Degree Of Degradation Research Articles

Internal response of vegetation growth to degrees of permafrost degradation in Northeast China from 2001 to 2020

ABSTRACT Ecosystems at the southern edge of the permafrost distribution are highly sensitive to global warming. Changes in soil freeze-thaw cycles can influence vegetation growth in permafrost regions. Extant studies mainly focused on analyzing the differences of vegetation dynamics in different permafrost regions. However, the intrinsic drivers of permafrost degradation on vegetation growth remain elusive yet. Based on the top temperature of permafrost (TTOP) model, we simulated the spatial distribution of permafrost in Northeast China (NEC) from 2001 to 2020. Using the data of the vegetation Net Primary Productivity (NPP), vegetation phenology, climate and permafrost phenology, and analytical methods including partial correlation, multiple linear regression, and path analysis, we explored the response of vegetation growth and phenology to soil freeze-thaw changes and climate change under different degrees of permafrost degradation. Overall, the start date of the growing season (SOS) was very sensitive to the start date of soil thaw (SOT) changes, and multiple regression analyses showed that SOT was the main factor influencing SOS in 41.8% of the NEC region. Climatic factors remain the main factors affecting vegetation NPP in NEC, and the results of partial correlation analysis showed that only 9.7% of the regional duration of soil thaw (DOT) had a strong correlation with vegetation NPP. Therefore, we determined the mechanism responsible for the soil freeze-thaw changes and vegetation growth relationship using the path analysis. The results indicated that there is a potential inhibitory effect of persistent permafrost degradation on vegetation growth. Our findings would contribute to the improvement of process-based models of forest dynamics in the boreal region, which would help to plan sustainable development and conservation strategies in permafrost areas.

Comparative study on seismic behavior of corroded RC columns strengthened by ECC combined with steel cage /fiber grid/CFRP

A method for strengthening was proposed to improve the seismic behavior of corroded reinforced concrete (RC) columns by using engineered cementitious composite (ECC) combined with a steel cage/fiber grid/carbon fibre reinforced plastics(CFRP). The corroded RC columns strengthened with ECC combined with a steel cage, fiber grid, and CFRP were subjected to low cyclic compression tests at design axial pressure ratios (n) of 0.3 and compared with corroded and uncorroded columns. Experimental results showed that ECC strengthening of corroded RC columns not only significantly improved their load-carrying capacity, displacement ductility, and energy dissipation capacity but also effectively reduced the degree of damage and stiffness degradation. The ductility coefficients of ECC/steel cage composite strengthened columns and ECC/CFRP composite strengthened columns are 35.58 % and 34.13 % higher, respectively, compared to ECC fully strengthened columns, while the ductility coefficient of ECC/fiber grid composite strengthened columns decreased by 4.33 % compared to ECC fully strengthened columns. Among them, the ECC/steel cage composite-strengthened columns exhibited the highest number of hysteresis loops, the strongest energy dissipation capacity, and the best strengthening effect. Additionally, a restoring force model for ECC-strengthened corroded RC columns was established, and its validity was verified through theoretical calculations.

Unsupervised feature extraction for lithium-ion battery electrochemical impedance spectroscopy and capacity estimation using deep learning method

In this paper, we propose an unsupervised feature extraction technique using a variational autoencoder and generative adversarial network (VAEGAN) that automatically extracts meaningful latent variables from the electrochemical impedance spectra (EIS) of lithium-ion (Li-ion) batteries. These variables accurately reflect the degree of Li-ion battery degradation and are closely related to its capacity. By analyzing the latent variables, it was found that the network can learn the effect of Li-ion battery capacity degradation on the EIS. The extracted latent variables are then used as input features for Gaussian Process Regression (GPR) to estimate the capacity of Li-ion batteries under uneven usage and with unknown historical data. The results show that the capacity prediction method proposed in this paper can significantly reduce prediction errors compared to the current state-of-the-art methods. The method not only provides a more reliable capacity estimation but is also robust to highly noisy EIS data, making it more suitable for practical application scenarios.

