黄土高原不同侵蚀类型区侵蚀产沙强度变化及其治理目标

Variation of Sediment Yield in Different Soil Erosion Areas and Its Control Standards on the Loess Plateau

为了确定黄土高原不同侵蚀类型区的治理目标,采取"水文—地貌法",利用98个水文站控制区和234个侵蚀产沙单元,在分析其不同治理阶段土壤侵蚀产沙变化特征与减沙幅度,不同侵蚀强度面积的变化及其空间分布的基础上,提出了未来20a黄土高原主要流失区的区域治理目标:土壤流失量控制在3.60×108 t左右,土壤侵蚀模数<1 300 t/(km2.a)左右。其中,黄土峁状丘陵沟壑区为3 000t/(km2.a),黄土梁状丘陵沟壑区为2 000t/(km2.a),干旱黄土丘陵沟壑区为2 000t/(km2.a),黄土平岗丘陵沟壑区为1 000t/(km2.a),风沙黄土丘陵沟壑区为1 000t/(km2.a),黄土山麓丘陵沟壑区为1 000t/(km2.a),森林黄土丘陵沟壑区为300t/(km2.a),黄土高塬沟壑区为1 500t/(km2.a),黄土残塬沟壑区为3 000t/(km2.a),黄土阶地区为500t/(km2.a),风沙草原区为500t/(km2.a),高原土石山区为100t/(km2.a)。未来20a黄土高原的治理重点区域为黄土峁状丘陵沟壑区(2.20×104 km2)、干旱黄土丘陵沟壑区(1.50×104 km2)、黄土高塬沟壑区(8 600km2)、黄土梁状丘陵沟壑区(4 600km2)。

Based on the distribution of hydrological stations,the study area was divided into 98 sections controlled by hydrological stations and then,234 soil erosion units were determined according to the different soil erosion areas.The variation of sediment yield,sediment reduction rate,and the area variation and spatial distribution were analyzed for different degrees of sediment yield in the different soil erosion areas in different control periods.The control standards for the different soil erosion areas on the Loess Plateau in the future 20 years were put forwarded： Soil loss is controlled at 3.6×108 t and soil erosion modulus is less than 1 300 t/（km2·a）.For the different soil erosion areas,soil erosion modulus is 3 000 t/（km2·a） in loess Mao hilly and gully region,2 000 t/（km2·a） in loess Liang hilly and gully region,2 000 t/（km2·a） in arid loess hilly and gully region,1 000 t/（km2·a） in loess gentle slope hilly and gully region,1 000 t/（km2·a） in wind and sand loess hilly and gully region,1 000 t/（km2·a） in loess piedmont hilly and gully region,300 t/（km2·a） in forest loess hilly and gully region,1 500 t/（km2·a） in loess tableland hilly and gully region,3 000 t/（km2·a） in loess residual plateau hilly and gully region,500 t/（km2·a） in loess terraces region,500 t/（km2·a） in wind and sand grassland region,and 100 t/（km2·a） in plateau mountain and rock region.The key control areas in the future 20 years are loess Mao hilly and gully region（2.20×104 km2）,arid loess hilly and gully region（1.50×104 km2）,loess tableland hilly and gully region（8 600 km2）,and loess Liang hilly and gully region（4 600 km2）.