基于遥感与GIS的扎鲁特旗土地盐渍化动态监测

以扎鲁特旗80年代末和2000年TM影像作为基本信息源,经合成、增强、几何纠正、镶嵌,并结合野外考察进行人机交互判读获取土地盐渍化空间数据,建立数据库。结果显示:在研究期内盐渍化土地面积增加不明显,但是程度恶化严重。从1988年到2000年研究区盐渍化土地面积由63919.5hm2增加到67949.4 hm2,净增4029.9hm2;年平均增长率为0.53%,占国土面积的比例由7.8%提高到8.3%;轻度盐渍化土地面积减少,而中度和强烈盐渍化土地以及盐土面积均增加,变化幅度分别为-58.8%,19.7%、117.6%和120.4%;中度以上盐渍化土地占全部盐渍化土地比例由52%提高到81%,强烈以上比例由25%提高到51%。空间上主要分布在乌力吉木仁河西北岸。土地盐渍化与研究区低洼的地形、地表水系特征、地下水以及干旱的气候条件密切相关,人类经济活动起到了促进作用。不断退化的盐渍化土壤结构恶化,有机质含量下降,土地生产力下降明显,严重制约了农牧业生产。为了控制因盐渍化而造成的土地退化,必须控制人口密度,加强土地管理,采取有效措施降低地下水位,恢复原生植被,对土地盐渍化进行综合防治。

Monitoring Salinification of Land in Zhalot Banner Using Remote Sensing and GIS

Taking Landsat TM image data in 1988 and 2000(The resolving power is 30m) of Zhalot Banner as main information source,the statistics of salinification area of lands in 2000 and 1988,and the conversion of salinification areas of land,and the proportions from 1988 to 2000 were gained and the databank were upbuilt by synthesizing,reinforcing,correcting,inlaying,judging of man and computer together and field investigation,then the status quo and changes of salinification of lands were analyzed.The results showed that the land of salinification had not obviously increased in area,but the degree of land deteriorated had been aggravated severely during the period from 1988 to 2000.The area of saline soil increased 4029.9hm2,from 63919.5hm2 to 67949.4 hm2,and the increase rate was 0.53% per year on average.The ratio of area increased from 7.8% to 8.3% between saline land and the total land of region,the light-degree of saline land area decreased by 58.8%,while mediate-degree and violent-degree of saline land area increased by 19.7%,117.6% and 120.4%,the mediate-degree and violent-degree and saline soil of saline land area in this region occupied 52% of whole saline land in 1988,and it has increased to 81% in 2000,the violent-degree and saline soil of saline land area in this region occupied 25% of whole saline land in 1988,and it increased to 51% in 2000.The main lands of salinification was near lowlands,natural lakes and swamps on the left strand of Wuljimuren River.The land salinization was closely related with low-lying topography,river system of the earth's surface,groundwater and arid climatic conditions of the studying area,also human economic activity played facilitation.The conditions that structure of saline soil worsened,the organic content dropped and land productivity decreased obviously restricted the local production of farming and animal husbandry seriously.To control the land of salinization,it is necessary to control the population density,strengthen land management,take the effective measures to reduce the water table,resume natural vegetation,carry on integrated control to the saline soil.