Spatiotemporal Evolution of Habitat Quality and Scenario Modeling Prediction in the Tuha Region

In recent years, increasing urbanization has profoundly impacted the quality of regional habitats, presenting a severe risk to the ability of a region to develop in a high-quality manner. Therefore, the scientific assessment of the features of habitat quality (HQ) evolution over time and space and the prediction of future trends in changes in the HQ are of great significance for the formulation of effective ecological protection policies. Based on five periods of land use and land cover (LULC) data from 2000 to 2020, InVEST model was used to estimate both geographical and chronological trends in the HQ in the Tuha region, China. Spatial autocorrelation analysis methods were used to assess HQ and spatial aggregation of habitat degradation, and ecological zoning was delineated in conjunction with the Human Footprint Index (HFI). Based on the results of ecological zoning, the study predicted changes in habitat quality (HQ) in 2040 under three scenarios: natural development (ND), ecological preservation (EP), and urban development (UD) by applying the Patch-Generating Land Use Simulation (PLUS) model. The results demonstrated that (1) from 2000 to 2020, the habitat quality in the Tuha region exhibited a downward trend, with the proportion of low HQ increasing from 83.63% to 84.24%. Spatially, high habitat quality (HQ) is mainly concentrated in the Tianshan Mountains. From 2000 to 2020, the Moran index for habitat quality (HQ) decreased from 0.967 to 0.959, while the Moran index for habitat degradation declined from 0.805 to 0.780. The habitat quality (HQ) and degradation exhibit significant spatial aggregation, and the degree of degradation has increased incrementally. (2) From 2000 to 2020, human activities in the Tuha area increased continuously and were mainly concentrated in Tuha district and counties. The proportion of high Human Footprint Index (HFI) increased from 0.66% to 1.32%, while the proportion of medium HFI increased from 3.13% to 7.46%. (3) The expansion of urbanized land has exacerbated habitat degradation. The proportion of high HQ in the EP scenario is higher than that in ND and UD scenario. The results show that the ecological protection scenario is more conducive to the sustainable development of habitat quality in the Tuha region. The results can provide a scientific basis for ecological management and protection in the Tuha area.

Degradation analysis of GaN-based high–electron-mobility transistors under different stresses in semi-on state conditions

The large numbers of high-energy carriers that occur in semiconductor devices under semi-on state conditions can cause significant device degradation. The effects of different stresses on the electrical and trapping characteristics of GaN-based high-electron-mobility transistors (HEMTs) are investigated. Test results for GaN HEMTs under semi-on state conditions show that the electrical characteristics of these devices degrade to a certain extent after they are subjected to electrical pulse stress cycles with different drain voltage, frequencies, and duty cycles; a degree of degradation also occurs in the electrical characteristics of the devices when they are subjected to direct current electrical stresses. After electrical stress is applied, the absolute amplitude of the traps in the device increases, thus indicating an increase in the trap density. The results show that voltage is the main driver for device damage, with the current playing an accelerating role through its effects on device temperature or by supplying hot electrons; therefore, the drain voltage has the most significant effect on device degradation, which is mainly due to channel high-energy hot electron injection.

Reseeding inhibits grassland vegetation degradation – Global evidence

Global grassland faces different degradation degrees, and reseeding is commonly used to restore degraded grasslands. However, the factors affecting the results of reseeding restorations worldwide remain unclear. Here, we screened 141 independently published articles and performed a meta-analysis of the extracted 1386 data pairs. We selected five quantitative indices and four α diversity indices to analyze the effects of reseeding on the degraded grassland. Our results showed that reseeding significantly increased the quantitative indices and diversity index of degraded grasslands worldwide. Mixed reseeding has the best effect on improving the diversity of degraded grassland. A high mixed reseeding number was more conducive to restoring degraded grassland diversity. The more severe the grassland degradation, the better the restoration effect of reseeding. Short- and medium-term restorations significantly increased the diversity of degraded grassland. However, the restoration time increased the response proportion of aboveground biomass and cover. After reseeding, the proportion of aboveground biomass (AGB) response in humid areas was greater than in arid regions. This study explored the overall effect of reseeding restoration and the factors affecting reseeding restoration, providing a basis for the global restoration of degraded grassland and promoting the healthy development and sustainable use of grassland.

Effects of Silicone Rubber on Rheological Properties and Aging Characteristics of Asphalt Binder.

Silicone rubber (SR) is a kind of polymer insulation material with excellent performance. With the service life of silicone rubber products reaching the limit, how to dispose of waste silicone rubber is an urgent problem to be solved. In this paper, silicone rubber-modified asphalt binder (SRMA) was prepared by SR and 90# base asphalt binder. The simulated short-term aging and long-term aging tests of SRMA were carried out using the thin film oven aging test (TFOT) and pressure aging vessel test (PAV). The rotary viscosity test and dynamic shear rheological test (DSR) were applied to the rheological properties of SRMA before and after aging. The degradation degree and chemical composition changes of SR were explored by the toluene insoluble matter test, Fourier transform infrared spectroscopy (FTIR), and a Fluorescence microscope (FM). The results demonstrate that SR can significantly affect the aging resistance, fatigue life, and high-temperature stability of SRMA. As the content of SR rose, the elastic component in SRMA increased, leading to a nice performance in stability at high temperatures and fatigue resistance. However, excessive content (14%wt and 16%wt) had a negative influence on the performance of SRMA. So, the optimal content was speculated to be between 12% and 14%. Furthermore, SR and asphalt binder would be aged and degraded together in the aging process, and this phenomenon was more obvious during long-term aging.

