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Despite the increasing awareness regarding the importance of ecologically fragile areas in maintaining human well-being, there is a lack of understanding of the comprehensive quantification of the basin-scale ecosystem services. In this study, based on risk zoning, the regional difference coefficient (RDC) was introduced into an existing method proposed by Costanza to value the ecosystem services. The modified method was then applied to value the ecosystem services of a debris flow alluvial fan in Awang basin, Yunnan, China from 2012 to 2018. The results indicated that in the debris flow area, the ecosystem service of water area is of great value; however, because of the limited area, the transformation between the adjacent land types can be easily triggered owing to human or natural influence. During this period, the ecosystem service demonstrated a downward trend, which could attribute to a decrease in the water area with a larger ecosystem service and an increase in the area of the construction land that led to the considerable depletion of the ecosystem service. The proposed modified method to value ecosystem services can be a valuable means to reflect the present situation of a basin-scale ecosystem and the effect of ecological restoration.
Songtang He; Daojie Wang; Peng Zhao; Yong Li; Huijuan Lan; Wenle Chen; Xiaoqing Chen. Quantification of basin-scale multiple ecosystem services in ecologically fragile areas. CATENA 2021, 202, 105247 .
AMA StyleSongtang He, Daojie Wang, Peng Zhao, Yong Li, Huijuan Lan, Wenle Chen, Xiaoqing Chen. Quantification of basin-scale multiple ecosystem services in ecologically fragile areas. CATENA. 2021; 202 ():105247.
Chicago/Turabian StyleSongtang He; Daojie Wang; Peng Zhao; Yong Li; Huijuan Lan; Wenle Chen; Xiaoqing Chen. 2021. "Quantification of basin-scale multiple ecosystem services in ecologically fragile areas." CATENA 202, no. : 105247.
The shortage of land resources is one of the most pressing policy challenges faced by China, where many attempts have been made to increase the quantity and quality of land available for human use while protecting the environment. In the regard, the use of debris flow waste-shoal land (DFWSL) has achieved success. Although DFWSL is being developed and used, it has not yet received sufficient attention, and many challenges remain in the process of utilization. In order to improve awareness regarding DFWSL use and identify the opportunities and challenges, we evaluated the current policies and practices guiding the use and management of DFWSL in China using a combination of literature review and field studies. The results show that DFWSL development in China can be classified into three main stages: initial (risk assessment), development (analysis of soil properties and production potential), and mature (efficient and safe use). Ongoing research has placed increasing attention on the coordinated development of economic and ecological security, but some problems remain. First, the geomorphic nature of DFWSL is not always clearly recognized, leading to utilization that does not follow best practices. Second, the current theoretical system for development is insufficient, presenting barriers to scientifically informed and rational utilization. Third, there is a lack of clear and comprehensive policy guidance from the government. Therefore, we propose a new conceptual framework for DFWSL development that emphasizes a landscape-friendly trajectory that balances economic development and security. We expect this study to increase the focus on development in mountainous regions of China and encourage further investigation of the marginal land use potential in ecologically fragile areas where debris flows frequently occur.
Songtang He; Daojie Wang; Peng Zhao; Yong Li; Huijuan Lan; Wenle Chen; Ali Akbar Jamali. A review and prospects of debris flow waste-shoal land use in typical debris flow areas, China. Land Use Policy 2020, 99, 105064 .
AMA StyleSongtang He, Daojie Wang, Peng Zhao, Yong Li, Huijuan Lan, Wenle Chen, Ali Akbar Jamali. A review and prospects of debris flow waste-shoal land use in typical debris flow areas, China. Land Use Policy. 2020; 99 ():105064.
Chicago/Turabian StyleSongtang He; Daojie Wang; Peng Zhao; Yong Li; Huijuan Lan; Wenle Chen; Ali Akbar Jamali. 2020. "A review and prospects of debris flow waste-shoal land use in typical debris flow areas, China." Land Use Policy 99, no. : 105064.
