Large-scale Erosion Research Articles

Remote sensing and big data: Google Earth Engine data to assist calibration processes in hydro-sediment modeling on large scales

Mathematical modeling aids in understanding large-scale erosion and sedimentation. However, sediment transport models calibration is constrained by data scarcity. This study explores the use of remote sensing (RS) imagery to supplement observed data, addressing three key questions: (1) How can high-resolution RS data be obtained using cloud-based methods for hydro-sediment applications, considering river changes? (2) What are the benefits of RS data in data-scarce conditions? (3) How can RS data improve hydro-sediment modeling in data-deficient regions? We developed a method to acquire large-scale RS data using Google Earth Engine (GEE) to obtain red and infrared reflectance from satellite imagery. After filtering errors, the data were used to calibrate a hydro-sediment model. Results showed that RS data, when combined with observed data, provided similar outcomes but performed better for lower values. Calibration with RS data alone improved the Kling-Gupta Efficiency (KGE) by 5%–18% and correlation by 5%–15%. Key conclusions are: (I) Cloud-based calibration is superior to using limited virtual stations; (II) RS data effectively complements observed data in hydro-sediment modeling; (III) Calibration using only RS data is beneficial in ungauged basins and preferable to no calibration.

Cohort-Specific Experiences of Industrial Decline and Intergenerational Income Mobility

Abstract The United States manufacturing industry has long been regarded as the economic engine that built and sustained the middle class. In recent decades, this pillar of economic opportunity has eroded substantially. Though much has been written about the decline of manufacturing sectors in United States communities, the potential consequences for economic mobility, and stratification processes more generally, remain largely unexplored. In this study, I develop a conceptual framework linking the study of labor market change to economic stratification. I examine how structural changes to United States labor markets have altered opportunities for economic advancement in the United States. I focus the analysis on birth cohorts in the 1980s, whose labor market entry spans the large-scale erosion of the manufacturing industry in the 2000s. I find strong evidence that declines in manufacturing employment have contributed to growing geographic disparities in upward intergenerational income mobility. Children raised in counties that experienced large contractions in manufacturing industries throughout adolescence experienced large economic penalties in adulthood via reduced levels of upward mobility. The results demonstrate how long-term macroeconomic changes can disrupt and redistribute opportunities within societies.

Bakrichhap Agro Tourism and Natural Products Private limited (BATNPPL): a case for community based entrepreneurship promoting integrated rural development

Learning outcomes The learning outcome of this study is to bring to the table of a wider intellectual audience, a unique model of community-based entrepreneurship, which is working wonders with its unique selling points (USPs) in promoting sustainability and conserving the ethos of villages and, at the same time, generating livelihoods through traditional farming techniques adopted by the rural population residing in the Himalayan region of India.The proposed case study can be used as a replicable model in other parts of rural India and other emerging economies to start and scale up a similar “integrated rural development model” through effective policy advocacy and public–private partnerships and to develop sustainable farmlands and livelihoods for rural India. It has a definite potential to be used as a pedagogical tool in postgraduate programmes offering courses in microfinance, financial inclusion, social and community entrepreneurship, sustainability, entrepreneurship, community development finance and rural immersions and public policy. Case overview This case study is set in the backdrop of 2023 having been declared by the UN as the International Year of Millets and India being the homeland for millet cultivation. The objective of the case study is to bring to the table of a wider intellectual audience, a unique model of community-based entrepreneurship operating in the Himalayan region of rural India. The community-based entrepreneurship model works on the USP of promoting sustainability and conserving the ethos of villages and generating livelihoods through traditional farming techniques. This case study traces the journey of Roopesh Rai (protagonist and the founder of Bakrichhap), the community-based entrepreneur and his challenges in setting up the enterprise. The narrative is built in the light of a series of interviews with Rai, the main protagonist and the founder of Bakrichhap, as well as the people of Goat village by Komal, a post-doctoral fellow in the area of community-based enterprises (CBEs). Through this narrative, the case writers’ endeavour was to understand how CBEs such as Bakrichhap were providing a means of integrated rural development in the hilly region of Uttarakhand, India. Also, how such enterprises were thereby curbing distress migration, unemployment and a large-scale erosion of the cultural heritage and traditional and indigenous farming techniques of the land. In the first seven years of the operations of this uniquely curated CBE, Rai endeavoured to iron out many bottlenecks. This case study also highlights the gamut of challenges faced by community-based entrepreneurs like Rai in designing strategy for growth and expansion. What strategy should Bakrichhap follow for expansion to the other regions of the country? Should all the three existing verticals of the enterprise be scaled up parallelly or should each individual vertical be expanded one after the other in a phased manner? Stemming out from the main dilemma of strategic expansion were the related issues of funding (finance) and the formation of an effective team (HR). Study level/applicability This case study can be used in undergraduate, graduate and executive programmes offering courses in microfinance, financial inclusion, social and community entrepreneurship, sustainability, entrepreneurship, community development finance and rural immersions and public policy. Research methods This comprehensive case study is written by using the triangulation of data collected through a series of personal interviews, website information, news articles, personal observation and field visits. The research design used is single case (holistic; Yin, 2003, 3rd edition). The timeline of this case study is 2021 to 2022 and place is Nag Tibba, Uttarakhand, a Himalayan state in North India. Supplementary materials Teaching notes are available for educators only. Case code CSS 3: Entrepreneurship.

