Core Zone Research Articles

The impact study of variable diameter stabilizer on drilling fluid and cuttings transport

Through numerical simulation, this study investigates the flow field characteristics of the variable diameter stabilizer in drilling tools under various conditions. It analyzes the influence of different flow rates and speeds on axial velocity and pressure distribution. The results indicate that more significant flow rates correspond to higher average axial velocities across sections, facilitating the transport of drilling fluid and cuttings. Increasing rotational speed leads to greater pressure differences between adjacent sections, consequently elevating the overall pressure drop of the tool, which, to some extent, aids in transporting drilling fluid with cuttings. During rotation, the vortex zone on the backside of the stabilizer creates a hovering and accumulation of cuttings, causing mud agglomeration, thereby affecting tool performance. During structural optimization of the tool, priority should be given to a transitional design of the outlet area in the functional core zone, aiming to alleviate the impact of abrupt structural expansions on cuttings transport.

Multi-physics analysis of SBLOCA by coupled Neutronics/Thermal-Hydraulics full plant model

With the development of computational tools, the accident analysis would be performed by best estimate approaches. The employment of multi-physics codes would be considered as new calculation procedure to obtain high valuable results by improving calculations with specialized codes. The small break loss of coolant accident (SBLOCA) is an accident that has typically been analyzed using system codes with a limited number of Thermal-Hydraulics (TH) channels in the core region, neglecting the use of multi-physics calculations. This approach results in insufficient accuracy and resolution in both neutronics and TH calculations within the core zone. To address this issue, this study proposes the implementation of a Neutronics/Thermal-Hydraulics coupling with one-to-one mapping in the core zone, achieved through the development of a comprehensive plant TH model. This approach aims to enhance the accuracy and resolution of calculations, enabling the identification of local phenomena, parameters, and feedback during accident simulations, and the incorporation of these effects on the macroscopic cross-sections at each time step. The results of SBLOCA simulation reveals the effects of conservative/best estimate approach on the sequence of events, the initiation time of the safety systems, the critical controlled parameters of the power plant, and the precise understanding of the accident. Also, it was found that the radial power distribution becomes disrupted and loses its symmetry immediately after the SCRAM leading to different characteristics of steam generators (SGs) and natural circulation flow rate in each loop of primary side.

Sustainable Agroforestry Model for Supporting Farming Communities by Identifying Land Development in Bone District

Agroforestry is an optimal land management approach that combines forestry, agriculture, livestock, and fisheries activities within the same area. Sustainable agroforestry models are implemented through community support in Bone District. The Bengo region is one of the initiatives undertaken by STIP YAPI BONE as part of a partnership scheme for the Agroforestry model, which represents a local wisdom aimed at safeguarding water sources by integrating several key components, including food crops, perennial plants, and livestock. It is undeniable that the Bengo region is highly unique, as it is divided into several zones, such as the core zone (Integrated Agrocomplex Gardens), buffer zone (Land for Integrated Forestry, Plantation, Agriculture, and Fisheries Commodities), and utilization zone. It holds significant social, cultural, economic, and ecological value. Bengo boasts two key farmers, Mr. Sahir and Mr. Asgar, who have successfully transformed their cocoa plantations into Agroforestry gardens. Therefore, Bengo has the potential to become a cornerstone for the partnership between the Research and Community Service Institution, offering economic, social, and ecological benefits. Hence, it is imperative to preserve Bengo. One approach to achieving this is to raise awareness among all stakeholders, including both the community and the government, regarding the importance of applying Sustainable Agroforestry models to critical lands in Bone District, particularly in South Sulawesi.

A Novel Approach to Cardiac Magnetic Resonance Scar Characterization in Patients Affected by Cardiac Amyloidosis: A Pilot Study.