Net primary productivity (NPP) is one of the essential indicators of regional eco-environment security. In ecologically fragile areas, debris flow prone areas are extremely sensitive to human and natural impacts. In this study, our goal was to explore the main driving forces and their characteristics that caused changes in NPP. This was achieved by collecting and analyzing multi-source data of a typical region in SW China. A pixel-based spatial analysis method was conducted in this study to quantify the co-evolution characteristics between NPP and the main driving forces. Our results showed that the overall NPP in the region exhibits an increasing trend. The main driving forces are NDVI and population density, which can explain >70% of the environmental states. In addition, co-evolution characteristics were obvious; generally, NDVI had a positive effect and population density had a negative effect. However, extremely significant negative correlations between NPP and NDVI were found in 12.01% of the study area. Therefore, carrying out reasonable ecological restoration and applicable human activities in debris flow prone areas could ensure eco-environment security and sustainable development. This study contributes to improving our understanding of eco-environment evolution of critical zones and provides a scientific basis for regional eco-environment security construction and eco-treatment of debris flow.
Peng Zhao; Daojie Wang; Songtang He; Huijuan Lan; Wenle Chen; Yuchao Qi. Driving forces of NPP change in debris flow prone area: A case study of a typical region in SW China. Ecological Indicators 2020, 119, 106811 .
AMA StylePeng Zhao, Daojie Wang, Songtang He, Huijuan Lan, Wenle Chen, Yuchao Qi. Driving forces of NPP change in debris flow prone area: A case study of a typical region in SW China. Ecological Indicators. 2020; 119 ():106811.
Chicago/Turabian StylePeng Zhao; Daojie Wang; Songtang He; Huijuan Lan; Wenle Chen; Yuchao Qi. 2020. "Driving forces of NPP change in debris flow prone area: A case study of a typical region in SW China." Ecological Indicators 119, no. : 106811.
Ecological engineering is an effective method to control mountain disasters, in which tree roots play an important role in stabilizing the slope and consolidating the soil in face of the landslide. The use of artificial roots to simulate real root is an important means of experimental research. To explore which tree planting patterns could achieve better stability on slopes of 20°, 35°, 50°, and 60° under extreme climatic conditions (rainfall intensity of 118 mm/h), this paper used an artificial root model to construct four types of slopes, i.e., slope with dense trees planted on wide bands, slope with dense trees planted on narrow bands, slope with equally and sparsely planted trees, and barren slope (control group). Sixteen groups of indoor slope rainfall experiments were carried out. To determine the stability effects of different slopes, the failure process and model of slopes during rainfall were analyzed, and the safety factor values Fs were calculated. The following conclusions are drawn: (1) Trees have different effects on the stability of slopes with different slope gradients. Planting trees on 20° and 35° slopes has good reinforcement effect, but planting trees on 50° or 60° slopes will lead to less stability. (2) The optimal planting patterns are different for different slopes. For example, the optimal planting pattern on the 20° and 35° slopes is wide-band dense planting, while it is not suitable to plant tall trees on the 50° and 60° slopes. (3) The change of slope gradient will not affect the failure mode of barren slopes but will change the failure process for vegetated slopes. (4) Wide-band dense planting pattern on all slopes can effectively intercept sediment, inhibit sediment slide, and prevent collapse. All in all, the research results provide a good theoretical guidance and practice to control landslides with ecological engineering.
Huijuan Lan; Daojie Wang; Songtang He; Yingchao Fang; Wenle Chen; Peng Zhao; Yuchao Qi. Experimental study on the effects of tree planting on slope stability. Landslides 2020, 17, 1021 -1035.
AMA StyleHuijuan Lan, Daojie Wang, Songtang He, Yingchao Fang, Wenle Chen, Peng Zhao, Yuchao Qi. Experimental study on the effects of tree planting on slope stability. Landslides. 2020; 17 (4):1021-1035.