A Study on the Characteristics of Beach Profile Evolution According to the Particle Size Variation of Beach Nourishment

This study investigated the beach nourishment effect and topographical changes when using nourishment sand with relatively large particle diameters to perform beach nourishment on a beach subject to erosion. A physical model test was conducted in a 2D wave flume with an installed wind tunnel. The experiment examined the sediment transport mechanism under conditions with wind and waves. Although applying nourishment sand with large particle diameters attenuated sediment transport, the increase in particle diameter was not always proportional to the reduction in topographical changes. Increasing the particle diameter of the nourishment sand increased the friction force between particles, resulting in large-scale erosion and accretion around the coastline, and this trend increased with winds. Also, with wind, the wave run-up height increased, the undertow became stronger, and large-scale scouring occurred at the boundary between the nourishment sand and the existing beach. Increasing the particle diameter of the nourishment sand played a role in reducing the run-up phenomenon (d50: 1.0 mm with 24–50%, d50: 5.0 mm with 59–83%), and the range of particles moved by winds also decreased (d50: 1.0 mm with 10–38%, d50: 5.0 mm with 5–37%).

Large-scale Terrain Authoring through Interactive Erosion Simulation

Large-scale terrains are essential in the definition of virtual worlds. Given the diversity of landforms and the geomorphological complexity, there is a need for authoring techniques offering hydrological consistency without sacrificing user control. In this article, we bridge the gap between large-scale erosion simulation and authoring into an efficient framework. We set aside modeling in the elevation domain in favour of the uplift domain and compute emerging reliefs by simulating the stream power erosion. Our simulation relies on a fast yet accurate approximation of drainage area and flow routing to compute the erosion interactively, which allows for incremental authoring. Our model provides landscape artists with tools for shaping mountain ranges and valleys, such as copy-and-paste operations; warping for imitating folds and faults; and point and curve elevation constraints to precisely sculpt ridges or carve river networks. It also lends itself to inverse procedural modeling by reconstructing the uplift from an input digital elevation model and allows hydrologically consistent blending between terrain patches.