The corrected H/G factors for accurately describing the delignification and depolymerization of industrial hemp stalks

Establishment of precise kinetic models is beneficial for the control of the degree of delignification and carbohydrate degradation in the pulping process. However, most kinetic models judge the degree of delignification and depolymerization only by holding time or fluctuating temperature, ignoring the effects of temperature and heating-up stage. Thus, this study explored in depth the delignification and depolymerization kinetic behaviors of the kraft pulping process of alkali-extracted hemp stalk material (HSM-AE). The chemical composition characteristics of the HSM-AE were firstly studied, followed by the investigation of the HSM-AE kraft pulping under different conditions. The H/G factor of the wood raw material was not suitable to describe the delignification and depolymerization behaviors during HSM-AE kraft pulping and needs to be corrected. Based on the corrected H/G factors, kinetic models of delignification and depolymerization were established. The parameter fitting results showed that the delignification and depolymerization were mainly dominated by sulfide cleavage and alkaline hydrolysis respectively. The activation energies of delignification caused by alkaline- and sulfide- cleavages were 66.8 and 72.7 kJ/mol; and the activation energies of cellulose depolymerization caused by peeling reaction and alkaline hydrolysis were 111.7 and 120.5 kJ/mol, respectively. Compared with eucalyptus kraft pulping, the activation energy ratio of delignification to cellulose depolymerization decreased, indicating that under the same delignification degree, the cellulose in HSM-AE was easier to alkaline degrade. At present, the process described in this experiment was more suitable to prepare dissolving-grade pulp for further production of viscose staple fiber.

Quantifying functional redundancy in polysaccharide-degrading prokaryotic communities

BackgroundFunctional redundancy (FR) is widely present, but there is no consensus on its formation process and influencing factors. Taxonomically distinct microorganisms possessing genes for the same function in a community lead to within-community FR, and distinct assemblies of microorganisms in different communities playing the same functional roles are termed between-community FR. We proposed two formulas to respectively quantify the degree of functional redundancy within and between communities and analyzed the FR degrees of carbohydrate degradation functions in global environment samples using the genetic information of glycoside hydrolases (GHs) encoded by prokaryotes.ResultsOur results revealed that GHs are each encoded by multiple taxonomically distinct prokaryotes within a community, and the enzyme-encoding prokaryotes are further distinct between almost any community pairs. The within- and between-FR degrees are primarily affected by the alpha and beta community diversities, respectively, and are also affected by environmental factors (e.g., pH, temperature, and salinity). The FR degree of the prokaryotic community is determined by deterministic factors.ConclusionsWe conclude that the functional redundancy of GHs is a stabilized community characteristic. This study helps to determine the FR formation process and influencing factors and provides new insights into the relationships between prokaryotic community biodiversity and ecosystem functions.719y1TiY6Es74zhUbSPagvVideo

Drought and Wildfire Trends in Native Forests of South-Central Chile in the 21st Century

Over the last decades, Chile has experienced a long-term drought with significant consequences for water availability, forest productivity, and soil degradation, ultimately dramatically increasing the surface of burned area. Here, we quantify the Palmer Drought Severity Index (PDSI) to ascertain the extent of “moisture deficiency” across the central-southern region of Chile from 2000 to 2023 to assess the drought’s relationship with the frequency of wildfires focusing on the impact of native forests. Our methodology quantifies the PDSI from the burned area data using MODIS MCD64A1 satellite imagery, validated by in situ wildfire occurrence records. The findings indicate that 85.2% of fires occurred under moderate to severe drought conditions. We identified 407,561 ha showing varying degrees of degradation due to wildfires, highlighting the critical areas for targeted conservation efforts. A significant increase in both the frequency of wildfires and the extent of the affected area in native forests was observed with the intensification of drought conditions in the 21st century within mesic to humid Mediterranean climatic zones where drought explains up to 41% of the variability in the burned area (r2 = 0.41; p < 0.05). This study highlights the relationship between drought conditions and wildfire frequency, showing the paramount need to adopt comprehensive wildfire mitigation management in native forests.

