scholarly journals Land use and landscape pattern impacts on water quality at multiple spatial scales in a subtropical large river

2021 ◽  
Author(s):  
Xiao Shu ◽  
Weibo Wang ◽  
Mingyong Zhu ◽  
Jilei Xu ◽  
Xiang Tan ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
River Water ◽  
Total Nitrogen ◽  
Landscape Pattern ◽  
Spatial Scales ◽  
Dry Season ◽  
Wet Season ◽  
Spatial And Temporal Scales ◽  
Multiple Spatial Scales

Abstract The coupling between land use/landscape pattern and water quality in river system varies across different spatial and temporal scales. It is important to understand the association between water quality and land use/landscape pattern across different spatial and temporal scales for the protection of water resources. Here, we measured seasonal water quality at 12 sub-basins in the upper reaches of the Han River (UHR) between 2010 and 2018. We conducted factor analysis and redundancy analysis to determine the links between land use and water quality at multiple spatial scales and to identify the main factors influencing water quality. We found that the concentration of nutrients, including total nitrogen, total phosphorus, nitrate-N, and ammonium-N were higher during the wet season than the dry season. Total nitrogen was identified as the main driver of nutrient pollution of UHR, whereas total phosphorus was identified as another potential nutrient pollutant. We also found that water quality parameters had a stronger related to land use types over the wet season than the dry season. Croplands and urban lands increased phosphorus concentrations of river water, whereas forest and grass lands decreased the nitrogen concentrations of river water at the sub-basins scale. Land use at riparian zone scales better explained variations in water quality than land use at sub-basin scales. The explained variations in landscape metrics were generally higher over the dry season compared to that over the wet season. The largest patch index and Shannon's diversity index were the main predictors of river water quality in UHR.

Impacts of land use and landscape pattern on water quality at multiple spatial scales in a subtropical large river

Ecohydrology ◽  
2021 ◽  
Author(s):  
Xiao Shu ◽  
Weibo Wang ◽  
Mingyong Zhu ◽  
Jilei Xu ◽  
Xiang Tan ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Landscape Pattern ◽  
Spatial Scales ◽  
Large River ◽  
Multiple Spatial Scales

Impact of landscape pattern at multiple spatial scales on water quality: A case study in a typical urbanised watershed in China

2015 ◽  
Vol 48 ◽  
pp. 417-427 ◽  
Author(s):  
Zhenyao Shen ◽  
Xiaoshu Hou ◽  
Wen Li ◽  
Guzhanuer Aini ◽  
Lei Chen ◽  
...  
Keyword(s):  
Water Quality ◽  
Landscape Pattern ◽  
Spatial Scales ◽  
Multiple Spatial Scales

scholarly journals Assessment of Surface Water Quality using Indices and Geographic Information System in the Sebou River Basin, Morocco

2021 ◽  
Vol 17 (10) ◽  
Author(s):  
Kanga Idé Soumaila ◽  
Naimi Mustapha ◽  
Chikhaoui Mohamed
Keyword(s):  
Water Quality ◽  
River Water ◽  
Oxygen Demand ◽  
Water Quality Monitoring ◽  
Dry Season ◽  
River Water Quality ◽  
Wet Season ◽  
Water Quality Variation ◽  
Quality Variation ◽  
Monitoring Stations

