Soil Erosion Assessment of Alpine Grassland in the Source Park of the Yellow River on the Qinghai-Tibetan Plateau, China

The source park of the Yellow River (SPYR), as a vital ecological shelter on the Qinghai-Tibetan Plateau, is suffering different degrees of degradation and desertification, resulting in soil erosion in recent decades. Therefore, studying the mechanism, influencing factors and current situation of soil erosion in the alpine grassland ecosystems of the SPYR are significant for protecting the ecological and productive functions. Based on the 137Cs element tracing technique and machine learning algorithms, five strategic variable selection algorithms based on machine learning algorithms are used to identify the minimal optimal set and analyze the main factors that influence soil erosion in the SPYR. The optimal model for estimating soil erosion in the SPYR is obtained by comparisons model outputs between the RUSLE and machine learning algorithms combined with variable selection models. We identify the spatial distribution pattern of soil erosion in the study area by the optimal model. The results indicated that: (1) A comprehensive set of variables is more objective than the RUSLE model. In terms of verification accuracy, the simulated annealing -Cubist model (R = 0.67, RMSD = 1,368 t km–2⋅a–1) simulation results represents the best while the RUSLE model (R = 0.49, RMSD = 1,769 t⋅km–2⋅a–1) goes on the worst. (2) The soil erosion is more severe in the north than the southeast of the SPYR. The average erosion modulus is 6,460.95 t⋅km–2⋅a–1 and roughly 99% of the survey region has an intensive erosion modulus (5,000–8,000 t⋅km–2⋅a–1). (3) Total erosion loss is relatively 8.45⋅108 t⋅a–1 in the SPYR, which is commonly 12.64 times greater than the allowable soil erosion loss. The economic monetization of SOC loss caused by soil erosion in the entire research area was almost $47.90 billion in 2014. These results will help provide scientific evidences not only for farmers and herdsmen but also for environmental science managers and administrators. In addition, a new ecological policy recommendation was proposed to balance grassland protection and animal husbandry economic production based on the value of soil erosion reclassification.

Environmental Services: A New Approach Toward Addressing Sustainable Development Goals in Sub-Saharan Africa

The physical environment provides resources and specific types of environmental services relevant to the maintenance of human livelihoods globally and with specific reference to sub-Saharan Africa, including soils, food, and water systems. Previous studies on the shared nexus of such resources commonly view these as self-contained systems operating independent of their physical contexts provided by landscape-scale geomorphology and its related processes. This study critically examines the viewpoints adopted by such nexus studies with specific reference to sub-Saharan Africa, arguing that these studies are reductive, considering only the shared disciplinary overlap (nexus) and not their wider contexts, and are based on only a limited understanding of the workings of physical systems. This study argues that considering the attributes of the physical landscape and its provision of environmental services provides a broader and scientifically-informed context for understanding of interlinked issues such as relationships between soil–food–water systems. Framing such “nexus” studies in this wider context can derive a better understanding of the connections between different elements such as soil, food, and water, amongst others, and with respect to the United Nations' Sustainable Development Goals. The concept of environmental services is therefore a more powerful tool to examine both the connections between physical and human environmental processes and properties in sub-Saharan Africa, and to address overarching environmental issues such as land degradation, soil erosion loss, water scarcity, and impacts of climate change.

Experimental Study on the Design and Behavior of Concrete Pavement Joint Sealants

Joints in concrete pavement are intended to provide freedom of movement in a concrete slab relative to the volumetric effects. Changes such as this can occur owing to drying shrinkage, temperature changes, and moisture differences that develop within the slab. A key reason to seal the rigid pavement joints is to prevent, or at least reduce, the amount of water from rainfall events infiltrating the pavement structure, which can ultimately contribute to subbase erosion, loss of support, and the build-up of a fine, incompressible material on the face of the joint. The strength of the joint sealant bond and stress of the interface between the sealant and the face of the joint reservoir play important roles in joint sealant failure. Thus, in this research, experimental coupling tests were conducted to investigate the geometric characteristics of the sealant/joint reservoir design. The stress–strain relationship on the interface was investigated according to its geometry, both with regard to the shape factor (SF) and the degree of curvature (DoC). The SF and DoC were evaluated through a tensile test of the joint sealant based on these geometric characteristics. Also discussed are the shape factors (SFs) of the joint sealant currently being recommended, the SF most appropriate for a narrow-width joint, and the surface finish of the joint sealant. Based on this study, the effects of sealant geometries (i.e., SF and DoC) should be considered during design and installation. Also, further research into more realistic SFs for narrow-width joints and self-leveling sealants is recommended.