Physicochemical characterization, sensory quality analysis, and shelf-life prediction during the storage of a total nutrient formula emulsion

The study evaluated the effects of storing total nutrient formula emulsion at 4 °C, 25 °C, and 45 °C for 6 months on its physicochemical characteristics and sensory scores. With the increase of storage temperature or prolongation of storage duration, the color of the emulsion shifted towards yellow-brown, pH and apparent viscosity gradually decreased, and vitamins A, E, and C all experienced varying degrees of degradation. Using the storage of the sample at 45 °C for 6 months as the evaluation criterion, a principal component analysis (PCA) and regression analysis were employed to establish a low-temperature storage shelf-life prediction model. The results indicated that, under storage conditions of 4 °C and 25 °C, the shelf-life of the complete nutrient formula emulsion was 18.74 and 12.19 months, respectively. The study guided the understanding of quality changes and shelf-life prediction for the total nutrient formula emulsion during storage and transportation.

Self-organized underwater image enhancement

Underwater images captured in diverse underwater scenes exhibit varying types and degrees of degradation, including color deviations, low contrast, blurry details, etc. Single image enhancement methods tend to insufficiently address the diverse degradation issues, resulting in inappropriate results that do not align well with human visual perception or underwater color prior. To overcome these deficiencies, we develop a novel reinforcement learning framework that selects a sequence of image enhancement methods and configures their parameters in a self-organized manner for the purpose of underwater image enhancement. In contrast to end-to-end deep learning-based black-box mechanisms, the novel framework operates in a white-box fashion where the mechanisms for the method selection and parameter configuration are transparent. Furthermore, our framework incorporates the human visual perception and the underwater color prior into non-reference score increments for rewarding the underwater image enhancement. This breaks through the training limit imposed by volunteer-selected enhanced images as references. Comprehensive qualitative and quantitative experiments ultimately demonstrate that our framework outperforms nine state-of-the-art underwater image enhancement methods in terms of visual quality, and achieves better performance in five underwater image quality assessment metrics on three underwater image datasets. We release our code at https://gitee.com/wanghaoupc/Self_organized_UIE.

Evaluation of the Effectiveness of Innovative Sorbents in Restoring Enzymatic Activity of Soil Contaminated with Bisphenol A (BPA).

As part of the multifaceted strategies developed to shape the common environmental policy, considerable attention is now being paid to assessing the degree of environmental degradation in soil under xenobiotic pressure. Bisphenol A (BPA) has only been marginally investigated in this ecosystem context. Therefore, research was carried out to determine the biochemical properties of soils contaminated with BPA at two levels of contamination: 500 mg and 1000 mg BPA kg-1 d.m. of soil. Reliable biochemical indicators of soil changes, whose activity was determined in the pot experiment conducted, were used: dehydrogenases, catalase, urease, acid phosphatase, alkaline phosphatase, arylsulfatase, and β-glucosidase. Using the definition of soil health as the ability to promote plant growth, the influence of BPA on the growth and development of Zea mays, a plant used for energy production, was also tested. As well as the biomass of aerial parts and roots, the leaf greenness index (SPAD) of Zea mays was also assessed. A key aspect of the research was to identify those of the six remediating substances-molecular sieve, zeolite, sepiolite, starch, grass compost, and fermented bark-whose use could become common practice in both environmental protection and agriculture. Exposure to BPA revealed the highest sensitivity of dehydrogenases, urease, and acid phosphatase and the lowest sensitivity of alkaline phosphatase and catalase to this phenolic compound. The enzyme response generated a reduction in the biochemical fertility index (BA21) of 64% (500 mg BPA) and 70% (1000 mg BPA kg-1 d.m. of soil). The toxicity of BPA led to a drastic reduction in root biomass and consequently in the aerial parts of Zea mays. Compost and molecular sieve proved to be the most effective in mitigating the negative effect of the xenobiotic on the parameters discussed. The results obtained are the first research step in the search for further substances with bioremediation potential against both soil and plants under BPA pressure.