Background and Objectives: Cardiac magnetic resonance (CMR) imaging has become an essential instrument in the study of cardiomyopathies; it has recently been integrated into the diagnostic workflow for cardiac amyloidosis (CA) with remarkable results. An additional emerging role is the stratification of the arrhythmogenic risk by scar analysis and the possibility of merging these data with electro-anatomical maps. This is made possible by using a software (ADAS 3D, Galgo Medical, Barcelona, Spain) able to provide 3D heart models by detecting fibrosis along the whole thickness of the myocardial walls. Little is known regarding the applications of this software in the wide spectrum of cardiomyopathies and the potential benefits have yet to be discovered. In this study, we tried to apply the ADAS 3D in the context of CA. Materials and Methods: This study was a retrospectively analysis of consecutive CMR imaging of patients affected by CA that were treated in our center (Marche University Hospital). Wherever possible, the data were processed with the ADAS 3D software and analyzed for a correlation between the morphometric parameters and follow-up events. The outcome was a composite of all-cause mortality, unplanned cardiovascular hospitalizations, sustained ventricular arrhythmias (VAs), permanent reduction in left ventricular ejection fraction, and pacemaker implantation. The secondary outcomes were the need for a pacemaker implantation and sustained VAs. Results: A total of 14 patients were deemed eligible for the software analysis: 8 patients with wild type transthyretin CA, 5 with light chain CA, and 1 with transthyretin hereditary CA. The vast majority of imaging features was not related to the composite outcome, but atrial wall thickening displayed a significant association with both the primary (p = 0.003) and the secondary outcome of pacemaker implantation (p = 0.003). The software was able to differentiate between core zones and border zones of scars, with the latter being the most extensively represented in all patients. Interestingly, in a huge percentage of CMR images, the software identified the highest degree of core zone fibrosis among the epicardial layers and, in those patients, we found a higher incidence of the primary outcome, without reaching statistical significance (p = 0.18). Channels were found in the scar zones in a substantial percentage of patients without a clear correlation with follow-up events. Conclusions: CMR imaging plays a pivotal role in cardiovascular diagnostics. Our analysis shows the feasibility and applicability of such instrument for all types of CA. We could not only differentiate between different layers of scars, but we were also able to identify the presence of fibrosis channels among the different scar zones. None of the data derived from the ADAS 3D software seemed to be related to cardiac events in the follow-up, but this might be imputable to the restricted number of patients enrolled in the study.

An assessment of the shade and ground cover influence on the mitigation of water-driven soil erosion in a coffee agroforestry system

Coffee cultivation under agroforestry systems is one of the main agricultural activities in Central America, but climate change is putting its sustainability at risk. Rainfall erosivity has worsened, thus driving soil losses. Although the vegetal covers in coffee agroforestry systems play a crucial role in controlling erosion, the specific influence of each cover layer remains unclear. In this study, we assessed the influence of the canopy (tree and banana cover and coffee cover) and ground cover (weed and litter) on water driven soil erosion, to determine which type of cover has the most influence on soil erosion control. The study site is situated in the core and buffer zones of the Macizo de Peñas Blancas National Park (Nicaragua), where seventeen coffee sampling plots with an agroforestry system composed of an Inga spp and Musa spp canopy cover were analysed. The results showed that the 19.2 ± 3.4% of the soil surface was affected by erosion and it was mainly related to the litter ground cover (r = –0.95, P < 0.001). Also, this cover presented the best partial correlation (ryl.tcw = –0.93, P < 0.001) when the effects of the other vegetal covers were eliminated. Specifically, the litter cover accounted for 90% of the erosion variability, while the impact of the other types of cover was negligible, accounting for just 1% of the erosion. We conclude that litter layer is more important than canopy cover for effective erosion control, and the main function of shade trees is as a source of litter biomass.

The Impact of Zoning Designations on Bird Communities: A Case Study of National Nature Reserves in Guangdong Province

One of the main management strategies of China’s nature reserve is “zonation”, dividing reserves into three zones (core, buffer, and experimental zones) to which different levels of restrictions on anthropogenic activities are applied. While zonation has a positive effect on the conservation of target species, it is unclear whether management zones can be effective in conserving biodiversity. Using bird data collected from five national nature reserves of Guangdong province in China during 2018–2019, we investigated how management zones and reserves are associated with bird diversity and community composition. We considered species richness, the community-weighted mean (CWM) values of 10 single traits, and beta diversity based on 2 dissimilarity indices (Jaccard and Bray–Curtis). The overall effects of zone management were weak or insignificant. Species richness and the CWMs of most traits were not associated with zone (p &gt; 0.08). Reserve itself was a strong factor influencing bird traits. Dissimilarity indices also showed variations in bird community composition between reserves in the north region and those in the south region, which were largely contributed by the turnover component of beta diversity (p ≥ 0.06 for nestedness and p ≤ 0.03 for turnover in both dissimilarity indices). The dominance of turnover indicates that these reserves could be equally important to maintain regional bird diversity, requiring a multiple-site management plan. Our study also suggests that current zoning designations of the five reserves may not be as effective in conserving bird species diversity and traits; however, caution is needed due to the limitations of our study design, such as potential observer effect and insufficient sampling effort.