The aim of this study is to access the quality of monitored rivers and to map the polluted river sections in the Sebou basin using Geographic Information System (GIS). The potential causes of water quality variation will also be added for suitable measures to be taken. A Water Quality Index (WQI) which developed in Morocco was applied to 17 river water quality monitoring stations with data on 6 parameters (Dissolved oxygen (DO), ammonium ion (NH4 + ), 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), fecal coliforms (FC) and total phosphorus (TP)) collected twice during the wet and dry season over 1990-2017 period. The result shows that river water quality is classified as bad, very bad and medium at 59% of the monitoring stations, while 41% are considered as good to excellent. Interpolation of mean values of overall WQI of the 17 river water quality monitoring stations, revealed evidence of quality degradation along several kilometers of most river sections in the Sebou basin. The correlation matrix between the sub-indices of water quality parameters and the overall WQI showed high positive correlation coefficients and highlights the contribution to water quality degradation as follows: TP (𝑟 = +0.96 ) ≥ NH4 + (𝑟 = +0.96 ) > BOD5 (𝑟 = +0.94) > COD (𝑟 = +0.86) > FC (𝑟 = +0.83) > DO (𝑟 = +0.79). The sections of Fès, Innaounene Rivers, and an extended stretch of Tizguit River must no longer be used for irrigation. River water quality is overall of better quality in the wet season compared to the dry season. Simple linear regressions between the seasonal water quality variation and the overall WQI showed higher coefficients of determination R 2 (0.67 and 0.60) between dry season WQI and the overall WQI and between wet season WQI and the overall WQI respectively. It is clear that discharges of industrial and domestic wastewater during the dry season and agricultural activities are most likely to be the causes of the degradation of river water quality.

The influence of land use patterns on water quality at multiple spatial scales in a river system

2013 ◽  
Vol 28 (20) ◽  
pp. 5259-5272 ◽  
Author(s):  
Guoqiang Wang ◽  
Yinglan A ◽  
Zongxue Xu ◽  
Shurong Zhang
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Spatial Scales ◽  
River System ◽  
Land Use Patterns ◽  
Use Patterns ◽  
Multiple Spatial Scales

scholarly journals Assessing the impact of watershed land use on Kebena river water quality in Addis Ababa, Ethiopia

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Kalkidan Asnake ◽  
Hailu Worku ◽  
Mekuria Argaw
Keyword(s):  
Water Quality ◽  
Land Use ◽  
River Water ◽  
Land Use Planning ◽  
Addis Ababa ◽  
Surface Water Quality ◽  
Wet Season ◽  
Watershed Land Use ◽  
Land Use Types ◽  
The Impact

Abstract Background The impact of watershed land-use on surface water quality is one of the under researched areas in mega cities of the developing countries like Addis Ababa. The study examined the impact of watershed land uses on the Kebena river water quality within its seasonal and spatial variation and assessed the relationship between river water pollution and dominant land-use types in the sub-watersheds. Method The main land use types in the sub-watersheds were digitized from aerial photograph of 2016, and quantified for water quality impact analysis. Water samples were collected from the main Kebena river and the three sub-watersheds source and outlet points. A total of 128 samples were collected during the dry and wet seasons of 2016 and 2017 and analyzed for various water quality parameters. The study employed ANOVA, independent t-tests and multiple regression analysis to examine variations in water quality and assess the influence of the different land uses on water quality. Results Forest, built-up area and cultivated lands are the three major land use types in the Kebena watershed accounting for 39.14, 32.51 and 27.25% of the total area, respectively. Kebena catchment is drained by three sub-watersheds namely, Denkaka (44.9% cultivated land), Little-Kebena (60.87% forested) and Ginfle (90.44% urban land). The concentration of pollutants in the Kebena river was significantly higher (P < 0.001) in the dry season than in the wet season. However, when compared to surface water quality standards, both the dry and wet season water quality records are exceptionally high. The urban and forest dominated sub-watersheds contribute significantly high amount of (P < 0.001) pollutant loads to the river which is associated with high runoff from impervious surfaces and sewerage discharge to the river from nearby urban settlements. Conclusion Integrating watershed planning with land use planning is of paramount importance to address water quality problems in urban areas. Thus, in the urban dominated sub-catchment, land-use planning should aim to relocating river front communities, providing sufficient river buffer-zones and forwarding appropriate storm water management schemes. In the forested sub-catchment, planning should protect, retain and enhance the existing natural green spaces through open space planning, and management schemes while providing wide river-buffer with natural vegetation cover to minimize pollution load to urban rivers from agriculture dominated sub-watershed.

