Effects Of Land Use Types Research Articles

Effect of Land Use Types and Slope on Selected Soil Physicochemical Properties in Bubisa Watershed, Adea Berga District, Central Ethiopia

Soil physicochemical properties can be affected by different land use type in Ethiopia. The nutrient content of soil in the three sites was varied based on; soil management systems, organic inputs and other factors. Cognizant of this fact, research was conducted in Bubisa Watershed to evaluate the effect of different land use types and slope on selected physicochemical properties of soil. Accordingly, lands such as; crop, grazing and forest land were nominated and twenty seven (27) core and composite soil samples were collected from 0-20 cm layers. Soil analysis was done and the highest (1.29 g cm<sup>-3</sup>) bulk density was recorded on the upper slope of crop land and lower (0.99 g cm<sup>-3</sup>) on the lower slope of forest land. Total porosity and Available water holding capacity were high (60.02%; 172 mm/m) in forest land and lower (49.56%); 152 mm/m) in crop land respectively. Soil pH was high in forest land and low in crop land soils. The result of soil organic carbon and total nitrogen were also high (4.51%; 0.22%) in forest land and low (1.4; 0.15) crop land soils, respectively. Moreover, CEC and basic cations varied across the three sites and high in forest land and low in crop land in the study watershed. Based on the results, it was concluded that forest has high concentration of soil nutrients except bulk density than crop land. As recommendation, studies should be expanded to provide more conclusive recommendation to have qualified; productive soils and estimate the effect of land use types and slope on soil properties for sustainable agricultural productivity.

The legacy effects of afforestation facilitate the maintenance of microbial C:N:P stoichiometric homeostasis amid land use change

Abstract Anthropogenic activities are altering the land cover of terrestrial ecosystems, wherein the influences of prior land use types on edaphic properties and soil microbes (i.e. legacy effects) may persist, influencing the soil processes of current ecosystems. However, the legacy effects of land use types on microbial homeostasis in terms of carbon (C), nitrogen (N) and phosphorus (P) stoichiometry remain greatly unknown, despite its pivotal roles in driving soil nutrient cycling. Here, we conducted a combined 35‐year of observational study with a short‐term soil‐microbe interactive inoculation experiment following afforestation in central China. Specifically, microbial communities from long‐term afforested soils (including shrubland and woodland, with adjacent cropland as the control) were extracted and then inoculated into soils across different land use types, in order to examine the legacy effects of priori land use on the current ecosystems. We showed that microbial communities in the woodland had more homeostatic C:N:P stoichiometric ratios when inoculated into soils across different land use types, compared to microbes originating from the cropland and shrubland. Further analyses revealed that changes in the composition of microbial community explained most of the variations in the C:P and N:P stoichiometric gaps between the microbial community and soil resources. Specifically, the C:P and N:P stoichiometric gaps showed positive relationships with the proportions of microbial r‐strategists that had fast‐growing life histories (e.g., Alphaproteobacteria, Bacteroidota and Firmicutes). Moreover, variations in the C:N and C:P stoichiometric gaps exhibited positive associations with N‐ and P‐acquisition enzyme activities, as well as microbial respiration. Our findings indicate that microbial efforts to maintain homeostatic C:N:P stoichiometry accelerate nutrient cycling in woodland, which may also involve energy costs and elevate C expenditure following afforestation. These results underscore the significance of ecological memory of historical land use in regulating microbial C:N:P stoichiometry, with important implications for the fate of soil C under land use changes. Read the free Plain Language Summary for this article on the Journal blog.

Access to bus services: an analysis of the influence of land use types

ABSTRACT During travel, commuters are naturally influenced by built environment factors, particularly land use types. However, the existing literature overlooks this impact and neglects the application of the adjusted Gaussian two-step floating catchment area method in studying accessibility to metro. To analyse the influence of land use types on accessibility to transit and the nature of such influence, we employed the adjusted Gaussian two-step floating catchment area method in measuring accessibility and the entropy index in gauging land use diversity. We also deduced the changes in accessibility scores to capture the effects of land use types. Additionally, we examined the differences in the bus and metro accessibility scores to clarify the influence of each mode. The accessibility scores in the study area were influenced by the land use types within it, and this influence was significant in the core administrative districts. These findings will support policymakers in land use and public transport planning.

