scholarly journals Effects of Land-Use and Land-Cover Change on Nitrogen Transport in Northern Taihu Basin, China during 1990–2017

2020 ◽  
Vol 12 (9) ◽  
pp. 3895
Author(s):  
Xi Chen ◽  
Yanhua Wang ◽  
Zucong Cai ◽  
Changbin Wu ◽  
Chun Ye
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
Land Surface ◽  
Nitrogen Transport ◽  
Overlying Water ◽  
Rapid Urbanization ◽  
Taihu Basin ◽  
Effects Of Land Use

Different land uses have varying degrees of impact on nitrogen transport in the catchments. In recent decades, rapid urbanization has dramatically changed the Earth’s land surface, which may cause excessive nitrogen losses and a negative influence on the environment. In the long-term scale, it is important to explore how the nitrogen transport responds to land use change and its effects on aquatic habitats. In this study, the water and sediment samples were collected from northern Taihu Basin, and nine periods of land use data were obtained using the techniques of supervised classification. Results revealed that the proportion of farmland area decreased from 28.33% to 7.09%, while that of constructed land area increased from 23.85% to 61.72% during 1990–2017. Most of the constructed land originated from farmland, which makes it the dominant land use type due to rapid urbanization. In spatial distribution, high total nitrogen (TN) losses regions remain distributed over constructed land and farmland, which may aggravate the trend of local water quality deterioration. Of these regions, constructed land was the dominant contributor (46.29%–63.62%) of TN losses from surface runoff. In temporal variation, the TN losses of runoff decreased by 47% from 175 t N·a−1 in 1990. However, they increased by 2.91% from 75.28 t N·a−1 after 2013 with rapid population growth and high fertilizer application (>570 kg·ha−1). The nitrogen load in sediments also has a significant response (t = 2.43, p = 0.02) to the effects of land use change on the overlying water, indicating that the role of nitrogen in the sediment as a source and/or sink to the waterbody may change frequently. Given the increasing accumulation of nitrogen loads in highly urbanized regions, water quality would cause more aggravation in the long-term without reasonable land management measures.

scholarly journals Warming increases carbon and nutrient fluxes from sediments in streams across land use

2013 ◽  
Vol 10 (2) ◽  
pp. 1193-1207 ◽  
Author(s):  
S.-W. Duan ◽  
S. S. Kaushal
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Land Use Change ◽  
Sulfate Reduction ◽  
Organic Matter Content ◽  
Soluble Reactive Phosphorus ◽  
Overlying Water ◽  
Sediment Fluxes ◽  
Urban Sites

Abstract. Rising water temperatures due to climate and land use change can accelerate biogeochemical fluxes from sediments to streams. We investigated impacts of increased streamwater temperatures on sediment fluxes of dissolved organic carbon (DOC), nitrate, soluble reactive phosphorus (SRP) and sulfate. Experiments were conducted at 8 long-term monitoring sites across land use (forest, agricultural, suburban, and urban) at the Baltimore Ecosystem Study Long-Term Ecological Research (LTER) site in the Chesapeake Bay watershed. Over 20 yr of routine water temperature data showed substantial variation across seasons and years. Lab incubations of sediment and overlying water were conducted at 4 temperatures (4 °C, 15 °C, 25 °C, and 35 °C) for 48 h. Results indicated: (1) warming significantly increased sediment DOC fluxes to overlying water across land use but decreased DOC quality via increases in the humic-like to protein-like fractions, (2) warming consistently increased SRP fluxes from sediments to overlying water across land use, (3) warming increased sulfate fluxes from sediments to overlying water at rural/suburban sites but decreased sulfate fluxes at some urban sites likely due to sulfate reduction, and (4) nitrate fluxes showed an increasing trend with temperature at some forest and urban sites but with larger variability than SRP. Sediment fluxes of nitrate, SRP and sulfate were strongly related to watershed urbanization and organic matter content. Using relationships of sediment fluxes with temperature, we estimate a 5 °C warming would increase mean sediment fluxes of SRP, DOC and nitrate-N across streams by 0.27–1.37 g m−2 yr−1, 0.03–0.14 kg m−2 yr−1, and 0.001–0.06 kg m−2 yr−1. Understanding warming impacts on coupled biogeochemical cycles in streams (e.g., organic matter mineralization, P sorption, nitrification, denitrification, and sulfate reduction) is critical for forecasting shifts in carbon and nutrient loads in response to interactive impacts of climate and land use change.