Laser sintering of polyamide 12 with limited thermal degradation

The paper presents, for the first time, the results of PA12 polyamide sintering using the original method of Dual Beam Laser Sintering of polymers (DBLS). The DBLS method, which is a modification of the standard polymer Laser Sintering (pLS) approach, allows to reduce the thermal degradation of the polymer by using selective (in terms of powder volume and process time) heating the material with laser radiation. The paper presents both the properties of sintered parts and the analysis of the degree of thermal degradation of post-process powders. Examination of the sintered parts included X-ray computed tomography (XCT) to visualize and analyze their porosity and a tensile test. Post-process powders were evaluated by Gel Permeation Chromatography (GPC), Melt Flow Rate (MFR), Dry Laser Diffraction Spectroscopy (DLD) and Powder Rheometer (FT4). The analysis of the result of PA12 sintering with the DBLS method was carried out in comparison with the classic pLS approach. As it has been shown, the DBLS approach allows to obtain comparable results for sintered parts compared to the pLS method. What is particularly important, it was shown that the post-process powder in the DBLS method has almost unchanged properties - the change in molecular weight and viscosity is at the level of the measurement error. Reducing thermal degradation is especially important in order to obtain continuous circulation of the powder in the manufacturing process.

Preparation and properties of walnut cake-based wood adhesive with oxidation modification

Walnut cake has the potential for use in preparing wood adhesives because of its richness in protein and carbohydrate. In this work, walnut cakes were treated with sodium periodate or potassium permanganate and then were directly used as wood adhesives. Their bonding properties, curing performances, thermal properties, and chemical structures were compared. The results showed that: (1) The oxidation by KMnO4was non-selective. The reaction was very intense, accompanied by the great variability of oxidation degree and degradation degree, enormous viscosity of oxidation products, high coating difficulty, and low content of active aldehyde groups. (2) The oxidation by NaIO4 was selective; the reaction was mild and easy to control. More active aldehydes could be produced and the treatment was beneficial for constructing a spatial net structure of the adhesive. (3) Compared with oxidation of KMnO4, the walnut cake adhesive prepared by NaIO4 oxidation exhibited a more compact structure, a higher crosslinking degree, low curing temperature, and high thermal stability after curing; its bonding performances met the requirements for Class II plywood specified in GB/T 17657(2013).

Study on the Degradation Pattern of Impact Crater Populations in Yutu-2′s Rovering Area

A detailed analysis of the panoramic camera data from the 27th to 33rd lunar days was conducted on the high-resolution scenes captured by the Yutu-2 rover stations. This analysis aimed to determine the detailed morphological parameters of the 2015 impact craters within the inspection area. The levels of degradation observed in the impact craters were determined alongside the surface features. Subsequently, the degradation patterns of the impact craters located within the Yutu-2’s roving area and the distribution patterns of the morphological parameters were analysed and investigated. The results of the analysis indicate that 94% of the impact craters exhibited severe degradation, 80% had depth-to-diameter ratios (DDRs) ranging from 0.07 to 0.17, and the remaining craters were moderately degraded. The DDRs of the impact craters exhibited a declining trend with an increase in the dimensions of the impact craters. Additionally, the degree of degradation of impact crater populations demonstrated a decreasing trend. In general, the impact craters along the rover’s route exhibited severe degradation, with the population of degradation degrees gradually decreasing with increasing diameter.

Stability of starch-folic acid/ polyethylene glycol particles for gastrointestinal drug delivery

This study takes a novel approach by exploring the potential of starch/polyethylene glycol core/shell particles, where folic acid was encapsulated, as effective gastrointestinal drug delivery systems. The results demonstrate the successful encapsulation of folic acid within the starch/PEG particles, with sizes ranging from 18 to 45 μm depending on the type of starch used (corn, potato, rice). Importantly, applying PEG coating had no negative impact on cell viability and did not induce alterations in fibroblast morphology. The investigation of stability in gastric and intestinal fluids revealed that the particles underwent different degrees of degradation. In simulated gastric fluid, a partial degradation of the PEG layer by 30–37% was observed, while the starch-folic acid core remained intact. However, the PEG layer underwent a 50% degradation in simulated intestinal fluid. This degradation of the PEG layer allowed the controlled and gradual release of folic acid. These findings underscore the role of fluid composition in influencing the stability and degradation behavior of the particles, with significant implications for their functionality as drug delivery systems in the gastrointestinal tract.

