RS Techniques Research Articles

The Role of Synthesis Methods of Ceria-Based Catalysts in Soot Combustion.

The removal of soot particles via high-performance catalysts is a critical area of research due to the growing concern regarding air pollution. Among various potential catalysts suitable for soot oxidation, cerium oxide-based materials have shown considerable promise. In this study, CeO2 samples obtained using a range of preparation methods (including hydrothermal synthesis (HT), sonochemical synthesis (SC), and hard template synthesis (TS)) were tested in soot combustion. They were compared to commercially available material (COM). All synthesized ceria catalysts were thoroughly characterized using XRD, RS, UV/Vis-DR, XPS, H2-TPR, SEM, and TEM techniques. As confirmed in the current study, every tested ceria sample can be used as an effective soot oxidation catalyst, with a temperature of 50% soot conversion not exceeding 400 °C in a tight contact mode. A strong correlation was observed between the catalysts' Ce3+ concentration and activity, with higher Ce3+ levels leading to improved performance. These findings underscore the importance of synthesis in optimizing ceria-based catalysts for environmental applications.

Identification of Groundwater Potential Zones using MIF, GIS and RS Techniques in Killa Saifullah District, Pakistan

Identification of Groundwater Potential Zones using MIF, GIS and RS Techniques in Killa Saifullah District, Pakistan

Optimizing Groundwater Resources in Arid Cratons: Harnessing RS, GIS, and ERT Techniques for Sustainable Water Management

Optimizing Groundwater Resources in Arid Cratons: Harnessing RS, GIS, and ERT Techniques for Sustainable Water Management

Characterization and classification of soils of farm, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani by using RS and GIS techniques

Characterization and classification of soils of farm, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani by using RS and GIS techniques

NDVI land cover classification for Krishna District, Andhra Pradesh, India for the year 2020 by RS and GIS techniques

NDVI land cover classification for Krishna District, Andhra Pradesh, India for the year 2020 by RS and GIS techniques

Evaluating groundwater potential in water-deficit laterite zones of Eastern India using RS and GIS techniques, combining an analytical hierarchical process for sustainable water resources management

Sustainable groundwater management in water-deficit, laterite-dominated regions need urgent planning, which involve accurate identification of groundwater potential zones (GWPZs). While unsustainable water extraction has exacerbated groundwater availability in laterite zones, laterite is globally known for its limited groundwater potential but has received relatively little research attention. Therefore, the present study aims to examine the role of laterite formation on groundwater potentiality and its relationship with the stage of groundwater development in Paschim Medinipur district of West Bengal in eastern India. This study integrated cost-effective and efficient time-saving tools like remote sensing, and GIS and to produce thematic map layers for overlay analysis and analytical hierarchy process (AHP) to delineate the GWPZs precisely using n = 10 parameters, while a consistency check was performed prior to the integration of these parameters to ensure low subjectivity in the GWPZ. The three identified GWPZ classes cover 30% of ‘good’, 44% of ‘moderate’ and 26% of ‘poor’ zones. The yield data and water level fluctuation analysis revealed that 70% and 60% match the delineated GWPZs. The cross-validation with the receiver operating characteristic curve also demonstrated good (75.1%) prediction accuracy. We found that hydrogeological factors like laterite formations witness around 80% of moderate to poor GWPZ, while poor GWPZ covers half of the laterite belt. However, flood plains and valley fill deposits in the lateritic parts demonstrate moderate to good GWPZ, suggesting laterite formation at variable depths that control groundwater recharge potential. The laterite regions with lower groundwater recharge potential have experienced a 17% increase in water extraction compared to non-laterite areas. Whereas four blocks within the district are partly overlapped with laterite formations and poor GWPZ, which encounter high stages of groundwater development (70–90%), leading to semi-critical to critical conditions. It is attributed to anthropogenic perturbations and hydrogeological conditions, which need urgent planning to ensure sustainable groundwater usage.