Plantation Technologies

In this article we investigate plantation agriculture as a technology aimed at extracting natural resources, utilising unpaid labour, and installing regulatory authority. Using the oil palm plantation territories of Johor State in Malaysia – a core zone of palm oil production, manufacturing and export – as a case study, we ask how more-than-human assemblages enabled the expansion and refinement of oil palm plantations in Malaysia and contributed to the material transformation of the territory. We also explore how plantations can be mobilised as an analytical device to study the urbanisation of territory through agro-industrial production. To explore those questions, we present three episodes of more-than-human involvement in assembling oil palm plantation territories in Johor. Through the conceptual frame of the operationalisation of territory, we bring into dialogue literature on the Plantationocene with critical urban studies and the history of urbanisation.

Ecological restoration trajectory of the Taitema Lake wetland in arid northwest China: A 36-year wetland health assessment using Landsat time series data

The Taitema Lake wetland in the lower reaches of the Tarim River (northwest China) is sensitive to hydrological changes and provides necessary ecosystem functions for biodiversity conservation. Monitoring and evaluating the long-term dynamics of the Taitema Lake wetland is essential for conserving and restoring regional wetland ecosystems. This paper used a dense time series of Landsat images from 1986 to 2021 to map the Taitema Lake wetlands. It analyzed the annual and seasonal variations of the wetlands by ten ecological indicators, which include area extent, vegetation, hydrology, and landscape features. A systematic assessment of the ecological quality of the wetlands over the past 36 years, along with their influencing factors, was conducted from the perspective of wetland health. The results showed that (1) the recovered water areas and the wetlands showed a clear trend of ecological restoration since 2000, accompanied by an increased fragmentation. The total wetland area increased from 69.95 km2 in 1986 to 1164.47 km2 in 2021, with a 15.6-fold increase, and the vegetation area increased twentyfold to 639.84 km2. (2) The wetness in the core zone increased consistently across seasons, coupled with a simultaneous vegetation expansion surrounding the core zone. The areas with increasing wetness levels account for 48 % during winter and spring, and the areas with vegetation expansion account for 81 % and 72 % in summer and autumn, respectively. (3) The wetland ecological health status recovered to a “Good” level in 2021 and has not reached the “Excellent” status. The expansion of the water body is the primary driver behind the promotion of wetland ecological recovery. Small water bodies within the area range of 0.05 to 0.1 km2 notably exhibited the most stimulating effects on the wetlands. Thus, increasing the count of smaller water bodies helps rehabilitate vegetation growth and mitigating the water supply’s stress to sustain large lacustrine bodies.

Seismic behaviour of Exterior RC beam-column joints repaired and strengthened using post-tensioned metal straps

Exterior beam-column joints are the most vulnerable part of substandard reinforced concrete (RC) buildings and are often the first to be damaged during earthquakes. This article presents an experimental and numerical investigation into the behaviour of exterior RC beam-column joints repaired and strengthened using Post-Tensioned Metal Straps (PTMS) for active confinement. The study focused on full-scale beam-column joints with an inadequate core zone detailing, thus emulating the deficiencies found in existing substandard RC buildings. Initially, four “bare” joints were subjected to cyclic tests to induce substantial damage within the core zone. Subsequently, the damaged core of the joints was repaired and recast with new concrete, and PTMS were applied to strengthen the joints, followed by another round of cyclic testing. The experimental findings were compared with predictions generated through established models from existing literature. The results revealed that ASCE/SEI 41–17 guidelines accurately predict the shear capacity of the bare joints. It is shown that recasting the core with new concrete significantly increased the joint’s shear capacity by up to 42% compared their bare counterparts. The use of PTMS strengthening further enhanced the capacity by up to 25%. A “scissors model” was employed for numerical simulations of both bare and PTMS-strengthened joints using DRAIN-2DX, which proved effective at predicting their nonlinear load-displacement envelope response. This article contributes towards the development of new cost-effective post-earthquake strengthening techniques for beam-column joints, with the potential to reduce the vulnerability of substandard RC buildings in developing countries.

