Soil erosion is a severe environmental problem worldwide as it washes away the fertile topsoil and reduces agricultural production. Nepal, being a hilly country, has significant erosion disputes as ...well. It is important to cognise the soil erosion processes occurring in a river basin to manage the erosion severity and plan for better soil conservation programs. This paper seeks to calculate the sediment yield and maximum outflow from the Sarada river basin located in the western hills of Nepal using the computer-graphic Intensity of Erosion and Outflow (IntErO) model. Asymmetry coefficient of 0.63 was calculated, which suggests a possibility of large floods to come in the river basin in the future whereas the maximum outflow from the river basin was 1918 m³ s−1. An erosion coefficient value of 0.40 was obtained, which indicates surface erosion of medium strength prevails in the river basin. Similarly, the gross soil loss rate of 10.74 Mg ha−1 year−1 was obtained with the IntErO modeling which compares well with the soil loss from the erosion plot measurements. The IntErO model was used for the very first time to calculate soil erosion rates in the Nepalese hills and has a very good opportunity to be applied in similar river basins.
Land use change in all river basins leads to changes in hydrologic response, soil erosion, and sediment dynamics characteristics. Those changes are often viewed as the main cause of accelerated ...erosion rates. We studied the impact of land use changes on soil erosion processes in one of the watersheds in Montenegro: the Miocki Potok, using this watershed as a pilot river basin for this area. We simulated responses of soil erosion processes by using a process-oriented soil erosion Intensity of Erosion and Outflow (IntErO) model, with different settings of land use for the years 1970, 1980, 1990, 2000, 2010, and 2020. The model provides fast, effective, and affordable insight into the effects of land use change on soil erosion processes. Testing of the applied procedures was important for the further establishment of watershed management methodologies at the national level, for the other 300 river basins of Montenegro. For the current state of land use, calculated peak discharge for the Miocki Potok was 364 m3 s−1 (2020)–372 m3 s−1 (1970) for the incidence of 100 years, and there is a possibility for large flood waves to appear in the studied basin. Real soil losses, Gyear, were calculated at 13680 m3 year−1 (2020) and specific 333 m3 km−2 year−1 (2020). A Z coefficient value of 0.439 (2020) indicated that the river basin belongs to destruction category III. The strength of the erosion process was medium, and according to the erosion type, it was mixed erosion. According to our analysis, the land use changes in the last 50 years influenced a decrease in the soil erosion intensity for 14% in the Miocki Potok River Basin. Further studies should be focused on the detailed analysis of the land use changes trends with the other river basins at the national level, closely following responses of soil erosion to the changed land use structure, and effects of plant-and-soil interaction on soil erosion and sediment dynamics.
Soil erosion, a land degradation process triggered by natural and anthropogenic factors, seriously impacts landscapes and water resources. The influence of vegetation cover and land use changes on ...intensity of soil erosion of two catchments in mountainous regions of Morocco is evident, as it alters hydrologic response and sediment dynamics. This research aims to analyze the interactions among plants, soil, geology, meteorology, and orography, assessing soil erosion responses using the process-oriented IntErO model - Erosion Potential Method to determine erosion rates. The obtained results indicate that the Tiguert river basin experiences higher soil losses (Ggod = 5184.47 m³/god) and soil losses per square kilometre (Ggod/km² = 508.28 m³/km² god) compared to the Wanmroud catchment (Ggod = 2555.66 m³/god, Ggod/km² = 381.44 m³/km² god), confirming the theory that areas with denser and more effective vegetation cover experience lower soil erosion rates. Furthermore, the Wanmroud basin exhibits a more regular shape and lower watershed development coefficient, implying lower human impact. This study has shown the relationships between land use changes, vegetation cover, and soil erosion dynamics, offering valuable insights for sustainable land management practices in mountainous regions of Morocco.
Green roof substrates—A literature review Kader, Shuraik; Chadalavada, Sreenivasulu; Jaufer, Lizny ...
