Lakeside Area Research Articles

Inequity in accessibility to urban parks in environmental gentrification areas based on Multi-G3SFCA: A case study of Wuhan’s main urban districts

Equitable access to urban parks is essential for promoting social fairness and sustainable urban development. However, in the context of urban renewal, environmental gentrification has exacerbated inequities in urban park accessibility. Although research on green space equity is relatively rich, studies focusing on inequities in urban park accessibility in environmental gentrification areas and their influencing factors remain limited. This study aims to analyse inequities in urban park accessibility in gentrified areas and explore the effect of physical spatial and socioeconomic factors on these disparities. With Wuhan’s main urban districts as the study area, environmental gentrification areas were identified using bivariate spatial autocorrelation analysis. An improved three-step floating catchment area(Multi-G3SFCA) method was used to assess the inequities in urban park accessibility across residential communities, and the Gini coefficient and Lorenz curve were used to quantify overall inequity in environmental gentrification areas. Finally, the RF-SHAP method was utilised to analyse the factors influencing accessibility inequities among residential communities. The results indicated that: (1) Environmental gentrification in Wuhan’s main urban districts primarily occurs in lakeside and riverside areas. The average Gini coefficients for community and pocket parks were 0.953 and 0.994, respectively, indicating severe inequity. (2) Physical spatial factors (63%) contributed to inequities in urban park accessibility more than socioeconomic factors (37%). Proximity to rail transit and commercial centres contributed 38% and 22% to inequities, respectively, making them the primary determinants. (3) Although socioeconomic factors had a relatively minor overall effect, they directly influenced inequities and interacted with physical spatial factors. Elements such as the proportion of the ageing population and income levels play a notable role. This study enriches the existing research on inequities in urban park accessibility in environmental gentrification areas. It provides valuable insights for the effective management and planning of urban parks in the context of environmental urban renewal and promotes the equitable development of urban green public spaces.

Evaluating thermal comfort indices for outdoor spaces on a university campus

This study evaluates the applicability of three thermal comfort indices—Physiologically Equivalent Temperature (PET), Standard Effective Temperature (SET), and Universal Thermal Climate Index (UTCI)—in various outdoor environments on the campus of Xi’an University, China. Meteorological data were collected on sunny days using a portable weather station at a height of 1.5 m, and subjective questionnaires were administered to 25 healthy university students over three months to gather Thermal Sensation Votes (TSV) and Thermal Comfort Votes (TCV). The study was conducted at four distinct outdoor locations: a lakeside area (Location 1), a shaded path (Location 2), a sports field (Location 3), and a plaza (Location 4). PET, SET, and UTCI values were calculated from the collected data using Rayman software. The analysis revealed significant differences in thermal comfort across the four locations, with the highest proportion of subjects feeling hot at the sports field (54.4%) and the highest proportion feeling cold at the lakeside (39%). The shaded path had the highest proportion of subjects feeling comfortable (79.4%), while the lakeside had the lowest (60.1%). The results indicated that SET underestimated thermal sensation at Locations 1, 3, and 4, necessitating calibration. PET was suitable for Locations 2, 3, and 4 but failed to reflect the thermal sensation at Location 1 due to prolonged sun exposure. In contrast, UTCI demonstrated applicability across all locations. To enhance accuracy, revised indices SET’ and PET’ were formulated using the mean-median method, providing more precise thermal comfort assessments. These findings underscore the limitations of SET and PET under specific conditions and highlight the robustness of UTCI, offering valuable insights for urban planning and design aimed at improving outdoor thermal comfort and well-being.

