scholarly journals Spatial and Long-Term Temporal Changes in Water Quality Dynamics of the Tonle Sap Ecosystem

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2059
Author(s):  
Savoeurn Soum ◽  
Peng Bun Ngor ◽  
Thomas E. Dilts ◽  
Sapana Lohani ◽  
Suzanne Kelson ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Water Level ◽  
Inorganic Nitrogen ◽  
Flood Pulse ◽  
Nutrient Ratios ◽  
Nitrogen And Phosphorus ◽  
Watershed Land Use ◽  
Tonle Sap

Tonle Sap lake-river floodplain ecosystem (TSE) is one of the world’s most productive freshwater systems. Changes in hydrology, climate, population density, and land use influence water quality in this system. We investigated long term water quality dynamics (22 years) in space and time and identified potential changes in nutrient limitation based on nutrient ratios of inorganic nitrogen and phosphorus. Water quality was assessed at five sites highlighting the dynamics in wet and dry seasons. Predictors of water quality included watershed land use, climate, population, and water level. Most water quality parameters varied across TSE, except pH and nitrate that remained constant at all sites. In the last decade, there is a change in the chemical nutrient ratio suggesting that nitrogen may be the primary limiting nutrient across the system. Water quality was strongly affected by development in the watershed i.e., flooded forest loss, climatic variation, population growth, and change in water level. Seasonal variations of water quality constituents were driven by precipitation and hydrology, notably the Mekong’s distinct seasonal flood pulse.

Influence of climate,geology and humans on spatial and temporal nutrient geochemistry in the subtropical Richmond River catchment, Australia

2001 ◽  
Vol 52 (2) ◽  
pp. 235 ◽  
Author(s):  
Lester J. McKee ◽  
Bradley D. Eyre ◽  
Shahadat Hossain ◽  
Peter R. Pepperell
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Agricultural Land ◽  
Anthropogenic Impacts ◽  
Inorganic Nitrogen ◽  
Point Sources ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Nitrogen And Phosphorus ◽  
River Catchment

Water quality was monitored on a spatial and temporal basis in the subtropical Richmond River catchment over two years. Nutrient concentrations varied seasonally in a complex manner with highest concentrations (maximum =3110 µg N L – 1 and 572 µg P L –1 ) associated with floods. However, median (444 µg N L – 1 and 55 µg P L – 1 ) concentrations were relatively low compared with other parts of the world. The forms of nitrogen and phosphorus in streams varied seasonally, with greater proportions of inorganic nitrogen and phosphorus during the wet season. Minimum nutrient concentrations were found 2—3 months after flood discharge. With the onset of the dry season, concentration increases were attributed to point sources and low river discharge. There were statistically significant relationships between geology and water quality and nutrient concentrations increased downstream and were significantly related to population density and dairy farming. In spite of varying geology and naturally higher phosphorus in soils and rocks in parts of the catchment, anthropogenic impacts had the greatest effects on water quality in the Richmond River catchment. Rainfall quality also appeared to be related both spatially and seasonally to human activity. Although the responses of the subtropical Richmond River catchment to changes in land use are similar to those of temperate systems of North America and Europe, the seasonal patterns appear to be more complex and perhaps typical of subtropical catchments dominated by agricultural land use.

scholarly journals The consequences for stream water quality of long-term changes in landscape patterns: Implications for land use management and policies

2021 ◽  
Vol 109 ◽  
pp. 105679
Author(s):  
António Carlos Pinheiro Fernandes ◽  
Lisa Maria de Oliveira Martins ◽  
Fernando António Leal Pacheco ◽  
Luís Filipe Sanches Fernandes
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Stream Water ◽  
Landscape Patterns ◽  
Land Use Management ◽  
Stream Water Quality ◽  
Long Term Changes

scholarly journals TO THE QUESTION OF COMPREHENSIVE ASSESSMENT OF SURFACE WATER IN THE CENTRAL CAUCASUS DURING WINTER BETWEEN AND SUMMER FLOOD

2021 ◽  
Vol 6 (5(55)) ◽  
pp. 22-27
Author(s):  
Liliya Zuberovna Zhinzhakova ◽  
Elena Alexandrovna Cherednik
Keyword(s):  
Water Quality ◽  
Surface Waters ◽  
Inorganic Nitrogen ◽  
High Water ◽  
Polluted Water ◽  
Trace Impurities ◽  
Central Caucasus ◽  
Summer Flood

