Topographic Features Research Articles

Nitrogen metabolism pathways and functional microorganisms in typical karst wetlands.

Aha Lake artificial reservoir wetland, Niangniang Mountain karst mountain wetland, and Caohai plateau lake wetland are typical karst wetlands in Guizhou Province with unique topography and geomorphic features. They were selected as research objects in this study to explore microorganisms and functional genes in nitrogen metabolism adopting macro-genome sequencing technology. It was found that Proteobacteria, Actinobacteria, and Acidobacteria were the dominant phyla in nitrogen metabolism in these three wetlands, similar to previous studies. However, at the genus level, there was a significant difference, with the dominant bacteria being Bradyrhizobium, Methylocystis, and Anaeromyxobacter. Six nitrogen metabolism pathways, including nitrogen fixation, nitrification, denitrification, dissimilatory nitrate reduction, assimilatory nitrate reduction, and complete nitrification, comammox, were revealed, but anaerobic ammonia oxidation genes were not detected. Nitrogen metabolism microorganisms and pathways were more affected by SOM, pH, NO3-, and EC in karst wetlands. This study further discussed microorganisms and functions of nitrogen metabolism in karst wetlands, which was of great significance to nitrogen cycles of karst wetland ecosystems.

Tissue structure transformations of the gallbladder in chronic calculous cholecystitis

Aim. To determine the morphofunctional characteristics of tissue changes in the structure of the gallbladder in chronic calculous cholecystitis.Materials and Methods. The macro- and microscopic structural walls of the gallbladder were studied using the method of injection anatomical dissection, histology, and morphometry in 61 patients (aged 36 to 60) with chronic calculous cholecystitis.Results and Discussion. The results of a morphological study show that in chronic calculous cholecystitis, changes are always observed in all layers of the gallbladder wall. The most severe dystrophic and sclerotic changes are observed in the mucous membrane and submucosal base, since, this layer has in functional, topographical and quantitative features, as well as a direct contact with stones (mechanical impact).Conclusion. Transformation of the gallbladder in chronic calculous cholecystitis are characterized by vascular tissue restructuring of the structures of the organ wall, accompanied by the phenomena of adaptive, exudative and proliferative transformations, and in the later stages (5-6 years) undergo sclerotic changes in the gallbladder wall.

An automatic mesh generator for coupled 1D–2D hydrodynamic models

Abstract. Two-dimensional (2D), depth-averaged shallow water equation (SWE) models are routinely used to simulate flooding in coastal areas – areas that often include vast networks of channels and flood-control topographic features and/or structures, such as barrier islands and levees. Adequately resolving these features within the confines of a 2D model can be computationally expensive, which has led to coupling 2D simulation tools to less expensive one-dimensional (1D) models. Under certain 1D–2D coupling approaches, this introduces internal constraints that must be considered in the generation of the 2D computational mesh used. In this paper, we further develop an existing automatic unstructured mesh generation tool for SWE models, ADMESH+, to sequentially (i) identify 1D constraints from the raw input data used in the mesh generation process, namely the digital elevation model (DEM) and land–water delineation data; (ii) distribute grid points along these internal constraints, according to feature curvature and user-prescribed minimum grid spacing; and (iii) integrate these internal constraints into the 2D mesh size function and mesh generation processes. The developed techniques, which include a novel approach for determining the so-called medial axis of a polygon, are described in detail and demonstrated on three test cases, including two inland watersheds with vast networks of channels and a complex estuarine system on the Texas, USA, coast.

Wear and friction behaviour of Cu-Gr-B4C composites and correlating to the topographical characteristics

The mechanical and tribological characteristics are important in applications such as bearing linings, bushings, and electrical contacts. In the current experiment, copper-chromium matrix composites reinforced with graphite (Gr.)-boron carbide (B4C) [at 1.5, 3, and 4.5 wt%] were made using powder metallurgy (P/M) process. As reinforcements, equal amounts of Gr and B4C were utilized. The microstructural characteristics of the sintered composites have been investigated using analytical techniques such as EDS mapping analysis, x-ray diffraction, and scanning electron microscopy (SEM). The composites with a copper matrix displayed a homogeneous distribution of the reinforcement phase within the material. The pin-on-disc tribometer was used to conduct dry sliding wear tests with loads ranging from 10 to 40 N, sliding speeds of 1–3 m s−1, and fixed sliding distances of 2 km. The hardness is 97.3 HV with 3 wt% of each graphite and B4C reinforcement, which is 70.1% harder than pure copper (57.2 HV). It has been discovered that the wear rate and COF of composites decrease as the quantity of reinforcing rises—the composite with 4.5 wt% graphite and 4.5 wt% B4C exhibits the least amount of wear. The wear rate showed a rising trend with the applied load and sliding velocity across every material. The study of the deteriorated surface also reveals that delamination is the primary wear mechanism for pure Cu specimens. B4C and graphite-reinforced composites have been subjected to abrasives, oxidative and delamination wear modes.

