scholarly journals The Water Availability on the Chinese Loess Plateau since the Implementation of the Grain for Green Project as Indicated by the Evaporative Stress Index

2021 ◽  
Vol 13 (16) ◽  
pp. 3302
Author(s):  
Linjing Qiu ◽  
Yuting Chen ◽  
Yiping Wu ◽  
Qingyue Xue ◽  
Zhaoyang Shi ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Water Availability ◽  
Water Conservation ◽  
Soil Depth ◽  
Vegetation Restoration ◽  
Stress Index ◽  
Area Index ◽  
Grain For Green ◽  
Increasing Trend ◽  
Grain For Green Project

The vegetation coverage on the Loess Plateau (LP) of China has clearly increased since the implementation of the Grain for Green Project in 1999, but there is a debate about whether the improved greenness was achieved at the expense of the balance between the supply and demand of water resources. Therefore, developing reliable indicators to evaluate the water availability is a prerequisite for maintaining ecological sustainability and ensuring the persistence of vegetation restoration. This study was designed to evaluate water availability on the LP during 2000–2015, using the evaporative stress index (ESI) derived from a remote sensing dataset. The relative dependences of the ESI on climatic and biological factors (including temperature, precipitation and land cover change) were also analyzed. The results showed that the leaf area index (LAI) in most regions of the LP showed a significant increasing trend (p < 0.05), and larger gradients of increase were mainly detected in the central and eastern parts of the LP. The evapotranspiration also exhibited an increasing trend in the central and eastern parts of the LP, with a gradient greater than 10 mm/year. However, almost the whole LP exhibited a decreased ESI from 2000 to 2015, and the largest decrease occurred on the central and eastern LP, indicating a wetting trend. The soil moisture storage in the 0–289-cm soil profiles showed an increasing trend in the central and eastern LP, and the area with an upward trend enlarged with the soil depth. Further analysis revealed that the decreased ESI on the central and eastern LP mainly depended on the increase in the LAI compared with climatic influences. This work not only demonstrated that the ESI was a useful indicator for understanding the water availability in natural and managed ecosystems under climate change but also indicated that vegetation restoration might have a positive effect on water conservation on the central LP.

The trade-off between vegetation restoration and soil & water conservation in Loess Plateau, China

2020 ◽  
Author(s):  
Haiqiang Gao ◽  
Shuguang Liu
Keyword(s):  
Soil Water ◽  
Loess Plateau ◽  
Growth Rates ◽  
Water Conservation ◽  
Growing Season ◽  
Vegetation Restoration ◽  
Annual Growth ◽  
Area Index ◽  
Water Condition ◽  
Soil And Water

&lt;p&gt;China has implemented an ambitious ecological project Grain for Green Project (GGP) on the Loess Plateau (LP) at the end of last century. The GGP was to increase vegetation coverage, reduce soil and water erosion and store Carbon by converting croplands on steep slopes barren hills and wasteland to forests. Assessing the ecological effects of GGP correctly could improve vegetation restoration activities worldwide. In this study, two major ecological indicators (vegetation restoration and soil &amp; water conservation) were used to evaluate the ecological benefits of GGP from 1982 to 2017. Our results show that the vegetation growth for most pixels of LP region have significantly increased at 21 century, annual growth rates of fraction of absorbed photosynthetically active Radiation (FPAR) in spring, summer, autumn and active growing season are 1.39, 4.49, 2.14 and 1.47, respectively. For leaf area index (LAI), these growth rates are 6.01, 20.06, 8.11 and 6.90, respectively. And for normalized difference vegetation index (NDVI), growth rates are 6.30, 25.46, 7.99 and 20.43, respectively. While the soil and water condition has differently changed, annual growth rates of soil moisture (SM) are 4.46, 2.79 and 2.30 for summer, active growing season and whole year, respectively. The coordinated responses of vegetation and soil &amp; water condition suggest that the interaction between organisms (vegetation, animal and human) and environment (soil, water and so on) in the process of vegetation restoration should be further recognized to evaluate the benefits of ecological engineering more comprehensively.&lt;/p&gt;

scholarly journals Effects of Vegetation Restoration on Soil Erosion on the Loess Plateau: A Case Study in the Ansai Watershed