Spatial and temporal heterogeneity of soil salinity and ionic coupling relationship under the water-saving renovation of a typical irrigation district in arid and semi-arid areas

Soil salinization is a global environmental problem. To investigate the spatiotemporal heterogeneity of soil salinity and the coupling relationship of soil salinity ions under water-saving renovation conditions, we chose Shenwu Irrigation Area, where water-saving renovation projects are being conducted comprehensively. Specifically, for our field experiments, we chose 46 soil sampling points. Specifically, we used different spatial interpolation methods and coupling coordination models were applied to study the spatial and temporal distribution of soil salinity and soil salt-based ion coupling relationship changes during different water-saving periods in the irrigation area between 2015 and 2022. The results showed that (1) the emergence of soil salinity extremes after water-saving renovation project led to an increase in the variability of soil salinity. (2) Compared with the Inverse Distance Weighted, Radial Basis Function, and Universal Kriging interpolations, the Mean Absolute Error of the Ordinary Kriging interpolation was reduced by 12.68 %, 43.96 %, and 38.77 %, the Root Mean Square Error was reduced by 14.34 %, 60.85 %, and 36.53 %, reflective of a significant improvement in accuracy, and thus confirming this method to be optimal for elucidating soil salinity. (3) Compared with pre-water-saving renovation project, the average soil desalination rates in the 0–50 cm soil layer during and after project implementation were 5.71 % and 35.67 %. The impact of the water-saving renovation project was highest in channelside areas, followed by croplands, and lowest in lakeside areas. (4) The growth rates of soil salt-based ion coupling degree and coupling coordination degree after project implementation, compared with before implementation, were 17.07 % and 10.81 %. The implementation of water-saving renovation project improved soil quality. This study provides scientific support for the prevention and control of soil salinization in irrigation areas.

Future changes in soil salinization across Central Asia under CMIP6 forcing scenarios

AbstractSoil salinization is a critical environmental and socio‐economic concern with global implications, and its severity is expected to amplify under changing climate. The impact of climate change on salinization in Central Asia is still not fully understood. This study addresses this gap by employing a digital soil mapping (DSM) framework. Cubist, random forest (RF), and quantile regression forests (QRF) are utilized to project variations in soil surface salinity (0‐10 cm) in Central Asia from 2025 to 2100 under two shared socio‐economic pathways (SSPs): SSP2‐4.5 and SSP5‐8.5. These models are developed using data from 20 global climate models (GCMs) obtained from the Coupled Model Intercomparison Project Phase 6 (CMIP6). The results reveal that the RF model exhibits superior predictive capability in estimating soil salinity. RF performed on the calibration set with a coefficient of determination (R2) of 0.86, root mean square error (RMSE) of 9.84 and 9.90 dS m−1, ratio of performance to interquartile distance (RPIQ) of 3.09 and 3.07, and a Nash–Sutcliffe efficiency (NSE) of 0.86. The multi‐GCM ensemble means revealed the potential for varying degrees of salinization in Central Asia, with higher levels predominantly observed in the southeast and southwest of the study area, particularly downstream of the river and in the lakeside areas. Temporal analysis of soil salinity evolution reveals an overall increase in salinity across the region, with more notable changes projected under SSP5‐8.5. Specifically, the projected increase rate in soil salinity for Central Asia was 0.0005 dS m−1/year under SSP2‐4.5 and 0.01 dS m−1/year under SSP5‐8.5. Turkmenistan is notable for possessing the highest regional average of soil salinity, with the exception of a declining trend observed within this area. The remaining regions of Central Asia exhibit an upward trend in average soil salinity, particularly noteworthy under the SSP5‐8.5 scenario, where variations in soil salinity are more obvious. These findings hold significant potential in enhancing our understanding of how Central Asia responds to global change, advances toward sustainable development, and enhances comprehension of the dynamics within the region.