Frontiers in built environment,
10/2022, Letnik:
8
Journal Article
Recenzirano
Odprti dostop
Green roofs are becoming increasingly popular in urban construction due to their wide array of benefits for creating a sustainable ecosystem. Many stakeholders invest in green roofs in the 21st ...century to enhance the environmental quality and mitigate urban ecological pollution. The substrate layer is the most important and critical component of green roof systems. The objective of the review study is to present the important information regarding the required elements that need to be considered for substrate selection of green roofs by critically reviewing the scientifically published articles. Research findings from past studies relevant to green roofs, vegetation and selective substrate parameters were extensively discussed under different topics related to water retention, drought resistance and related physico-chemical parameters. The generalities in past research articles were presented and special focus was provided on specific research articles those presented novelty regarding green roof substrates. Furthermore, the hotspots in all the considered research articles were commentatively identified and the appropriate solutions were evaluated. The critical review of published research articles indicates that most of the research on green roof substrates was conducted in either controlled laboratories or greenhouses and did not provide much importance to actual field tests. Therefore, these research findings are not sufficient to obtain the realistic field outcomes of the research. Future studies on green roof substrates should need to incorporate field experiments along with classical controlled tests by adhering to standard guidelines for assimilating climatic influences in substrates. Few studies have focused on dry climates, and further research needs to be conducted on dry climates due to their high susceptibility to drought and evapotranspiration. This manuscript would be the first review article that mainly focuses on substrates for green roofs, which is a novel aspect.
Land use change is known as one of the main influencing factors on soil erosion and sediment production processes. The objective of the article is to study on how land use change impacts on soil ...erosion by using Intensity of Erosion and Outflow (IntErO) as a process-oriented soil erosion model. The study has been conducted under land use changes within the period of 1991–2014 in the Talar watershed located in northern Iran. The GIS environment was used to prepare the required maps including Digital Elevation Model (DEM), geology, land use, soil, and drainage network. The climatology data including average annual precipitation and air temperature as well as the volume of torrential rain were extracted from the data of meteorological stations located inside and around the study watershed. The results indicates that, within the period of 1991–2014, the forest area decreased by 12,478.04 ha (6%), while the other land uses including rainfed agriculture, rangeland, irrigated agriculture, and residential area increased by 7248.25, 4481.05, 476.00, and 273.95 ha, respectively. The estimated outflow with 100 year return interval was 432.14 m3 s−1 in 1991, which increased to 446.91 m3 s−1 in 2014. It can be concluded that the probability of larger and/or more frequent floods waves in the Talar River is expected to increase. In addition, the amount of production of erosion material (gross erosion) in the watershed increased from 1,918,186 to 2,183,558 m3 yr−1, and the real soil losses per year (sediment yield) of the watershed increased from 440,482.4 to 501,421.3 m3 yr−1. The results clearly emphasized how the lack of appropriate land management and planning leads to increase the maximum flow discharge and sediment yield of the watershed.
We bring a practical and comprehensive GIS-based framework to utilize freely available remotely sensed datasets to assess wildfire ignition probability and spreading capacities of vegetated ...landscapes. The study area consists of the country-level scale of the Romanian territory, characterized by a diversity of vegetated landscapes threatened by climate change. We utilize the Wildfire Ignition Probability/Wildfire Spreading Capacity Index (WIPI/WSCI). WIPI/WSCI models rely on a multi-criteria data mining procedure assessing the study area’s social, environmental, geophysical, and fuel properties based on open access remotely sensed data. We utilized the Receiver Operating Characteristic (ROC) analysis to weigh each indexing criterion’s impact factor and assess the model’s overall sensitivity. Introducing ROC analysis at an earlier stage of the workflow elevated the final Area Under the Curve (AUC) of WIPI from 0.705 to 0.778 and WSCI from 0.586 to 0.802. The modeling results enable discussion on the vulnerability of protected areas and the exposure of man-made structures to wildfire risk. Our study shows that within the wildland–urban interface of Bucharest’s metropolitan area, there is a remarkable building stock of healthcare, residential and educational functions, which are significantly exposed and vulnerable to wildfire spreading risk.