A combinatorial prediction model for the performance of fuel cell air compressor with air bearings considering accelerated decay characteristics

As the core component in air supply system, the air compressor plays a key role in efficient operation of fuel cell system. In this research, accelerated endurance tests for air compressor with air bearings were conducted based on designed operating condition, and the Hybrid Variational Artificial Bee Colony (HyVABC) algorithm was proposed to achieve enhancement and balance of global optimization capability and local feature capture ability. On this basis, combinatorial prediction models were developed to realize accurate performance prediction of the compressor considering accelerated decay characteristics. The results indicate that the degradation degree of pressure ratio is the greatest at the flow rate of 133 g/s and the speed of 100000 rpm, with the degradation rate of 25.9% compared with that before break-in. The HyVABC algorithm obtains optimal values on 16 out of 20 test problems, which highlights its strong optimization performance, fast convergence speed and high robustness. The XGBoost-HyVABC model is chosen to describe mapping relationship between operating and performance parameters of the compressor, and absolute values of relative errors between predicted and test values are below 3%. All these provide efficient heuristic algorithm and accurate combinatorial model for accelerated decay performance prediction of fuel cell air compressors.

Microstructural and photocatalytic properties of nanostructured near-β Ti-Nb-Zr alloy for total hip prosthesis use

With its unique corrosion resistance, light weight, mechanical strength, and biocompatibility, TNZ is a versatile metal alloy that is used in the aerospace and medical industries. The current study aims to investigate the effect of milling time (2, 12, 24, and 36 h) on the nanostructured ternary alloy Ti-25Nb-25Zr (TNZ) prepared by high energy ball milling, a process involving the use of a high-energy ball mill to mix and grind the alloy powders, on its structural, physical, and photocatalytic characterizations. The alloys' characteristics, such as morphology, structural properties, relative density/porosity, surface roughness, hardness, and Young's modulus, were evaluated using SEM, XRD, surface profilometer, and microdurometer, respectively. The photocatalytic characterization was conducted by measuring their absorbance as a function of time using a spectrophotometer of visible and ultraviolet light in the wavelength range of 250–650 nm. Results showed that the crystallite and mean pore size reduced with increasing milling time, with the smallest values of 25 nm and 34 μm, respectively, after 36 h. This indicates that longer milling times result in a more compact and uniform structure, which could enhance the mechanical properties of the alloy. Structural characterization shows that the amount of the β-Ti phase increased with increasing milling time, resulting in the spherical morphology and texturing of the synthesized alloys. The milled alloys' structural evolution and morphological changes were sensitive to their milling times. Also, the relative density, Young's modulus, and hardness increased, reaching values of 89 %, 105 GPa, and 352 HV, respectively, due to grain size decreasing with increasing milling time. This suggests that longer milling times lead to a denser and harder alloy, which could be beneficial for its use in total hip prostheses. The photocatalytical characterization demonstrated that the degradation of orange II (OII) increased with increasing milling time. The Ti-25Nb-25Zr catalyst gave the best degree of degradation, which meant that the decolorization process could be operated rapidly and at a relatively low cost without UV irradiation.

SWAT model to simulate hydrological responses to land use and land cover changes in a tropical catchment: A study in Sri Lanka

A significant concern is the modification and conversion of the land cover in river basins as a consequence of different influences on ecosystems. A hydrological investigation was performed in the Kelani River basin in Sri Lanka using the Soil and Water Assessment Tool (SWAT) to analyze the impact of changes in land use and land cover (LULC) on the hydrological response. In order to calibrate (2003–2012) and validate (2013–2020) the model, input data from four hydrological stations, namely Glencose, Hanwella, Norwood, and Kitulgala, were utilized. Three distinct LULC scenarios were analyzed and compared to the existing urban land pattern. Scenario I involves the conversion of urban land into pasture, Scenario II comprises the conversion of urban land into rubber plantations, and Scenario III entails the conversion of urban land into bare soil. In accordance with the study, the SWAT model's calibration in the Kelani River was successful. The evaluation indices for both the calibration and validation periods were satisfactory at Norwood (R2 = 0.76, NE = 0.88), Hanwella (R2 = 0.83, NE = 0.57), Glencourse (R2 = 0.78, NE = −0.32), and Kitulgala (R2 = 0.69, NE = 0.59). This finding suggests that the SWAT model demonstrated better accuracy in predicting streamflow at a station with high flow compared to stations with low or medium flow conditions. However, the calibrated model did not perform as expected when used to forecast daily streamflow at Glencourse, where the evaluation indices showed an R2 of 0.78 and NE of −0.32. Compared to the current urban land cover, scenario III had the greatest impact on runoff, potential evapotranspiration (PET), and sediment yield, with increases of 14.1%, 15.2%, and 26.3%, respectively. As a consequence of the significant degree of land degradation that was observed throughout the duration of the study, regions in the northern and western parts of the basin have been highlighted as requiring immediate attention for the establishment of vegetation.