2021 ◽  
Vol 18 (12) ◽  
pp. 6266
Author(s):  
Hui Wei ◽  
Wenwu Zhao ◽  
Han Wang
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Loess Plateau ◽  
Water Conservation ◽  
Large Scale ◽  
Land Use Changes ◽  
Vegetation Restoration ◽  
The Loess Plateau ◽  
Local Soil ◽  
Erosion Environment

Large-scale vegetation restoration greatly changed the soil erosion environment in the Loess Plateau since the implementation of the “Grain for Green Project” (GGP) in 1999. Evaluating the effects of vegetation restoration on soil erosion is significant to local soil and water conservation and vegetation construction. Taking the Ansai Watershed as the case area, this study calculated the soil erosion modulus from 2000 to 2015 under the initial and current scenarios of vegetation restoration, using the Chinese Soil Loess Equation (CSLE), based on rainfall and soil data, remote sensing images and socio-economic data. The effect of vegetation restoration on soil erosion was evaluated by comparing the average annual soil erosion modulus under two scenarios among 16 years. The results showed: (1) vegetation restoration significantly changed the local land use, characterized by the conversion of farmland to grassland, arboreal land, and shrub land. From 2000 to 2015, the area of arboreal land, shrub land, and grassland increased from 19.46 km2, 19.43 km2, and 719.49 km2 to 99.26 km2, 75.97 km2, and 1084.24 km2; while the farmland area decreased from 547.90 km2 to 34.35 km2; (2) the average annual soil erosion modulus from 2000 to 2015 under the initial and current scenarios of vegetation restoration was 114.44 t/(hm²·a) and 78.42 t/(hm²·a), respectively, with an average annual reduction of 4.81 × 106 t of soil erosion amount thanks to the vegetation restoration; (3) the dominant soil erosion intensity changed from “severe and light erosion” to “moderate and light erosion”, vegetation restoration greatly improved the soil erosion environment in the study area; (4) areas with increased erosion and decreased erosion were alternately distributed, accounting for 48% and 52% of the total land area, and mainly distributed in the northwest and southeast of the watershed, respectively. Irrational land use changes in local areas (such as the conversion of farmland and grassland into construction land, etc.) and the ineffective implementation of vegetation restoration are the main reasons leading to the existence of areas with increased erosion.

Soil and water conservation on the Loess Plateau in China: review and perspective

2007 ◽  
Vol 31 (4) ◽  
pp. 389-403 ◽  
Author(s):  
Liding Chen ◽  
Wei Wei ◽  
Bojie Fu ◽  
Yihe Lü
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Loess Plateau ◽  
Water Conservation ◽  
Vegetation Restoration ◽  
Soil And Water Conservation ◽  
The Loess Plateau ◽  
The Past ◽  
Soil And Water ◽  
Made In

The Loess Plateau, China, has long been suffering from serious soil erosion. About 2000 years ago, larger areas were used for grain production and soil erosion was thus becoming severe with increase in human activity. Severe soil and water loss led to widespread land degradation. During the past decades, great efforts were made in vegetation restoration to reduce soil erosion. However, the efficiency of vegetation restoration was not as satisfactory as expected due to water shortage. China initiated another state-funded scheme, the `Grain-for-Green' project in 1999, on the Loess Plateau to reduce soil erosion and improve land quality. However, the control of soil erosion effectively by land-use modification raised problems. In this paper, the lessons and experiences regarding soil and water conservation in the Loess Plateau in the past decades are analysed first. Urgent problems are then elaborated, such as the contradiction between land resource and human population, shortage of water both in amount and tempospatial distribution for vegetation growth, weak awareness of the problems of soil conservation by local officials, and poor public participation in soil and water conservation. Finally, suggestions regarding soil and water conservation in the Loess Plateau are given. In order to control soil erosion and improve vegetation, a scientific and detailed land-use plan for the Loess Plateau has to be made, in the first instance, and then planning for wise use of water resources should be undertaken to control mass movement effectively and to improve land productivity. Methods of improving public awareness of environmental conservation and public involvement in vegetation rehabilitation are also important.