Effects of land use types on the soil physicochemical characteristics of Inyi community, Enugu State, Nigeria: Application of multivariate statistical, and eco-toxicological and human risk model approaches

The constant and increased use of arable lands for cultivation has led to its degradation; hence the impacts of different land-use patterns on the soil physical and chemical properties were investigated. Soil samples (n = 36) were collected from the oil palm plantation (OPP), cashew plantation (CP) and untampered forest (UF), in Inyi community, Enugu State, Nigeria. They were air-dried, sieved, and analyzed for their physicochemical properties. The results revealed that the average soil pH ranged from 5.9 to 8.2. Moisture and carbon contents ranged from 6.3 to 35.4, and 3.5 to 6.7 % respectively. Low CEC values were recorded for all the soil samples. The total mean soil textural fractions decreased as follows: sand > clay > silt. Also, the total mean concentrations of N, P, K, and Mg in the study area decreased in the order: OPP>UF>CP, OPP>UF>CP, UF>OPP>CP, and OPP>UF>CP respectively while the S, NO3-, NO2-, and HCO3- followed the order; OPP>UF>CP, UF>OPP>CP, OPP>CP>UF, and CP>OPP>UF respectively. The soil ecological risk index was < 40 in all sample locations, indicating slight contamination of the study area. Therefore, regular monitoring and soil nutrient management practices should be maintained and encouraged.

Geospatial modelling of housing rents from TOD using MGWR and implications on integrated transportation-land use planning

Revealing the effect of transit-oriented development (TOD) on housing rents is critical for supporting transportation financing and sustainable urban development. However, existing research has not thoroughly examined the effects of land use type and TOD type on housing rents, crucially lacking geospatial modelling. This study investigates the spatial effect of TOD on housing rents using multi-scale geographically weighted regression (MGWR) and the relationship of land use type and TOD type to this effect. The results show that MGWR accurately quantifies the spatial effect. Meanwhile, the important TOD variables (integrated transit index, land use entropy, overall walkability) have positive effects on housing rents, which show spatial heterogeneity. Moreover, the premium effect of TOD station areas with a smaller proportion of residential and commercial land and a larger proportion of educational and cultural facilities is higher. Furthermore, in TOD station areas where transportation supply capacity is high but urban development is lagging, land use entropy and overall walkability have a strong influence on housing rents. Based on the study's results, we offer three recommendations for implementing TOD practices into integrated transportation and land use planning. This study renews our understanding of the outcomes of TOD both perspectively and methodologically.

Effect of Land Use Type on Soil Moisture Dynamics in the Sloping Lands of the Black Soil (Mollisols) Region of Northeast China

This study investigates the spatial and temporal heterogeneity of soil moisture on slopes of China’s northeastern black soil region, focusing on the effects of terrain adjustment and vegetation. Soil moisture dynamics in the 0–60 cm soil layer were measured at 10 cm intervals using the TRIME-PICO64 TDR® device on slopes with similar gradients representing three land use types: transverse ridge tillage (TRT) farmland, terraced fields (TFs) farmland, and pure forest woodland (WL). The results indicate significant variations in soil moisture content and water storage across different land use types in the order of TF &gt; TRT &gt; WL. The study further identified that soil bulk density, porosity, and water-holding indicators were in the order of WL &gt; TF &gt; TRT, inconsistent with the soil moisture results, indicating that soil quality cannot be the sole reason for the differences in moisture. The moisture differences between farmland types (TRT and TF) and WL are substantial, especially during the rainy season. In the rainy season (0–60 cm) and the dry season (30–60 cm), significant differences in moisture content are observed (p &lt; 0.05). Significant differences in moisture content between farmland types are found at 0–40 cm during the rainy season and at 0–10 cm during the dry season. In the rainy season, soil moisture for TRT and TFs first decreases from 26.76% and 30.85% to 22.44% and 25.38%, then slightly increases to 27.01% and 27.07% along the slope. Meanwhile, WL displays the opposite pattern on upper, relatively steep slopes, with soil moisture increasing from 16.66% to 17.81%, and exhibits a pattern of change similar to TRT and TFs on lower, gentler slopes. TFs consistently show higher soil moisture and water storage at all slope positions than TRT and WL. TFs improve soil quality, reduce erosion and sedimentation, and shift the lowest soil moisture content to a lower slope position. During the dry season, soil moisture differences between slope positions for TRT and WL were small. In general, terracing can effectively modulate moisture distribution along slopes, increasing moisture by an average of 0.26~12.43%, while afforestation, despite improving soil quality, leads to an 18.14~31.13% reduction in soil moisture content, with the impact being particularly significant during the rainy season. These findings provide important insights for optimizing land use and ecological construction, including keeping the balance between soil and water conservation, especially for sub-humid slope terrain areas.

