洪水前后半干旱区盐碱地景观变化分析——以镇赉县为例  

The Landscape Change of Salt and Alkaline Land in Semi-Arid District before and after Flooding: A Case Study in Zhenlai County

作　　者：包春红[1] 许林书[2] 吴运军[3] 张树文[4] 

机构地区：[1]湖南农业大学资源环境学院,长沙410128 [2]东北师范大学城市与环境科学学院,长春130024 [3]湖南省国土资源规划院,长沙410007 [4]中国科学院研究生院,北京100049

出　　处：《资源科学》2007年第4期92-96,共5页Resources Science

基　　金：国家自然科学基金项目(编号:50139020);中国科学院知识创新工程重要方向项目(编号:KZCX2-SW-320-1);湖南农业大学校青年基金项目(编号:06QN21)

摘　　要：本文采用地形图和SAR、TM影像,运用遥感图像处理技术、地理信息系统的空间分析技术,结合景观生态学理论,从盐碱地数量、空间分布和景观格局几个方面分析了1998年洪水前后镇赉县盐碱地景观的动态变化,进而揭示洪水对土壤盐渍化的影响机制。结果表明,洪水前后,镇赉县盐碱地面积增加13 929.5 hm2,盐碱地斑块之间连通性和结合度增加,盐碱地的重心由西部向东部转移1.57km;其中洪泛区和非洪泛区分别为1.53km和3.68km,非洪泛区盐碱地的迁移距离远大于洪泛区,说明洪水对洪泛区盐碱地的迁移起到滞缓作用,同时对非洪泛区起到推进作用。对比洪泛区与非洪泛区单位各类盐碱地单位面积变化率发现:洪泛区各类盐碱地的单位面积变化率普遍高于非洪泛区,其中洪泛区重度盐碱地单位面积变化率是非洪泛区的5倍,中度盐碱地单位面积的变化率是非洪泛区的4.5倍,轻度盐碱地也已经达到了1.1倍,这说明,在半干旱区洪水过境后对盐碱地的扩张起到了促进效应。通过对斑块结合度、斑块平均面积等景观格局指数研究表明,洪泛区盐碱地景观格局明显不同于非洪泛区,且在洪水过后洪泛区的盐碱化程度高于非洪泛区,洪水促进了地势低洼且地下水位较高的半干旱区土壤的盐碱化程度和速度。This paper adopted relief map and TM, SAR image, impaling the image disposal technology of Remote Sensing and the space analysis technology of Geography Information System, and combining landscape ecology theory to analyze the effect of flooding before and after 1998 on soil salinization. The analysis includes several aspects such as quantity, spatial distribution and landscape distribution of salt and alkaline land in Zhenlai County. The results show that the sum-acreage of saline-alkali land in Zhenlai County increased by 13 929.5 hm2 after the flood. The connectivity and integrity of saline-alkali land increased as well. Furthermore, the center of Gravity of saline-alkali offset from west to east 1.57km. The offset of the flooded area is 1.53km, and that of the non-flooded area is 3.68km. The offset distance of the saline-alkali land in the non- flooded area is much bigger than that of the flooded area. Therefore, flooding has the effect to slow up the offset of the saline-alkali land while having the effect to push forward the offset of the saline-alkali land. By contrasting the change ratio of unit area of saline- alkali land between flooding zone and no-flooding zone, it is found that the change ratio of all kind of saline-alkali land in flooding zone is higher than that in no-flooding zone at large. For example, the ratio of heavy grade of saline-alkali land in flooding zone is 5 times of that in no-flooding zone. The ratio of moderate grade saline-alkali land in flooding zone is 4.5 times of that in no-flooding zone. The ratio of gentleness grade saline-alkali land in flooding zone is 1.1 times of that in no-flooding zone. It is concluded that the flooding has the effect to promote the extension of saline-alkali land in half arid district after the flooding. Though studying the integrity and average area of the saline-alkali patch of the landscape distribution, the landscape distribution of the saline-alkali land in the flooded area is obviously different from the non-flooded area. At the same time, the d

关 键 词：洪水 盐渍化 景观格局 盐碱地 半干旱区 遥感和GIS 

分 类 号：S156.4[农业科学—土壤学]