The role of indigenous plant species in controlling the erosion of top soil in sub-tropical environment: In-situ field observation and validation

Due to soil erosion, agricultural land productivity has declined in monsoon-dominated region of India. In this perspective, food security is threatened due to large-scale erosion and its associated declining tendency of fertility. So, people are trying to maximize production by considering HYVs (high-yielding varieties) seed, the large amount of fertilizer, and the agricultural system's alteration. For this reason, the intensity and amount of erosion have increased eventually. In the Indian context, most of the research regarding soil erosion has been done with the help of various established empirical and semi-empirical methods. These methods were developed universally and were less accurate in the Indian climatic context. This research establish a new (Indian soil erosion model: ISEM) on soil erosion considering the Indian climatic condition. This model was validated with the measured soil erosion and is much more reliable regarding optimal capacity than other established models. There is currently no such model for soil erosion in the Indian climate. So, our study has validated the innovative technique to soil erosion modelling that we created and presented. We used vegetation indices from several plots, including those with indigenous species land, external species land, and shrub land, to correlate the projected soil erosion using ISEM. The r2 values for the native, outside, and shrub land are, respectively, 0.5112, 0.2827, and 0.3028. From this, we can easily understand the optimal capacity of the model and the suitable measures in the plantation programme.

Quantitative Long-Term Monitoring (1890–2020) of Morphodynamic and Land-Cover Changes of a LIA Lateral Moraine Section

Aerial photographs of the European Alps usually only reach back to the middle of the 20th century, which limits the time span of corresponding studies that quantitatively analyse long-term surface changes of proglacial areas using georeferenced orthophotos. To the end of the Little Ice Age, this leads to a gap of about 100 years. Using digital monoplotting and several historical terrestrial photographs, we show the quantification of surface changes of a Little Ice Age lateral moraine section until the late second half of the 19th century, reaching a total study period of 130 years (1890–2020). The (initial) gully system expands (almost) continuously over the entire study period from 1890 to 2020. Until 1953, the vegetation-covered areas also expanded (mainly scree communities, alpine grasslands and dwarf shrub communities), before decreasing again, especially between 1990 and 2003, due to large-scale erosion within the gully system. Furthermore, our results show that the land-cover development was impacted by temperature and precipitation changes. With the 130-year study period, we contribute to a substantial improvement in the understanding of the processes in the proglacial by analysing the early phase and thus the immediate response of the lateral moraine to the ice exposure.

Scouring effect of the middle and lower reaches of the Yangtze River and its impact after the impoundment of the Three Gorges Project

三峡及其上游干支流梯级水库建成运用后,大坝下游“清水下泄”引起了长江中下游河道发生长时间、长距离的冲刷。2001-2021年期间宜昌至长江口已累计冲刷了50.3亿m³,需厘清河道冲刷对河势、防洪、航运等方面产生影响。分析表明:三峡工程运用后,长江中下游河势总体稳定,弯道段出现切滩撇弯、汊道段出现塞支强干等现象;河道槽蓄量的持续增加,进一步增大了河道调蓄和行洪能力,但水流顶冲点的变化和近岸河床的冲刷下切,使得河道崩岸频发,并影响河势稳定和防洪安全;在河道冲刷、河势控制与航道工程综合作用下,长江中下游航道条件总体得到改善,但河道不均衡冲刷使得坝下游砂卵石河段出现“坡陡流急”,沙质河段出现洲滩散乱、航槽移位等现象,影响航道条件;同流量下枯水位呈下降态势,逢极枯年份影响长江中下游用水安全;江湖关系发生新变化,“三口”分流道由原淤积转为冲刷,两湖湖区水位不同程度的降低,枯水位出现时间有所提前,不利于湖区水资源和生态环境的安全与可持续发展;三峡工程实施枯水期补水调度和“压咸潮”调度以及长江口北支淤积减缓,对于遏制长江口咸潮入侵有利,入海泥沙显著减少引起长江口近岸河床冲刷,影响沿岸码头的安全运行。;After the construction of cascade reservoirs in the Three Gorges and its upper reaches, the downstream clear water of the dam was discharged, and a long-term and long-distance erosion occurred in the middle and lower reaches of the Yangtze River. From Yichang to the Yangtze Estuary, a total of 5030 million m³ was scoured. Under the background of large-scale erosion in the middle and lower reaches of the Yangtze River, it has a profound impact on river regime, flood control and shipping. The analysis shows that the river regime in the middle and lower reaches of the Yangtze River is generally stable, and the river regime in some parts of the river changes greatly, resulting in the phenomenon of beach cutting and bending, and the phenomenon of strong trunk. The increase of channel storage capacity increases the capacity of river discharge and flood storage, but the change of flow top scour point and the erosion of nearshore riverbed also make the river bank collapse frequently, affecting the stability of river regime and flood control safety. Under the combined action of channel scour, river regime control and channel engineering, channel conditions in the middle and lower reaches of the Yangtze River improved overall. However, due to the unbalanced scouring of the river channel, the sandy pebble river section in the downstream of the dam has a 'steep slope and rapid flow’, and the sandy river section has phenomena such as scattered beaches and channel displacement, affecting the channel conditions; the continuous erosion of river bed results in the decrease of low water level, which affects the water supply safety of life, production and ecology along the middle and lower reaches of the Yangtze River in extremely dry years. The relationship between rivers and lakes has undergone new changes. The three diversion channels have changed from original siltation to erosion. The water levels in the two lakes have decreased to varying degrees, and the low water level has appeared earlier, which has adversely affected the water resources and ecological environment in the lake area. The regulation of water replenishment and saltwater intrusion in dry season of the Three Gorges Project and the slowing down of siltation in the north branch are beneficial to the control of saltwater intrusion in the Yangtze Estuary. The sediment discharged into the sea from the Yangtze Estuary is significantly reduced and the riverbed near the Yangtze Estuary is scoured strongly. It seriously threatens the safety of the main structure of coastal enterprise wharf.