Chicago/Turabian StyleHuijuan Lan; Daojie Wang; Songtang He; Yingchao Fang; Wenle Chen; Peng Zhao; Yuchao Qi. 2020. "Experimental study on the effects of tree planting on slope stability." Landslides 17, no. 4: 1021-1035.
Major earthquakes can cause serious vegetation destruction in affected areas. However, little is known about the spatial patterns of damaged vegetation and its influencing factors. Elucidating the main influencing factors and finding out the key vegetation type to reflect spatial patterns of damaged vegetation are of great interest in order to improve the assessment of vegetation loss and the prediction of the spatial distribution of damaged vegetation caused by earthquakes. In this study, we used Moran’s I correlograms to study the spatial autocorrelation of damaged vegetation and its potential driving factors in the nine worst-hit Wenchuan earthquake-affected cities and counties. Both dependent and independent variables showed a positive spatial autocorrelation but with great differences at four aggregation levels (625 × 625 m, 1250 × 1250 m, 2500 × 2500 m, and 5000 × 5000 m). Shrubs can represent the characteristics of all damaged vegetation due to the significant linear relationship between their Moran’s I at the four aggregation levels. Clustering of similar high coverage of damaged vegetation occurred in the study area. The residuals of the standard linear regression model also show a significantly positive autocorrelation, indicating that the standard linear regression model cannot explain all the spatial patterns in damaged vegetation. Spatial autoregressive models without spatially autocorrelated residuals had the better goodness-of-fit to deal with damaged vegetation. The aggregation level 8 × 8 is a scale threshold for spatial autocorrelation. There are other environmental factors affecting vegetation destruction. Our study provides useful information for the countermeasures of vegetation protection and conservation, as well as the prediction of the spatial distribution of damaged vegetation, to improve vegetation restoration in earthquake-affected areas.
Jian Li; Jingwen He; Ying Liu; Daojie Wang; Loretta Rafay; Can Chen; Tao Hong; Hailan Fan; Yongming Lin. Spatial Autocorrelation Analysis of Multi-Scale Damaged Vegetation in the Wenchuan Earthquake-Affected Area, Southwest China. Forests 2019, 10, 195 .
AMA StyleJian Li, Jingwen He, Ying Liu, Daojie Wang, Loretta Rafay, Can Chen, Tao Hong, Hailan Fan, Yongming Lin. Spatial Autocorrelation Analysis of Multi-Scale Damaged Vegetation in the Wenchuan Earthquake-Affected Area, Southwest China. Forests. 2019; 10 (2):195.
Chicago/Turabian StyleJian Li; Jingwen He; Ying Liu; Daojie Wang; Loretta Rafay; Can Chen; Tao Hong; Hailan Fan; Yongming Lin. 2019. "Spatial Autocorrelation Analysis of Multi-Scale Damaged Vegetation in the Wenchuan Earthquake-Affected Area, Southwest China." Forests 10, no. 2: 195.
Debris flow waste-shoal land (DFWSL) is a significant and potential land resource that is largely ignored in ecologically fragile mountainous areas. Yeyatang Basin, in Yunnan Province, China, is a typical mountainous debris flow area with a large amount of DFWSL. In order to achieve efficient use of DFWSL in this area, we built a demonstration plot and implemented a landscape ecological use pattern (LEUP) model for the DFWSL, with which we analyzed the economic, ecological, and social benefits. The results showed that the LEUP significantly improved incomes and vegetation coverage, and it reduced soil and water loss, controlled the debris flow, and ensured the safety of residents. To some extent, the LEUP alleviated the conflict between socioeconomic development and environmental protection and increased local employment opportunities, which could help to resolve the socioeconomic issues associated with rural hollow villages and left-behind children. The model demonstration results will provide a “road map” to wasteland use and serve as an important information resource for policymakers. Leaders should consider shifting their perspectives toward exploring land resources that had previously been deemed unavailable and pay more attention to the management and development of DFWSL, which could potentially enable the sustainable development of mountain ecosystems and economies, and enhance the prevention and control of natural disasters in mountainous regions.
