典型喀斯特地区土壤水分遥感反演——以涟江流域为例

Remote Sensing Inversion of Soil Moisture in Typical Karst Region: A Case Study of Lianjiang River Basin

土壤水分是水文循环中的关键因素,尤其对喀斯特地区的生态环境具有十分重要的意义。基于Landsat 8 OLI_TIRS数据,采用温度植被干旱指数(TVDI)对涟江流域的土壤水分进行估算。结果表明:研究区内旱情分布较广,轻旱占流域总面积30%。土壤含水量与TDVI较好地符合y=-149.47TVDI+97.255的关系,喀斯特流域土壤含水量可通过TVDI进行估算。土壤水分随着坡度增大而增加,阴坡土壤水分含量大于阳坡与无坡向,季节上冬季大于秋季和春季,春季和秋季差异相对较小。不同土地利用土壤水涵养能力表现为:林地>灌木林地>草地>耕地>其他用地。研究结果可为喀斯特流域相关部门制定合理有效的抗旱、防旱措施提供一定的科学依据。

Soil moisture is a key factor in the dynamics of hydrological cycle,and it also plays an important role in the ecological environment in an Karst region.Based on the Landsat 8 OLI_TIRS data,this paper estimates the soil moisture in Lianjiang River Basin by the temperature vegetation dryness index (TVDI).The results show that the distribution of drought in the study area is wide,and the area in light drought accounts for more than 30% of the total area.The calculation between soil moisture and TDVI is y =-149.47× TVDI +97.255.Therefore,the soil moisture in Karst basin can be estimated by TVDI.In term of soil moisture,it increases with the increase of slope,it is higher in the shady slope than the sunny slope and no slope,it is higher in winter than autumn and spring,and its difference between spring and autumn is relatively small.The soil water conservation capacity of different land use types is as follows:forest land > shrub land > grassland > cultivated land > other land.Moreover,the research results can provide a scientific basis for the relevant departments of the Karst region to develop reasonable and effective drought resistance and prevention measures.