Integrated remote sensing and geographic information system overlay analysis for groundwater potential evaluation using AHP and fuzzy AHP: Southern sections of the western Afar rift margin and associated rift floor

A persistent drought commonly affects the southern sections of the western Afar rift margin and the associated rift floor, leaving the populace concerned about their access to food. A comprehensive assessment and usage of the local groundwater resource is therefore essential to overcoming the ongoing drought and meeting the area's increasing demand for sustainable water. With the aid of RS, GIS, AHP, and Fuzzy AHP methods, this study aims to assess the area's groundwater potential. Lineament density, Geology,Topographic Wetness Index (TWI), Recharge, Slope, Land Use and Land Cover, Soil, and Drainage Density were created using GIS and RS techniques and are the thematic layers taken into consideration for this purpose. The weight of these themes for their relative significance to groundwater occurrence was determined using AHP and Fuzzy AHP (FAHP). Lineament density is the primary factor influencing the presence of groundwater, followed by geology, TWI, and recharge. The Very low (221.48 km2), Low (9084.46 km2), Moderate (8281.96 km2), High (1441.65 km2), and Very High (102.45 km2) groundwater potential zones (GWPZs) were delineated using the GIS-overlay analysis technique. The validation of the groundwater potential zone map was completed using the well discharge, transmissivity, and specific capacity, and the scatter plot demonstrated a strong connection with R2 values of 0.81, 0.79, and 0.80, respectively. The sensitivity index (SI) shows that lineament density and geology, which have SI values of 2.08% and 1.74%, respectively, have the greatest influence on the distributions of groundwater potentiality in the catchment, while drainage density has the least influence, with a SI value of −0.89%. By ensuring sustainable management and development, the study's findings will help with decision-making for the long-term supply of groundwater. Additionally, the approach utilized in the study can be applied to other comparable arid to semiarid regions.

LAND USE MAPPING AND GEOSPATIAL ANALYSIS OF THE BAHAWALNAGAR LANDSCAPE TRANSITION: UNRAVELING CLIMATE CHANGE FORCES

The study was conducted to monitor the transformation of Bahawalnagar Landscape due to Climate Change through GIS & RS techniques. Data was collected from the past 30 years from 1990 to 2020 with a 10-year interval. Similarly, climate data, which includes temperature and rainfall also collected for respective years. With the help of supervised classification, NDVI, and NDBI, it is revealed that change occurred in the landscape in the proceeding years. The built-up land increased with the passage of time. Similarly, open land and water resources are reduced with time due to low rainfall, which declines the ratio of water sources from 1990 to 2020. So, in 2020, the construction area showed a further increase and covered 20.04%, agricultural land increased to 1.46% and open land decreased by 18.58% (the decrease in open land portion is directly linked with built-up and a small portion with agricultural land) and water bodies decreased by 2.8% in the thirty-year time period. Comparison graphs and figures further highlight the relation of climate change with the landscape. The relationship has a direct link such as high temperature reducing the agricultural land and change occurring more. In the same way, low rainfall also changes or fluctuates the landscape pattern of Bahawalnagar. In short, recommendations have been given to minimize the impacts of climate on the landscape.

A comprehensive review of urban growth studies and predictions using the Sleuth model

Urban growth is a complex phenomenon It has been the subject of in-depth research for the last few years. There are various models used to measure and simulate urban growth. Most of these methods are founded on GIS & RS techniques coupled with the CA algorithm, as only these tools and techniques have the capabilities to conduct spatiotemporal studies, manage spatiotemporal dynamics, and provide a detailed depiction and modeling from the bottom-up tactic. Recently, the slope, land use, exclusion, urbanization, transportation, and hill shade (SLEUTH) model has been the most commonly used model. It is easily accessible because it is open source; moreover, its source code is also easily accessible. The SLEUTH model’s name alludes to the necessary inputs —slope, land use, excluded area, urban extension, transportation, network and hillshade. The model has been used in many cities and has proven to be efficient. The present review paper reviews the past literature pertaining to urban development and prediction to further support the research on urban planning, urban growth and prediction.