scholarly journals Effects of Urbanization on Watershed Evapotranspiration and Its Components in Southern China

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 645 ◽  
Author(s):  
Qingzhou Zheng ◽  
Lu Hao ◽  
Xiaolin Huang ◽  
Lei Sun ◽  
Ge Sun
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Land Surface ◽  
Southern China ◽  
Hydrologic Model ◽  
Water Evaporation ◽  
Water Yield ◽  
Positive Trend ◽  
Significant Downward Trend ◽  
Effects Of Land Use

Understanding the effects of land use change on evapotranspiration (ET) and its partitioning to transpiration and evaporation is important for accurately evaluating the likely environmental impacts on watershed water supply, climate moderation, and other ecosystem services (e.g., carbon sequestration and biodiversity). This study used a distributed hydrologic model, MIKE SHE, to partition evapotranspiration into soil evaporation, transpiration, ponded water evaporation, and interception, and examined how the ET partitions affected the water balance in the Qinhuai River Basin from 2000 to 2013. Simulated daily ET was compared to measurements at an eddy flux research site during 2016–2017 (R2 = 0.72). Degradation in rice-wheat rotation fields and expansion of impervious surfaces impacted not only total watershed evapotranspiration, which showed a significant downward trend (p < 0.05), but also its partitioning. A significant (p < 0.01) decrease in transpiration was detected. Ponded water evaporation was the only ET partition that exhibited a significant positive trend (p < 0.05). We concluded that the reduced transpiration as a result of land use and land cover change was the primary factor driving the variation of watershed scale evapotranspiration. In addition, there was an increase in annual water yield (23%) as a response to significant reduction in ET (7%) due to a 175% expansion of urban area in the study watershed. Our study provided insights to the mechanisms of land surface–water cycle interaction and better understanding of the effects of land use change on urban micro-climate such as “urban dry island” and “urban heat island” effects.

scholarly journals Effects of long-term flooding on biogeochemistry and vegetation development in floodplains – a mesocosm experiment to study interacting effects of land use and water quality

2009 ◽  
Vol 6 (2) ◽  
pp. 3263-3301
Author(s):  
A. M. Banach ◽  
K. Banach ◽  
R. C. J. H. Peters ◽  
R. H. M. Jansen ◽  
E. J. W. Visser ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Sediment Pore Water ◽  
Vegetation Development ◽  
River Floodplains ◽  
Fertilized Soil ◽  
Agricultural Use ◽  
Peat Formation ◽  
Effects Of Land Use

Abstract. The frequent occurrence of summer floods in Eastern Europe, possibly related to climate change, urges the need to understand the consequences of combined water storage and nature rehabilitation as an alternative safety measure instead of raising and reinforcing dykes, for floodplain biogeochemistry and vegetation development. We used a mesocosm design to investigate the possibilities for the creation of permanently flooded wetlands along rivers, in relation to water quality (nitrate, sulphate) and land use (fertilization). Flooding resulted in severe eutrophication of both sediment pore water and surface water, particularly for more fertilized soil and sulphate pollution. Vegetation development was mainly determined by soil quality, resulting in a strong decline of most species from the highly fertilized location, especially in combination with higher nitrate and sulphate concentrations. Soils from the less fertilized location showed, in contrast, luxurious growth of target Carex species regardless water quality. The observed interacting effects of water quality and agricultural use are important in assessing the consequences of planned measures for ecosystem functioning (including peat formation) and biodiversity in river floodplains.

Assessment of the Effects of Land Use Change in Upper Catchments of Lake Kivu on its Water Quality

2012 ◽  
Vol 535-537 ◽  
pp. 2162-2165
Author(s):  
Jean De Dieu Bazimenyera ◽  
Qiang Fu ◽  
Niragire Théophila
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
Seasonal Variations ◽  
Water Samples ◽  
Catchment Area ◽  
Major Elements ◽  
Laboratory Analysis ◽  
Lake Kivu ◽  
Effects Of Land Use

This paper analyzed the effects of land use change in the catchment area of Lake Kivu on its water quality. The results of laboratory analysis of water samples from 4 locations testing the concentration of major elements showed that Mn, N, P and K are high during the growing and raining seasons and low during the dry and harvesting seasons. They also indicated that the concentrations of Cr, Al were considerably low in all seasons but vary with the seasons at Nyamasheke and Karongi stations. The variations of other major elements were not depending on the seasonal variations.

scholarly journals Effects of long-term flooding on biogeochemistry and vegetation development in floodplains; a mesocosm experiment to study interacting effects of land use and water quality