Songtang He; Daojie Wang; Yong Li; Yingchao Fang; Huijuan Lan; Wenle Chen. Implementation of a landscape ecological use pattern model: Debris flow waste-shoal land use in the Yeyatang Basin, Yunnan Province, China. Land Use Policy 2018, 81, 483 -492.
AMA StyleSongtang He, Daojie Wang, Yong Li, Yingchao Fang, Huijuan Lan, Wenle Chen. Implementation of a landscape ecological use pattern model: Debris flow waste-shoal land use in the Yeyatang Basin, Yunnan Province, China. Land Use Policy. 2018; 81 ():483-492.
Chicago/Turabian StyleSongtang He; Daojie Wang; Yong Li; Yingchao Fang; Huijuan Lan; Wenle Chen. 2018. "Implementation of a landscape ecological use pattern model: Debris flow waste-shoal land use in the Yeyatang Basin, Yunnan Province, China." Land Use Policy 81, no. : 483-492.
Songtang He; Daojie Wang; Shiqiu Chang; Yingchao Fang; Huijuan Lan. Correction to: Effects of the morphology of sediment-transporting channels on the erosion and deposition of debris flows. Environmental Earth Sciences 2018, 77, 599 .
AMA StyleSongtang He, Daojie Wang, Shiqiu Chang, Yingchao Fang, Huijuan Lan. Correction to: Effects of the morphology of sediment-transporting channels on the erosion and deposition of debris flows. Environmental Earth Sciences. 2018; 77 (17):599.
Chicago/Turabian StyleSongtang He; Daojie Wang; Shiqiu Chang; Yingchao Fang; Huijuan Lan. 2018. "Correction to: Effects of the morphology of sediment-transporting channels on the erosion and deposition of debris flows." Environmental Earth Sciences 77, no. 17: 599.
Land use change is extremely sensitive to natural factors and human influence in active debris flow. It is therefore necessary to determine the factors that influence land use change. This paper took Wudu District, Gansu Province, China as a study area, and a systemic analysis of the transformational extent and rate of debris flow waste-shoal land (DFWSL) was carried out from 2005 to 2015. The results show that from 2005 to 2015, cultivated land resources transformed to other types of land; cultivated lands mainly transformed to grassland from 2005 to 2010 and construction land from 2010 to 2015. Moreover, the growth rate of construction land from 2005 to 2010 was only 0.11%, but increased to 6.87% between 2010 and 2015. The latter is more than 60 times the former. This increase was brought about by natural disasters (debris flow, earthquakes, and landslides) and anthropogenic factors (national policies or strategies), which acted as driving forces in debris flow area. The former determines the initial use type of the DFWSL while the latter only affects the direction of land use and transformation.
Songtang He; Daojie Wang; Yong Li; Peng Zhao. Land Use Changes and Their Driving Forces in a Debris Flow Active Area of Gansu Province, China. Sustainability 2018, 10, 2759 .
AMA StyleSongtang He, Daojie Wang, Yong Li, Peng Zhao. Land Use Changes and Their Driving Forces in a Debris Flow Active Area of Gansu Province, China. Sustainability. 2018; 10 (8):2759.
Chicago/Turabian StyleSongtang He; Daojie Wang; Yong Li; Peng Zhao. 2018. "Land Use Changes and Their Driving Forces in a Debris Flow Active Area of Gansu Province, China." Sustainability 10, no. 8: 2759.