Development of MWCNTs@PDMS nanocomposites with enhanced hydrophobicity and thermo-oxidative stability

This paper presents the fabrication of hydrophobic polymer nanomaterials with improved thermal characteristics based on MWCNTs and poly(dimethylsiloxane). The samples were synthesized by physical adsorption of poly(dimethylsiloxane) onto P-MWCNTs surfaces in the amount from 5 to 20 wt%. The effect of different content of adsorbed polymer on the structure and properties of the prepared nanocomposites was studied in detail using ATR-FTIR, SEM, TEM, XRD and RS techniques. XPS results showed that with the increase of adsorbed PDMS onto the MWCNTs surfaces, the Si 2p atomic percentage increased from 1.5 to 5.0 at.%. The investigation of thermal properties using TGA/DSC techniques in air atmosphere revealed that polymer adsorption on the MWCNTs surfaces enhances the thermo-oxidative stability of the nanocomposites to a great extent. The WCA of MWCNTs@PDMS-1000(20) nanocomposite reached 138.9° while this value was 81.8° in the case of the P-MWCNTs. The electrical characterization of the examined samples demonstrated a non-linear current–voltage behaviour and the invariance of the electrical current value with the increasing polymer content in the nanocomposites. The results suggest that the obtained nanocomposites have multi-functional surfaces and are promising for integration into a silicon-based polymer matrix for the development of new materials for electronic devices.

An Investigation of the Impact of Spatiotemporal Changes of Land Use and Land Cover and Land Surface Temperature Using RS Techniques for Selected Cities in Sri Lanka

Changes in land use and land cover (LULC) have an impact on land surface temperature (LST) locally, regionally, and globally. This research focused on the spatiotemporal dynamics of LULC and LST between 2000 and 2021 at six selected meteorological stations, belonging to the different climatic zones of Sri Lanka. The LULC were classified from Landsat ETM+ and OLI/TIRS data using the maximum likelihood classification approach, while LST was retrieved using the thermal band of both Landsat images. Resultsreveal that the built-up areas have increased in all selected locations and bare land, vegetation cover, and agricultural land have all declined in the last 20 years. In Galle and Batticaloa areas, built-up areas have grown significantly by 11.9% and 11.14% respectively, by 2021. The thermal environment spatiotemporal alterations were consistent with the urbanization trend. Since many other land use types have been converted into urban areas, the average LST in Vavuniya, Anuradhapura, Batticaloa, and Galle has been rising steadily. This showed that increasing built-up area density has played a significant role in raising LST in the study areas. The vegetation cover, agricultural land, and water bodies showed the least LST change. By examining the correlation analysis between the Normalized Difference Vegetation Index (NDVI) and LST, a somewhat positive relationship was revealed only in the areas of Galle, Batticaloa, and Hambantota. Nevertheless, the findings of this study will serve as a helpful benchmark for future landscape and urban design initiatives aimed at reducing the detrimental effects of LST on urban sustainability.

THE ASSESSMENT OF SCENIC ATTRACTIVENESS ON COASTAL WAYS: A CASE STUDY OF PERSEMBE-BOLAMAN (ORDU-TURKEY)

The biophysical characteristics of the areas that can be seen while travelling on motorways have an impact on the perception of the landscape. Highways provide diverse landscape experiences to travellers according to their natural and cultural qualities. Especially coastal ways that combine with nature and the sea have a high potential for scenic attractiveness. This study aims to analyse the scenic attractiveness of coastal ways using GIS and RS techniques. Persembe-Bolaman coastal way in the Black Sea Region of Turkey was selected as a case study. Three road features and seven viewshed features that are assumed to affect landscape attractiveness on the Persembe-Bolaman coastal road were selected. The data set of these features was categorised into three clusters by k-means clustering, one of the unsupervised learning algorithms. The most attractive cluster in terms of scenic attractiveness was selected by determining the characteristics of the clusters. In conclusion, it was found that the scenic attractiveness was the highest in Cluster-1, which corresponds to 46.3% of the selected route.