Monitoring of Älvkarleby test embankment dam using 3D electrical resistivity tomography for detection of internal defects

Electrical resistivity tomography (ERT) is a potential-based method for detecting internal erosion in the core of embankment dams using the electrodes installed outside. This study aims at evaluating the practical capability of ERT monitoring for detecting internal defects in embankment dams. A test embankment dam with in-built well-defined defects was built in Älvkarleby, Sweden, to assess different monitoring systems including ERT and the defect locations were unknown to the monitoring teams. Between 7500 and 14,000 ERT data points were acquired daily, which were used to create the distribution of electrical resistivity models of the dam using 3D time-lapse inversion. The inversion models revealed a layered resistivity structure in the core that might be related to variations in water content or unintentional variations in material properties. Several anomalous zones that were not associated with the defects were detected, which might be caused by unintentional variations in material properties, temperature, water content, or other installations. The results located two out of five defects in the core, horizontal and vertical crushed rock zones, with a slight location shift for the horizontal zone. The concrete block defect in the core was indicated, although not as distinctly and with a lateral shift. The two remaining defects in the core, a crushed rock zone at the abutment and a wooden block and a crushed rock zone in the filter, were not discovered. The results cannot be used to fully evaluate the capability of ERT in detecting internal erosion under typical Swedish conditions due to limited seepage associated with the defects. Furthermore, scale effects need to be considered for larger dams.

Development of a rapid assessment tool for integrating thermal comfort in early design stage of energy-efficient office buildings

Comprehending and predicting energy performance of existing buildings and new constructions is crucial towards decarbonization. Instead of utilizing simulation software, multiple regression models are utilized to predict building energy consumption while ensuring indoor thermal comfort to speed up this process. However, previous predictive models prioritize reducing energy demand, with limited focus on thermal comfort. This study aims to support decision-making during retrofitting and new construction planning though developing a prediction model. An air-conditioned office building served as a reference building for simulation. 21 design parameters were analyzed, including aspects of weather, building envelope, internal loads, ventilation, and temperature settings. Stepwise regression results unveiled the crucial variables in the final model, with 8, 9, 13, and 6 variables remaining for peak cooling load, annual cooling load, overheating hours (WE), and Environmental Quality Index for thermal comfort (EQITC) in the perimeter zones, and 5, 6, 8, and 5 variables for the core zones, respectively. Furthermore, insights into the important variables regarding cooling load and thermal comfort were respectively provided. Weather- and envelope-related variables, such as cooling degree-days, global solar radiation, solar heat gain coefficient (SHGC), and U-value, have the highest impacts on cooling load. For thermal comfort, variables including temperature setpoint, occupant activity level, and factors related to window sunlight transmission performance, such as SHGC, window area ratio, and overhang projection ratio, proved to be influential. Overall, this study provided accurate models for assessing optimal strategies for energy efficiency and thermal comfort during the early design phases, advancing building performance practices.

CORRELATE OF SOCIO-ECONOMIC CHARACTERISTICS AND USE OF ANTI-BURGLARY DEVICES IN RESIDENTIAL AREA OF OGBOMOSO, NIGERIA

This study examines relationship between the residents’ Socio-economic Status (SeS) and choices in the adoption of anti-burglary devices across the residential zones of Ogbomoso City. It surveys households’ houses and their environments across the Core, Intermediate and Suburb residential zones of the study area. The variables used to examine the analysis of installed anti-burglary devices include the adoption of iron / steel bar, electronic devices, wire mesh, ethno-medical, and others. The examination of the aforementioned devices in relation to the socio-economic status of residents using Spearman’s rho Correlation analysis revealed that there is positive correlation between monthly income of residents and all the housing anti-burglary devices adopted with the p-values of 0.000, 0.010, 0.000, and 0.014 for Iron/steel bar, electronic devices, wire mesh and ethno-medical devices respectively. It further revealed that education has a significant correlation but negative with ethno-medical devices due to the p-value of 0.051and r-value of -0.070. This implies that increase in education reduces the use of ethno-medical devices in the study area. The study concluded that Socio-economics Status of residents have a great influence on the type and choice of anti-burglary devices adopted in the fight against residential burglary and home invasion across the City.