Multiscale Analysis for Identifying the Impact of Human and Natural Factors on Water-Related Ecosystem Services

Accurately identifying and obtaining changes in ecosystem drivers and the spatial heterogeneity of their impacts on ecosystem services can provide comprehensive support information for ecological governance. In this study, we investigate the changes in the relationship between human and natural factors and water-related ecosystem services (WESs) in different sub-watersheds across various time periods, focusing on four aspects: single-factor effect, nonlinear effect, interactive effects, and spatial characteristics. Taking the southern basins, which have complex topographic, climatic, and economic characteristics, as a study area, the study area was divided into four sub-basins with different characteristics. WESs of water yield, soil conservation, and water purification were quantified using the InVEST model for five periods from 2000 to 2020, and the OPGD and MGWR models were integrated to assess the impacts of 15 factors on WESs and their spatial characteristics. The results show the following: (1) After comparing the data over multiple time periods, climate factors such as precipitation (0.4033) are the primary factors affecting WESs in the southern basins, and human factors such as construction area (0.0688) have a weaker influence. The direct impact of human factors on WESs is not significant in the short term but increases over time. (2) Different sub-watersheds have different impacts on WESs. For instance, human activity intensity (0.3518) is a key factor affecting WESs in the Inward Flowing Area, while precipitation is the primary factor influencing WESs in other sub-watersheds. (3) Influencing factors and WES changes are often nonlinearly correlated; however, once a certain threshold is exceeded, they may have adverse impacts on WESs. (4) When a single factor interacts with other factors, its explanatory power tends to increase. (5) Compared to traditional methods, the estimation accuracy of MGWR is higher. Intense human activities can adversely affect WESs, while abundant precipitation creates favorable conditions for the formation of WESs. Therefore, integrating long-time-series multi-remote sensing data with OPGD and MGWR models is suitable for identifying and analyzing the driving mechanisms of human and natural factors that influence changes in WESs. Against the backdrop of global change, elucidating the driving factors of ecosystem services can provide crucial insights for developing practical policies and land management applications.

Climate and landform interact to control the source and transport of nitrate in Pacific Northwest rivers

The hydrological effects of climate change are documented in many regions; however, climate-driven impacts to the source and transport of river nutrients remain poorly understood. Understanding the factors controlling nutrient dynamics across river systems is critical to preserve ecosystem function yet challenging given the complexity of landscape and climate interactions. Here, we harness a large regional dataset of nitrate (NO3–) yield, concentration, and isotopic composition (δ15N and δ18O) to evaluate the strength of hydroclimate and landscape variables in controlling the seasonal source and transport of NO3–. We show that hydroclimate strongly influenced the seasonality of river NO3–, producing distinct, source-dependent NO3– regimes across rivers from two mountain ranges. Riverine responses to hydroclimate were also constrained by watershed-scale topographic features, demonstrating that while regional climate strongly influences the timing of river NO3– transport, watershed topography plays a distinct role in mediating the sensitivity of river NO3– dynamics to future change.

Environmental factors differentially influence species distributions across tree size classes in a dry evergreen forest in Sakaerat Biosphere Reserve, northeastern Thailand

ABSTRACT Plant communities in tropical forests are influenced by multiple environmental variables. For trees, soil and topographic characteristics are key factors that impact the establishment of many species. In this study, the impacts of soil properties and topography on forest structure, species composition, α- and β-diversity, and tree species distribution across size classes were investigated in a dry evergreen forest (DEF) in the Sakaerat Biosphere Reserve, northeastern Thailand. Within a 16 ha permanent plot, all trees with a diameter at breast height (DBH) ≥ 1 cm were recorded. Tree species distributions mostly respected gradients of plot elevation and soil nutrient, including available P; these variables were strongly associated for most size classes. Structural attributes (basal area and tree density) of trees with a DBH of 5–10 cm were highly sensitive to these variables. For trees with a DBH of 2–5 cm, α-diversity was negatively associated with available P while β-diversity was associated with topography and available P. These findings demonstrate the strong influence of topographic and edaphic variables in shaping the DEF. Sensitivity to these variables, particularly elevation and increases in available P, increased with increasing tree size among size classes, as small trees were less sensitive than were larger trees. Our study provides an example of how different environments affect many of the features of tropical forest structure, such as tree size class and species composition.