Looking through the Orange Glass – A Novel Perspective on Key Seismic Features and Their Influence on Hydrocarbon Potential within the Orange Basin, South Africa

This work evaluates the hydrocarbon potential of the Orange Basin offshore South Africa by considering key seismic features such as basement, Gravity Slide Systems (GSS), Mass Transport Complexes/Deposits (MTCs/MTDs), contourites, mixed depositional systems, and seafloor morphology. Further, by integrating an updated structural domains classification, we revise the chronostratigraphy of the basin. Two gravity slide systems within the northern and southern parts of the basin are mapped in their entirety and named the Orange-Senqu and Bergoli Deepwater Fold and Thrust Belts (DWFTBs), respectively. In addition to uplift, gravitational collapse, and differential sediment loading, sediment failure is likely also triggered by fluid expulsion from the basement and gas hydrate dissociation. MTCs comprise 70–90% of the Cretaceous succession from the slope seaward. We propose the name ‘crestal deformation surface’(creds) for the top of an MTC. Contourite and mixed depositional systems are described for the first time in the basin. The Sandhaai prospect is a new turbidite-contourite fan play type. Venus and Graff-type analogues, and ‘intra MTC’ plays are also recorded within the basin. Finally, we document a segmented continental slope. Segmentation is attributed to sediment mass failure and deposition, and large-scale erosion driven by bottom currents, giving the slope a graded-to-stepped appearance.

Modeling of sediment transport in rapidly-varying flow for coastal morphological changes caused by tsunamis

Tsunamis can cause significant coastal erosion and harbor sedimentation that exacerbate the concomitant flood hazards and hamper recovery efforts. Coupling of the non-hydrostatic model NEOWAVE and the sediment transport model STM provides a tool to understand and predict these morphological changes. The non-hydrostatic model can describe flow fields associated with tsunami generation, wave dispersion as well as shock-related and separation-driven coastal processes. The sediment transport module includes non-equilibrium states under rapidly-varying flows with a variable exchange rate between bed and suspended loads. A previous flume experiment of solitary wave runup on a sandy beach provides measurements for a systematic evaluation of sediment transport driven by shock-related processes. The extensive impacts at Rikuzentakata, Iwate, Japan and Crescent City Harbor, California, USA from the 2011 Tohoku tsunami provide pertinent case studies for model benchmarking. We utilize a self-consistent fault-slip model to define the tsunami source mechanism and field survey data to determine the characteristic grain sizes and morphological changes. The near-field modeling at Rikuzentakata gives reasonable fits with observed large-scale erosion and sedimentation associated with transition of the incoming wave into a surge and formation of a hydraulic jump in the receding flow. The non-hydrostatic module becomes instrumental in resolving tsunami waves at the far-field shore of Crescent City. The results show good agreement with local tide-gauge records as well as observed scour around coastal structures and deposition in basins resulting from separation-driven processes. While the erosion patterns in the laboratory and field cases can be explained by suspended sediment transport in the receding flow, bed load transport can be a dominant mechanism in sediment laden flows and scour around coastal structures.