A numerical research on transient transport of high-temperature particles associated with air gouging process

The high-temperature particles produced by air gouging processes are common pollutants in cleaning workshops, which could endanger workers’ health. In this research, a two-way coupled Eulerian-Lagrangian method based on discrete phase modelling (DPM) was used to investigate the transport characteristics of high-temperature particles generated from air gouging processes. The particle group in the movement was divided into core zone and boundary zone, and the kinetic mechanism of particles in different zones was analysed. The results show particles in the boundary zone are more susceptible to the vortex entrainment effect than particles in the core zone, and some particles could be moved from the vortex diffusion zone to the vortex recirculation zone. The smaller the particle size, the better the followability to the hot airflow. The slower the temperature decay of particles, the more significant the thermophoresis effect, which could enhance the diffusion behaviour of the small particles. By analysing the average residence time of particles in the breathing zone, the influence of different factors on the average vertical diffusion height [Formula: see text] of particles is summarized, and a nonlinear regression prediction model of [Formula: see text] is established. The results can contribute to health risk assessment and industrial ventilation design.

Transpositional transformations of the adverbialized instrumental case of a name in the nuclear adverbs’ zone

INTRODUCTION. The study of the transitivity and syncretism’s phenomena at different levels of the language system is one of the urgent modern linguistics’ tasks. The relevance of the study is due to the need for a the stages’ and limits’ comprehensive analysis of the substantive word forms’ adverbial transposition, as well as the interaction features of grammatical and semantic in syncrets representing different stages of adverbialization. The purpose of the study is to deduce the signs and the limit of the functional–semantic transposition of the creative case without a preposition into the adverbs class.MATERIALS AND METHODS. The research material used is sentences from the National Corpus of the Russian Language and the authors’ own examples. In the course of the analysis of linguistic units, methods of oppositional analysis and indexing, elements of component, transformational and distributive analysis are used.RESULTS AND DISCUSSION. When analyzing the types of substantive word forms’ use in the adverbialization context different degrees (stages) of their departure from nouns and approximation to adverbs are revealed. The focus is on word forms such as “next”, explicating the core zone of the substantive adverbs.CONCLUSION. When indexing the functional and semantic adverbialization degrees of the word form “next”, it is found that it demonstrates in the area of the core of adverbs 0 % compliance with the original nuclear noun and 73 % compliance with the substantive nuclear adverbs (“gift”). The results obtained can be used in the quantitative study of the adverbialization degrees of other nonprepositional nouns’ forms in the Russian language, as well as in the general problems development of the transposition and syncretism theory.

Diagenesis and lateral sealing types of fault zones in the Lishu Depression, Songliao Basin, NE China

The Lishu Depression in the Songliao Basin is characterized by well-developed faults, and the accumulation of oil and gas is closely related to fault sealing. However, there remains a dearth of comprehensive investigation into the diagenesis of fault zones and their influence on lateral sealing. This study employed electron probe analysis, cathodoluminescence, and carbon and oxygen isotope techniques to investigate the diagenetic processes in fault zones. This research also reconstructed the evolution of porosity and displacement pressure of fault rocks, and identified the lateral sealing characteristics of fault zones and their impact on oil and gas accumulation. The majority of faults in the study region formed earlier, and the fault zones experienced intricate diagenesis, characterized by compaction, cementation, replacement, and dissolution. The displacement pressure of fault rocks is higher during fault intermittent and static periods compared to active periods, and it is influenced by diagenesis. Late-stage calcite and pore-filling chlorite were deposited subsequent to the period of fault activity, filling dissolution pores. This led to relatively higher displacement pressure and improved lateral sealing of fault zone. The kaolinite cement exhibits a relatively elevated potassium concentration, due to its connection with the dissolution of feldspar, resulting in lower displacement pressure and poor sealing of fault zone. Based on the evolutionary characteristics of displacement pressure in fault rock and reservoir during various transportation stages, this study identified six types of lateral sealing of fault zones. Notably, the sealing types characterized by "fault core and damage zone sealing during static periods" and "fault core and damage zone sealing during intermittent and static periods" exhibit superior lateral sealing properties, effectively controlling the accumulation of oil and gas in the sand bodies on either side of the fault zone.