2009 ◽  
Vol 6 (7) ◽  
pp. 1325-1339 ◽  
Author(s):  
A. M. Banach ◽  
K. Banach ◽  
R. C. J. H. Peters ◽  
R. H. M. Jansen ◽  
E. J. W. Visser ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Floodplain Wetlands ◽  
Vegetation Development ◽  
River Floodplains ◽  
Fertilized Soil ◽  
Agricultural Use ◽  
Effects Of Land Use

Abstract. Raising safety levees and reinforcing dykes is not a sufficient and sustainable solution to the intense winter and summer floods occurring with increasing frequency in Eastern Europe. An alternative, creating permanently flooded floodplain wetlands, requires improved understanding of ecological consequences. A 9 month mesocosm study (starting in January), under natural light and temperature conditions, was initiated to understand the role of previous land use (fertility intensity) and flooding water quality on soil biogeochemistry and vegetation development. Flooding resulted in severe eutrophication of both sediment pore water and surface water, particularly for more fertilized soil and sulphate pollution. Vegetation development was mainly determined by soil quality, resulting in a strong decline of most species from the highly fertilized location, especially in combination with higher nitrate and sulphate concentrations. Soils from the less fertilized location showed, in contrast, luxurious growth of target Carex species regardless water quality. The observed interacting effects of water quality and agricultural use are important in assessing the consequences of planned measures for ecosystem functioning and biodiversity in river floodplains.

scholarly journals Effects of land use change on streamflow and stream water quality of a coastal catchment

Water SA ◽  
2017 ◽  
Vol 43 (1) ◽  
pp. 139 ◽  
Author(s):  
CR Petersen ◽  
NZ Jovanovic ◽  
DC Le Maitre ◽  
MC Grenfell
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
Stream Water ◽  
Stream Water Quality ◽  
Effects Of Land Use

scholarly journals ASSESSING THE EFFECTS OF LAND USE CONVERSION ON RUNOFF AND NUTRIENT LOAD

2018 ◽  
Vol 30 (3) ◽  
Author(s):  
Khairul Anuar Mohamad ◽  
Noorbaharim Hashim ◽  
Ilya Khairanis Othman ◽  
Mohd Syazwan Faisal Mohd
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Agricultural Land ◽  
Fold Increase ◽  
Base Flow ◽  
Point Sources ◽  
Plant Management ◽  
Water Quality And Quantity ◽  
Effects Of Land Use

An agricultural land with intensive cultivation, large catchments with extended rivers and agricultural population of high-density are the primary reasons for higher pollutant loads in freshwater. However, there are problems in pursuing nutrient losses since several parameters, such as variability in soils and climate are associated with heavy rainfall, especially in tropic regions; plant management, limited resources, and insufficient technical support are not consistent in every crop management. Changes in agricultural practices and unmonitored point sources discharge from watershed, have led to algal bloom in abundance, and thus generated eutrophication at the downstream. The complex watershed processes and forecasting the effects of land use change on water quality can be determined by using tools of watershed models. The Hydrological Simulation Programme-FORTRAN (HSPF) uses lumped parameters, continuous model to predict the long-term evaluation, and deterministic for simulating the water quality and quantity process that occur at the watershed. Pervious land segments (PERLND), impervious land segments (IMPLND), and channel reach (RCHRES) modules were used to determine the general water quality and quantity on Johor watershed. Based on calibration and validation, the HSPF model was capable of simulating different runoff seasons. An increment of 60% in agricultural land had increased the annual mean total phosphorus (TP) load and total nitrogen (TN) load by 3.82% and 5.34%, respectively. A 2-fold increase in agricultural land would result in an approximately 2-fold increase in the quantity of annual TN and TP loads. Between TN and TP loads, TP load has potentially increased more than TN load during the dry, wet, and base-flow years. Upon the long-term of water quality and quantity simulation, this study provides essential knowledge for a method-based runoff and nutrient management plan for the Johor watershed.

scholarly journals Long‐term effects of land‐use change on bird communities depend on spatial scale and land‐use type

Ecosphere ◽  
2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Daniel C. Allen ◽  
Heather L. Bateman ◽  
Paige S. Warren ◽  
Fabio Suzart Albuquerque ◽  
Sky Arnett‐Romero ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Spatial Scale ◽  
Bird Communities ◽  
Land Use Type ◽  
Long Term Effects ◽  
Effects Of Land Use
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