Fruit and flower phenology at two sites in Kibale National Park, Uganda

1999 ◽  
Vol 15 (2) ◽  
pp. 189-211 ◽  
Author(s):  
C. A. Chapman ◽  
R. W. Wrangham ◽  
L. J. Chapman ◽  
D. K. Kennard ◽  
A. E. Zanne
Keyword(s):  
Minimum Temperature ◽  
National Park ◽  
Spatial Scales ◽  
Abiotic Factors ◽  
Dry Season ◽  
High Irradiance ◽  
Community Level ◽  
Kibale National Park ◽  
Wet Season ◽  
Spatial And Temporal Scales

Examination of phenological patterns of tropical trees at different temporal and spatial scales can elucidate biotic and abiotic factors that correlate with fruiting, flowering and/or leaf set patterns. In this study, 3793 trees from 104 species in Kibale National Park, Uganda were monitored. The trees were selected from two sites (Kanyawara and Ngogo) separated by 10 km. Trees were monitored monthly to document community-wide and population-level fruiting and flowering patterns for a maximum of 76 mo. Analysis of two sites over a number of years permitted examination of generalities of patterns found on smaller spatial and temporal scales. Spectral analysis indicated that community-level flowering and fruiting at Kanyawara exhibited regular annual peaks, although the flowering peaks were of shorter duration. At Ngogo, community-level flowering also displayed regular annual peaks, but fruiting had an irregular pattern with no distinct peaks. The abundance of fruiting trees at Kanyawara was negatively related to the minimum temperature in the previous season (3–7 mo prior). Since fruiting tended to peak when the first wet season of the year was ending and the dry season was beginning, this suggests that the minimum temperature in the previous dry season is important in determining how many individuals fruit. Flowering at Kanyawara peaked immediately after the maximum annual period of high irradiance. Within-species synchronization was evident in the flowering for all species examined at Ngogo and for 64% of those at Kanyawara. Fruiting was synchronous within species for 64% of the species at both sites. Despite this general community-level synchronization, the months of peak fruiting and flowering for some species varied markedly among years. Furthermore, for a number of species the timing of fruiting or flowering events differed between Kanyawara and Ngogo. For some species, trends that were suggested from one year of data were not supported when additional years were considered. Although these two sites are close together, share many of the same species, and experience similar climatic regimes, many phenological patterns were site-dependent.

Periphyton, water quality, and land use at multiple spatial scales in Alberta rivers

2005 ◽  
Vol 62 (6) ◽  
pp. 1309-1319 ◽  
Author(s):  
Geneviève M Carr ◽  
Patricia A Chambers ◽  
Antoine Morin
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Population Density ◽  
Chlorophyll A ◽  
Regional Differences ◽  
Regression Models ◽  
Spatial Scales ◽  
Data Set ◽  
Multiple Spatial Scales ◽  
Land Use Effects

The ability of land use to replace water quality variables in predictive models of periphyton chlorophyll a was tested with a 21-year data set for Alberta rivers. Nutrients (total dissolved P and NO2 + NO3) explained 23%–24% of the variability in seasonal chlorophyll a, whereas land use (human population density) explained 25%–28% of the variability. The best models included the combination of total dissolved P and population density, explaining 32%–34% of periphyton chlorophyll a variability. However, analysis of variance of chlorophyll a by ecoregions and ecozones explained about as much variability (28%–30%), and the inclusion of an ecoregion term into the regression models showed a diminished importance of land use as a predictor of chlorophyll a, with best models based on the combination of nutrients and ecoregion and explaining up to 43%–44% of periphyton chlorophyll a variability. Within ecoregions, land use was sometimes a good surrogate for nutrient data in predicting chlorophyll a concentrations. Overall, land use is a suitable surrogate for nutrients in regression models for chlorophyll a, but its inclusion in general models may reflect regional differences in nutrient–chlorophyll relationships rather than true land use effects on chlorophyll a.