Holocene deposits at the lower shoreface and inner shelf of the Dutch coast

To further detail insights into the composition and distribution of Holocene and late Pleistocene deposits at the surface and in the shallow subsurface of the lower shoreface of the Dutch coast, vibrocores were collected in three coastal sections. The study areas Noordwijk, Terschelling and Ameland Inlet represent contrasting settings: closed Holland coast vs. segmented Wadden coast (Noordwijk – Terschelling) and lower shoreface of a barrier island vs. lower shoreface of an ebb-tidal delta (Terschelling – Ameland Inlet).Six different depositional environments were distinguished: 1. the active layer, 2. seabed deposits, 3. lower-shoreface deposits, 4. ebb-delta channel deposits, 5. tidal channel deposits, and 6. alluvial (river) channel deposits. The several dm-thick active layer forms the mobile top of the seabed-, lower-shoreface- and ebb-delta channel deposits. Ebb-delta channel deposits (probably grading into terminal-lobe deposits) are restricted to the Terschelling and Ameland Inlet areas, fluvial deposits to the Noordwijk site. The front of the Ameland Inlet ebb-tidal delta is steep and consists of material supplied by the main ebb channel. These ebb-delta channel deposits are reworked by waves and currents, they grade seawards into seabed deposits. The low-gradient shoreface of the Terschelling site consists of a thin active layer on top of ebb-delta channel deposits. At the Noordwijk site fluvial deposits with incised bodies of tidal channel sand underlie a steep shoreface and a ridge-swale topography farther offshore.The ebb-delta channel deposits at the shoreface of Terschelling are similar to those at the front of the ebb-tidal delta of Ameland Inlet. Moreover, the tidal channel deposits that are common in the Noordwijk area, occur in only one core at Terschelling. This indicates that the deposits underlying the shoreface of Terschelling were formed in the ebb-tidal delta of a precursor of Ameland Inlet and not in the transgressive setting of a retreating barrier island. These deposits were possibly formed as part of the ebb delta of the Middelzee, a large medieval predecessor of the Ameland tidal basin, this needs to be confirmed by dating.Reworking of the shoreface of the prograded Subboreal beach barriers at Noordwijk at water depths of 12.5–13.5 m produced a 1.1-m-thick series of fining-upwards storm beds, including the active layer. At the shoreface of Terschelling storm beds are missing at these depths and only an active layer 0.2 m thick occurs. This suggests that the largest part of reworked sediment at Terschelling is carried off, which implies large-scale erosion of the shoreface. This needs further investigation.

Large-scale sediment modeling with inertial flow routing: Assessment of Madeira river basin

The flow routing module in several large-scale erosion and sediment transport models generally adopts simplifications that ignore important physical aspects of river dynamics. In this study we compare for the first time the results generated by a large-scale erosion and sediment transport model, using two different flow routing approaches: a combined Saint-Venant and Muskingum-Cunge method and the Inertial flow routing. For this assessment, simulations are performed with the MGB-SED model. We evaluate sediment characteristics such as suspended sediment load and concentration, floodplain effects, and the flux of suspended sediment within the Madeira River basin. The simulation with the inertial approach presents satisfactory results, similar to those achieved with the combined Saint-Venant approach for lowland rivers and the Muskingum-Cunge method for steeper rivers. Also, Inertial module is capable to represent the complex processes of the basin, but with easier preprocessing and numerical features, thus promising expanded capabilities for large-scale simulations.