A series experiments are conducted to investigate the effects of streambed profile on the erosion and deposition of debris flows. It is found that straight channel can increase the run out of debris flows by 10–25%, compared to that of surfaces without channels, and that travel distance was positively correlated with the hydraulic radius of the channel. In addition, the presence of straight channels caused the volume of debris flow deposition to become normally distributed with respect to travel distance. In the case of curved channels, increases in the sinuosity index resulted in significant blockage and obstruction. In the deposition zone, the maximum deposition volume for a channel with a comparatively low sinuosity index (1.05) was < 50% of the minimum deposition volume for a straight channel. Furthermore, the channel curvature affected not only the positions of deposition peaks along the travel distance but also the debris flow magnitudes in each unit interval (0.5 m). This study demonstrates the effects of differences in channel morphology on the erosional and depositional processes of gully debris flows. These findings are of significant importance for guiding debris flow risk assessment and for the restoration and reconstruction of downstream regions.
Songtang He; Daojie Wang; Shiqiu Chang; Yingchao Fang; Huijuan Lan. Effects of the morphology of sediment-transporting channels on the erosion and deposition of debris flows. Environmental Earth Sciences 2018, 77, 544 .
AMA StyleSongtang He, Daojie Wang, Shiqiu Chang, Yingchao Fang, Huijuan Lan. Effects of the morphology of sediment-transporting channels on the erosion and deposition of debris flows. Environmental Earth Sciences. 2018; 77 (14):544.
Chicago/Turabian StyleSongtang He; Daojie Wang; Shiqiu Chang; Yingchao Fang; Huijuan Lan. 2018. "Effects of the morphology of sediment-transporting channels on the erosion and deposition of debris flows." Environmental Earth Sciences 77, no. 14: 544.
Ecological environment issues caused by soil erosion have always been the attractive and significant problems all over the world. Under the background of global warming, debris flow, landslide, and other intense gravitational erosion activities have become aggravated, which leads to the decrease of biological diversity, ecosystem stability, resistance, productivity, and the like, which presents new challenges to traditional measures of soil and water conservation. This article, based on research conducted on controlling mountain hazard on the Xiaojiang River basin over the last 30 years, summarizes the managerial achievement of typical ecological engineering technologies and analyzes the principles and application of each type of treatment. The results indicated that established ecological engineering technologies play a significant role in the prevention and treatment of intense gravitational erosion caused by mountain hazard. However, there are still a great deal of limitation of application condition and maneuverability during management process. How to furtherly develop the rational combining pattern between ecological engineering (e.g. contour hedgerow) and geotechnical engineering (e.g. slit dam) and how to strengthen the risk control and improve management strategy will be the key points for preventing intense gravitational erosion in future by ecological engineering. Keywords: Soil and water conservation, Ecological engineering, Gravitational erosion, Risk control, Mountain hazard
Songtang He; Daojie Wang; Yingchao Fang; Huijuan Lan. Guidelines for integrating ecological and biological engineering technologies for control of severe erosion in mountainous areas – A case study of the Xiaojiang River Basin, China. International Soil and Water Conservation Research 2017, 5, 335 -344.
AMA StyleSongtang He, Daojie Wang, Yingchao Fang, Huijuan Lan. Guidelines for integrating ecological and biological engineering technologies for control of severe erosion in mountainous areas – A case study of the Xiaojiang River Basin, China. International Soil and Water Conservation Research. 2017; 5 (4):335-344.
Chicago/Turabian StyleSongtang He; Daojie Wang; Yingchao Fang; Huijuan Lan. 2017. "Guidelines for integrating ecological and biological engineering technologies for control of severe erosion in mountainous areas – A case study of the Xiaojiang River Basin, China." International Soil and Water Conservation Research 5, no. 4: 335-344.
