A Study on Topographic Differentiation of Small-Watershed Landscapes in the Loess Hilly Region Based on Ecological Restoration Measures

Abstract

Small watershed is the basic unit of soil and water conservation management in the Loess Hilly Region, and the spatial distribution of different landscapes for land use in small watershed has restricted a variety of ecological processes and ecological benefits of landscapes. This paper combines a geographic information system (GIS) and statistical analysis to reveal the relationship between the spatial distribution of landscape types and topographic factors such as elevation, slope and aspect so as to explore the influences of topographic factors on the spatial distribution pattern of different ecological restoration measures. Gaojianbao Watershed, a typical loess hilly region , is the study area. A land-use map (scale1:50000,2013) of the study area and the topographic map (1:100,000) were used as the base data. The study area is divided into 8 landscape types by the classification of ecological restoration measures. The results showed that: topographic factor is an important factor affecting the watershed ecological restoration, and the spatial distribution of ecological restoration landscapes in Gaojianpu Watershed was significantly associated with topographic factors, featuring obvious vertical distribution. With the rise of elevation, the distribution of landscape types showed the order of ditch protection forest to fruit forest to afforestation (grassland restoration) to barren hills under natural enclosing to level terrace to fish-scale pit to barren hill under afforestation; the spatial distribution of each landscape component was greatly influenced by slope, and the distribution ratio first increased gradually and then decreased; when the aspect shifts from shady to sunny, the distribution ratio of landscapes like afforestation (grassland restoration), level terrace and barren hills under afforestation decreased while the distribution ratio of barren hills under natural enclosing and fruit forests increased, and the landscapes of fish-scale pits and ditch protection forests were basically not affected by aspect.