Transgressive nature and chilled margins of the Upper Zone in the western Bushveld Complex, South Africa

ABSTRACT The Upper Zone of the Bushveld Complex has long been known to have formed from a major influx of magma into the chamber that caused large-scale erosion of the chamber floor cumulates. The most dramatic manifestations of this process are two major gap areas (Northern and Southern) in the western Bushveld Complex in which the Upper Zone appears to have eroded away the underlying cumulates down to the very base of the Complex. However, due to almost complete lack of outcrops in the gap areas, no direct field observations have ever been reported to confirm the transgressive nature of the Upper Zone. Here, we present for the first time such observations from the Kameelhoek chromite mine located at the margin of the Northern Gap. In the open pit we have documented several transgressive depressions (up to 40 m in width) in the orthopyroxenite and chromitites of the Lower Critical Zone that are filled in with magnetite gabbro of the Upper Zone. The magnetite gabbro is chilled against the sidewalls of the depressions, forming glassy and fine-grained textured rocks with plagioclase laths arranged in radial clusters. Mineralogically and chemically, the magnetite gabbro correlates with cumulates from the lowermost part of the Upper Zone at its normal position in the complex. Three major points that have emerged from this study are: (1) the Critical Zone has been eroded away by magma that was parental to the Upper Zone, (2) this eroding magma was not the one that initiated formation of the Pyroxenite Marker, but rather the evolved melt that replenished the chamber at some later stage, and (3) the melt was phenocryst-free and likely derived from a deep-seated staging chamber. Our study thus supports a recent notion that even during the formation of the Upper Zone, the Bushveld chamber had still been operating as an open system that was replenished by melts from deeper magma sources.

Varietal Threat Index for Monitoring Crop Diversity on Farms in Five Agro-Ecological Regions in India

Our knowledge about the status of agrobiodiversity on farms is still very limited. While several studies to assess the crop genetic diversity on farms have been undertaken, there are no systematic documentation and monitoring practices for varietal diversity in space and time. Achievement of the agrobiodiversity Aichi Target 13, established under the Biodiversity Strategy Plan 2011–2020, have failed due to the lack of existing data on varietal diversity at country, regional and global levels. Here, we propose a method for calculating the Varietal Threat Index using the four-cell analysis (FCA) participatory methodology at different geographical scales to monitor changes in the varietal diversity on farms and to compare between areas. We tested the method with datasets collected from the UN-Environment GEF project implemented in India, in which data on crop and varietal diversity were collected across seven states in India, covering five agroecological regions. Results showed that landraces are still commonly grown in the study sites, especially in the central and western regions, and that more than 50% of landraces are considered threatened, suggesting that conservation interventions are required to prevent large-scale genetic erosion. A long-term monitoring framework for varietal diversity in India is proposed.

Calcium carbonate production in the southernmost subtropical Atlantic coral reef

Emerging evidence have been supporting the idea that the better known South Atlantic coral reefs (located between 18°S and 24°S) are now essentially senescent structures that have experienced little or no additional vertical reef growth over the past millennia. This has often coincided with a shift to a dominance of non-coral calcifying organisms becoming the main CaCO3 producers in these high latitude and marginal marine settings. Here, we used Calcification Accretion Units (CAUs) and census-based methods to measure non-coral rates of CaCO3 production on the geologically senescent reef and adjacent rhodolith beds within the southernmost subtropical Atlantic reef (i.e., Queimada Grande Reef, QGR). The reef habitat is currently producing CaCO3 at rates of ∼126 g m−2 yr−1. In contrast, fragments of dead corals skeletons deposited adjacent to the reef over the last ∼2000 years are now colonized by crustose coralline red algae. These form a rhodolith bed that produces CaCO3 at rates of 858 g m−2 yr−1. Our results indicate that, whilst not sufficient to promote active net framework accumulation, CaCO3 production by coralline algae and bryozoans on the QGR appears to be sufficient to at least limit net large-scale erosion of the underlying reef structure, allowing the reef structure to persist in a state close to budgetary stasis. Finally, our results are also of relevance for providing insights regarding the balance of CaCO3 production/dissolution/erosion processes in coral reefs, especially in these less understood marginal reefs.