Spatial variation and controls of soil microbial necromass carbon in a tropical montane rainforest

Soil microbial necromass carbon is an important component of the soil organic carbon (SOC) pool which helps to improve soil fertility and texture. However, the spatial pattern and variation mechanisms of fungal- and bacterial-derived necromass carbon at local scales in tropical rainforests are uncertain. This study showed that microbial necromass carbon and its proportion in SOC in tropical montane rainforest exhibited large spatial variation and significant autocorrelation, with significant high-high and low-low clustering patterns. Microbial necromass carbon accounted for approximately one-third of SOC, and the fungal-derived microbial necromass carbon and its proportion in SOC were, on average, approximately five times greater than those of bacterial-derived necromass. Structural equation models indicated that soil properties (SOC, total nitrogen, total phosphorus) and topographic features (elevation, convexity, and aspect) had significant positive effects on microbial necromass carbon concentrations, but negative effects on its proportions in SOC (especially the carbon:nitrogen ratio). Plant biomass also had significant negative effects on the proportion of microbial necromass carbon in SOC, but was not correlated with its concentration. The different spatial variation mechanisms of microbial necromass carbon and their proportions in SOC are possibly related to a slower accumulation rate of microbial necromass carbon than of plant-derived organic carbon. Geographic spatial correlations can significantly improve the microbial necromass carbon model fit, and low sampling resolution may lead to large uncertainties in estimating soil carbon dynamics at specific sites. Our work will be valuable for understanding microbial necromass carbon variation in tropical forests and soil carbon prediction model construction with microbial participation.

Abiotic factors impact on oak forest decline in Lorestan Province, Western Iran

The Zagros oak forests in Iran are facing a concerning decline due to prolonged and severe drought conditions over several decades, compounded by the simultaneous impact of temperature on oak populations. This study in oak woodlands of central Zagros forests in Lorestan province analyzed abiotic factors such as climate properties, topographic features, land use, and soil properties from 1958 to 2022. We found that higher elevation areas with steeper slopes and diverse topography show significant potential for enhancing oak tree resilience in the face of climate change. Additionally, traditional land use practices like livestock keeping and dryland farming contribute to a widespread decline in oak populations. Preserving forest biodiversity and ensuring ecological sustainability requires immediate attention. Implementing effective land-use management strategies, such as protecting and regulating human-forest interaction, and considering meteorological factors to address this issue is crucial. Collaborative efforts from stakeholders, policymakers, and local communities are essential to oppose destructive suburban sprawl and other developments. Sustainable forestry practices should be implemented to improve the living standards of local communities that rely on forests and traditional livestock keeping, offer forestry-related jobs, and ensure social security. Such efforts are necessary to promote conservation awareness and sustainable practices, safeguarding this unique and vital ecosystem for future generations.

Exploring the Impact of TiO2 and MgO Nanoparticles on the Mechanical and Topographical Characteristics of Glass Fiber Reinforced Polymer (GFRP) Composites with Varied Lay-up Sequences: A Taguchi Analysis

A revolutionary composite material, blending Glass Fiber Reinforced Polymer (GFRP) with advanced nanofillers like TiO2 and MgO, showcases remarkable versatility in various industries due to its unique properties. The process involves precise control of key factors, including fiber stacking sequence (F.S.S) and nanofiller integration (MgO and TiO2). The vacuum bagging process is employed in the production of nanocomposite laminates. Experimental studies have been conducted to assess the performance of composites with and without nanofillers, with a specific focus on crucial mechanical properties, namely ultimate tensile strength (U.T.S), flexural strength (F.S), impact strength (I.S), and hardness (H). The Taguchi L9 orthogonal array design optimizes parameters and enhances mechanical properties. Comparisons reveal significant improvements with nanofillers, including a 31.96% increase in ultimate tensile strength and a substantial 68.43% enhancement in flexural strength. ANOVA results highlight the critical impact of fiber stacking sequence on ultimate tensile strength (63.65%), flexural strength (65.70%), and impact strength (9.30%), while nanofillers play a lesser role, contributing 11.71% to ultimate tensile strength, 2.66% to flexural strength, and 3.61% to impact strength. Notably, in composite hardness, nanofillers play a more significant role, contributing 39.22%, while the influence of fiber stacking sequence is lower at 3.29%.

