GIS-based effect assessment of soil erosion before and after gully land consolidation: A case study of Wangjiagou project region, Loess Plateau

Abstract

Abstract:The Loess Plateau is one typical area of serious soil erosion in the world. China has implemented ′Grain for Green′ (GFG) project to restore the eco-environment of the Loess Plateau since 1999. With the GFG project subsidy approaching the end, it is concerned that farmers of fewer subsidies may reclaim land again. Thus, ′Gully Land Consolidation Project′ (GLCP) was initiated in 2010. The core of the GLCP was to create more land suitable for farming in gullies so as to reduce land reclamation on the slopes which are ecological vulnerable areas. This paper aims to assess the effect of the GLCP on soil erosion problems by studying Wangjiagou project region located in the central part of Anzi valley in the middle of the Loess Plateau, mainly using the revised universal soil loss equation (RUSLE) based on GIS. The findings show that the GLCP can help to reduce soil shipment by 9.87% and it creates more terraces and river-nearby land suitable for farming which account for 27.41% of the whole study area. Thus, it is feasible to implement the GLCP in places below gradient 15°, though the GLCP also intensifies soil erosion in certain places such as field ridge, village land, floodplain, natural grassland, and shrub land. In short, the GLCP develops new generation dam land and balances the short-term and long-term interests to ease the conflicts between economic development and environmental protection. Furthermore, the GLCP and the GFG could also be combined preferably. On the one hand, the GFG improves the ecological environment, which could offer certain safety to the GLCP, on the other hand, the GLCP creates more farmland favorable for farming in gullies instead of land reclamation on the slopes, which could indirectly protect the GFG project.

When and where did the Loess Plateau turn “green”? Analysis of the tendency and breakpoints of the normalized difference vegetation index

“…The Loess Plateau, located in the middle and upper reaches of the Yellow River, has the most serious soil erosion problems in China and possibly even globally (Liu, Guo, Li, & Li, ; McVicar et al, ; B. Q. Zhang, Wu, Zhao, Wang, & Gao, ). The average erosion modulus in this area is 5,000–10,000 t·km −2 , with the highest rate being in the range of 20,000–30,000 t·km −2 (Cai, ; Lü et al, ).…”

Does Anthropogenic Land Use Change Play a Role in Changes of Precipitation Frequency and Intensity over the Loess Plateau of China?

“…The Loess Plateau, one of China's four plateaus, together with the Tibetan Plateau, the Inner Mongolia Plateau and the Yun-Gui Plateau, is one of the most ecologically fragile regions in the world. Unreasonable land use and severe soil erosion have limited the regional sustainable development of the Loess Plateau and worsened its environment [6][7][8][9][10]. Since the year of 1999, the 'Grain for Green' (also regarded as 'conversion from slope croplands to forests or grasslands') project was carried out, which evidently led to reductions in the area of slope croplands and the amount of soil erosion by means of revegetation (e.g., afforestation and natural restoration) in the Loess Plateau [11,12].…”

Transforming the Loess Plateau of China

“…The successful transformation of the Loess Plateau shows the benefits of a holistic approach incorporating various components of the human and natural systems [23] . This achievement is made following the laws of nature and of social development.…”