关键词: 总悬浮物 ; PIE-Engine Studio ; 遥感反演 ; 云计算 ; 高原湖泊 ; 西藏

Abstract: The concentration of total suspended matter (TSM) is one of the key parameters for water environment assessment and can significantly influence other parameters of the water body in various aspects. The lakes on the Qinghai - Tibet Plateau are currently undergoing significant environmental changes ,and the distribution and dynamic variation of TSM concentration are close- ly related to the environmental conditions of these lakes. Based on the in - situ water quality data from 29 sampling points in typi- cal lakes in Tibet and Landsat 8 Collection 2 remote sensing data ,a comparative analysis was conducted using the PIE- Engine Studio remote sensing cloud computing platform to evaluate various TSM concentration retrieval models that based on single - band and multi - band combinations. The optimal TSM concentration retrieval model was selected and subsequently used to analyze the spatiotemporal variations of TSM in Siling Co ,zhari Namco ,and Taro Co from 2013 to 2023 . The results indicated that:① TSM was most sensitive to the green and red light bands. Athree - band model using band reflectance combinations ( B3 +B4) , ( B2/ B3) (where B2 represented the blue band ,B3 represented the green band ,and B4 represented the red band) as independent var- iables and TSM concentration as the dependent variable ,was the optimal model for remote sensing retrieval of TSM concentration in typical lakes of Tibet. ② The annual variation in TSM concentration generally followed a seasonal pattern ,with higher concen- trations in summer and lower concentrations in spring and autumn. In Siling Co ,the concentration was higher in the northern re- gion ,with high values mainly distributed along the northwest shore in summer and shifting to the northeast shore in autumn and winter ,significantly influenced by wind direction. In zhari Namco ,higher concentrations were observed in the western part ,while in Taro Co ,the southern region showed higher concentrations during summer. All three lakes exhibited a phenomenon that the TSM concentrations rose again in the eastern regions in November. ③ There was a high correlation between annual precipitation and TSM concentration in these lakes. From 2013 to 2023 ,the annual average TSM concentration initially increased year by year but began to gradually decrease or stabilize after 2018 as the annual precipitation decreased. Additionally ,the surface areas of Siling Co ,zhari Namco ,and Taro Co expanded by 2 . 87% ( approximately 68 . 14 km2 ) , 3 . 01% ( approximately 30 . 31 km2 ) , and 1 . 01% (approximately 4 . 87 km2 ) ,respectively . Siling Co continued to expand ,while zhari Namco and Taro Co initially expand- ed rapidly and then contracted. The changes in lake surface area were closely synchronized with the average TSM concentration , influenced by precipitation and runoff. The findings can provide a theoretical basis for assessing water quality in plateau lakes and offer scientific guidance for soil erosion control and water resource protection.

Key words: total suspended matter ; PIE-Engine Studio ; remote sensing inversion ; cloud computing ; plateau lakes ; Tibet