基于Landsat影像准东矿区土壤湿度分布特征研究

Study on soil moisture distribution characteristics in Zhundong mining area based on Landsat images

为研究准东矿区土壤湿度时空分布特征及变化趋势,选取2001—2021年11期的Landsat遥感影像,计算归一化植被指数和地表温度,并以NDVI-LST特征空间为基础构造TVDI模型,反演准东矿区土壤湿度并进行分级,得到准东矿区各级土壤湿度面积,并采用灰色预测GM(1,1)模型对土壤湿度分布进行了预测。结果表明:2001—2021年,准东矿区总体土壤湿度较低,以四级和五级土壤湿度为主,两者面积总和占矿区总面积的85%以上;北部和东部区域土壤湿度较高,中部和西南部区域土壤湿度较低;矿区内一级、二级、三级土壤湿度面积年际变化不大,在0~2000 km^(2)波动;四级、五级土壤湿度面积变化表现出互为相反趋势。灰色预测GM(1,1)结果表明:2023—2039年,在0~1000 km^(2)内,一级土壤湿度面积略有增大,二级土壤湿度面积逐渐减小并趋于0,三级土壤湿度面积逐年下降,四级土壤湿度面积呈现逐年上升趋势,五级土壤湿度面积稳定在3000 km^(2)左右,表明该矿区土壤湿度整体呈减小趋势。

In order to investigate the spatial and temporal distribution characteristics and the variation trends of soil moisture in Zhundong mining area,11 periods of Landsat remote sensing images from 2001 to 2021 were selected to calculate the normalized vegetation index and surface temperature.Based on normalized difference vegetation index(NDVI)-land surface temperature(LST)characteristic space,the temperature vegetation dryness index(TVDI)model was constructed to invert and classify the soil moisture in Zhundong mining area,and the soil moisture area at all grades was obtained.The grey prediction GM(1,1)model was used to predict the soil moisture distribution.The results show that from 2001 to 2021,the total soil moisture in Zhundong mining area is low,mainly the grade 4 and the grade 5 soil moisture,and areas of the two accounts for more than 85%of the total area;the soil moisture was higher in the northern and eastern regions,and lower in the central and southwestern regions;there is a little annual variation of soil moisture for the grade 1,the grade 2 and the grade 3 areas,and fluctuates within the range of 0 km^(2)to 2000 km^(2);the changes of soil moisture for the grade 4 and the grade 5 areas show opposite trend.The results of the GM(1,1)prediction show that from 2023 to 2039,the grade 1 area of soil moisture will increases slightly within the range of 0 km^(2)to 1000 km 2,the grade 2 area of soil moisture will gradually decrease and tends to 0 km 2,the grade 3 area of soil moisture will decrease annually,the grade 4 area of soil moisture shows an increasing trend,and the grade 5 area of soil moisture stays stable at about 3000 km 2.This indicates an overall decreasing trend for soil moisture in this mining area.