CAJ | 학술논문

地表温度（ Ts ）是土壤湿度和植被生长状态等因素的综合反映，利用植被指数和 Ts 能够监测土壤湿度的时空分布特征。利用农田气候模型CUPID的 Ts 模拟结果，发展了利用温度与叶面积指数（LAI）的新型土壤水分反演方法（advanced temperature vegetation dryness index ，ATVDI）。前人研究表明归一化植被指数（NDVI）容易达到饱和状态，因此利用LAI代替NDVI开展土壤水分反演。利用CUPID模型模拟结果构建LAI‐Ts 散点图，分析 Ts 随LAI与土壤湿度的变化特征，利用对数关系式改进了温度植被干旱指数（TVDI）中相同土壤湿度时 Ts 与植被指数之间的线性关系，建立了ATVDI方法。在实际应用中，首先利用LAI与Ts 的散点图确定对数曲线的上边界与下边界，然后采用查找表的方法将每个像元对应的 Ts 变换为研究区最小叶面积指数对应的 Ts 。以陕西省关中作为研究区，利用 MODIS 的 LAI和 Ts 产品（MOD11A2和MOD15A2）以及野外观测土壤湿度数据对ATVDI模型进行验证，结果表明该方法具有较高的监测精度，R2达到0.62。此外，A T VDI的计算结果具有一定的物理意义，使得不同时期的监测结果具有一致性，因而可更好地满足不同空间尺度土壤湿度的动态监测。
지표온도（ Ts ）시토양습도화식피생장상태등인소적종합반영，이용식피지수화 Ts 능구감측토양습도적시공분포특정。이용농전기후모형CUPID적 Ts 모의결과，발전료이용온도여협면적지수（LAI）적신형토양수분반연방법（advanced temperature vegetation dryness index ，ATVDI）。전인연구표명귀일화식피지수（NDVI）용역체도포화상태，인차이용LAI대체NDVI개전토양수분반연。이용CUPID모형모의결과구건LAI‐Ts 산점도，분석 Ts 수LAI여토양습도적변화특정，이용대수관계식개진료온도식피간한지수（TVDI）중상동토양습도시 Ts 여식피지수지간적선성관계，건립료ATVDI방법。재실제응용중，수선이용LAI여Ts 적산점도학정대수곡선적상변계여하변계，연후채용사조표적방법장매개상원대응적 Ts 변환위연구구최소협면적지수대응적 Ts 。이합서성관중작위연구구，이용 MODIS 적 LAI화 Ts 산품（MOD11A2화MOD15A2）이급야외관측토양습도수거대ATVDI모형진행험증，결과표명해방법구유교고적감측정도，R2체도0.62。차외，A T VDI적계산결과구유일정적물리의의，사득불동시기적감측결과구유일치성，인이가경호지만족불동공간척도토양습도적동태감측。
Land surface temperature (Ts ) is influenced by soil background and vegetation growing conditions ,and the combina‐tion of Ts and vegetation indices (Vis) can indicate the status of surface soil moisture content (SMC) .In this study ,Advanced Temperature Vegetation Dryness Index (ATVDI) used for monitoring SMC was proposed on the basis of the simulation results with agricultural climate model CUPID .Previous studies have concluded that Normalized Difference Vegetation Index (NDVI) easily reaches the saturation point ,andLeaf Area Index (LAI) was then used instead of NDVI to estimate soil moisture content in the paper .With LAI‐Ts scatter diagram established by the simulation results of CUPID model ,how Ts varied with LAI and SMC was found .In the case of the identical soil background ,the logarithmic relations between Ts and LAI were more accurate than the linear relations included in Temperature Vegetation Dryness Index (TVDI) ,based on which ATVDI was then devel‐oped .LAI‐Ts scatter diagram with satellite imagery were necessary for determining the expression of the upper and lower loga‐rithmic curves while ATVDI was used for monitoring SMC .Ts derived from satellite imagery were then transformed to the Ts‐value which has the same SMC and the minimum LAI in study area with look–up table .The measured SMC from the field sites in Weihe Plain ,Shanxi Province ,China ,and the products of LAI and Ts (MOD15A2 and MOD11A2 ,respectively) produced by the image derived from Moderate Resolution Imaging Spectrometer (MODIS) were collected to validate the new method proposed in this study .The validation results shown that ATVDI (R2 =0.62) was accurate enough to monitor SMC ,and it achieved bet‐ter result than TVDI .Moreover ,ATVDI‐derived result were Ts values with some physical meanings ,which made it comparative in different periods .Therefore ,ATVDI is a promising method for monitoring SMC in different time‐spatial scales in agricultural fields .