Source Analysis and Bioavailability of Soil Cadmium in Poyang Lake Plain of China Based on Principal Component Analysis and Positive Definite Matrix Factor

In order to identify the source and bioavailability of soil Cd in the alluvial geological high background area, 3799 topsoil samples and 140 root soil samples were collected from the Jiulong area on the south bank of Poyang Lake, Jiangxi Province. The results confidently indicate that the range of topsoil Cd content is 0.02~8.12 ppm, with an exceedance rate of 14.6%. It is noteworthy that exceedance points were mostly distributed in quaternary sediments. The geostatistical analysis clearly shows that the spatial distribution characteristic of topsoil Cd is higher in the north and lower in the south. The area with extremely high values (>90% quantile) is predominantly located in the tidal flat and low-lying areas of the mainstream of the Xinjiang River. The PCA analysis confirms that the main source of topsoil Cd is man-made activities related to industry and mining. Soil Cd is primarily derived from upstream industrial and mining discharge (58.5%), as revealed by the PMF model analysis. The active Cd content in root soil is 77 ppb, with higher levels observed in the north and lower levels in the south. These findings suggest a significant risk of Cd diffusion along the upstream stream and deposition in the low-lying parts of the north. It is worth noting that Cd’s bioavailability and active forms in paddy fields are the highest, which can have a detrimental effect on food security. The correlation analysis suggests that genetic sources primarily control the bioavailability of soil Cd, followed by soil physicochemical properties such as SOC, Fe-Al oxides, and soil texture. Preventing source pollution and cutting off water system transmission are effective methods for preventing and controlling soil Cd pollution. These methods ensure the safety of cultivated land in the lakeside area of Poyang Lake Plain.

Traditional Village Morphological Characteristics and Driving Mechanism from a Rural Sustainability Perspective: Evidence from Jiangsu Province

(1) Background: The sustainable development of rural areas has become a critical factor in global economic and social transformation. As an essential part of China’s rural ecological and cultural system, traditional villages are now facing a crisis of yearly decline, and sustainable development has become a meaningful way to solve the problem. This study utilized morphological indicator analysis and the SDGs as an evaluation framework to reveal the correlation and driving factors between traditional villages’ spatial form and sustainability indicators. From the perspective of the spatial form, this approach has specific reference significance for improving the sustainability of traditional villages. (2) Methods: A framework for detecting the driving factors of rural sustainability based on four dimensions (morphology, environment, economy, and society) was constructed. A geographic information system (GIS) was used to analyze the geographic patterns and morphological indicator characteristics of traditional villages in Jiangsu Province, and GeoDetector was used to analyze the driving mechanisms of the spatial patterns of sustainability in traditional villages, providing the basis for spatial zoning and differentiated policy design for the construction, planning, and management of sustainable villages. (3) Results: ➀ The spatial patterns and morphological characteristics of traditional villages exhibit prominent geographical imbalances and significant cluster cores. ➁ The high-density and low-aspect-ratio rural form in the southern region (where rural industries are developed) promotes good economic sustainability in rural areas but also leads to poor environmental performance. The rural areas in the southwest and north (high-density forest areas) have medium density and a high aspect ratio, and the lack of agricultural space and external connections affects their social performance. The main focus is on poverty reduction and urban cooperation. The central and northern lakeside areas and the eastern coastal areas (important ecological protection areas) have low density and high aspect ratios, which have helped them to achieve excellent environmental performance but also led to contradictions in environmental, economic, and social performance. Maintaining low-density patterns, using clean energy, and protecting terrestrial and underwater biodiversity are essential to the sustainability of the rural environment. The agglomeration of spatial patterns promotes cooperation between rural and urban areas and improves industrial development, contributing to the sustainability of the rural economy. Improving social welfare and agricultural development contributes to the sustainability of rural societies. ➂ The impacts of various factors vary significantly; for example, Life below Water (SDG14), Climate Action (SDG13), and No Poverty (SDG1) are the most prominent, followed by Partnerships for the Goals (SDG17), Affordable and Clean Energy (SDG7), and Recent Work and Economic Growth (SDG8). (4) Conclusions: It is recommended that the government, with the driving mechanisms, divide the spatial management zoning of traditional villages in Jiangsu into three types of policy areas: environmental-oriented, economic-oriented, and social-oriented. Differentiated and targeted suggestions should be proposed to provide a critical decision-making basis for protecting and utilizing traditional villages in Jiangsu and similar provinces, as well as to help promote rural revitalization and sustainable rural construction in China.

