| Lishan-hengling Mountain is the latest ecological fragile area of soil loss from Xi'an,which is also one of the most severe soil and water loss areas in Xi'an.Soil erosion has caused a large amount of sediment to accumulate in the river bed for many years,so that substantial pollutants and nutrients in soil have posed a serious threat to the downstream ecological environment and Water safety of the Chan-Ba National Ecological Regions and even Xi'an city.Therefore,it is of great significance for regional soil and water conservation,ecological environment protection and governance to study regional soil erosion assessment and the relationship between soil erosion and LUCC(Land Use and Land Cover Change)of human factors-led.The object of study is Lishan-Hengling Mountain in the southeast of Xi'an City in this paper,which used the Chinese Soil Loss Equation(CSLE)that based on the Arc GIS and RS platforms to study the soil erosion modulus and LUCC dynamics of 1992,2002,2010 and2016 respectively,and explored the impact of LUCC dynamic changes quantitatively and soil erosion intensity.The author mainly analyzed two aspects,including the LUCC dynamic change analysis and the response of soil erosion intensity to LUC dynamic changes.The main results are as follows:(1)LUCC dynamic change analysis: The increase of cultivated area in the Lishan-Hengling area from 1992 to 2002 was the most significant,followed by residential land use,grassland area decrease obviously,and forest land decreasing slightly.As the grassland and forest land area reduced in different degree,which resulted in vegetation coverage also decreased.The overall land use change from 2002 to 2016 was reversed from 1992 to 2002,and the large area of arable land was converted to forest,grass,and residential land,and the growth of forest land was the most significant,which bringing the peak of vegetation coverage to58.04% in 2016.(2)Analysis of soil erosion showed that the soil erosion intensity in the study area showed a trend of increasing first and then decreasing from 1992 to 2016.The average erosion modulus increased from 1994.51t/km2.a in 1992 to 2736.17t/km2.a in 2002,thendecreased to 2461.73t/km2.a in 2010,and further decreased to 2187.07t/km2.a by 2016,which indicating that soil erosion control achieved significant effect,but soil erosion grade of local areas(such as relatively dense Heng-ling slope piedmont)are still severe.(3)The study of the relationship between soil erosion and LUCC showed that: arable land is the most important type of land use in the respect of affecting regional soil erosion,with the highest level of soil erosion,mainly including moderate and intensity erosion,and the highest correlation with slightness and extreme intensity,which has the most significant effect on both.Forest land and grassland are the main types of land use for soil erosion control,with micro and slight erosion,but the change of woodland have the most significant effect on slight,moderate and severe erosion while the slightness and intensity are the most sensitive to grassland.The correlation between vegetation coverage and slight erosion and severe erosion was the most significant,with the significant coefficients reaching 0.042 and0.036,respectively.In general,the characteristics of soil erosion change in the study area are as follows:Ssoil erosion increased with the increase of arable area,decrease of forest and grassland area and the decrease of vegetation coverage,and vice versa. |
PDF Full Text Request