scholarly journals Response of Bat Activity to Land-Cover and Land-Use Change in Savannas is Scale-, Season-, and Guild-Specific

2019 ◽  
Author(s):  
Julie Teresa Shapiro ◽  
Ara Monadjem ◽  
Timo Röder ◽  
Robert A. McCleery
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Land Cover ◽  
Vegetation Structure ◽  
Spatial Scales ◽  
Dry Season ◽  
Fine Scale ◽  
Wet Season ◽  
Bat Activity ◽  
Water Cover

AbstractTropical savannas are biomes of global importance that are under severe pressure from anthropogenic change, including land-cover and land-use change. Bats, the second-most diverse group of mammals, are critical to ecosystem functioning, but may be vulnerable to such anthropogenic stresses. However, there is little information on the response of savanna bats to land-cover and land-use change, especially in Africa. This limits our ability to develop conservation strategies for bats and maintain the ecosystem functions and services they provide in this biome. Using acoustic monitoring, we measured how guild-specific (aerial, edge, and clutter forager) bat activity responded to both fine-scale metrics of vegetation structure and landscape-scale metrics of land-cover composition and configuration across the wet and dry seasons in a savanna in southern Africa undergoing rapid land-cover and land-use change. We found that all three guilds responded more strongly to landscape metrics than fine-scale vegetation structure, although the specific metrics varied between guilds. Aerial and edge bats responded most strongly to the percent savanna cover and savanna fragmentation in both seasons while clutter bats responded to percent rural cover in the wet season and percent water cover in the dry. All three guilds responded more strongly to the landscape in the dry season than the wet season. Our results show it is possible to conserve bats, and the ecosystem services they can provide, in savannas undergoing anthropogenic land-use and land-cover change but strategies to do so must consider foraging guild, large spatial scales, and seasonal variation in bat activity.HighlightsBats in savannas respond to land-cover and land-use change on large spatial scalesLandscape had a greater influence on bat activity in the dry season than the wetAerial and edge forager activity responded to savanna cover and fragmentationClutter forager activity was best explained by rural and water coverMinimizing fragmentation and maintaining water promotes bat activity in modified savannas

scholarly journals Changing Land Use and Population Density Are Degrading Water Quality in the Lower Mekong Basin

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1948
Author(s):  
Flavia Tromboni ◽  
Thomas E. Dilts ◽  
Sarah E. Null ◽  
Sapana Lohani ◽  
Peng Bun Ngor ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Population Density ◽  
Local Population ◽  
Reference Conditions ◽  
Mekong River ◽  
Land Use Impacts ◽  
Wet Season ◽  
Mekong Basin ◽  
Lower Mekong Basin

Establishing reference conditions in rivers is important to understand environmental change and protect ecosystem integrity. Ranked third globally for fish biodiversity, the Mekong River has the world’s largest inland fishery providing livelihoods, food security, and protein to the local population. It is therefore of paramount importance to maintain the water quality and biotic integrity of this ecosystem. We analyzed land use impacts on water quality constituents (TSS, TN, TP, DO, NO3−, NH4+, PO43−) in the Lower Mekong Basin. We then used a best-model regression approach with anthropogenic land-use as independent variables and water quality parameters as the dependent variables, to define reference conditions in the absence of human activities (corresponding to the intercept value). From 2000–2017, the population and the percentage of crop, rice, and plantation land cover increased, while there was a decrease in upland forest and flooded forest. Agriculture, urbanization, and population density were associated with decreasing water quality health in the Lower Mekong Basin. In several sites, Thailand and Laos had higher TN, NO3−, and NH4+ concentrations compared to reference conditions, while Cambodia had higher TP values than reference conditions, showing water quality degradation. TSS was higher than reference conditions in the dry season in Cambodia, but was lower than reference values in the wet season in Thailand and Laos. This study shows how deforestation from agriculture conversion and increasing urbanization pressure causes water quality decline in the Lower Mekong Basin, and provides a first characterization of reference water quality conditions for the Lower Mekong River and its tributaries.

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