ENVIRONMENTAL AND HEALTH EFFECTS OF CLIMATE CHANGE IN KADUNA METROPOLIS

This study examined environmental and health effects of climate change in Kaduna metropolis. Primary data were obtained through randomly administered 184 structured and semi structured survey questionnaires to purposefully selected groups of people, workers and students in the metropolis. Secondary data were obtained from desk reviews of other literatures and interviews of staff of Nigerian Metrological (NiMET) Agency and Ministry of Environment Kaduna. Descriptive statistics using Likert rating scale was employed for the analyses of the data. Findings revealed percentage range of strongly agree and agree of 80% - 59.8% that climate change has negative environmental and health effects in Kaduna metropolis. The environmental effects identified are: flooding, desert encroachment, drought, land degradation, run-off, soil erosion, loss of water resources and biodiversity and poor agricultural productions while the health effects are: hyperthermia, vector and water borne diseases (cholera, malaria), heart ailments, dehydration and diseased crops. The study also discovered that the comprehension of the concept climate change in the metropolis is limited. Finally, the study recommends intensive public education and enlightenment on the causes and effects of climate change, strong legislations and enforcement of environmental laws and adaptation measures.

African Yam Bean the Choice for Climate Change Resilience: Need for Conservation and Policy

Global warming has emerged as a major challenge to development and human wellbeing in Sub-Saharan Africa in general and Nigeria in particular. Periodic incidents show that this challenge will continue and increase in impact on all aspects of natural resources – agriculture, ecosystems services, biodiversity depletion, environmental degradation and human health. Recognizing the enormous potential of underutilized plant genetic resources (PGRs) is crucial as sources of solutions to a number of these threatening challenges emanating from climate change (food and nutrition insecurity, genetic erosion, loss of agro-biodiversity, green job growth and income generation) cannot be over-emphasized. Sphenostylis stenocarpa (Hochst. ex. A. Rich) Harms., commonly known as African yam bean (AYB) belonging to the leguminous Fabaceae, is an underutilized PGR with rich portfolio which could serve as vital source of robust adaption and resilient germplasm for vulnerable local communities in Nigeria. Its substantial nutritional, environmental, cultural, social, medicinal, industrial and soil restorative potentials underpins its position as climate – smart species. Enhancing the potentials of African yam bean via robust innovative approaches for wider utilization through accelerated research, farmer seed exchanges, in-situ and ex-situ conservations, farmers selection, and policy programs such as seed sovereignty will accentuate its adaptation and used as resilient climate –smart species for the vulnerable groups in Nigeria to cushion impact of climate change.

Mangrove in Bedono Village: Past, Present and Future

Bedono Village is experiencing environmental problems due to land use, so that the mangroves area is converted into ponds and villages. On the other hand, this change causes erosion, loss of hundreds of hectares of land, disturbing the livelihoods. This study aimed to analyze the type and area of mangroves in Bedono Village. The mangrove data were obtained from field studies by exploration. Each location was chosen subjectively to determine the station based on mangrove species information. After that, the plot was determined. The mangrove area was processed based on high-resolution imagery data from 2015 to 2020. Based on the identification, six types of mangroves were found in Bedono Village, Demak. Meanwhile, the mangrove area in Bedono Village has decreased from 2015 to 2020. The efforts made by the community in replanting mangroves have been successful based on indicators of mangrove areas. For this reason, the effort that must be done now and in the future is to maintain the existence of mangroves by properly implementing existing regulations