Insect herbivory on Acer rubrum varies across income and urbanization gradients in the D.C. metropolitan area

Urbanization has increased wealth disparity within the United States, impacting the urban landscape and species interactions. In particular, the interactions between street trees and the arthropod communities that live among them may be modified by both human population densities across urban to suburban locations, as well as income levels within these areas. We examined the effect of land use type (urban vs. suburban) and median household income on variation in leaf damage and arthropod abundance of red maples (Acer rubrum) in the District of Columbia metropolitan region. We compared these levels of leaf damage to rates observed in a nearby temperate deciduous forest. We predicted leaf damage would be positively correlated with urbanization (forested < suburban < urban) and negatively correlated with neighborhood income level (low > medium > high). Instead, we observed higher levels of leaf damage on trees in the forest environment compared to the urban and suburban areas. Leaves from urban medium and high-income areas were less likely to exhibit herbivore damage than those from suburban areas. Of the leaves with damage, those in urban high-income and suburban low-income areas exhibited the most leaf area missing. These trends may be related to specific factors associated with urbanization and income level, such as impervious surface coverage and tree coverage. This study highlights differences in biotic interactions across individual neighborhoods and the importance of including socio-economic variables when examining species interactions in urban environments.

A dataset of land use types in the Lijiang River Basin from 2016 to 2020

Land use monitoring is an important basis for land resource management. On the basis of Sentinel-2 remote sensing image data, we used multiple preprocessing methods such as original data calibration, Mosaic and tailoring, and established remote sensing interpretation markers as classification training samples. Then we adopted the maximum likelihood method to classify the land use situation of the Lijiang River Basin in Guilin City from 2016 to 2020. Moreover, in combined with the original random test samples, we used the confusion matrix analysis method to evaluate the accuracy of the dataset. The classification results show a relatively good classification effect of land use types in the Lijiang River Basin, with an overall classification accuracy above 95%, and the kappa coefficient above 0.8. On the whole, the land use types in the Lijiang River basin changed little, and the main land use type is woodland, accounting for about 65.2%. The spatial heterogeneity show that the construction land area expanded from 4.17% to 5.19% from 2016 to 2020. This dataset can provide data support for the study of spatio-temporal changes of land pattern and land use transfer and evolution.

Effect of land-use types and topographic positions on soil physico-chemical properties in urago and mendi micro-watersheds, Becho District, Central Highlands of Ethiopia

Effect of land-use types and topographic positions on soil physico-chemical properties in urago and mendi micro-watersheds, Becho District, Central Highlands of Ethiopia

Weather impact on ambient air pollution and its association with land use types/activities over 5,572 municipalities in Brazil

Quantify the impact of meteorological changes on air pollution levels is the aim of numerous recent studies. However, there is still a lack of investigations assessing the influence of land use/activities on the relationship between climate and air quality. In this study, we used a two-stage design to estimate the influence of land use types and activities on the association between weather changes and air pollution (PM2.5, NO2, SO2, O3) over 5572 municipalities in Brazil. To calculate the influence of recent weather change on air pollution concentration for each municipality, we used the “weather penalty” concept. This approach considers differences in linear trend coefficients between two generalized additive models. Then, using quantile regression, we estimated the effect of land use types and activities (8 variables related to transportation, energy generation, and land use) on weather-related increases in ambient air pollution. We found that an increase in PM2.5 was associated to recent weather changes in most municipalities (average increase of 0.07μg/m3per year) and a decrease in NO2 in most municipalities (average decrease of 0.0003 ppb per year). O3 and SO2 had more intense increases associated with weather changes in the North region. Our findings suggest the most robust positive associations between weather penalties on PM2.5 and areas with non-clean energy and oil refineries (average increase of 0.006μg/m3per year and 0.04μg/m3per year, respectively). We also found positive associations between Pasture areas, urban areas, and transportation and the weather penalties of this pollutant. In contrast, forest areas were negatively associated with PM2.5 penalties. We also found that oil refineries, urban areas, and transportation significantly positively influenced weather penalties for SO2 and O3. Overall, the study highlights the importance of considering the influence of land use types and activities on weather-related changes in ambient air pollution.