Spatiotemporal dynamics of cholera hotspots in the Democratic Republic of the Congo from 1973 to 2022

Background Since the early 1970s, cholera outbreaks have been a major public health burden in the Democratic Republic of Congo (DRC). Cholera cases have been reported in a quasi-continuous manner in certain lakeside areas in the Great Lakes Region. As these cholera-endemic health zones constitute a starting point for outbreaks and diffusion towards other at-risk areas, they play a major role in cholera dynamics in the country. Monitoring the spatiotemporal dynamics of cholera hotspots and adjusting interventions accordingly thus reduces the disease burden in an efficient and cost-effective manner.Methods A literature review was conducted to describe the spatiotemporal dynamics of cholera in the DRC at the province level from 1973 to 1999. We then identified and classified cholera hotspots at the provincial and health zone levels from 2003 to 2022 and described the spatiotemporal evolution of hotspots. We also applied and compared three different classification methods to ensure that cholera hotspots are identified and classified according to the DRC context.ResultsAccording to all three methods, high-priority hotspots were concentrated in the eastern Great Lakes Region. Overall, hotspots largely remained unchanged over the course of the study period, although slight improvements were observed in some eastern hotspots, while other non-endemic areas in the west experienced an increase in cholera outbreaks. The Global Task Force on Cholera Control (GTFCC) and the Department of Ecology and Infectious Disease Control (DEIDC) methods largely yielded similar results for the high-risk hotspots. However, the medium-priority hotspots identified by the GTFCC method were further sub-classified by the DEIDC method, thereby providing a more detailed ranking for priority targeting.ConclusionsOverall, the findings of this comprehensive study shed light on the dynamics of cholera hotspots in the DRC from 1973 to 2022. These results may serve as an evidence-based foundation for public health officials and policymakers to improve the implementation of the Multisectoral Cholera Elimination Plan, guiding targeted interventions and resource allocation to mitigate the impact of cholera in vulnerable communities.

Emerging Sialylated Class R Lipooligosaccharides in Campylobacter jejuni from Seagulls Has the Potential to Trigger Guillain-Barré Syndrome - Yunnan Province, China, 2018-2023.

Lipooligosaccharides from Campylobacter jejuni (C. jejuni) have a mimicry antigen structure with gangliosides, which explains the mechanism by which C. jejuni caused Guillain-Barré syndrome (GBS). All 12 C. jejuni strains with class R LOSs and specific serotypes were isolated from seagulls in south China. These emerging C. jejuni strains had ganglioside-mimicry antigen structures and possessed a high potential for triggering GBS. Sialylated lipooligosaccharides (LOS) class R with GBS-associated serotypes isolated from seagulls highlight the risk of induced GBS around coastal or lakeside areas.

Wrack line formation and composition on shores of a large Alpine lake: The role of littoral topography and wave exposure.

Wrack lines are a key formation along shorelines that provide organic matter and bring ecological diversity to the local environment. Although wrack line formation has been extensively studied along marine beaches and estuaries, in contrast, knowledge about the environmental variables that promote wrack line formation within inland lakes is widely lacking. In one of the first studies to focus on wrack line formation on lakesides, we analysed the dimensions, volume, elevation and particulate composition of 36 wrack lines across 20 shore sections of a large, oligotrophic Alpine lake with natural water level fluctuations (Lake Constance-Obersee). Using multivariate partial least squares (PLS) regression, we identified the key environmental variables that drive wrack accumulation in lakeside areas. Our results demonstrate that wrack line volume increased with (1) the width of the eulittoral zone as an indicator of the swash conditions (up-rush vs. down-wash), (2) high exposure to wind waves as indicated by the total effective fetch, (3) high exposure to ship waves (catamaran ferry), and (4) the width of the sublittoral zone as an indicator of the availability of source material (Chara spp.) and of the wave energy dissipation rate of the incoming deep water waves. Sediment texture played only a minor role. Wide eulittoral zones and high ship wave exposure favoured high proportions of lake-borne components (Chara remains, mollusc shells), while the reverse was true for land-based components. Anthropogenic wastes were only present in small proportions. We discuss four main factor groups influencing the amount of wrack in marine beaches and on lakeshores considering similarities (waves, breakers, swash, dissipation, relief) and differences (tides vs. annual water level fluctuations) of the two systems, and point out research gaps. We demonstrate that wrack line formation is also important in large inland lakes and can be analysed using basic ideas from relevant marine studies.