Dynamic of coral recruits in the Karimunjawa National Park, Central Java, Indonesia

Abstract. Tarigan SAR, Munasik, Wijayanti DP, Muhidin, Rohman EA, Pardede S. 2024. Dynamic of coral recruits in the Karimunjawa National Park, Central Java, Indonesia. Biodiversitas 25: 869-880. After a disturbance event, coral reefs can recover naturally by recruiting new corals. These can be affected by environmental factors like the substrate's physical and biological structure, predation, and accidental mortality of recruits by grazers, as well as the number and size of parent corals supplying larvae. This study examined the connection between newly recruited corals and biological factors such as sea urchin density, herbivorous fish abundance, and hard coral coverage. The study was monitored changes in coral cover, juvenile coral density, herbivore abundance, and hard coral coverage at 43 locations and two depths (shallow; 2-3 m) and deep (8-10 m) from 2013 to 2022. The locations were distributed across six different zone systems: the core zone, protection zone, tourism zone, traditional fisheries zone, aquaculture zone, and rehabilitation zone. Multiple Linae Regression, ANOVA test, and Principal Component Analysis were employed to assess the relationship between coral recruitment and other variables. Results indicated that the coral recruitment density was not significantly different when comparing different zoning systems (two-way ANOVA test, P-value&gt;0.05). Based on the PCA analysis, we found that in 2013 and 2019, excavator, sea urchin, browser, and hard coral have a positive relationship with coral recruitment, which implies that coral recruitment would increase as sea urchin, browser, and hard coral increase. Meanwhile, in 2019 and 2022, coral recruitment has a negative relationship with scraper, and also with hard coral growth (although only in 2022), implying that coral recruitment would decrease if scraper and hard coral increase. The study recommends restoring the role of herbivorous species in Karimunjawa National Park (KNP) by prioritizing them in conservation efforts and managing their populations.

Ecological Risk Assessment of Forest Landscapes in Lushan National Nature Reserve in Jiangxi Province, China

It is highly valuable to analyze and assess the landscape ecological risk of nature reserves to prevent and resolve ecological risks, as well as to effectively protect and maintain the sustainable development of nature reserves. Taking the forest landscape of the Lushan National Nature Reserve as its study object, this study performed grid processing for the nature reserve and classified forest landscape types using the Forest Resource Inventory Database in 2019. A landscape ecological index model was constructed to evaluate the ecological risk. Global and local Moran index values were used to reveal the autocorrelations for ecological risk. The geodetector method was used to comprehensively analyze the effects of natural and human factors on ecological risk. The results showed that, in general, the ecological risk level of the nature reserve was relatively low, as the proportion of the lowest-, lower-, and medium-risk areas to the total forestry land area accounted for 91.03%. The ecological risk ranking of each functional zone, from high to low, was in the order of the experimental zone, the buffer zone, and the core zone. The ecological risk levels of different forest landscape types were closely related to their area, spatial distribution, and succession stage, as well as human factors, such as the proximity to roads and settlements, etc. The forest landscape with the highest ecological risk was the Cunninghamia lanceolata (Lamb.) Hook. forest, and the forest landscape with the lowest ecological risk was other forestry land. Ecological risk had a positive spatial correlation and tended to be aggregated in space, demonstrating coupling with the proximity to roads and settlements. The ecological risk was affected by both human and natural factors, among which human factors played a dominant role. The proximity to roads and settlements, the relative humidity, and the temperature were the main driving factors. The interaction of pairwise factors had a stronger influence than that of single factors. Therefore, controlling the intensity of human activities and enhancing the coordination between humans and nature are beneficial for alleviating the ecological risks in the forest landscapes of nature reserves.

