Spatial Distribution and Key Prevention Areas of Ephemeral Gully under the 'Grain for Green Project' in Loess Plateau, China

2021 ◽  
Author(s):  
Yuan Zhong ◽  
Chunmei Wang ◽  
Guowei Pang ◽  
Qinke Yang ◽  
Zitian Guo ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
Loess Plateau ◽  
Average Length ◽  
Regional Distribution ◽  
Google Earth ◽  
The Loess Plateau ◽  
Grain For Green ◽  
Ephemeral Gully ◽  
Grain For Green Project

<p>Soil erosion is an important threat in the high-quality development of the Loess Plateau of China, and Ephemeral Gully (EG) erosion is an important erosion type. Answering the distribution characteristics of EG at the regional scale is an important basis for EG control. The regional distribution of EG and the areas that still at high risk of EG development after the 'Grain for Green Project' since more than 20 years ago remain poorly understood. This study aimed to solve the above problems by using visual interpretation based on sub-meter Google Earth images in 137 systematically selected small watersheds in the Loess Plateau. The EG density, length, land use of the hillslope where each EG existed, and other parameters were obtained and analyzed using the GIS method. The spatial distribution of EG density, average length, and spatial correlation in the Loess Plateau was explored. The current EG distribution and key prevention areas in the Loess Plateau were identified. The results showed that: (1) EGs were found in 46 surveyed watersheds accounting for 33.6% of the total watershed number, with an EG density average value of 3.41km/km<sup>2</sup> and maximum value of 21.92 km/km<sup>2</sup>. The average number of EG was 60.32/km<sup>2</sup>. EG length was mainly distributed in 20 ~ 60 m, with an average length of 63.31 m; The critical slope length of EGs was mainly 40 ~ 60 m, with an average 56.20 m. (2) The watersheds with EGs were mainly located in the north-central, the west, and northwest of the Loess Plateau. EG erosion is extremely strong in loess hilly and gully region, and moderate in loess plateau gully region.(3) 38.3% of EG was distributed in cropland; 35.3% distributed in grassland; 22.8% distributed in forest land. After the 'Grain for Green Project', the EGs that were still distributed on cropland were a more important threat to soil erosion and need better prevention efforts. EGs located on cropland were still widely distributed in many areas of Loess Plateau, such as the northwest of Yan 'an City in the middle and upper reaches of Beiluo River, Suide and Luliang in the lower reaches of Wuding River, at the junction of Dingxi and Huining and in Qingyang area. This research would help in a more reasonable distribution of erosion control practices in the Loess Plateau.</p>

scholarly journals Spatial Variabilities of Runoff Erosion and Different Underlying Surfaces in the Xihe River Basin

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 352 ◽  
Author(s):  
Ning Wang ◽  
Zhihong Yao ◽  
Wanqing Liu ◽  
Xizhi Lv ◽  
Mengdie Ma
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
River Basin ◽  
Loess Plateau ◽  
Arable Land ◽  
Alluvial Soil ◽  
Underlying Surface ◽  
Spatial Gradient ◽  
Hydrological Process ◽  
The Loess Plateau

Runoff erosion capacity has significant effects on the spatial distribution of soil erosion and soil losses. But few studies have been conducted to evaluate these effects in the Loess Plateau. In this study, an adjusted SWAT model was used to simulate the hydrological process of the Xihe River basin from 1993 to 2012. The spatial variabilities between runoff erosion capacity and underlying surface factors were analyzed by combining spatial gradient analysis and GWR (Geographically Weighted Regression) analysis. The results show that the spatial distribution of runoff erosion capacity in the studying area has the following characteristics: strong in the north, weak in the south, strong in the west, and weak in the east. Topographic factors are the dominant factors of runoff erosion in the upper reaches of the basin. Runoff erosion capacity becomes stronger with the increase of altitude and gradient. In the middle reaches area, the land with low vegetation coverage, as well as arable land, show strong runoff erosion ability. In the downstream areas, the runoff erosion capacity is weak because of better underlying surface conditions. Compared with topographic and vegetation factors, soil factors have less impact on runoff erosion. The red clay and mountain soil in this region have stronger runoff erosion capacities compared with other types of soils, with average runoff modulus of 1.79 × 10−3 m3/s·km2 and 1.68 × 10−3 m3/s·km2, respectively, and runoff erosion power of 0.48 × 10−4 m4/s·km2 and 0.34 × 10−4 m4/s·km2, respectively. The runoff erosion capacity of the alluvial soil is weak, with an average runoff modulus of 0.96 × 10−3 m3/s·km2 and average erosion power of 0.198 × 10−4 m4/s·km2. This study illustrates the spatial distribution characteristics and influencing factors of hydraulic erosion in the Xihe River Basin from the perspective of energy. It contributes to the purposeful utilization of water and soil resources in the Xihe River Basin and provides a theoretical support for controlling the soil erosion in the Hilly-gully region of the Loess Plateau.

