Acta Geographica Sinica ›› 2014, Vol. 69 ›› Issue (7): 933-944.doi: 10.11821/dlxb201407006

• Orginal Article • Previous Articles     Next Articles

Landscape pattern and hydrological processes in Yanhe River basin of China

Jing LI(), Zixiang ZHOU   

  1. College of Tourism and Environment, Shaanxi Normal University, Xi'an 710062, China
  • Received:2013-04-15 Revised:2014-06-05 Online:2014-07-20 Published:2014-09-12
  • Supported by:
    National Natural Science Foundation of China, No.41371020;Natural Science Foundation of Shaanxi Province, No.2012JM5011]

Abstract:

As a typical experimental Soil and Water Conservation District, the Yanhe River basin has long been plagued by soil erosion due to severe human disturbances. The 'Grain-For-Green' project has been practiced to increase grain yield to feed the mass population in starvation and curbed the continually deteriorating ecological situation. It is importantly scientific to explore watershed landscape pattern and hydrological processes. Exerting remote sensing and geographic information technology, this paper firstly analyzed simulated ecological hydrological process in the Yanhe River basin based on SWAT model. On this basis, it applied landscape indices method, land use change on eco-hydrological processes was quantitatively described, particularly those soil erosion influences caused by the change of landscape pattern with the complicated topography and soil type status; then we defined the landscape unit including topography, soil and land use/land cover change (LUCC) information, constructed a comprehensive landscape indices which was closely related to soil erosion, and reflected the coupling relationship between regional landscape pattern change and soil erosion. The results are as follows: (1) this paper constituted the spatial heterogeneity of hydrological response units (HRUs) by several factors such as land use type, soil type, topography, etc. At the landscape level, seven landscape indices were selected with principal component factor analysis, which are DCAD, GYRATE_SD, COHESION, SHEI, TCA, PAFRAC, IJI, etc. Coupled analysis on relationships of landscape indices, annual runoff and annual sediment in each sub-basin, the correlation coefficient of seven selected landscape indices and runoff is very small and cannot pass all significant tests. But correlation among the indices except for TCA and IJI and sediment yield is significant; the absolute value of the correlation coefficient is between 0.3 and 0.5. (2) This paper built Slope-HRU landscape index: coupling relationship between Slope-HRU landscape indices and annual sediment in each sub-basin is very comprehensible, and correlation coefficient is -0.6, which is significantly negatively correlated. Based on 'source-sink' landscape theory of soil erosion, Slope-HRU landscape index was fabricated to reflect the relationship between landscape pattern and soil erosion process to a certain extent. According to the space distribution of R value of Slope-HRU landscape index in 41 sub-basins, the results showed that: in the sub-basin scale, Slope-HRU landscape indices and annual sediment have obvious regional differentiation regularity. And R value spatial variation of Slope-HRU landscape indices and the variation of annual sediment amount were on contrary. On the other hand, the R value increased from southeast to northwest, with annual sediment decreasing from southeast to northwest.

Key words: Yanhe River basin, landscape pattern, hydrological processes, hydrological response units (HRUs), landscape index