基于3S的地下水位埋深与土地盐渍化时空动态变化关系研究——以山东省德州市齐河县为例

Relationship of the Spatial-temporal Dynamic Change between Groundwater Level Depth and Land Salinization Based on 3S——A Case Study of Qihe County in Dezhou City,Shandong Province

分析研究盐渍地产生原因、空间分布及发展变化趋势,将为优化配置水资源,改善农田土地利用现状,改良盐渍化土地具有重要意义。选取山东省德州市齐河县作为研究区,利用ERDAS对该区2002年10月、2006年10月、2009年10月和2003年4月Landsat 5卫星TM遥感影像进行处理,提取盐渍地等相关土地利用信息;采用ArcGIS生成2002-2006年、2006-2009年及2002年10月至2003年4月土地类型转移矩阵,分析该区盐渍地的来源、去向、变化速率和产生原因;运用ArcGIS空间分析模块对研究区2000-2009年及2009年播种期前后地下水位埋深数据进行分析,研究该区埋深时空变化规律;利用ArcGIS邻域统计和分类区统计分析方法对该区埋深和盐渍地时空分布进行联合分析,研究该区盐渍地变化趋势和主导因素。结果表明:该研究区盐渍地时空分布年度、季节差异明显,全县地下水位埋深较浅,大部分地区埋深2m左右,极少量地区年均最大埋深达到5m。盐渍地多分布在相对浅埋区或埋深变化波动性较强地区,埋深是该区控制盐渍地变化的主要因素。

The objective of this study was to characterize the causes,spatial distribution and trend of land salinization in Dezhou of Shandong Province,and to provide some suggestions on optimizing and allocating water resources and improving salinized land and land use status of farmland.The rule of the spatial-temporal change in this area was studied by using spatial analysis module of ArcGIS and analyzing groundwater level depth data from 2000 to 2009 and during seedtime around in 2009.Utilizing ERDAS to process TM remote sensing image of October 2002,October 2006,October 2009 and April,2003,information on land use as salinized land was extracted.the source,target,change rate and causes of the salinized land in the targeted area were examined by generating transfer matrix of land use during 2002-2006,2006-2009,and October 2002-April 2003 under ArcGIS.Groundwater level depth and spatial-temporal distribution of salinized land in this area were analyzed to learn the variation tendency and leading factors of salinization by using neighborhood statistics and classification area statistics of ArcGIS.Results show that the annual and seasonal differences are significant in terms of the spatial-temporal distribution of salinized land in the area.The county-wide underground water level is shallow and about 2 m in most of the areas,and up to annual maximum depth of 5 m in few areas.Salinized land shares much distribution in relatively shallow buried areas or areas that suffer stronger fluctuating change in buried depth.Buried depth is the main factor for the salinized land change in the area.