Table 2.
Classification of degraded land in the Heihe River Basin of arid northwestern China.
| Categories (Geomorphic position-Vegetation-Soil) | Area (km2) | Percentage of degradation land | Percentage of basin area |
|---|---|---|---|
| Water erosion | 5932.6 | 19.16 | 4.3 |
| Sub-alpine-Crops-Mot-Ustic Cambisols | 428.0 | 0.15 | 0.03 |
| Middle mountain-Crops- Mot-Ustic Cambisols | 39.4 | 0.14 | 0.03 |
| Middle mountain-Stipa,Salsola passerine-Hap-Orthic Aridisols | 1292.9 | 4.46 | 1.00 |
| Middle mountain-Crops-Cal-Ustic Isohumisols | 107.1 | 0.37 | 0.08 |
| Middle mountain-Caragana stenophylla,Stipa krylovii-Hap- Ustic Isohumisols | 245.3 | 0.85 | 0.19 |
| Middle mountain-Stipa spp.,Sympegma regelii-Cal- Orthic Aridisols | 213.3 | 0.74 | 0.17 |
| Low mountain- Crops-Cal-Ustic Isohumisols | 130.2 | 0.45 | 0.10 |
| Middle mountain Crops-Hap-Ustic Isohumisols | 345.2 | 1.19 | 0.27 |
| Middle mountain-Agropyron cristatum, Stipa spp.- Cal-Ustic Isohumisols | 1914.4 | 6.61 | 1.48 |
| Middle mountain- Stipa spp., Artemisia frigida, Caragana spp.- Hap-Ustic Isohumisols | 1216.8 | 4.20 | 0.94 |
|
| |||
| Aridization | 1169.4 | 4.03 | 0.90 |
| Bottomland-Phragmites communis, Achnatherum splendens, Glycyrrhiza inflate-Mot- Ustic Cambisols | 829.5 | 2.86 | 0.64 |
| Wet Bottomland-Populus euphratica, Elaeagnus angustifolia, Tamarix spp.-Och-Aquic Cambisols | 339.9 | 1.17 | 0.26 |
|
| |||
| Salinization | 10391.3 | 35.86 | 8.05 |
| Artificial oasis-Crops-Pas-Sil-Orthic Anthrosols | 302.2 | 1.04 | 0.23 |
| Wet Bottomland-Phragmites communis, Achnatherum splendens-Mot-Ustic Cambisols | 911.9 | 3.15 | 0.71 |
| Wet Bottomland-Phragmites communis, Tamarix spp., Sophara alopecuroides, Lycium uthenicum-Pas-Gen-Aquic Cambisols | 2830.6 | 9.77 | 2.19 |
| Artificial forest-Elaeagnus angustifolia, Populus spp.-Pas-Sil-Ustic Cambisols | 67.7 | 0.23 | 0.05 |
| Wet Bottomland- Tamarix spp., Phragmites communis, Elaeagnus angustifolia, Populus euphratica-Pas-Och-Aquic Cambisols | 433.0 | 1.49 | 0.34 |
| Bottomland-Phragmites communis, Tamarix spp., Populus euphratica-Aqu-Orthic Halosols | 1436.3 | 4.96 | 1.11 |
| Bottomland-Kalidium gracile, Lycium ruthenicum, Orthic Halosols alostachys belangeriana, Tamarix spp.-Ari- Orthic Halosols | 362.0 | 1.25 | 0.28 |
| Loam flat-Karelinia caspica, Glycyrrhiza inflate, Tamarix spp., Phragmites communis, Aqu-Orthic Halosols | 2 554.4 | 8.82 | 1.98 |
| Bottomland- Ari- Orthic Halosols | 1493.2 | 5.15 | 1.1 6 |
|
| |||
| Sandification | 10571.8 | 36.49 | 8.19 |
| Stabilised dune-Tamarix spp. Haloxylon ammodendron, Nitraria spp.-Ari-Sandic Entisols | 1084.0 | 3.74 | 0.84 |
| Semi- Stabilised dune-Haloxylon ammodendron, Reaumuria soongorica-Ari-Sandic Entisols | 1264.1 | 4.36 | 0.98 |
| Semi- Stabilised dune-Artemisia spp., Populus euphratica, Tamarix spp.- Ari-Sandic Entisols | 1450.7 | 5.01 | 1.12 |
| Sandy flat-Ari-Sandic Entisols | 350.3 | 1.21 | 0.27 |
| Mobile dune-Ari-Sandic Entisols | 6 422.7 | 22.17 | 4.98 |
|
| |||
| Vegetation degradation | 1290.4 | 4.45 | 1.00 |
| Middle mountain-Stipa spp., Sympegma regelii, Reaumuria soongorica-Hap-Orthic Aridisols | 907.9 | 3.13 | 0.70 |
| Loam flat- Sympegma regelii, Salsola passerine, Artemisia spp.-Hap-Orthic Aridisols-Loam flat | 254.7 | 0.88 | 0.20 |
| Middle mountain river valley-Carerx Montana, Kobresia spp., weeds-Mot-Udic Cambisols | 36.8 | 0.13 | 0.03 |
| Alluvial flood plain-Stipa spp., Salsola passerine, Artemisia spp.-Cal-Orthic Aridisols | 64.5 | 0.22 | 0.05 |
| Wet bottomland-Phragmites communis, Achnatherum splendens, Aneurolepidium dasystachys, Calamagrogstis spp.-Gen-Aquic Cambisols-Wet bottomland | 26.5 | 0.09 | 0.02 |
|
| |||
| Total | 29355.5 | 100.00 | 22.58 |