RETRACTED ARTICLE: Simulation of coastal beach stability and coastal running based on embedded image system

Approximately 80% of the sandy beaches along the coastline have been eroded, resulting in the coarsening, narrowing of sandy beaches, steeper slopes, accelerated shoreline retreat, loss of a large amount of coastal land, and destruction of the ecological environment. Coastal beach stability assessment technology, through more than 1 year of field data observation, the stability analysis of the coastal beaches, from the observations of various data shows that the coastal beaches are in a dynamic and stable equilibrium state during the measurement period; around the beach, there is no large-scale erosion and accumulation. Moreover, because society is progressing, people’s concept of life is also constantly changing, and the requirements for health are also constantly improving. People have begun to advocate sports, and running has become people’s main sport due to its low economic cost and convenience. In this way, even many people who have no experience in running start to run. However, due to the constraints of the runners’ physical fitness and the surrounding sports environment and other objective conditions, coupled with the current running styles and even insufficient research on the prevention of injuries during the running process, they cannot meet the actual needs of people during the running process. People who experience sports are more likely to get injured. Using the embedded image system to conduct sustainable simulations of people running along the coast can fully analyze and investigate the injuries related to running, so that people can exercise more scientifically and promote running along the coast. At the same time, in order to improve the image display effect and algorithm efficiency of embedded image processing system in low resolution environment, Bresenham anti aliasing algorithm of region cloth is improved. The combination of linear scan conversion algorithm and region anti aliasing algorithm can effectively improve the drawing speed and operation efficiency of anti aliasing algorithm.

Effects of vegetation and climate on the changes of soil erosion in the Loess Plateau of China

Soil erosion is simultaneously driven by multiple factors. Identifying the dominant controlling factors and quantifying the contribution of each factor would be helpful to sustain water and soil resources. China's Loess Plateau was taken as an example area to investigate the above issues since it is the most eroded region in the world, and its soil loss is being controlled by a large-scale revegetation program. We extended the Revised Universal Soil Loss Equation (RUSLE) to large-scale erosion estimation with the aid of GIS for the period of 1986–2015, analyzed the relationship between erosion and controlling factors by correlation and wavelet coherence analysis, and quantified the contribution of each factor to erosion change by the elasticity coefficient method. Results showed that the soil erosion decreased from 1013 t·km−2·a−1 in 1991–1995 to 595 t·km−2·a−1 in 2011–2015, with a downward trend in the whole period. Spatially, most areas had soil erosion of slight intensity, and the areas with high-intensity erosion concentrated in a northeast-southwest strip with hilly-gully landscapes or densely distributed rivers. The changes in surface conditions including vegetation cover and soil conservation measures had dominant effects on the spatial heterogeneity of erosion, their contribution to erosion reduction was 119%. But rainfall erosivity increased soil erosion, and it had a contribution to erosion reduction of −28%. These results are helpful in understanding the mechanism behind the changes in soil erosion and providing information for sustainable soil and water management and vegetation restoration.

New progress and prospect of Middle Permian natural gas exploration in the Sichuan Basin

