物层,水平方向呈镶嵌分布。群丛类型为胡杨—柽柳—骆驼刺群落。淡化带外共有植物2种,同属柽柳科柽柳属,群落垂直和水平结构单一,为柽柳群丛。淡化带内近河道处为高丰富度低均匀度的物种多样性组合特征,远河道处为低丰富度高均匀度的组合特征;淡化带外物种多样性和丰富度低、但均匀度较高,反映出群落的不稳定性。(4)沿河淡化带与植被关系。排序分析将物种类群可分为:高水位适盐植物类群,生存于适水-适盐的生境类型,具有多物种-低盖度与寡物种-高盖度的群落特征;低水位适盐植物类群,生存于低水位中盐分区的生境类型,具有多物种-高盖度的群落特征;低水位耐盐植物类群,生存于低水位高盐分区的生境类型,具有寡物种-低盖度的群落特征。时间序列分析得出,地下水埋深多年变化在淡化带内、外都成逐年减小趋势但趋势不显著(P0.05);淡化带外地下水矿化度以二次曲线模型y=-0.0035x2-0.7866x+23.959(R2=0.8956,P0.01)显著递减;淡化带外植被盖度呈显著的y=5.13x-1.6787(R2=0.5471,P0.05)的线性增长趋势;而淡化带内植被的线性趋势并不明显;低矿化度、高水位的环境下,淡化带内物种分配利用资源基础上,加之人为干扰,其物种多样性表现为显著的线性减小趋势(P0.05);而淡化带外,水盐状况逐年转好未改变高矿化度、高埋深的环境本质,其多样性保持较为稳定的水平,线性递减趋势不显著(P0.05)。
[Abstract]:The river water in the arid land is in the high water period. The river water is extended to both sides of the river under the lateral seepage supply, and the soluble salt in the soil is accepted along the way. The salt is pushed along with the water and is pushed to the head of water. Thus the water quality and salt of a certain width are formed on both sides of the river, and the depth of the groundwater and the soil water are moderate, so it is suitable for a variety of famine. The region of the desert vegetation is called the desalination zone along the river. Under the influence of ecological engineering, the lower reaches of the Tarim River formed a desalination zone with the characteristics of water transport. On the basis of monitoring data in the field for many years, combining with the data of vegetation and soil, this paper combines the analysis of the surface with the typical analysis, and uses the sort classification and time series, and so on. The formation characteristics of the desalination zone along the lower reaches of the Tarim River and its response to the water transport are discussed. The soil and water environment and the distribution characteristics of vegetation in the desalination zone along the river are analyzed. The vegetation groups in the desalination zone along the river and their multi-year response to the water and salt factors are clarified. The results show that (1) the formation and response law of the desalination zone along the river. Under the influence of the freshwater source of the lake, the data of the British Soviet section for many years show that the salinity in the 450m range is lower than that in the river course, while the soluble salt along the path along the route is accepted in 750m, and the mineralization degree increases dramatically. Thus, the desalination zone of the 750m width of the section is formed. Similarly, the desalination zone of 850 m has been formed in kalda's fault surface. It is a gradual process, and there is a certain regularity. The water body is dissolved by soluble salt, the salinity of underground water in the reach will fluctuate. With the continuous flow of water, the mineralization degree will decrease, but the higher mineralization value will not fall at the desalination zone boundary. The typical section, British Soviet, is fifth times. The water and soil characteristics along the river were initially formed. (2) the water and soil characteristics along the river desalination zone. Under the influence of the ecological water transport, the underground water depth of the channel 50m, 250m, 350m, 450m was 3.39M, 5.10M, 5.11m, 5.17m, and the water depth was separated to 5.21m, the depth of groundwater was increased to 5.21m, 5.91m, 6.27m, 6.13m, and the largest variation of water level from the river. The groundwater depth of 750m, 1050m, 5.61m, 6.26m, 6.26m, 6.74m and 6.72m, and little change in the groundwater level at 1050m. The value of each ion content in the desalinated zone is obviously less than the desalination zone, and the value of the desalination is 11.4 times the average of the desalination zone. The difference is great. Under the influence of the extreme drought climate with less precipitation and strong evaporation, the soluble ions in the soil, under the strong "uplink" evaporation, have high soil water content near the river, and the soil salt content is relatively high, while the salinity of the soil with high buried depth and low water content outside the desalination zone is relatively low; The soil nutrient in the desalination zone is higher than the desalination zone. (3) the vegetation distribution along the river desalination zone. On the English Soviet section, there are 7 species of common plants in the desalination zone, belonging to 5 families and 6 genera. The vertical structure of the community can be divided into arbor layer, shrub layer and herb layer, and the horizontal direction is inlaid distribution. The group type is the Chinese Tamarix Tamarix. Camel thorn community. 2 species of common plants were desalinated, and Tamarix was genus Tamarix of Tamarix. The vertical and horizontal structure of the community was single, and it was a cluster of Tamarix. The near channel in the desalinated zone was characterized by high abundance and low evenness. The far channel was the combination of low richness and high evenness; the diversity and richness of the species in the desalination zone were found. Low, but higher evenness, reflecting the instability of the community. (4) the relationship between the desalination zone along the river and the vegetation. The taxa can be divided into the high water level and salt tolerant plant groups, living in the habitats of suitable water and salt, with the characteristics of multi species low coverage and oligo high coverage; low water level salt plant groups, living in low water. The habitat type of the middle salt subregion has the characteristics of multi species and high coverage; low water level and salt tolerant plant groups, living in low water level and high salinity habitat types, with oligotaxis low coverage community characteristics. (P0.05); the two curve model y=-0.0035x2-0.7866x+23.959 (R2=0.8956, P0.01) decreased significantly in the desalination zone, and the coverage of the desalting zone was linearly increased in y=5.13x-1.6787 (R2=0.5471, P0.05), while the linear trend of the vegetation in the desalination zone was not obvious; the low salinity and the high water level were desalinated. On the basis of species distribution and utilization, and human disturbance, the species diversity of species shows a significant linear decreasing trend (P0.05), while the water and salt conditions in the desalination zone do not change high salinity year by year, the nature of high buried depth, the diversity of its diversity remains stable, and the linear decreasing trend is not significant (P0.05).
【学位授予单位】：聊城大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948

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