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 Prediction of Ecosystem Service Function of Grain for Green Project Based on Ensemble Learning

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 537
Author(s):  
Huijie Li ◽  
Xiang Niu ◽  
Bing Wang
Keyword(s):  
Economic Development ◽  
Ensemble Learning ◽  
Water Conservation ◽  
Ecological Monitoring ◽  
Learning System ◽  
Monitoring Data ◽  
Grain For Green ◽  
The Future ◽  
Grain For Green Project ◽  
Coordination Degree

The Grain for Green Project (GGP) was implemented over 20 years ago as one of six major forestry projects in China, and its scope of implementation is still expanding. However, it is still unclear how many ecosystem services (ESs) the project will produce in the future. The GGP’s large-scale ecological monitoring officially started in 2015 and there is a lack of early monitoring data, making it challenging to predict the future ecological benefits. Therefore, this paper proposes a method to predict future ESs by using ecological monitoring data. First, a new ensemble learning system, auto-XGBoost-ET-DT, is developed based on ensemble learning theory. Using the GGP’s known ESs in 2015, 2017, and 2019, the missing ESs of the past decade have been evaluated via reverse regression. Data from 2020 to 2022 within a convolution neural network and the coupling coordination degree model have been used to analyze the coupling between the prediction results and economic development. The results show that the growth distributions of ESs in three years were as follows: soil consolidation, 3.70–6.34%; forest nutrient retention, 2.72–.71%; water conservation, 2.52–6.09%; carbon fixation and oxygen release, 3.00–4.64%; and dust retention, 3.82–5.75%. The coupling coordination degree of the ESs and economic development has been improved in 97% of counties in 2020 compared with 2019. The results verify a feasible ES prediction method and provide a basis for the progressive implementation of the GGP.

scholarly journals Impact of Grain for Green Project on Water Resources and Ecological Water Stress in Yanhe River Basin

2021 ◽  
Author(s):  
Yuping Han ◽  
Fan Xia ◽  
Huiping Huang ◽  
Wenbin Mu
Keyword(s):  
Land Use ◽  
Water Stress ◽  
Water Resources ◽  
Water Flow ◽  
Green Water ◽  
Stress Index ◽  
Grain For Green ◽  
Water Stress Index ◽  
Grain For Green Project ◽  
Regional Water

Grain for Green project (GGP) initialed by China government since 1999 has achieved substantial achievements accompanied with surface runoff decrease in the Loess Plateau but impacts of large-scale afforestation on regional water resources are uncertain. Hence, the objective of this study is to explore the impact of land use change on generalized water resources and ecological water stress using blue and green water concept taking Yanhe River Basin as a case study. Soil and Water Assessment Tool (SWAT) is applied to quantify summary of green and blue water which is defined as generalized water resources, ecological water requirement of vegetation (forest and grass), agricultural water footprint and virtual water flow are considered as regional water requirements. Land use types of 1980 (scenario?), 2017 (scenario?) are input in SWAT model while keeps other parameters constant in order to isolate the influence of land use changes. Results show that average annual difference of blue, green and generalized water resources is -72.08 million m 3 , 24.34 million m 3 , -47.74 million m 3  respectively when simulation results of scenario? subtracts scenario?and it presents that land use change caused by GGP leads to decrease in blue and generalized water resources whereas increase in green water resources. SURQ in scenario?is more than that in scenario?in all the study period from 1980-2017, green water storage in scenario?is more than that in scenario? in all the study period except in 1998; whereas LATQ in scenario?is less than that in scenario? except in 2000 and 2015, GWQ in 1992, 2000 and 2015, green water flow in 1998. Blue water, green water storage and green water flow in scenario? is less than that in scenario?in the whole basin, 12.89 percent of the basin and 99.21 percent of the basin respectively. Total WF increases from 1995 to 2010 because forest WF increases significantly in this period though agricultural WF and grass WF decreases. Ecological water stress index has no obvious temporal change trend in both land use scenarios but ecological water stress index in scenario? is more than that in scenario?which illustrates that GGP leads to increase of ecological water stress from perspective of generalized water resources

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