The effect of micro topographic features on the site selection of European ground squirrels (Spermophilus citellus): A case study from Tekirdag province, Thrace Peninsula (Türkiye)

The effect of micro topographic features on the site selection of European ground squirrels (Spermophilus citellus): A case study from Tekirdag province, Thrace Peninsula (Türkiye)

A 10-m national-scale map of ground-mounted photovoltaic power stations in China of 2020

We provide a remote sensing derived dataset for large-scale ground-mounted photovoltaic (PV) power stations in China of 2020, which has high spatial resolution of 10 meters. The dataset is based on the Google Earth Engine (GEE) cloud computing platform via random forest classifier and active learning strategy. Specifically, ground samples are carefully collected across China via both field survey and visual interpretation. Afterwards, spectral and texture features are calculated from publicly available Sentinel-2 imagery. Meanwhile, topographic features consisting of slope and aspect that are sensitive to PV locations are also included, aiming to construct a multi-dimensional and discriminative feature space. Finally, the trained random forest model is adopted to predict PV power stations of China parallelly on GEE. Technical validation has been carefully performed across China which achieved a satisfactory accuracy over 89%. Above all, as the first publicly released 10-m national-scale distribution dataset of China’s ground-mounted PV power stations, it can provide data references for relevant researchers in fields such as energy, land, remote sensing and environmental sciences.

Effect of process parameters involved in SWJP on surface integrity and biocompatibility characteristics of AZ31B Mg alloy

This study mainly investigates the influence of combined parametric conditions employed in submerged waterjet peening for biomedical applications. On measuring the microhardness and roughness on the peened surface, the finding corresponded directly with the strengthening of subsurface layers and different parametric combinations. The optimum parametric combination was determined by TOPSIS, considering microhardness and surface roughness as input. Under optimal parametric combinations, surface morphology and topography analysis, XRD analysis, corrosion behaviour examination, and cell morphology and viability analysis were studied and compared to unpeened surface. From the experimental results, the water bubbles create impulsive pressure that impacts the AZ31B Mg alloy's surface, promoting plastic deformation in the subsurface, enhancing the surface morphological and topographical characteristics, and making the alloy more suitable for bioimplant manufacture. Following that, these samples underwent an electrochemical corrosion study, which indicates the peened region's corrosion rate was reduced considerably compared to the unpeened region. In the course of biocompatibility analysis, the non-toxic nature of the peened region in the MG63 cell line was observed after 24 and 72 h.

Seasonal and Monthly Climate Variability in South Korea’s River Basins: Insights from a Multi-Model Ensemble Approach

This study conducts a comprehensive analysis of the impacts of climate change on South Korea’s climate and hydrology, utilizing a Multi-Model Ensemble (MME) approach with thirteen Climate Model Intercomparison Project Phase 5 (CMIP5) models under two Representative Concentration Pathways, RCP4.5 and RCP8.5. We observed an average temperature increase of up to 3.5 °C under RCP8.5 and around 2.0 °C under RCP4.5. Precipitation patterns showed an overall increase, particularly during the summer months, with increases up to 20% under RCP8.5 and 15% under RCP4.5, characterized by more intense and frequent rainfall events. Evapotranspiration rates are projected to rise by approximately 5–10% under RCP8.5 and 3–7% under RCP4.5. Runoff is expected to increase significantly, particularly in the summer and autumn months, with increases up to 25% under RCP8.5 and 18% under RCP4.5. This research focuses on employing the Precipitation Runoff Modeling System (PRMS) to project future streamflow across South Korea, with an emphasis on both monthly and seasonal scales to understand the varying impacts of climate change on different river basins. These climatic changes have profound implications for agriculture, urban water management, and ecosystem sustainability, stressing the need for dynamic and region-specific adaptation measures. This study emphasizes the critical role of localized factors, such as topography, land use, and basin-specific characteristics, in influencing the hydrological cycle under changing climatic conditions.