The diversity and function of microbial community in the sediment and terrestrial area of thermokarst lakes

Thermokarst lakes are widely distributed across the Qinghai-Tibet Plateau (QTP) and have been identified as an important source of greenhouse gases. However, previous studies on soil microbes have mainly focused on the aquatic area of thermokarst lakes, and the changes in microbial communities in the terrestrial area around thermokarst lakes are still unclear. We used high-throughput sequencing to analyse the soil microbial communities in the sediment and terrestrial area around three thermokarst lakes on the QTP. The results showed that the relative abundances of Bacteroidetes and Proteobacteria were high in the sediment areas, while the relative abundances of Actinobacteria and Acidobacteria were high in the terrestrial area around the thermokarst lakes. As the distance from the thermokarst lakes decreases, the α-diversity of the microbial communities increased in the mature thermokarst lake (MTL), whereas the α-diversity of the microbial communities decreased in the developing thermokarst lake (DTL). The β-diversity of the microbial communities also varied significantly as the distance from the thermokarst lakes decreases. As the distance from the thermokarst lakes decreases, the abundances of most genes responsible for C decomposition decreased in the MTL and were high in the middle lakeside areas and sediment of the DTL. Soil organic carbon (SOC), total nitrogen (TN), pH, soil water content (SWC) and the pore equivalent diameter were critical factors that affected the microbial community. The microbial richness increased in relatively arid areas (SWC < 60%) and decreased in relatively humid areas (SWC > 60%) as the distance from the thermokarst lakes decreases. These results suggest that the potential C decomposition was high in the far lakeside areas of the MTL and was high in the middle lakeside areas and sediment of the DTL.

Urbanization affects the composition, source, and risk of soil PAHs in lakeside residential area of the Yangtze River Delta, China

Urbanization affects the composition, source, and risk of soil PAHs in lakeside residential area of the Yangtze River Delta, China

Study on the Spatial Heterogeneity of the Impact of Forest Land Change on Landscape Ecological Risk: A Case Study of Erhai Rim Region in China

As an important ecological ecotone of water and land ecosystems, the lakeside is characterized by a variety ecosystem services and high vulnerability. Forest land is important in resolving the ecological risks of the lakeside area and building its ecological base. It is important to explore the effect of change in forest land on landscape ecological risk in the lakeside area, alleviate the contradiction between ecological protection and construction and development in the area, and realize sustainable development. The present study attempted to explore the spatial and temporal evolutionary features of forest land in the Erhai rim region from 2000 to 2020 using bivariate spatial autocorrelation and multi-scale geographical weighted regression (MGWR) models. The following are the findings of this investigation of the 2000–2020 period: (1) the forest land area in the region generally decreased, first increasing and then decreasing, and was mainly occupied by cultivated land and artificial surfaces; (2) the total landscape ecological risk in the region presented an upward trend, and medium- and higher-risk areas were the main risk areas, with the latter increasing; (3) the impact of forest land expansion and contraction intensity on landscape ecological risk exhibited spatial and temporal heterogeneity. The main forms of forest land change at different stages differed, and the impacts on landscape ecological risk were also different. Reasonable forest land expansion can effectively alleviate the growth in landscape ecological risk, whereas the shrinkage of forest land would aggravate the landscape ecological risk in the Erhai rim region. Moreover, the findings can offer reference for the exploration of ecological protection and coordinated optimization of economic development in Erhai Lake.