Long-term evolution and driving mechanisms of the Baiyangdian wetland based on land cover frequency characteristics

For sustainable conservation and management of wetlands, it is essential to quantify the evolution progress and driving mechanisms of wetlands. This study examined Baiyangdian Wetland as a research area, and remote images and statistical yearbooks were used as data sources. Dominant zones of wetland were defined based on spatial characteristics of land cover frequency. A transfer matrix and random forest were used to analyze the evolution process and driving mechanism of typical wetlands in the North China Plain. Based on the results, following conclusions were arrived: (1) There was significant spatial differentiation of land cover frequency characteristics in the Baiyangdian wetland, with the cultivated land-dominated zone, the aquatic vegetation-dominated zone, and the water body-dominated zone being the three core zones of wetland ecosystem evolution. (2) There was a frequent and significant change of the Baiyangdian wetland due to extreme climatic conditions. Between 1987 and 2017, the built-up land area and the water body area increased by 4.62 and 16.17 km2, respectively, while the aquatic vegetation area decreased by 20.70 km2. A combination of natural and human factors caused changes in the wetland’s structure. (3) The driving mechanisms of ecosystem evolution in the Baiyangdian wetland were influenced significantly by space, time, and land cover types. Specifically, on a spatial scale, social factors were the predominant factors contributing to changes in water body and cultivated land in the cultivated land-dominant zone and the aquatic vegetation-dominant zone. In contrast, natural factors were the dominant factors leading to changes in aquatic vegetation. There was a greater contribution from social factors to the driving mechanism of changes in the water body, aquatic vegetation, and cultivated land in the water body-dominant zone than from natural factors. On a temporal scale, it was primarily influenced by natural factors in the early stages and socio-economic factors in the late stages, with the year 2002 serving as a turning point. The scale of land cover types can be seen primarily in the differences among the agricultural lands, aquatic vegetation, and water body. In particular, the Secondary Industry Out Value (SIOV) was highly sensitive to changes in the cultivated area. In addition, cumulative evaporation (EC) has been identified as the main factor responsible for the evolution of aquatic vegetation, which is closely related to the changes in water body.

Potential deformation assessment of Semantok Main Dam in North Nganjuk Region at East Java Indonesia

Semantok Dam was constructed using a zone l embankment type and required safety measures for deformation control. This study aims to understand material specifications, geological conditions, and deformation behavior. The results of the material specifications indicate that the core material and fine filter material meet the design criteria. The geological conditions comprise sand, sandstone, and claystone. The rock’s bearing capacity and settlement in the core zone are considered safe. The elastic vertical deformation of the foundation, analyzed using a flexible foundation approach by Lord, is estimated to be between 4.36 and 6.10 cm. Dynamic analysis is also performed using the Plaxis 8.6 version software to estimate deformation. The software input includes soil properties from the borrow and quarry areas surrounding the dam site. Earthquake design criteria are based on the Operating Basis Earthquake (OBE) with a 100-year return period and the Maximum Design Earthquake (MDE) with a 10,000-year return period. The dynamic analysis results indicate that the maximum deformation during a 100-year return period earthquake is 7.37 cm (horizontal deformation) and 12.68 cm (vertical deformation). In the case of a 10,000-year return period earthquake, the maximum deformation is 83.41 cm (horizontal deformation) and 175 cm (vertical deformation) during rapid drawdown.

Prediction of the future landuse and land cover changes in the Parangtritis sand dune : a spatio temporal analysis using QGIS MOLUSCE

This study was aimed to analyze the changes and predict the future land use in the Parangtritis Sand Dunes, located in Bantul Regency, Yogyakarta Special Region, Indonesia. Parangtritis Sand Dunes face the threat of damage due to various human factors such as settlements, tourism, agriculture, plantations, etc. The Cellular Automata method, coupled with the Modules for Land Use Change Evaluation (MOLUSCE) plug-in, was employed to assess the dynamics of land cover/land use and make projections for the future. The analysis revealed significant changes in several land cover classes between 2019 and 2021, while others remained relatively stable. From 2019 to 2021, the change in area amounted to 5.6 hectares, while from 2021 to 2031 the change was only slight, amounting to 0.7 hectares. So it can be concluded that the change in the area of sand dunes in the future, namely in 2031, has not changed much, only increased by 0.7 Ha. So that more effort is needed to curb the core zone intended for the preservation of the Parangtritis sand dunes. Further investigation into the underlying causes of these shifts could provide valuable insights for effective land management and conservation efforts.