Responses of vegetation cover to the Grain for Green Program and their driving forces in the He-Long region of the middle reaches of the Yellow River

Abstract

The implementation of the Grain for Green Program is a great breakthrough in the history of China's ecological environment construction, which can control soil erosion effectively, increase land productivity and improve the ecological environment. To investigate the eco-environmental benefits brought by the Grain for Green Program, the spatiotemporal variations of vegetation cover in the growing season from 2000 to 2010 across the Hekou-Longmen (He-Long) region were analyzed by using remote sensing information, meteorological data and land use data. Moreover, the impacts of climate and human activities on vegetation change were evaluated objectively. Annual vegetation cover in the growing season increased very significantly. Increased vegetation cover occurred in 98.7% of the region, of which the area for vegetation cover improved slightly constituted 79.8% of the whole area. Vegetation moderately improved was mainly distributed in the south of the He-Long region, covering 9.6% of the area, and the area for vegetation basically unchanged concentrated in the middle and upper reaches of the Wuding River. Precipitation was found to be an important natural factor influencing vegetation cover change. The area of vegetation cover showing a significantly positive correlation with precipitation occupied 22.14% of the region. As driven by policies from the Grain for Green Program, forestland increased significantly and land use structure became more intensive. Human activities played a positive and effective role in the protection, restoration and improvement of vegetation in the places where vegetation cover was basically unchanged, even though precipitation declined greatly, and vegetation improved moderately with massive increases of forestland and grassland.

A River Basin over the Course of Time: Multi-Temporal Analyses of Land Surface Dynamics in the Yellow River Basin (China) Based on Medium Resolution Remote Sensing Data

“…As already shown in Sections 4.1 and 4.2, our results revealed changing ecological conditions, with the revegetation of barren and sparse land and transformation of sloped cropland to grass or woodland. Our results are analogous to a number of local remote sensing and landscape analysis studies, confirming an ecological and environmental enhancement also at larger scales [4,11,[67][68][69]. Studies investigating the net primary productivity (NPP), a crucial proxy for vegetation productivity and carbon fluxes, indicated a steady increase over the last decade [70,71] stemming from land conservation programs.…”

Human activity and climate variability impacts on sediment discharge and runoff in the Yellow River of China

“…Significant changes have recently taken place in the Yellow River basin environment under the influences of intensive human activities and global climate change coupled with the fragile ecosystem (Wang and Cheng 2000). For example, the sediment discharge and water discharge of the Yellow River have significantly declined during the past 50 years (Yang et al 2004a;Liu and Zheng 2004;Fu et al 2004;Xu 2005a;Miao et al 2010;Gao et al 2011;Mu et al 2012;Liu et al 2013;He et al 2015a). Because the middle reaches of the Yellow River run through the Loess Plateau, they have become the main source of sediment due to the improper land use and excessive exploitation in the surrounding area.…”

Coupling Analysis of Hydrometeorology and Erosive Landforms Evolution in Loess Plateau, China

“…Gully density and segmentation of the ground are as high as 8 km/km 2 , and segmentation of the ground is about 43.7% in some area. The average erosion modulus reaches 5000-10000 t⋅km −2 ⋅a −1 , sometimes even reaching to 20000-30000 t⋅km −2 ⋅a −1 , and it decreased to 2205.4 t⋅km −2 ⋅a −1 in He-Long region in 2011 [51]. The sediment discharge of He-Long section of Yellow River was about 3.1 × 10 8 t during 1980-2010 and 1.6 × 10 8 t during 2000-2010 [51].…”

“…The average erosion modulus reaches 5000-10000 t⋅km −2 ⋅a −1 , sometimes even reaching to 20000-30000 t⋅km −2 ⋅a −1 , and it decreased to 2205.4 t⋅km −2 ⋅a −1 in He-Long region in 2011 [51]. The sediment discharge of He-Long section of Yellow River was about 3.1 × 10 8 t during 1980-2010 and 1.6 × 10 8 t during 2000-2010 [51]. Vegetation destruction was one of the key contributors to soil erosion in Loess Plateau for decades because of improper human activities (such as cultivation, deforestation, and development of economy).…”