摘要
为探究青铜峡灌区土壤盐渍化风险及其与潜水位埋深和矿化度关系,综合运用GIS和非参数地质统计学的指示克立格法,研究了2018、2019两年4月份春灌前0~20、20~40和40~60 cm深度土壤全盐量,潜水位埋深、潜水矿化度空间变异性,并分析满足一定阈值条件的概率分布图及其相互关系。结果表明:(1)青铜峡灌区土壤全盐量、潜水位埋深、潜水矿化度的变异系数均大于1,都属于强变异;频率分布呈现明显的“高顶”现象。(2)青铜峡灌区不同深度不同阈值土壤全盐量的指示半方差函数符合球状模型、指数模型、高斯模型等不同类型。潜水位埋深的指示半方差函数符合指数模型。潜水矿化度阈值为1.0和2.0 g/L时指示半方差函数符合指数模型,阈值为2.5和3.0 g/L时指示半方差函数符合高斯模型。不同阈值条件下的土壤全盐量和潜水位埋深呈中等~较强的空间自相关,潜水矿化度表现出较强的空间自相关。(3)青铜峡灌区0~20 cm深度土壤发生轻度、中度、重度盐化和盐土化的高概率区占灌区总面积的92.38%、73.71%、51.83%、24.61%;20~40 cm深度比例为92.15%、50.21%、6.87%、0.53%;40~60 cm深度比例为89.16%、43.06%、6.09%、0.46%。潜水位阈值为1.5、2.0、2.5、3.0 m时高概率区占灌区总面积的13.42%、30.25%、41.87%、65.18%。潜水矿化度阈值为1.0、2.0、2.5、3.0 g/L时高概率区面积占灌区总面积的59.13%、55.22%、33.76%和31.96%。随着阈值增加,高概率区面积均明显较少。(4)青铜峡灌区土壤发生中度和重度盐渍化时的潜水临界埋深为2.0 m,潜水临界矿化度分别为2.0 g/L。研究获取的综合指示概率分布图和概率风险评价对青铜峡灌区土壤盐渍化防治具有指导意义,可为土地资源高质量保护和利用提供参考。
This paper uses GIS and indicator Kriging method to analyze the spatial variability of soil total salinity,burial depth of phreatic water level and phreatic salinity before spring irrigation in Qingtongxia Irrigation Area at depths of 0~20,20~40 and 40~60 cm,and satisfy the probability distribution map of certain threshold conditions,and the relationship between them is judged.The result shows:①The coefficients of variation of total soil salinity,burial depth of phreatic water level,and phreatic salinity in Qingtongxia Irrigation Area are all more than 1,which belongs to strong variation;the frequency distribution shows an obvious“high-top”phenomenon.②The indicated semi-variance function of soil total salinity at different depths and thresholds in Qingtongxia Irrigation Area conforms to different types such as spherical model,exponential model and Gaussian model.The indicated semi-variance function of the burial depth of the phreatic water level conforms to the exponential model.When the salinity thresholds are 1.0 and 2.0 g/L,the semi-variance function conforms to the exponential model,and when the thresholds are 2.5 and 3.0 g/L,the semi-variance function conforms to the Gaussian model.The soil total salinity and the burial depth of the phreatic water table under different threshold conditions show moderate-strong spatial autocorrelation,and the phreatic salinity shows a strong spatial autocorrelation.③The areas with high probability of mild,moderate and severe salinization and salinization of soil at the depth of 0~20 cm in Qingtongxia irrigation area account for 92.38%,73.71%,51.83%and 24.61%of the irrigation area.20~40 cm depth ratio is 92.15%,50.21%,6.87%,0.53%;40~60 cm depth ratio is 89.16%,43.06%,6.09%,0.46%.When the depth of phreatic water thresholds are 1.5,2.0,2.5 and 3.0 m,the high probability areas account for 13.42%,30.25%,41.87%and 65.18%of the irrigation area.The high probability area accounts for 59.13%,55.22%,33.76%and 31.96%of the irrigated area when the phreatic salinity thresholds ar
作者
赵志鹏
黄小琴
方磊
ZHAO Zhi-peng;HUANG Xiao-qin;FANG Lei(Institute of Hydrogeology and Environmental Geology of Ningxia Hui Autonomous Region,Yinchuan 750011,Ningxia,China)
出处
《中国农村水利水电》
北大核心
2023年第6期226-235,共10页
China Rural Water and Hydropower
基金
宁夏财政厅项目(6400201901273、NXCZ20220201)
宁夏回族自治区人才小高地建设项目
青年科技托人才举工程项目联合资助。
关键词
青铜峡灌区
土壤盐渍化
潜水位埋深
潜水矿化度
空间分布
指示克里格
Qingtongxia Irrigation Area
soil salinization
groundwater depth
groundwater salinity
spatial distribution
indicator Kriging