Groundwater quality and potential analysis using geospatial techniques: The case of Ashanti Region in Ghana

The ecosystem and economy's reliance on clean water is influenced by various factors such as geology, topography, soil types, activities, and the presence of plants and animals. The Ghana Water Company is encountering difficulties in delivering water to consumers in the Ashanti Region due to the shortage of surface water resources, leading to water rationing in the area. Furthermore, poor waste disposal practices, illegal mining, use of fertilizers, and industrial activities have resulted in surface and groundwater source damage. Therefore, there is a need to implement a reliable, simple, and timely method to assess groundwater quality. This study aims to employ GIS and RS techniques to evaluate groundwater quality and potential in the Ashanti Region, Ghana. The Water Quality Index (WQI) was estimated using pH, Total Dissolve Solid (TDS), Chloride, Total Hardness (TH), Nitrate, Temperature, Turbidity, Iron, and Electrical Conductivity (EC). The study then used the WQI distribution to conduct a groundwater potential analysis to identify suitable areas for borehole placement. Digital thematic layers and maps were developed to expose the spatial distribution of water quality parameters, enabling the identification of groundwater pollution control and remedial measures. The study estimated the region's groundwater potential using an integrated GIS and Analytical Hierarchical Process (AHP) technique, grouping under excellent, good, fair, and poor potential. The WQI in the Ashanti Region ranged from 5.208 to 134.232, with 32.252% of the study area having an excellent WQI and 60.168% of the study area having a good WQI. Poor water quality covered 7.550% of the study area. The results showed that the GIS-based AHP approach accurately mapped the spatial distribution of WQI and Groundwater Potential Zones (GWPZ). This information is helpful to planners in water resource management in groundwater exploration and future planning. Policymakers and stakeholders must ensure that groundwater sources are protected from pollution.

Delineation of potential alternative agriculture region using RS and AHP-based GIS techniques in the drought prone upper Dwarakeswer river basin, West Bengal, India

Delineation of potential alternative agriculture region is an essential tactics of the drought prone to mitigate the harmful effect of drought for maintaining food security and sustainable economy. These alternatives can be integrated into existing cropping systems for providing additional income to farmers. The present study deals with site suitability analysis of alternative agriculture in the drought-prone upper Dwarakeswer river basin considering 15 parameters using Analytical Hierarchy Process (AHP) based Geographic Information System (GIS) techniques. The alternative agriculture zones are then delineated on the basis of 15 separate thematic layers such as Slope, landuse and landcover, soil depth, ground water, distance from roads, soil texture, distance from settlements, ruggedness index, drainage density, soil drainage, proximity to ponds, distance from vegetation, distance from streams, nitrogen and organic carbon. Finally, seven alternative agricultural zones are identified; these are plantation agriculture, integrated farming, fruit culture, folk rice culture, medicinal plant farming, mixed farming and horticulture covering an area of 96 km2, 234 km2, 295 km2, 341 km2, 298 km2, 199 km2 and 74 km2 respectively. This is also to note that the ‘Not Suitable Zone’ has been identified accounting 397 km2 area and covering 20.5% of total study area. A total of 350 alternative agricultural sites are identified for validation purpose and the computed kappa coefficient (k) of 95.34 denote a overall accuracy of 96%.

Potential for the complementary and integrative use of citizen science and modern science in flood risk reduction: A case study from Sri Lanka

This study sheds light on the complementation of citizen science, powered by indigenous knowledge and self-experience and modern science to reduce the flood risk. A questionnaire survey was conducted to recognize the perception of the community residing in the Kalu river basin which is frequently flooded, on floods, its impacts, causes, spatio-temporal changes and the possible solutions for mitigating the flood impacts. Data were analysed using statistical methods along with GIS and RS techniques and compared with scientific literature. The results exposed that the insights of the residents on the occurrence of high impact floods and Land Use Land Cover changes matched with scientific information. The indigenous knowledge gained throughout many centuries, influences on the attitudes and makes the residents prepare for floods. Also, the residents practice many measures to reduce risk. However, the residents prioritize engineering solutions over Nature-based solutions in flood risk reduction which can be attributed to the lack of awareness on ecosystem services. We conclude that the joint use of citizen science and scientific information is necessary to improve better understanding on the flood risk. Nevertheless, it is important to re-consider whether such outcomes reach the policy makers and the communities effectively.