: Pore water pressure and water content are important indicators to both deposition and consolidation of debris flows, enabling a direct assessment of consolidation degree. This article gained a more comprehensive understanding about the entire consolidation process and focused on exploring pore water pressure and volumetric water content variations of the deposit body during natural consolidation under different conditions taking the viscous debris flow mass as a study subject and by flume experiments. The results indicate that, as the color of the debris changed from initial dark green to grayish-white color, the initial deposit thickness declined by 3% and 2.8% over a permeable and impermeable sand bed, respectively. A positive correlation was observed between pore water pressure and depth in the deposit for both scenarios, with deeper depths being related to greater pore water pressure. For the permeable environment, the average dissipation rate of pore water pressure measured at depths of 0.10 m and 0.05 m were 0.0172 Pa/d and 0.0144 Pa/d, respectively, showing a positive changing trend with increasing depth. Under impermeable conditions, the average dissipation rates at different depths were similar, while the volumetric water content in the deposit had a positive correlation with depth. The reduction of water content in the deposit accelerated with depth under impermeable sand bed boundary conditions, but was not considerably correlated with depth under permeable sand bed boundary conditions. However, the amount of discharged water from the deposit was greater and consolidation occurred faster in permeable conditions. This indicates that the permeability of the boundary sand bed has a significant impact on the progress of consolidation. This research demonstrates that pore water and pressure dissipations are present during the entire viscous debris consolidation process. Contrasting with dilute flows, pore pressure dissipation in viscous flows cannot be completed in a matter of minutes or even hours, requiring longer completion time — 3 to 5 days and even more. Additionally, the dissipation of the pore water pressure lagged the reduction of the water content. During the experiment, the dissipation rate fluctuated substantially, indicating a close relationship between the dissipation process and the physical properties of broadly graded soils.
Song-Tang He; Dao-Jie Wang; Shun Chen; Shu-Juan Zhang; Shi-Qiu Chang. Natural consolidation characteristics of viscous debris flow deposition. Journal of Mountain Science 2016, 13, 1723 -1734.
AMA StyleSong-Tang He, Dao-Jie Wang, Shun Chen, Shu-Juan Zhang, Shi-Qiu Chang. Natural consolidation characteristics of viscous debris flow deposition. Journal of Mountain Science. 2016; 13 (10):1723-1734.
Chicago/Turabian StyleSong-Tang He; Dao-Jie Wang; Shun Chen; Shu-Juan Zhang; Shi-Qiu Chang. 2016. "Natural consolidation characteristics of viscous debris flow deposition." Journal of Mountain Science 13, no. 10: 1723-1734.
Fine root is critical to restrain soil erosion and its distribution pattern is of great influence on the restraining effects. This study studied the fine root biomass (B r ) distribution of different aged Leucaena leucocephala (5, 10, 15 years) in debris flow source area in Jiangjia Gully by digging downward to the bottom at different distances to stem in three directions on slope. The results showed the B r increased dramatically by 143% from 5 years to 10 years and then rose slowly by 38% from 10 years to 15 years. The B r of 5 years was significantly asymmetric between uphill and alonghill directions, but there was little difference among directions for other ages, and a concentration trend appeared to exist in downhill and alonghill directions. Moreover, fine root (D≤1 mm) was significantly heavier than that of fine root (1mm
Ling-Hui Guo; Dao-Jie Wang; Xiang-Min Sun; Dong Chen; Xiao-Yan Chen. Fine root distribution pattern of different aged Leucaena leucocephala trees in debris flow source area in Jiangjia Gully, China. Journal of Mountain Science 2014, 11, 941 -949.
AMA StyleLing-Hui Guo, Dao-Jie Wang, Xiang-Min Sun, Dong Chen, Xiao-Yan Chen. Fine root distribution pattern of different aged Leucaena leucocephala trees in debris flow source area in Jiangjia Gully, China. Journal of Mountain Science. 2014; 11 (4):941-949.
Chicago/Turabian StyleLing-Hui Guo; Dao-Jie Wang; Xiang-Min Sun; Dong Chen; Xiao-Yan Chen. 2014. "Fine root distribution pattern of different aged Leucaena leucocephala trees in debris flow source area in Jiangjia Gully, China." Journal of Mountain Science 11, no. 4: 941-949.