Spatial distribution of non-point source pollution from total nitrogen and total phosphorous in the African city of Mwanza (Tanzania)

Rapid urbanization has caused widespread environmental pollution in Africa, restricting sustainable development programs. Today, non-point source pollution has become a major threat to many African cities. In this study, we have classified urban land use followed by the identification of urban functional areas based on multi-source data. We have then evaluated non-point source pollution based on nitrogen and phosphorus loads at a spatial scale in Mwanza city (Tanzania). We have estimated the spatial distribution of total nitrogen (TN) and total phosphorus (TP) loads at a scale of 1 square kilometer grid. The results show that ① the built-up area of the city was identified as 28.9 km2, accounting for 6.8% of the total area of the city. The area of informal settlements was 56.9 km2, accounting for 13.4% of the total area of the city. About 90.38% of 2.41×105 kg of the total TN load and 87.23% of 4.00×104 kg of the total TP load in the city were derived from the informal settlements alone in 2020. ② The average load intensities of TN and TP in Mwanza city were 6.90 kg·hm-2·yr-1 and 1.14 kg·hm-2·yr-1, respectively. The average TN and TP intensities in Mwanza city were slightly higher than the average TN and TP load intensities in the Lake Victoria basin. However, given the high population density of the Mwanza city area, the average TN and TP intensities were found to be consistent. ③ The TN and TP pollution loads were relatively concentrated in the inner urban area, including the lower reaches of the Mirongo River basin, the eastern side of the Nyamagana Peninsula, and the lakeside area extending north and south from the peninsula, and gradually decreased toward the city’s outskirts. We propose that the identified riparian areas in our study should be prioritized as potentially key construction zones for pollution treatment plant facilities and urban renewal pilot programs for restraining the widespread informal settlements. This study contributes to the development of an innovative urban non-point source pollution control measure, which may be applicable to low-income countries in Africa and elsewhere.

Lake ecological evaluation and land use planning in lakeside area from the perspective of two-way interaction

The healthy development of the lakeside area needs a detailed assessment of lake ecology and land use, and to adopt a targeted dynamic maintenance strategy. This paper is based on the micro perspective. On the one hand, through the subdivision of land use types in lakeside area, the paper discusses the impact of non-point source (NPS) pollution from different types of land on lake ecology. On the other hand, the paper studies the impact of water environmental capacity and water ecological health assessment on lakeside area construction. From a two-way perspective, we can unify the two as a whole, and jointly promote the healthy development of the lakeside area. Studies have shown that the construction of lakeside area needs to control scale and land use types to meet the needs of water ecological protection. The 2-levels, 5-categories, and 17-subcategories of the lake ecological health assessment index can provide effective support for dynamic monitoring and optimization and adjustment of planning strategies. Lakeside area developing is a dynamic and gradual process. The paper provides a feasible method to realize lake ecological protection and urban development.

Reactive nitrogen budgets in human-nature coupling system in lakeside area with insufficient data - A case study of Mwanza, Tanzania

Nitrogen (N) is an essential nutrient element for life, and also a major element involved in the composition of greenhouse gases, surface water pollutants, air pollutants, etc. Quantifying and evaluating the nitrogen budget of a region is very important for effectively controlling the nitrogen discharge and scientifically managing the nitrogen cycle. In this paper, the urban Rural Complex N Cycling (URCNC) model was used to analyze the nitrogen budget of Mwanza region, a typical lakeside area with insufficient data, and the nitrogen flow process of livestock subsystem, cropland subsystem, human subsystem and landfill subsystem was clearly described and the nitrogen input sources of atmospheric subsystem and surface water subsystem were clarified. And the results demonstrated: (1) the cropland subsystem was the subsystem with the largest nitrogen flux, and the input, output and accumulation of nitrogen were 33,116 t of N, 31,925 t of N and 1191 t of N, respectively. Livestock subsystem was the second largest subsystem of nitrogen flux, and the input, output and accumulation of nitrogen were 31,013 t, 30,183 t and 830 t, respectively. The nitrogen flux of the human subsystem was also large, and the nitrogen input, output and accumulation were 17,905, 17,125 and 780 t, respectively. The nitrogen input, output and accumulation of the landfill subsystem were 3700 t, 770 t and 2930 t, respectively. (2) 8093 t of N, 6864 t of N, 3959 t of N, and 758 t of N emitted into the atmospheric subsystem from the livestock subsystem, cropland subsystem, human subsystem, and landfill subsystem, respectively. (3) The total Nr input of surface water subsystem increased from 18,545 t of N in 2010 to 20,174 t of N in 2020, with an increase of 8.78 % in the past decade. It was estimated that by 2030, the total Nr input of the surface water subsystem would reach 24,946 t of N with an increase of 23.65 % compared with 2020. The livestock subsystem was the largest source, the cropland subsystem was the second largest source and human subsystem was an important source. (4) Population growth, economic development and urbanization are the main nitrogen driving factor. (5) Technology and policy together have important contributions to the reduction of nitrogen pollution in surface water.