The Environmental Impacts of Post-Disaster Rehabilitation and Reconstruction Facilities in Garut Regency-Indonesia

Garut Regency is referred to as a miniature natural disaster in Indonesia. This is because Garut Regency is surrounded by active mountains with topographic characteristics of the northern part consisting of plateaus and mountains, while the southern part of the surface has a steep steepness and in some areas is unstable. Garut Regency, which is geographically prone to disasters, is the duty of the District Government and the community to protect Garut Regency and the community from disasters. As part of the overall disaster management, the implementation of rehabilitation and reconstruction stages becomes an important stage. Analysis of environmental impacts of post-disaster rehabilitation and reconstruction facilities is an activity needed to assess the impacts that arise on post-disaster rehabilitation and reconstruction facilities in Garut Regency. The research objective was to analyze the environmental impact of post-disaster rehabilitation and reconstruction facilities in Garut Regency on domestic solid waste generation and runoff. The results showed that the activities in post-disaster rehabilitation and reconstruction amenities in Garut Regency will change the land use, generate the solid waste of 1,07 m3/day and runoff of 2,73 m3/day. Land use changes can be maintaining by providing the green open space according to the regulation standard, moreover, the possible treatment for solid waste management is through TPS 3R (reduce, reuse, recycle at temporary waste collection site (TPS)) meanwhile runoff management can be managed by providing the proper drainage and infiltration wells.

The Impacts and Spatial Characteristics of High-Standard Farmland Construction on Agricultural Carbon Productivity

Agricultural carbon productivity combines the dual attributes of reducing carbon emissions and stabilizing economic growth, and is a core aspect of the new era of low-carbon agricultural development. The construction of high-standard farmland is an important initiative to promote high-yield and high-efficiency agriculture, as well as environmentally sustainable development through land improvement in China. However, the impact of high-standard farmland construction on agricultural carbon productivity and its mechanisms is still in the process of being determined. In order to fill this gap, this study aims to construct a theoretical, analytical framework for the impact of high-standard farmland construction on agricultural carbon productivity. Based on the current situation of high-standard farmland construction and the characteristics of agricultural carbon productivity in China, this study used the panel data of 31 provinces, from 2003 to 2017 in China, to empirically examine the effects, mediating paths, and spatial characteristics of the construction of high-standard farmland on agricultural carbon productivity using a double fixed-effects regression model, a mediating-effects model, and a spatial econometric model. The results show that: (1) High-standard farmland construction has a positive effect on agricultural carbon productivity, with a direct effect coefficient of 0.139 after adding a series of control variables. (2) Furthermore, heterogeneity analysis shows that the impact of high-standard farmland construction on agricultural carbon productivity will vary greatly depending on the topographic characteristics of the studied area, the level of economic development, and whether it is a main grain-producing area. (3) Mechanism analysis shows that agricultural scale operation, agricultural planting structure, and agricultural technology progress all have partial mediating roles in the impact of high-standard farmland construction on agricultural carbon productivity, with mediating effect coefficients of 0.025, 0.024, and 0.013, respectively. (4) Agricultural carbon productivity has a spatial correlation, and for every 1% increase in the level of high-standard farmland construction, agricultural carbon productivity increases by 0.117%, with a direct effect of 0.074% and a spatial spillover effect of 0.043%. Our study explains the impact effects, mechanisms, and spatial spillover effects of high-standard farmland construction on agricultural carbon productivity from theoretical and empirical perspectives, thus deepening the literature on the relationship between high-standard farmland construction and agricultural carbon productivity, and providing a theoretical basis and practical references for improving agricultural carbon productivity from the perspective of high-standard farmland construction policy.

Susceptibility of Landslide Debris Flow in Yanghe Township Based on Multi-Source Remote Sensing Information Extraction Technology (Sichuan, China)

The extraction of real geological environment information is a key factor in accurately evaluating the vulnerability to geological hazards. Yanghe Township is located in the mountainous area of western Sichuan and lacks geological survey data. Therefore, it is important predict the spatial and temporal development law of landslide debris flow in this area and improve the effectiveness and accuracy of monitoring changes in landslide debris flow, this article proposes a method for extracting information on the changes in landslide debris flows combined with NDVI variation, which is based on short baseline interferometry (SBAS-InSAR) and optical remote sensing interpretation. In this article, we present relevant maps based on six main factors: vegetation index, slope, slope orientation, elevation, topographic relief, and formation lithology. At the same time, different remote sensing images were compared to improve the accuracy of landslide debris flow sensitivity assessments. The research showed that the highest altitude of the region extracted by multi-source remote sensing technology is 2877 m, and the lowest is 630 m, which can truly reflect the topographic relief characteristics of the region. The pixel binary model’s lack of regional restrictions enables a more accurate estimation of the Normalized Difference Vegetation Index (NDVI), bringing it closer to the actual vegetation situation. The study uncovered a bidirectional relationship between vegetation coverage changes and landslide deformation in the study area, revealing spatial–temporal evolution patterns. By employing multi-source remote sensing technology, the research effectively utilized changes in multi-period imagery and feature extraction methods to accurately depict the development process and distribution characteristics of landslide debris flow. This approach not only offers technical support but also provides guidance for evaluating the vulnerability of landslide debris flow in the region.

