Table 2 The K-Means value and Delta E of element features in 4 geographical areas

North

Dawuyuan village

Wall

(159, 151, 136)

ΔE ≤ 35.029

Xiaoqiyuan village

Roof

(150, 142, 128)

ΔE ≤ 34.163

Road

(187, 181, 168)

ΔE ≤ 21.227

Fuling village

Earth

(156, 149, 135)

ΔE ≤ 27.346

Pond

(102, 103, 100)

ΔE ≤ 43.084

Dongchong village

Plants

(123, 120, 109)

ΔE ≤ 37.330

East

Longmenhe village

Wall

(163, 159, 147)

ΔE ≤ 24.853

Pailou village

Roof

(150, 146, 131)

ΔE ≤ 43.203

Road

(206, 200, 189)

ΔE ≤ 14.182

Liujiawan village

Earth

(146, 140, 122)

ΔE ≤ 30.896

Pond

(85, 86, 69)

ΔE ≤ 51.634

Wangjiafan village

Plants

(126, 129, 114)

ΔE ≤ 35.454

Center

Shiqiaoyuan village

Wall

(190, 182, 161)

ΔE ≤ 22.134

Roof

(132, 124, 105)

ΔE ≤ 36.587

Lishushan village

Road

(206, 200, 189)

ΔE ≤ 14.182

Earth

(140, 130, 104)

ΔE ≤ 35.507

Dongyuan village

Pond

(81, 76, 51)

ΔE ≤ 56.845

Plants

(134, 126, 101)

ΔE ≤ 38.032

Southwest

Fuxingwan village

Wall

(132, 127, 119)

ΔE ≤ 34.545

Yatoushan village

Roof

(126, 126, 122)

ΔE ≤ 36.588

Xinhua village

Road

(186, 182, 171)

ΔE ≤ 20.252

Xiedian village

Earth

(154, 151, 148)

ΔE ≤ 26.525

Longjing village

Pond

(120, 123, 116);

ΔE ≤ 37.901

Plants

(99, 104, 98)

ΔE ≤ 43.373