Based on long-term observations, the assessment of the pollution of the rivers of the Central Caucasus was carried out by comparing the calculated coefficients of the complexity of pollution and the specific combinatorial index of pollution of surface waters, and the quality classes were determined. The results of chemical analysis of the concentration levels of trace impurities (Mo, Pb, Zn, V, Ni, Cr, Mn, Ag) and inorganic nitrogen compounds (NO2 -, NO3 — and NH4 +) in the waters of 13 rivers in two permanent sections of each watercourse were used. The results of calculating the indicators of pollution in the waters of rivers of winter low water and summer high water are presented. The most polluted watercourses and the frequency of pollution in each river are identified, estimated by the values of the specific combinatorial index of water pollution, the coefficient of complexity of pollution, and the class of water quality is presented. The assessment of the most polluted water bodies during the winter low-water period and summer flood is given according to the classification of water quality. According to long-term observations, the features of watercourses and their differences in terms of pollution are presented.

scholarly journals The effect of land-use change on river watershed quality (case study: Cimahi Watershed, West Java, Indonesia)

2021 ◽  
Vol 933 (1) ◽  
pp. 012010
Author(s):  
S A Nurhayati ◽  
M Marselina ◽  
A Sabar
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
Pearson Correlation ◽  
Land Use Changes ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Watershed Area ◽  
Watershed Land Use ◽  
Main River

Abstract Increasing population growth is one of the impacts of the growth of a city or district in an area. This also happened in the Cimahi watershed area. As the population grows, so does the need for land which increases the land-use change in the Cimahi watershed. Land-use changes will affect the surrounding environment and one of them is the river, especially river water quality. As a watershed area, there is one main river that is the source of life as well as the Cimahi watershed, whose main river is the Cimahi River. The purpose of this study was calculated the relationship between land-use change in the Cimahi watershed and the water quality parameters of the Cimahi River. The correlation between the two was calculated using Pearson correlation. Water quality parameters can be seen based on BOD and DO values. BOD and DO values are the opposite because good water quality has high DO values and low BOD values. The correlation between land-use change and BOD was 0.328 is in the area of settlements area. In contrast, to DO values, an increase in settlements/industrial zones will further reduce DO values so that both have a negative correlation, which is indicated by a value of -0,535. The correlation between settlements with pH and temperature values is 0.664 and 0.812. While the correlation between settlements with TSS and TDS values are 0.333 and 0.529, respectively. In this study, it can be seen that there is a relationship between the decline in water quality and changes in land use.

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.

scholarly journals Effects of Lake level changes on water quality and fisheries production of Lake Baringo, Kenya

2021 ◽  
Author(s):  
Jacques Walumona ◽  
Boaz Arara ◽  
Cyprian Ogombe ◽  
James Murakaru ◽  
Phillip Raburu ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Level ◽  
Fish Species ◽  
Lake Level ◽  
Water Level Fluctuations ◽  
Regression Analyses ◽  
Lake Level Fluctuations ◽  
Lake Level Changes ◽  
Over Time

The study was conducted in Lake Baringo and determined quantitative relationships between water level changes, water quality, and fishery production for informed lake basin management. Long-term (2008 to 2020) data on water level, water quality, and fisheries yields from Lake Baringo were analyzed using a combination of statistical methods. Linear and waveform regression analyses described patterns of lake level fluctuations over time while, Pearson’s correlation determined the concordance of lake level changes with water quality parameters, landings, and condition of fish species. PCA results grouped the study period into different years based on annual water quality variable levels. LOWESS analysis showed the decline of annual lake level amplitude over time with peak values in 1964 (8.6 m) and 2008 (9.4 m). The waveform regression significantly modeled lake level fluctuations as indexed by annual deviations from the long-term average (DLTM) and showed a 20-year oscillation between peak water levels in the lake. There were significant positive correlations of Water Level Fluctuations (WLFs) with water quality variables and water quality index (WQI) in Lake Baringo. Linear regression analyses showed a significant concordance (p < 0.05) between the annual fishery yield and the rising WLFs (r = 0.66). Overall, the results demonstrate that WLFs of Lake Baringo are a driver of fish species biomass and physico-chemical properties of the lake. We recommend the integration of fisheries yields, water quality assessment, and WLFs modeling at different temporal scales in the management of Afrotropical lake ecosystems

scholarly journals VULNERABILITY ANALYSIS OF UNDERGROUND AQUIFERS TO CONTAMINATION USING THE DRASTIC METHOD AND RISK DETERMINATION

2021 ◽  
Vol 22 (84) ◽  
pp. 227-245
Author(s):  
Berenice de Paula Amaral ◽  
Renato Farias Do Valle junior ◽  
Emerson Ribeiro Machado ◽  
Hygor Evangelista Siqueira
Keyword(s):  
Water Quality ◽  
Environmental Management ◽  
Land Use ◽  
Action Planning ◽  
Industrial Activities ◽  
The World ◽  
Drastic Method ◽  
Short And Long Term ◽  
Sandstone Formation