Risk Management of Coastal Ring Roads to Rate Abrasion on The Lhokseumawe City

This paper presents an approach for developing risk management strategies for ring roads in coastal abrasion Lhokseumawe ring roads. Currently, management strategies in these regions are designed to rubble mount breakwaters on coastal performance under traffic loads. However, recent large-scale waves and their associated damage to coastal areas have demonstrated the need to consider the height when making coastal management decisions. This paper aims to develop a risk management strategy that includes handling/controlling accelerated beach abrasion which damages coastal infrastructure buildings and the application of the ALARP scheme as an acceptable risk control limit for decision makers in risk management so as to minimize the potential impact at any given time... The methods consider the rate of coastal abrasion associated with hazards and the economic, social, and environmental consequences of collapse under high tide. The data were collected from the satellite Landsat range of the 1995-2021 year. The analysis adopted Digital Shoreline Analysis System with Enhanced Thematic Mapper (ETM). The risk management strategies are achieved by formulating and solving a multi-objective optimization problem. This problem's findings include abrasion -2.11 m/year and accretion maximum at 111.34 m or 4.45%. The height of the wave was found approximately range 2.33-10.25 sec, and the period average 4.57 m/year. In addition, the periods of the wave were in the range of 2.33-10.25 sec, and the average period was 4.57 sec. The topography characteristics were found between 0 and 8.60 meters, with an average level, is 4.30 meters. The percentage of the slope of the shoreline was found to be 2.90 to 4.47%, and the average beach slope was 3.76%. The risk management achieved in ring roads was relevant to the application scheme ALARP zone to solve the problem from very high to hight risk. The rubble mound breakwaters along the coast were believed to minimize abrasion and mitigate disasters to protect infrastructure ring roads for a long time.

Accurate superposition modeling method of grinding-shot peening surfaces

Abstract The coexistence of initial surface texture features and shot peening texture features in the final surface topography is a significant feature of shot peening. After the initial surface topography is strengthened by shot peening, the wave peak will produce more substantial deformation relative to the wave valley, which has not been considered in the existing superposition modeling methods. And this will affect the correlation study between surface topography and performance. Taking the surface generated by the grinding-shot peening process as the research object, based on the feature extraction of measured topography, the concept of ‘Shot peening texture depth distribution surface’ is put forward. And the proposed precise superposition method uses the texture depth distribution surface to optimize the characteristic baseline of shot peening based on the existing theory. The measured grinding-shot peening surfaces verify the given method. It is found that the topographical and spatial features of the surfaces superimposed by this method are consistent with those of the measured surfaces, and the error of roughness parameters defined by ISO25178 are all less than 8%. Among them, the percentage errors of the critical parameters Spd, Sdq, and Sdr related to friction and lubrication are significantly reduced to 5%.

Small- and medium-sized rice fields identification in hilly areas using all available sentinel-1/2 images

BackgroundMastering the spatial distribution and planting area of paddy can provide a scientific basis for monitoring rice production, and planning grain production layout. Previous remote sensing studies on paddy concentrated in the plain areas with large-sized fields, ignored the fact that rice is also widely planted in vast hilly regions. In addition, the land cover types here are diverse, rice fields are characterized by a scattered and fragmented distribution with small- or medium-sized, which pose difficulties for high-precision rice recognition.MethodsIn the paper, we proposed a solution based on Sentinel-1 SAR, Sentinel-2 MSI, DEM, and rice calendar data to focus on the rice fields identification in hilly areas. This solution mainly included the construction of rice feature dataset at four crucial phenological periods, the generation of rice standard spectral curve, and the proposal of spectral similarity algorithm for rice identification.ResultsThe solution, integrating topographical and rice phenological characteristics, manifested its effectiveness with overall accuracy exceeding 0.85. Comparing the results with UAV, it presented that rice fields with an area exceeding 400 m2 (equivalent to 4 pixels) exhibited a recognition success rate of over 79%, which reached to 89% for fields exceeding 800 m2. ConclusionsThe study illustrated that the proposed solution, integrating topographical and rice phenological characteristics, has the capability for charting various rice field sizes with fragmented and dispersed distribution. It also revealed that the synergy of Sentinel-1 SAR and Sentinel-2 MSI data significantly enhanced the recognition ability of rice paddy fields ranging from 400 m2 to 2000 m2.