Table 1 Number of matchups between isotope and remote sensing data selected for algorithm development

From: A framework for tracing the sources of nitrate in surface water through remote sensing data coupled with machine learning

Continents

Site

Country

Water Type

Sample Size

Data Source

ETM + (282)

MSI(129)

UAV(89)

Asia

Chaohu

China

Lake

11

  

43

Asia

Beijiang

China

River

1

  

44

Asia

Wudalianhu

China

Lake

6

13

 

45

Asia

Huanghe River

China

River

6

  

46

Asia

Taihu

China

Lake

9

  

47

Asia

Bangonghu Basin

China

River

4

  

48

Asia

Qixiangcuo

China

Lake

6

9

 

49

Asia

Chenghai

China

Lake

4

4

 

50

Asia

Yangtse River

China

River

16

  

51

Asia

Qiandao Hu

China

Lake

15

16

 

52

Asia

Xihu

China

Lake

8

  

53

Asia

Changzhaohu

China

Lake

4

9

 

54

Asia

Qianwu Reservoir

China

Reservoir

45

43

48

In situ

Asia

Longjing Reservoir

China

Reservoir

21

20

25

In situ

Asia

Nanshan Reservoir

China

Reservoir

14

7

16

In situ

Asia

Red River

Vietnam

River

 

6

 

GNIR

Europe

Sava River

Croatia

River

1

  

GNIR

North America

Winnipeg River

U.S.

River

3

  

GNIR

North America

Red River

U.S.

River

6

  

GNIR

North America

Dauphin River

U.S.

River

1

  

GNIR

North America

Saskatchewan River

U.S.

River

2

  

GNIR

North America

Sacramento River

U.S.

River

99

  

GNIR

North America

Damuji River

Cuba

River

 

2

 

GNIR