Wild capybaras as reservoir of shiga toxin-producing Escherichia coli in urban Amazonian Region.

Capybaras are rodent widely distributed in South America, which inhabit lakeside areas including ecological parks and urban sites. Due to anthropological interaction, monitoring zoonotic pathogens in wildlife is essential for One Health. We investigated faecal samples from capybaras living in an urban area in Rio Branco (Acre, Brazil) for the presence diarrhoeagenic E.coli. Virulence factors from shiga toxin-producing E.coli (STEC), enterohaemorrhagic E.coli (EHEC), and enteropathogenic E.coli (EPEC) were screened by PCR. We detected at least one virulence factor in 81% of the animals, being classified as STEC and EHEC pathotypes. The presence of zoonotic E.coli in capybaras is a warning due to the highly frequent anthropological interactions with wild animals in this area. Our findings highlight the importance of investigating wild animals as carriers of zoonotic E.coli, requiring further investigations into wildlife surveillance and epidemiological monitoring.

Estimation of Soil Organic Carbon Content in the Ebinur Lake Wetland, Xinjiang, China, Based on Multisource Remote Sensing Data and Ensemble Learning Algorithms.

Soil organic carbon (SOC), as the largest carbon pool on the land surface, plays an important role in soil quality, ecological security and the global carbon cycle. Multisource remote sensing data-driven modeling strategies are not well understood for accurately mapping soil organic carbon. Here, we hypothesized that the Sentinel-2 Multispectral Sensor Instrument (MSI) data-driven modeling strategy produced superior outcomes compared to modeling based on Landsat 8 Operational Land Imager (OLI) data due to the finer spatial and spectral resolutions of the Sentinel-2A MSI data. To test this hypothesis, the Ebinur Lake wetland in Xinjiang was selected as the study area. In this study, SOC estimation was carried out using Sentinel-2A and Landsat 8 data, combining climatic variables, topographic factors, index variables and Sentinel-1A data to construct a common variable model for Sentinel-2A data and Landsat 8 data, and a full variable model for Sentinel-2A data, respectively. We utilized ensemble learning algorithms to assess the prediction performance of modeling strategies, including random forest (RF), gradient boosted decision tree (GBDT) and extreme gradient boosting (XGBoost) algorithms. The results show that: (1) The Sentinel-2A model outperformed the Landsat 8 model in the prediction of SOC contents, and the Sentinel-2A full variable model under the XGBoost algorithm achieved the best results R2 = 0.804, RMSE = 1.771, RPIQ = 2.687). (2) The full variable model of Sentinel-2A with the addition of the red-edge band and red-edge index improved R2 by 6% and 3.2% over the common variable Landsat 8 and Sentinel-2A models, respectively. (3) In the SOC mapping of the Ebinur Lake wetland, the areas with higher SOC content were mainly concentrated in the oasis, while the mountainous and lakeside areas had lower SOC contents. Our results provide a program to monitor the sustainability of terrestrial ecosystems through a satellite perspective.