Soil conservation on the Loess Plateau and the regional effect: impact of the ‘Grain for Green' Project

2018 ◽  
Vol 109 (3-4) ◽  
pp. 461-471
Author(s):  
Xiaofeng WANG ◽  
Feiyan XIAO ◽  
Xiaoming FENG ◽  
Bojie FU ◽  
Zixiang ZHOU ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Land Cover ◽  
Loess Plateau ◽  
Soil Conservation ◽  
Yellow River ◽  
Vegetation Coverage ◽  
The Yellow River ◽  
The Loess Plateau ◽  
Regional Effect ◽  
Grain For Green

ABSTRACTSoil conservation on the Loess Plateau is important not only for local residents but also for reducing sediment downstream in the Yellow River. In this paper, we report a decrease in soil erosion from 2000 to 2010 as a result of the ‘Grain for Green' (GFG) Project. By using the Revised Universal Soil Loss Equation and data on land cover, climate and sediment yield, we found that soil erosion decreased from 6579.55tkm–2yr–1 in 2000 to 1986.66tkm–2yr–1 in 2010. During this period, there was a major land cover change from farmland to grassland in response to the GFG. The area of low vegetation coverage with severe erosion decreased dramatically, whereas the area of high vegetation coverage with slight erosion increased. Our study demonstrates that the reduction in soil erosion on the Loess Plateau contributed to the decrease in the sediment concentration in the Yellow River.

scholarly journals Estimation of Actual Evapotranspiration in a Semiarid Region Based on GRACE Gravity Satellite Data—A Case Study in Loess Plateau

2018 ◽  
Vol 10 (12) ◽  
pp. 2032 ◽  
Author(s):  
Miao Sun ◽  
Qin’ge Dong ◽  
Mengyan Jiao ◽  
Xining Zhao ◽  
Xuerui Gao ◽  
...  
Keyword(s):  
Soil Water ◽  
Loess Plateau ◽  
Water Consumption ◽  
Satellite Data ◽  
Potential Evapotranspiration ◽  
Sustainable Growth ◽  
Actual Evapotranspiration ◽  
The Loess Plateau ◽  
Grain For Green ◽  
Grain For Green Project

Jointly influenced by natural factors and artificial protection measures in recent years, the vegetation coverage of the Loess Plateau has significantly increased. However, extensive vegetation recovery can result in massive water consumption and a severe soil water deficit, which poses a great threat to the sustainable development of the regional ecological system. Maintaining the balance between precipitation and water consumption is an important foundation of ecological security in the Loess Plateau. Based on this, the present study used the GRACE (Gravity Recovery and Climate Experiment) gravity satellite data to simulate the annual actual water consumption from 2003 to 2014 and to analyze the temporal and spatial evolution of the regional precipitation and the actual evapotranspiration (AET). This study also applied the newly developed rainwater utilization potential index (IRUP) to quantify the sustainability of the water balance in the Loess Plateau. The spatial-temporal patterns of precipitation, potential evapotranspiration, and AET from 2003 to 2014 in the Loess Plateau were all analyzed in this study. Based on the results, the annual average precipitation (AAP) and AET in the entire Loess Plateau had significant increasing trends. The analysis of the spatial distribution reveals that the AET was decreasing from the southeast to the northwest in the Loess Plateau. However, the average values of potential evapotranspiration did not obviously change. Based on the estimated AET result, it was determined that the average IRUP had an increasing trend. The increase in the IRUP is due to an increased rate of precipitation that is statistically higher than that of the AET. Consequently, the Loess Plateau experienced a wetting trend during the period of 2003–2014, especially after the Grain for Green project was implemented. The results in this paper were proven by using three different depths of ERA-Interim (a global atmospheric reanalysis product created by the European Centre for Medium-Range Weather Forecasts) soil water content data from the same period and the observed runoff data from 18 different hydrological sites. Consequently, it seems that the vegetation could maintain a sustainable growth with the implementation of the Grain for Green Project.

scholarly journals Quantifying the Effects of Vegetation Restorations on the Soil Erosion Export and Nutrient Loss on the Loess Plateau

2020 ◽  
Vol 11 ◽  
Author(s):  
Jun Zhao ◽  
Xiaoming Feng ◽  
Lei Deng ◽  
Yanzheng Yang ◽  
Zhong Zhao ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Loess Plateau ◽  
Vegetation Cover ◽  
Vegetation Change ◽  
Soil Nutrient ◽  
Vegetation Restoration ◽  
Nutrient Loss ◽  
The Loess Plateau ◽  
Erosion Processes ◽  
Grain For Green Project