Spatial and Temporal Dynamics of Ecological Parameters in Various Land Use Types in China during the First 20 Years of the 21st Century

Ecological quality in China has experienced significant improvements due to the interplay of climate change and human activities. Nevertheless, previous studies exploring the trend of ecological parameters have always overlooked the effects of land use types. Therefore, in this study, we explored the spatiotemporal variation in ecological parameters in various land use types and discussed the relationship between ecological parameters and climatic factors in China during the first 20 years of the 21st century. The results show that: (1) The area of grassland and unutilized land decreased, and the area of other land use types increased. (2) Distinct variations in the average, slope, and interval distribution of ecological parameters across various land use types were evident. Particularly significant increases in ecological parameters were observed in cultivated land and forest. (3) The influence of land use and land cover change on ecological parameters was evident. The conversion of cultivated land, forest, and grassland into water bodies, constructive land, and unutilized land resulted in a significant decrease in ecological parameters. (4) The distinct climatic conditions resulted in heightened monthly variations in the ecological parameters. Significant monthly fluctuations in ecological parameters were observed for cultivated land, forest, grassland, and constructed land, while water bodies and unutilized land did not exhibit such variations. (5) The correlation between ecological parameters and climatic factors varied considerably in various land use types in different regions.

Effects of Land-Use Type and Salinity on Soil Carbon Mineralization in Coastal Areas of Northern Jiangsu Province

Sea level rise due to glacier melting caused by climate warming is a major global challenge, but the mechanism of the effect of salinity on soil carbon (C) mineralization in different land types is not clear. The pathways by which salinity indirectly affects soil carbon mineralization rates need to be investigated. Whether or not the response mode is consistent among different land-use types, as well as the intrinsic links and interactions between soil microbial resource limitation, environmental stress, microbial extracellular enzyme activity, and soil carbon mineralization, remain to be demonstrated. In this paper, three typical land-use types (wetland, forest, and agroforestry) were selected, and different salinity levels (0‰, 3‰, 6‰, and 32‰) were designed to conduct a 125-day laboratory incubation experiment to determine the soil CO2 release rate, soil physicochemical properties, and soil enzyme activities, and to correlate C mineralization with biotic and abiotic factors. A correlation analysis of soil physical and chemical properties, extracellular enzyme activities, and carbon mineralization rates was conducted to investigate their intrinsic linkages, and a multiple linear regression of C mineralization at different sites was performed to explore the variability of mineralization among different site types. Structural equation models were established in the pre- and post-incubation stages to study the pathways of soil C mineralization at different incubation times, and the mechanism of mineralization was further verified by enzyme stoichiometry. The results showed that, at the end of 125 days of incubation, the 32‰ salinity addition reduced the cumulative mineralization of forest and agroforestry types by 28.41% and 34.35%, respectively, compared to the 0‰ salinity addition. Soil C mineralization in the three different land-use types was highly correlated with the active C fractions of readily oxidizable C (ROC), dissolved organic C, and microbial biomass C (MBC) in the soil, with the standardized coefficients of multivariate linear regression reaching 0.67 for MBC in the wetland and −0.843 for ROC in the forest. Under long-term salinity additions, increased salinity would reduce the microbial respiratory quotient value by inhibiting β-glucosidase activity, thus indirectly affecting the rate of CO2 release. With added salinity, the mineralization of non-saline soil was more susceptible to the inhibitory effect of salinity, whereas the mineralization of salinized soil was more controlled by soil C pools.