THE RESEARCH PROJECT “EARTHEN ARCHITECTURE IN THE IBERIAN PENINSULA: STUDY OF NATURAL, SOCIAL AND ANTHROPIC RISKS AND STRATEGIES TO IMPROVE RESILIENCE (RISK-TERRA)”. OBJECTIVES AND FIRST METHODOLOGY

The Iberian Peninsula possesses extensive earthen monumental and vernacular architectural heritage. The extension of the territory and its heterogeneous geography and climate, variety of available materials, and cultural diversity are the main factors which have brought about the great wealth of both the architecture, urban and rural settings, and the constructive techniques mainly using earth (rammed earth, adobe, half-timber, cob and its variants). However, despite being an essential part of the Iberian culture, this heritage has been greatly abandoned due to changes in ways of life, the depopulation of rural areas, the lack of social recognition, etc. The research project “Risk-Terra – Earthen architecture in the Iberian Peninsula: study of natural, social and anthropic risks and strategies to improve resilience” (ref. RTI2018-095302-B-I00), funded by the Spanish Ministry of Science, Innovation and University (2019–2021) aims to provide a scientific study of natural hazards (floods, landslides, earthquakes, winds, rise of temperatures), social hazards (abandonment, loss of social reputation, demographic pressure, tourism development…) and anthropic hazards (carelessness and negligence, lack of protection and maintenance…), as well as deterioration mechanisms (erosion, loss of materials/parts, collapse…) and transformation dynamics (replacement, use of incompatible techniques and materials…), to which the earthen architecture of the Iberian Peninsula is currently subject. This paper presents the general and specific objectives and the methodology to be used in the project.

ASSESSMENT OF SOIL EROSION BY RUSLE MODEL USING GIS: A CASE STUDY OF CHEMORAH BASIN, ALGERIA

Soil erosion by water is one of the major sources of land degradation. Erosion contributes to the temporary or permanent lowering of the productive capacity of agricultural land and sedimentation of dams. The purpose of this study is to assess soil loss rate using a GIS/RUSLE approach at the Chemorah basin by focusing on two catchments, namely, Reboa and Soultez. The assessment of soil erosion aims thus to identify the lands more prone to erosion which are vital for erosion management process. RUSLE model supported by GIS software is to predict the spatial variability of erosion occurring in the Chemorah basin and its sub-basins. Five inputs such as rainfall erosivity, soil erodibility, slope and length of slope, plant cover and anti-erosion practices, are used in the model to compute the erosion loss rates. The mean annual soil loss in Chemorah river basin is estimated at 7.52 T/ha/year, and varying between 3.78 T/ha/year in Soultez catchment and 6.06 T/ha/year in Reboa sub-basin. The study shows that low erosion (≤ 7 T/ha/year) covers 52% and high to very high erosion (> 7 T/ha/year) which does not exceed 23% of the Chemorah basin area. The results indicate that Reboa catchment faces the greatest risk of soil erosion compared to Soultez one, with contributions of 44 % and 32 % of their basin areas respectively. Use of the erosion factors’ information coupled with GIS/RUSLE program can help to design the appropriate land management to minimize soil erosion in the basin.

Modeling of Erosion Response of Cold-Sprayed In718-Ni Composite Coating Using Full Factorial Design

In this work, the cold-spray technique was used to deposit Inconel 718–nickel (1:1) composite coatings on stainless steel substrate. A general full factorial design was adopted to identify the statistically significant operating variables, i.e., impingement angle, erodent size, and feed rate on the coating erosion response. Erodent feed rate, impingement angle, and the interaction between impingement angle and erodent size were identified as the highly significant variables on the erosion rate. Then, a model correlating the identified variables with the erosion rate was derived. The best combination of control variables for minimum erosion loss with respect to erodent feed rate, erodent size, and impingement angle was 2 mg/min, 60 μm, and 90°, respectively. To analyze the erosion mechanism, the erodent samples were finally observed using Scanning Electron Microscope (SEM).