The transport of eroded soil to rivers changes the nutrient cycles of river ecosystems and has significant impacts on the regional eco-environment and human health. The Loess Plateau, a leading vegetation restoration region in China and the world, has experienced severe soil erosion and nutrient loss, however, the extent to which vegetation restoration prevents soil erosion export (to rivers) and it caused nutrient loss is unknown. To evaluate the effects of the first stage of the Grain for Green Project (GFGP) on the Loess Plateau (started in 1999 and ended in 2013), we analyzed the vegetation change trends and quantified the effects of GFGP on soil erosion export (to rivers) and it caused nutrient loss by considering soil erosion processes. The results were as follows: (1) in the first half of study period (from 1982 to 1998), the vegetation cover changed little, but after the implementation of the first stage of the GFGP (from 1999 to 2013), the vegetation cover of 75.0% of the study area showed a significant increase; (2) The proportion of eroded areas decreased from 41.8 to 26.7% as a result of the GFGP, and the erosion intensity lessened in most regions; the implementation significantly reduce the soil nutrient loss; (3) at the county level, soil erosion export could be avoided significantly by the increasing of vegetation greenness in the study area (R = −0.49). These results illustrate the relationships among changes in vegetation cover, soil erosion and nutrient export, which could provide a reference for local government for making ecology-relative policies.

scholarly journals Vegetation Restoration Alleviated the Soil Surface Organic Carbon Redistribution in the Hillslope Scale on the Loess Plateau, China

2021 ◽  
Vol 8 ◽  
Author(s):  
Yipeng Liang ◽  
Xiang Li ◽  
Tonggang Zha ◽  
Xiaoxia Zhang
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
Organic Carbon ◽  
Loess Plateau ◽  
Effective Means ◽  
Soil Surface ◽  
Vegetation Restoration ◽  
The Loess Plateau ◽  
Loess Slope ◽  
Carbon Redistribution

The redistribution of soil organic carbon (SOC) in response to soil erosion along the loess slope, China, plays an important role in understanding the mechanisms that underlie SOC’s spatial distribution and turnover. Consequently, SOC redistribution is key to understanding the global carbon cycle. Vegetation restoration has been identified as an effective method to alleviate soil erosion on the Loess Plateau; however, little research has addressed vegetation restoration’s effect on the SOC redistribution processes, particularly SOC’s spatial distribution and stability. This study quantified the SOC stock and pool distribution on slopes along geomorphic gradients in naturally regenerating forests (NF) and an artificial black locust plantation (BP) and used a corn field as a control (CK). The following results were obtained: 1) vegetation restoration, particularly NF, slowed the migration of SOC and reduced the heterogeneity of its distribution effectively. The topsoil SOC ratios of the sedimentary area to the stable area were 109%, 143%, and 210% for NF, BP, and CK, respectively; 2) during migration, vegetation restoration decreased the loss of labile organic carbon by alleviating the loss of dissolved organic carbon (DOC) and easily oxidized organic carbon (EOC). The DOC/SOC in the BP and NF increased significantly and was 13.14 and 17.57 times higher, respectively, than that in the CK (p < 0.05), while the EOC/SOC in the BP and NF was slightly higher than that in the CK. A relevant schematic diagram of SOC cycle patterns and redistribution along the loess slope was drawn under vegetation restoration. The results suggest that vegetation restoration in the loess slope, NF in particular, is an effective means to alleviate the redistribution and spatial heterogeneity of SOC and reduce soil erosion.

Evolution Characteristics and Simulation Prediction of Forest and Grass Landscape Fragmentation Based on the “Grain for Green” Projects on the Loess Plateau, P.R. China

2021 ◽  
Author(s):  
Li Gu ◽  
Zhiwen Gong ◽  
Yuankun Bu
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Loess Plateau ◽  
Global Climate Change ◽  
Global Climate ◽  
Landscape Fragmentation ◽  
The Loess Plateau ◽  
Grain For Green ◽  
Grain For Green Project ◽  
The Impact

Abstract Forest fragmentation is one of the major environmental issues that the international community is generally concerned about under the background of global climate change. Studying the impact and the interaction mechanism of land use change processes on landscape fragmentation is important to gaining a comprehensive understanding of the ecosystem response to human activities and global climate change. Based on the implementation background for the “Grain for Green” Project, we selected the Loess Plateau as the research area and used the coupled future land use simulation (FLUS) model and landscape fragmentation model to explore the temporal and spatial changes in forest and grass landscape fragmentation. The results showed that (1) Woodland, grassland, and cropland are the main landscape types, accounting for about 90% of the total area. In addition, the area of cropland initially increased and then decreased, while the area of woodland and grassland exhibited the opposite trend Oover the last 35 years. In particular, the period from 2000 to 2015 was a forest and grass restoration stage, and the average annual rate of forest and grass restoration reached 0.56%. (2) The FLUS model was used to predict the land use on the Loess Plateau in 2030. The kappa coefficient was 0.85, and the figure of merit coefficient (FOM) was 0.11 for a 1% random sampling, which are within a reasonable range, and the simulation results are also consistent with the objective change in the current social and economic development. (3) The fragmentation of woodland and grassland were dominated by edge type and core type. The core type had a concentrated distribution and an absolute advantage, accounting for more than 75% of the total area. It is predicted that the landscape fragmentation will gradually slowdown in 2030 under different intensities of the “Grain for Green” project. The dynamics of landscape fragmentation based on land use changes are conducive to the reasonable planning and objective evaluation of woodland and grassland spatial allocation and quality improvement, and provide an important basis for the formulation of ecological protection and land management policies.

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