Soil Carbon: Pool, Loss, Emission and Climate Change Sources and Knowledge Level of Some Land Use Systems in Sudan Savanna, Kwara State

This research work was carried out in Sudan savanna of Kwara State to determine the effects of land use types on soil carbon pool, loss, emission and to determine the farmer’s knowledge level and sources of information on climate change. Six villages were selected randomly and in each Local Government Area, three villages were visited and three farms planted each with maize/cassava intercrop, cashew plantation and natural forest were sampled. Soil samples were collected from the farmland randomly at the depth of 0–20cm and analysed for physical and chemical properties in the laboratory. Carbon pool index was higher under cashew plantation. The mass of carbon lost recorded was higher under maize/cassava intercrop and cashew plantation recorded the lowest mass of carbon lost. Equivalent Carbon dioxide emitted recorded was lower under cashew plantation and maize/cassava intercrop recorded higher equivalent of carbon dioxide emitted. Natural forest had the highest organic carbon. Simple random sampling of 126 respondents were interviewed. Results revealed majority (71.4%) are willing to invest in residue retention and 92.9% are willing to engage in climate change mitigation practices free of charge. Maize/cassava intercrop recorded the lowest carbon pool due to burning of plant residues and the use of tillage practices. The highest carbon pool index recorded under cashew plantation was due to leaves litter decomposition. Carbon emitted was generally higher under maize/cassava intercrop as a result of continuous and vigorous cultivation leading to loss of carbon. Some farmers are not fully aware of climate change mitigation practices, therefore, more observation should be given to afforestation scheme to mitigate climate change and government and nongovernmental organization (NGOs) should educate and encourage farmers to practice crop residue retention and also minimize bush burning.

The effects of land use types on microplastics in river water: A case study on the mainstream of the Wei River, China

Microplastics are widely found in rivers and their sediments, which will cause harm to the water ecological environment. The Wei River is a first-class tributary of the Yellow River, the fifth largest river in the world, and has vulnerable ecological environment and most sediment in the world. However, understanding how anthropogenic activities and environmental factors affect the microplastics distribution in this river is not clear. Based on this, the spatiotemporal distribution of microplastics in the Wei River were investigated. The abundance of microplastics ranged from 1033 to 8333 items/m3 and from 120 to 840 items/kg in the water and in the sediment, respectively. Fibers and fragments were the main shapes of Wei River, microplastics less than 500 μm were the main sizes, and black and white/transparent were the main colors. In Wei River, the abundance of microplastics in urban areas was higher than that in agricultural areas and mountainous areas. Furthermore, the correlation analysis revealed that microplastic abundance in the water was related to anthropogenic activities (population density, per capita GDP and distance) and environmental factors (water temperature, NH3-N, ORP), while in the sediments was correlated with anthropogenic activities (per capita GDP) and environmental factors (water temperature and NH3-N). This study reveals new patterns in microplastic pollution in the Wei River, underscoring the need for targeted environmental strategies. Our findings provide novel insights into the characteristics and distribution of microplastics, significantly adding to the current understanding of riverine microplastic pollution.

Effects of Land Use Types on Water Quality at Different Buffer Scales: Tianjin Section of the Haihe River Basin as an Example

It is important to explore the relationship between land use types and water quality to improve the surface water environment. Based on monthly water quality monitoring data from 16 nationally controlled surface water quality monitoring stations in Tianjin and land use data in 2021, GIS spatial analysis and mathematical and statistical methods were used to study the influence of land use types on surface water quality in buffer zones at different scales. The results showed that:① the land use types in the study area were mainly construction land, farmland, and water areas, which had significant effects on river water quality. Except for water temperature (WT) and pH, the farmland, construction land, and water areas were negatively correlated with each water quality indicator; forest land and grassland were positively correlated with dissolved oxygen (DO) and total nitrogen (TN) and negatively correlated with other water quality indicators. ② The water quality indicators showed obvious spatial differences in different seasons. The pH, DO and TN concentrations were higher in the dry season, whereas the permanganate index, ammonia nitrogen (NH4+-N), and total phosphorus (TP) concentrations were higher in the rainy season. ③ The results of the RDA analysis showed that the 800 m buffer zone land use had the greatest explanatory power for water quality changes in the dry season (50.4%), whereas the 3 000 m buffer zone land use could explain the water quality changes in the rainy season to the greatest extent (49.6%); from the average explanation rate of the dry and rainy seasons, the 3 000 m buffer zone was the best impact scale (50.0%) on water quality indicators in Tianjin. ④ The partial least squares regression (PLSR) analysis showed that the most important variables affecting surface water quality changes were construction land, farmland, and water areas. The predictive ability of the PLSR model of most water quality indicators was stronger in the dry season than that in the rainy season. In the dry season, all water quality indicators, except WT and pH, were most influenced by farmland. In the rainy season, construction land had the greatest influence on WT and NH4+-N concentrations, and the most important influencing factor for the remaining water quality indicators was still farmland. This study showed that the rational planning of land use types within 3 000 m of rivers or lakes was beneficial to improving the water quality of surface water.