A Review on Remote Sensing Based Forest Vegetation Health Assessment: Bangladesh Perspective

This paper aims to present a critical review of the published scientific papers that have addressed the issue of forest health in Bangladesh using remote sensing techniques. A systematic review approach has been followed in this study where all the available papers on the application of remote sensing to assess the forest health vegetation condition of Bangladesh were considered for review. That search resulted in the selection of 48 papers. The findings indicate that remote-sensing-based studies have focused mostly on forest cover mapping and change, and landcover change detection rather than assessing the overall health condition of those forests. Also, among the major forests of the country, most studies have been conducted on Mangrove (Sundarban) forests whereas the least number of studies were found for the forests in the Chittagong Hill Tracts Forests areas and those studies were mostly conducted after the Rohingya crisis. Landsat satellite products have been most extensively used for their broader temporal resolution and availability while a few studies have worked with other products like MODIS, Sentinel, SPOT, etc. The application of advanced classification approaches incorporating machine learning algorithms and ground validation has shown effectiveness for investigating the forest or overall ecosystem health in a more detailed way. Although the RS techniques are increasingly used to study the forests of Bangladesh, forest health-specific and indicator-based research is yet to be done which can ensure sustainable forest management.
 The Dhaka University Journal of Earth and Environmental Sciences, Vol. 12(1), 2023, P 107-121

Identification of ground water potential zones for Mula river basin using RS and GIS techniques

Identification of ground water potential zones for Mula river basin using RS and GIS techniques

An assessment of geo-ecological richness in the Kalsa river basin (Himalayan region) using RS and GIS techniques

An assessment of geo-ecological richness in the Kalsa river basin (Himalayan region) using RS and GIS techniques

Examining the spatio-temporal relationship between LST, NDVI, NDBI and LULC change of Pachhua dun, Dehradun, Uttarakhand (India)

Recent climate change has had a negative impact on a wide range of human and natural systems, and it is clear that humans influence the climate. Because, as anthropogenic influence increases, the heat output from the land surface increases, speeding up the rate of climate change. In this regard, the use of RS and GIS techniques has provided various opportunities for research to examine these changes. The current analysis is based on the Landsat 1989, and 2020. Over the study period of 31 years, the built-up regions increased in size from 44.23 km2 to 154.56 km2. Whereas, the area covered by scrubland, water bodies, and vegetation cover has significantly decreased. The LST study further supports the outcome, showing that the mean and standard deviation increased from 14.81°C±1.32(1989) to 18.82°C±1.57(2020). The study also made an effort to examine how LULC affected LST; while vegetation cover has consistently helped to lower mean LST, built-up areas and scrubland are the main drivers of mean LST rise. The LST and NDBI revealed a positive correlation, while the NDVI/SLOPE and LST showed a negative correlation. Subsequently, the multiple linear regression (MLR) models concluded that the BUAs has evolved into a serious threat to the increase in LST, but increase in vegetation cover and SLOPE would result in slight decrease in LST. the study recommended that the government create policies that restrict future land encroachment and conversion, notably of forested area and water bodies, and make an immediate effort to increase the quantity and quality of urban green cover in the study area. So that we may, respectively, minimize the potential hazard posed by future LST rise and LULC change.

Land Use and Land Cover Change Detection of Teknaf Upazila Due to Rohingya Crisis by Using GIS, and RS Techniques

Bangladesh is in a terrible condition due to forced migration of Rohingya refugees from Myanmar to Bangladesh. Study focused on mapping and estimating changes in Teknaf Upazila's land use and land cover (LULC) between the years of 2010 and 2022. For the purpose of conducting this study, both primary and secondary data have been collected. The study found that the growing population has created unexpected and uncontrolled changes in LULC. It was found that between the years of 2010 and 2022, there was a drop in forest (1.68 SKM), vegetation (10.99 SKM), and bare soil (10.71 SKM). It was found that residences (22.96 SKM) and water bodies (42 SKM) increased during the course of these twelve years. Unplanned construction of refugee camps, political unrest, consumption of wood from surrounding forest, and the large influx of Rohingya refugees into the area are main causes for rising built-up area and drastic reduction of vegetation. As a result, the Rohingya population put pressure on Teknaf's established natural surround-dings and land cover.