In recent years, natural gas exploration in the deep marine carbonates of the Sichuan Basin has been strengthened continuously. And based on the research results in the regional geological setting, a great number of new geological understandings are obtained in terms of lithofacies palaogeography, reservoir genesis and hydrocarbon accumulation evolution. What's more, new progress of natural gas exploration is achieved in many strata and domains in the Sichuan Basin, e.g. Qixia Fm of Middle Permian, Maokou Fm and Emeishan basalt, and the prospect of natural gas exploration is promising. In this paper, the recent exploration achievements of Middle Permian natural gas in the Sichuan Basin were summarized. First, under the control of palaeogeomorphology of late Caledonian, marginal platform shoal and girdle intra-platform shoal that are distributed in a large scale were developed at the edge of western Sichuan sea basin and in the periphery of central Sichuan paleo-uplift during the sedimentation of Qixia Fm, and they are large in scale and extensive in distribution range. Dolomite reservoirs are developed with good gas bearing property. Second, two kinds of reservoir bodies are mainly developed in the Maokou Fm of the Sichuan Basin. One is the shoal body which is developed along the marginal platform and the intra-platform high belt under the control of facies belt superimposed with late dolomitization, and the other is the effective karst reservoir which is distributed at the karst slope belt under the action of large-scale erosion in the late Maokou period. Third, volcanic gas reservoirs are discovered in the areas of Chengdu and Jianyang, and their quality reservoirs are of volcanic eruption facies and characterized by great thickness, good physical properties and extensive distribution. The discovery of this new type of gas reservoir expands the exploration domain of Middle Permian natural gas in the Sichuan Basin. In conclusion, the improvement of the large-scale natural gas exploration potential in many strata and domains of Middle Permian in the Sichuan Basin promotes it to be one important replacement domain of the further increase of natural gas production and reserves in the Sichuan Basin.

River-ice effects on bank erosion along the middle segment of the Susitna river, Alaska

This paper presents findings quantifying the extent to which river ice impacted and eroded banks along the middle segment of the Susitna River, Alaska. Analyses of aerial photography (taken over two, one-year periods) established bank-erosion rates for two reaches of differing morphology (multi-channel; and, single channel). Reconnaissance videos were used to establish the timing of erosion within each one-year period. Whereas the first winter ended with a thermal breakup of the river's ice cover, the second winter ended with the dynamic breakup of the ice cover in both reaches. The relatively low flow rate and weak ice associated with thermal breakup caused no large-scale erosion in the reaches, while the higher flow rates and stronger ice associated with dynamic breakup initiated large-scale bank erosion; up to 61% of bank erosion over a one-year period. Single year erosion values ranged from 10 to 30% of the historical erosion over two 30-yr periods. Analysis of the erosion and ice-scar data along the Middle River suggest the recurrence interval for dynamic ice-breakup is about 5–13 years. During dynamic breakup, ice-laden flows abraded banks, and directly impacted trees and shrubs. Thicker ice covers and ice jam development compounded ice-induced bank erosion in the multi-channel reach compared to the single channel reach.

National issues and their reflections in The Cheviot, the Stag and the Black, Black Oil

Having left an immense impact on audiences of almost all ages and social backgrounds in Scotland, the Cheviot, the Stag and the Black, Black Oil is a theatrical show which raises national issues like Scottish identity, sense of belonging, Gaelic culture with direct references to economic and cultural policies implemented by central government in Britain. On the one hand, the play mainly gives a universal message that the working-class should gather under the roof of socialism against capitalism which has led to the economic and cultural destruction; on the other hand, it celebrates revival of Scottish culture, which has undergone a large-scale erosion and degeneration by the dominant culture, namely the English. The national issues depicted in the play have led to a growing awareness about Scottishness among Scottish audiences who started questioning their political positions in the UK. The fact that the indigenous people have been invited to re-assess the past events and make direct links with the present events such as the discovery of North Sea Oil has triggered the Scottish communities to raise a louder voice against British policies on Scotland. The play has probably had a direct impact on cultural and political relations between Scotland and Britain, for the number of independence supporters has been on the rise since the 1970s. With the devolution in 1998, Scotland re-established its parliament, adjourned with the Act of Union in 1707. Such political gains and the UK’s withdrawal from the EU have enhanced Scottish people’s desire to officially separate from the UK through a new referendum, which they believe, will result in success. This paper puts forward that the play could be used as a means of propaganda to increase the number of ‘Yes’ votes in the referendum process.