Distribution And Inventory Of Gastropods Species In Lake Duo, Kerinci Regency, Jambi

Lake Duo has the potential to be used by the community as a place to find fish and tourism. Tourist activities and land changes in the lakeside area as fields are suspected to damage the environment and disrupt the life of lake organisms, namely gastropods. Therefore, the purpose of this study was to determine the distribution and types of gastropods in Duo Lake, Kerinci Regency, Jambi. This research was conducted in October 2018 using the survey method. Meanwhile, the research was conducted purposively based on differences in environmental characteristics, namely station 1 (near primary forest) and station 2 (area near community fields). Each station consists of 3 sampling sub-stations. Gastropod sampling was carried out at water depths of 0.5 m, 1 m, and 1.5 m using the Ekman Dredge. Subsequently, the gastropod samples were identified at the Ecology Laboratory, Andalas University. The results found 322 gastropods from 4 families and 6 species, namely Ampullaridae (P. canaliculata), Viviparidae (F. sumantrensis), Planorbidae (Physastra sp.), and Thiaridae (M. tuberculata, Melanoides sp., and T. scabra). Melanoides sp. dominant with a total of 211 individuals. P. canaliculata and F. sumantrensis were the lowest species found, each with 5 individuals.

Beautification of Pokhara City with a Special Focus on Phewa Lake and Lakeside Area

Pokhara is one of the rapidly growing cities of Nepal. It is the second-largest metropolitan city after Kathmandu. Because of the renowned temples, monasteries, lakes, adventure sports, and being close to the well-known Annapurna Range, it is considered as the tourism capital of Nepal. Millions of tourist visit this naturally gifted city every year contributing to considerable economic development. This economic prospect has attracted thousands of migrants every year leading to 67% growth in population in the last decade. The rapid population growth and urbanization without long-term planning and firm regulation have severely affected the development of sustainable infrastructure, preservation of the public space and natural resources. This has further impacted the tourism, economy, health and wellbeing, environment, and social aspect of the city. This article aims to generate strategies for retaining and improving the natural beauty of the city (focusing on the Phewa Lake area) by enhancing the economy and environment, rejuvenating social and cultural values, elevating the health and wellbeing of the people, and strengthening and promoting sustainable development. In this article, literature reviews, interviews, and field surveys were undertaken and four major improvements/developments are recommended for the beautification of Pokhara City. The recommendations are: preservation and development of open space into self-sustaining cohesive community parks, citizen-centred urban development, improvement of current transport infrastructure, and conservation of natural resources such as water, vegetation, and landscape.

Impacts of Urban Land Use Changes on Ecosystem Services in Dianchi Lake Basin, China

Land use change is widely regarded as a key factor altering the structure and function of ecosystems. Urbanization is a particular driver and influence in land use change and is expanding globally, especially in developing countries like China. The InVEST model was employed in this study to comprehensively assess the temporal-spatial impacts of urban land use changes (ULUC) on ecosystem services (ESs) and clarify the tradeoffs between urbanization and ecosystem services provision (ESP) in Dianchi Lake Basin (DLB), China, during 1995–2015. The results showed that DLB’s constructed land, particularly in lakeside areas, has increased substantially because of rapid urbanization (built-up area increase 51%, urbanization rate increase 91%), at the expense of agriculture, grassland, and scrubland, greatly altering ESP. Compared with 1995, carbon storage in 2015 decreased, while soil retention and nitrogen exports only fluctuated slightly. Although water yield increased, the ecological water volume of the whole DLB decreased through an increase in regional surface runoff. This resulted in more pollutants being carried into Dianchi Lake, impairing water quality and causing serious ecological and environmental issues. Thus, this study provides empirical evidence of the significant influence of ULUC on ESP. For eco-friendly urbanization in DLB and similar areas with rapid urbanization, a sustainable pattern of urbanization should be followed. The best tradeoffs between urbanization and ESP should be identified and considered in decision-making relating to urban planning, land use management, optimal natural resources management, and ecological conservation.