寒地盐碱地时空动态变化分析——以黑龙江省安达市为例

Analysis of temporal and spatial dynamics of saline-alkali land in cold region：Take Anda City of Heilongjiang Province for example

关键词:  盐碱地  动态变化  安达市

Key words:  saline-alkali land  dynamic change  Anda City

摘要:

【目的】 监测近20年安达市土地盐碱化的时空演变特征，为盐碱地的改良提供参考依据。【方法】 以2002年和2020年Landsat影像为数据源，在GIS和RS的技术支持下，通过非监督分类和目视解译相结合，评估安达市土地盐碱化程度并分析其空间分布规律。【结果】 ①土地盐碱化的程度呈减缓趋势，盐碱地总面积减少81.3 km²，盐碱地主要类型由轻度盐碱地转化为中度盐碱地。②盐碱地斑块数减少20块，聚合度减少，分离度增加，景观格局呈现破碎化趋势。③轻度盐碱地主要转移为非盐碱地，中度盐碱地主要转移为轻度盐碱地，重度盐碱地主要转移为中度盐碱地。④盐碱地重心总体向西南迁移8 km，盐渍化程度由东北向西南扩张。【结论】 安达市盐碱地受社会—生态系统的影响，通过禁牧和开垦种稻等措施，土地盐碱化程度减轻。

Abstract:

Purpose To monitor the spatio-temporal evolution of land salinization in Anda in the past 20 years，so as to provide reference for the improvement of saline-alkali land.Method Using 2002 and 2020 Landsat images as data sources，and with the technical support of GIS and Rs，the degree of Salinization in Anda was assessed and its spatial distribution was analyzed by unsupervised classification and visual interpretation.Result ①The degree of land salinization showed a slow trend，the total area of saline-alkali land decreased by 81.3 km²，and the degree of saline-alkali land changed from light saline-alkali land to moderate saline-alkali land. ②The number of patches decreased by 20，the degree of aggregation decreased and the degree of separation increased，and the landscape pattern showed a trend of fragmentation. ③The light saline-alkali land was mainly transferred to the moderate saline-alkali land，the moderate saline-alkali land was mainly transferred to the light saline-alkali land，and the heavy saline-alkali land was mainly transferred to the moderate saline-alkali land. ④The center of gravity of saline-alkali land moved 8 km to the southwest，and the degree of Salinization expanded from northeast to southwest.Conclusion The saline-alkali soil in Anda County was affected by the social-ecological system，and the degree of saline-alkali soil was reduced by measures such as banning grazing and cultivating rice.