We present the first high-resolution Holocene pollen, plant-macrofossil, and charcoal records from the upper-montane zone in the central Dinaric Alps. Drawing on these new records from well-dated ...lacustrine sediments of Zminje Jezero (ca. 1500 m a.s.l.; Montenegro) and on independent chironomid-inferred summer temperatures, we explore long-term ecosystem responses to variations in climate, fire disturbances and land use, as well as legacy effects of past environmental changes. A mixed spruce-fir forest established in the upper-montane zone around 9500 cal BP, and Fagus sylvatica became co-dominant with the two conifers after 5000 cal BP. Prehistoric land-use pressure was overall remarkably low, but increased since 2000 cal BP and was highest after the Middle Ages. We found a significant positive relationship between biomass burning and summer temperature, indicating that fires were mostly climate driven. Picea abies was insensitive to summer temperature, biomass burning and human impact, which supports the view that spruce forests may not be significantly impacted by fire. In contrast, Abies alba and other disturbance-sensitive trees (Tilia, Ulmus, Fraxinus excelsior-type) show significant negative responses to land-use pressure and positive responses to summer temperature. This supports the notion that these species may be well-adapted to warmer-than present summer temperatures and that their populations declined in recent millennia due to land-use activities. Conversely, F. sylvatica was sensitive to summer temperatures but was promoted by low biomass burning, indicating that its expansion in the spruce-fir dominated forest was enhanced by the onset of cooler and possibly also moister climatic conditions as well as by fire disturbances.
Water pollution is a pressing global concern, with per- and polyfluoroalkyl substances (PFAS) being considered as “forever contaminants.” Among them, perfluorooctanesulfonic acid (PFOS) has received ...significant attention for its adverse effects on human health and aquatic ecosystems. This study aimed to design an innovative adsorbent for effective PFOS removal with exceptional water stability, improving its cost-performance trade-off. The current work simultaneously improved the stability of water of Cu-based metal–organic framework (CMOF) and increased its PFOS removal capacity by modifying it with amine-functionalized SiO
2
nanoparticles (AF-CMOF). AF-CMOF presented a lower specific surface area of 999 m
2
g
−1
compared to CMOF with a surface area of 1098 m
2
g
−1
. AF-CMOF showed remarkable PFOS uptake performance of 670 mg/g compared to the performance of the Cu-based MOF which exhibited a PFOS uptake capacity of only 22 mg/g. The most suitable pH for PFOS removal using both adsorbents was determined to be 3. In addition, AF-CMOF demonstrated excellent water stability, retaining its structural integrity even after seven days of water contact, while CMOF structure collapsed rapidly after four days of water exposure. Moreover, the study identified the significant pH influence on the PFOS uptake process, with electrostatic interactions between protonated amine functionalities and PFOS molecules identified as the dominant mechanism. The study’s findings present the potential of synthesized adsorbent as a superior candidate for PFOS uptake and contribute to the development of effective water treatment technologies.
This study delves into the realm of water treatment by conducting a comprehensive techno-economic evaluation of direct contact membrane distillation (DCMD) and nanofiltration (NF) processes. While ...previous research has explored the technical aspects of membrane distillation (MD) and nanofiltration, there remains a notable gap in economic analyses. Our research aims to bridge this gap by assessing the financial feasibility of employing MD and NF technologies for water desalination. Specifically, we scrutinize the performance of hydrophobic microporous flat sheet membranes crafted from polytetrafluoroethylene (PTFE) supported by non-woven polypropylene (PP) in desalinating brackish water through DCMD and NF processes. By varying operating conditions such as flow rate and feed temperature, we evaluate the membrane's efficacy. Employing an analytical model based on heat and mass transfer equations, we predict process performance across diverse scenarios. Our model demonstrates a high level of accuracy, with flux predictions deviating by less than 10% when utilizing the Knudsen-molecular mechanism model. Furthermore, through a detailed design and economic analysis of industrial-scale units for both processes, we reveal that the cost of permeated water is lower with NF compared to DCMD. Specifically, our calculations indicate a water cost of 1.34 USD/m
3
for DCMD at a feed temperature of 65 °C with an 80% recovery rate, positioning it as a competitive option among conventional desalination methods. Notably, our financial assessment highlights that steam cost constitutes the primary expense in DCMD operations, contingent upon heating value and fuel prices. Noteworthy findings suggest that natural gas emerges as the most cost-effective fuel for steam production in a DCMD plant. This study underscores the economic viability and potential cost efficiencies associated with NF over DCMD in water treatment applications.
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