Direct and indirect impacts of land use/cover change on urban heat environment: a 15-year panel data study across 365 Chinese cities during summer daytime and nighttime

ContextLand use/cover change (LUCC) can directly and indirectly affect surface urban heat island intensity (SUHII) and the effects need to be decomposed.ObjectivesTo perform long-term trend analyses of contribution indexes (CIs) of land use types to urban heat environment in cities and to deconstruct direct and indirect effects of LUCC on SUHII within geographical regions.MethodsMann–Kendall test and Sen’s slope were used to examine the trends of CIs and SUHII in 365 cities during summer of 2005–2019. Structural equation models were established to quantify direct and indirect effects of land use types’ CIs on SUHII in six geographical regions of China.ResultsFirst, SUHII in 78.08% and 73.70% of the Chinese cities increased during summer daytime and nighttime, respectively. Second, the CI of built-up land significantly increased across more than half of the cities in all the six regions. Third, not all land use types exerted both direct and indirect effects on SUHII. At daytime, the CI of cropland (direct) was the dominant factor in East China (1.386), South-central (− 0.637), and Northwest (− 0.399) regions. At nighttime, the CI of water bodies (both direct and indirect) was the dominant factor in Northwest (0.506) and Northeast (0.697) regions while CI of built-up land (both direct and indirect) determined in North China (0.476).ConclusionsSeparation of direct and indirect effects of land use types on SUHII had practical implications for cities to optimize the structures and functions of ecosystems and to take regionally based actions improving the urban heat environment.

Effect of land use type on macrobenthos assemblages, distribution, and functional guild in Upstream Citarum River

Aquatic community biodiversity is gradually impacted by the expansion and intensification of agricultural and urbanization land use. However, data on macrobenthos responses to land use in tropical streams are relatively limited. This study aims to investigate the responses of macrobenthos diversity, functional guild, and physicochemical parameters in Upstream Citarum River land use type, agricultural and urbanization area. A total of 317 species from 21 families, 11 orders and three phyla were identified, with agricultural land use having the highest abundance of macroinvertebrates (222 individuals), followed by urbanization land use (95 individuals). Ecological indices, including diversity, evenness, dominance, and margalef displayed similar patterns across different land use types. Contribution of macrobenthos species in the upstream Citarum River based on Similarity Percentage (SIMPER) analysis are Hydropychidae and Palaemonidae. Filter collectors (FC) had the highest density (78.829%) in agricultural land use, while scrapers (SC) had the highest density (87.37%) in urbanization land use. Nepidae and Palaemonidae showed positive correlations with temperature, total organic carbon (TOC) and total organic matter (TOM). The study concludes that the river of macrobenthos communities and functional guilds were influenced by the land use type and water quality. This study of the effect of land use type on macrobenthos will provide river management for further help the sustainability of tropical stream and implication of land use policy for future studies.

Physical Properties of Soil in Relation to Saturated Hydraulic Conductivity of Soils Under Selected Land Use Practices in Akwa Ibom State

This study assessed the effects of land use types on selected physical properties of soil in Akwa Ibom State, south-south Nigeria. Four land use types, intensive cultivated land (ICL), natural forest (NF), oil palm plantation (OPP) and gmelina plantation (GP), were considered. Each land use was represented by three profile pits which were sampled according to genetic horizons for laboratory analysis. Data generated were analyzed statistically using descriptive and regression analyses. The results showed that ICL had the highest bulk density (Bd) ( 1.7g/cm3) followed by NF and OPP (1.6g/cm3) while GP had the least (1.5g/cm3), OPP had the highest total porosity (Tp) (43.7%) followed by GP (42.6%), NF (41.1%) while ICL had the least (36.2%), ICL and NF had the highest water stable aggregates (WSA) (12.9%) followed by OPP (8.3%) while GP had the least (4.3%). However, OPP had the highest saturated hydraulic conductivity (Ksat) (8.4cm/h) followed by NF (8.2cm/h) while ICL and GP had the least (4.3cm/h). Result further showed that Ksat was significantly correlated with clay with r2 value of 0.53 (Ƿ˂ 0.01). Across the four land use types, Ksat was moderately rapid. Irrespective of land use type, soils were dominated by sand-sized fraction which generally decreased with depth, reflecting the influence of the parent material(coastal plain sands). This study shows that the land use types were similar in their effects on Ksat but there were no significant differences.