Groundwater represents an important component in the supply of freshwater in several regions around the world. The contamination of these waters is a worrisome problem in the management of water resources. Since underground aquifers are vulnerable to contamination by human and industrial activities, including land use, the diagnosis associated with land use is critical for environmental management. The present study was carried out in the Uberaba sandstone formation, in which the vulnerability of the subterranean aquifers was determined using the DRASTIC method, by evaluating the interaction between the use and occupation of the land using a geographic information system. Thus, the risk of contamination of the underground aquifer was determined by evaluating the land use with the water quality and fertility. The tool applied in the present study proved effective for the diagnosis, management and action planning in the short and long term, with the intention of preserving these natural resources.

scholarly journals Trends in water quality of five dairy farming streams in response to adoption of best practice and benefits of long-term monitoring at the catchment scale

2013 ◽  
Vol 64 (5) ◽  
pp. 401 ◽  
Author(s):  
Robert J. Wilcock ◽  
Ross M. Monaghan ◽  
John M. Quinn ◽  
M. S. Srinivasan ◽  
David J. Houlbrooke ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Best Management Practices ◽  
Management Practices ◽  
Stream Water ◽  
Dairy Farming ◽  
E Coli ◽  
Long Term Monitoring ◽  
Term Monitoring

Five streams in catchments with pastoral dairy farming as the dominant land use were monitored for periods of 7–16 years to detect changes in response to adoption of best management practices (BMPs). Stream water quality was degraded at the start with respect to N, P, suspended solids (SS) and E. coli concentrations, and was typical of catchments with intensive pastoral agriculture land use. Trend analysis showed a decrease in SS concentration for all streams, generally increasing water clarity, and lower E. coli concentrations in three of the streams. These are attributed to improved stream fencing (cattle exclusion) and greater use of irrigation for treated effluent disposal with less reliance on pond systems discharging to streams. Linkages between water quality and farm actions based on survey data were used to develop BMPs that were discussed at stakeholder workshops. Generic and specific BMPs were developed for the five catchments. The 3–7 year periodicity of major climate cycles, as well as market forces and a slow rate of farmer adoption of simple BMPs mean that monitoring programs in New Zealand need to be much longer than 10 years to detect changes caused by farmer actions. Long-term monitoring is also needed to detect responses to newly legislated requirements for improved water quality.

scholarly journals A Review of the Integrated Effects of Changing Climate, Land Use, and Dams on Mekong River Hydrology

Water ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 266 ◽  
Author(s):  
Yadu Pokhrel ◽  
Mateo Burbano ◽  
Jacob Roush ◽  
Hyunwoo Kang ◽  
Venkataramana Sridhar ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Large Scale ◽  
Flood Pulse ◽  
Ecological Systems ◽  
Mekong River ◽  
Future Research ◽  
Infrastructure Development ◽  
Tonle Sap ◽  
River Hydrology

The ongoing and proposed construction of large-scale hydropower dams in the Mekong river basin is a subject of intense debate and growing international concern due to the unprecedented and potentially irreversible impacts these dams are likely to have on the hydrological, agricultural, and ecological systems across the basin. Studies have shown that some of the dams built in the tributaries and the main stem of the upper Mekong have already caused basin-wide impacts by altering the magnitude and seasonality of flows, blocking sediment transport, affecting fisheries and livelihoods of downstream inhabitants, and changing the flood pulse to the Tonle Sap Lake. There are hundreds of additional dams planned for the near future that would result in further changes, potentially causing permanent damage to the highly productive agricultural systems and fisheries, as well as the riverine and floodplain ecosystems. Several studies have examined the potential impacts of existing and planned dams but the integrated effects of the dams when combined with the adverse hydrologic consequences of climate change remain largely unknown. Here, we provide a detailed review of the existing literature on the changes in climate, land use, and dam construction and the resulting impacts on hydrological, agricultural, and ecological systems across the Mekong. The review provides a basis to better understand the effects of climate change and accelerating human water management activities on the coupled hydrological-agricultural-ecological systems, and identifies existing challenges to study the region’s Water, Energy, and Food (WEF) nexus with emphasis on the influence of future dams and projected climate change. In the last section, we synthesize the results and highlight the urgent need to develop integrated models to holistically study the coupled natural-human systems across the basin that account for the impacts of climate change and water infrastructure development. This review provides a framework for future research in the Mekong, including studies that integrate hydrological, agricultural, and ecological modeling systems.

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