Untreated Rainfall Runoff Water Quality Characteristics of Different Land Uses in Infilled Lake Areas—The Case of Wuhan Shahu

Fast urbanization in developing countries contributes to heavier pollution in urban water environments, as urbanization enhances land development and even requires lake filling to meet urban land needs, which produces significant water runoff pollution. Centralized construction brings heavier non-point source pollution, which is one of the most crucial types of pollution in urban areas. However, the pollution caused by urbanization in infilled lake areas is lack of attention. To reduce the negative impact of pollution brought on by urbanization, it is important to monitor the characteristics of runoff water qualities and their relationship with rainfall features. In this study, runoff water quality was monitored from 10 rainfall events, totaling 157 samples in the Wuhan Shahu area, an infilled lake area, to characterize the pollutant event mean concentrations (EMCs) and to explore the different effects of land-use types. COD (chemical oxygen demand), TN (total nitrogen), and TP (total phosphorus) were selected as water quality indicators. The results show that the pollutants have a significant spatial variation. Residential runoff had the largest COD (averaged EMC = 54.02 (mg/L)) and TN (averaged EMC = 2.69 (mg/L)) pollution, while road runoff had the second largest COD (averaged EMC = 48.05 (mg/L)) and TN (2.572 (mg/L)) pollution. The TP pollution level is opposite to COD and TN, as commercial and green spaces have heavier pollution, while the differences in TP pollution levels between the four types of land are not significant. The release of organic matter and nitrogen is closely related to human activities on land types, while phosphorus emission is relatively stable, indicating that it is not easily affected or controlled. In addition, the variation in pollutants between land types is also related to a certain extent. The correlation analysis shows that parameters like antecedent dry days (ADDs), rainfall intensity, and rainfall duration most significantly affect the EMCs of commercial and green spaces. Phosphorus pollutants on roads are harder to reduce. These results may help researchers to identify the specific pollutant source and find an effective method to reduce pollution in infilled lake areas and other areas.

Soil Fertility Status as Influenced by Slope Gradient and Land Use Types in Southern Ethiopia

Understanding the effects of land use types and slope gradients on the physicochemical properties of soil is essential for sustainable soil management. Therefore, this study was conducted at the Azit subwatershed of Gedebano Gutazer Welene Woreda, Southern Ethiopia, with the objectives to evaluate the effect of land use types, examine the interaction of land use and slope gradient, and evaluate the effect of slope gradient on selected soil physicochemical properties. A total of 27 soil samples using a simple random sampling technique with randomized complete block design from 3 land use types (cultivated, eucalyptus, and grazing lands) ×3 slope gradients (upper 10–15%, middle 5–10%, and lower 2–5% slopes) ×3 replications and depth (0–20 cm) were collected. Results indicated that most of the physicochemical properties of soils were significantly ( P &lt; 0.01 ) affected by land use and slope gradient. Silt and sand particles did not vary significantly ( P &gt; 0.05 ) among the land use types. The interaction effect of land use and slope was not significant ( P &gt; 0.05 ) for most of the soil properties except for organic carbon (OC). Results of data analysis also showed that soil fertility was low under cultivated and eucalyptus lands coupled with the upper slope gradient. Therefore, based on the study’s findings, it can be recommended that integrated soil fertility management practices, such as the addition of soil organic matter and appropriate use of inorganic fertilizers, need to be implemented to restore the lost soil fertility status on the cultivated land and ultimately increase agricultural productivity on a sustainable basis. Eucalyptus plantings should also gradually be replaced by those that assist the soil in restoring its fertility.