scholarly journals FOREST MANAGEMENT AND WATER QUALITY IN LATVIA: IDENTIFYING CHALLENGES AND SEEKING SOLUTIONS

Author(s):  
Zane KALVITE ◽  
Zane LIBIETE ◽  
Arta BARDULE Arta BARDULE

Rise in human population, industrialization, urbanization, intensified agriculture and forestry pose considerable risks to water supply and quality both on global and regional scale. While freshwater resources are abundant in Latvia, during recent years increased attention has been devoted to water quality in relation to anthropogenic impacts. Forest cover in Latvia equals 52% and forest management and forest infrastructure building and maintenance are among the activities that may, directly or indirectly, affect water quality in headwater catchments. Sedimentation, eutrophication and export of hazardous substances, especially mercury (Hg), are of highest concern. To address these topics, several initiatives have started recently. In 2011, cooperation programme between Latvian State Forest Research Institute (LSFRI) “Silava” and JSC “Latvia’s State Forests” was launched to evaluate the impact of forest management on the environment. This programme included research on the efficiency of water protection structures used at drainage system maintenance (sedimentation ponds, overland flow) and regeneration felling (bufferzones). In 2016, within the second stage of this cooperation programme, a study on the impact of forest management on water quality (forest road construction, drainage system maintenance, felling) was started on a catchment scale. Since 2016 LSFRI Silava is partner in the Interreg Baltic Sea Region Programme project “Water management in Baltic forests”. By focusing on drainage systems, riparian zones and beaver activity, this project aims at reducing nutrient and Hg export from forestry sites to streams and lakes. While this project mostly has a demonstration character, it will also offer novel results on Hg and methylmercury (MeHg) concentrations in beaver ponds in all participating states. This paper aims at summarizing most important challenges related to the impact of forest management on water quality and corresponding recent initiatives striving to offer solutions.

Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 313 ◽  
Author(s):  
C. Carroll ◽  
L. Merton ◽  
P. Burger

In 1993, a field study commenced to determine the impact of vegetative cover and slope on runoff, erosion, and water quality at 3 open-cut coal mine sites. Runoff, sediment, and water quality were measured on 0.01-ha field plots from 3 slope gradients (10, 20, 30%), with pasture and tree treatments imposed on soil and spoil material, and 2 soil and spoil plots left bare. The greatest soil erosion occurred before pasture cover established, when a large surface area of soil (>0.5 plot area) was exposed to rainfall and overland flow. Once buffel grass (Cenchrus ciliaris) colonised soil plots, there were negligible differences in soil erosion between slope gradients. On spoil, Rhodes grass (Chloris gayana) reduced in situ soluble salt content, and reduced runoff electrical conductivity to levels measured in surrounding creeks. Where spoil crusted there was poor vegetative growth and unacceptably large runoff and erosion rates throughout the study.


2021 ◽  
Author(s):  
Alexandre Gauvain ◽  
Ronan Abhervé ◽  
Jean-Raynald de Dreuzy ◽  
Luc Aquilina ◽  
Frédéric Gresselin

<p>Like in other relatively flat coastal areas, flooding by aquifer overflow is a recurring problem on the western coast of Normandy (France). Threats are expected to be enhanced by the rise of the sea level and to have critical consequences on the future development and management of the territory. The delineation of the increased saturation areas is a required step to assess the impact of climate change locally. Preliminary models showed that vulnerability does not result only from the sea side but also from the continental side through the modifications of the hydrological regime.</p><p>We investigate the processes controlling these coastal flooding phenomena by using hydrogeological models calibrated at large scale with an innovative method reproducing the hydrographic network. Reference study sites selected for their proven sensitivity to flooding have been used to validate the methodology and determine the influence of the different geomorphological configurations frequently encountered along the coastal line.</p><p>Hydrogeological models show that the rise of the sea level induces an irregular increase in coastal aquifer saturations extending up to several kilometers inland. Back-littoral channels traditionally used as a large-scale drainage system against high tides limits the propagation of aquifer saturation upstream, provided that channels are not dominantly under maritime influence. High seepage fed by increased recharge occurring in climatic extremes may extend the vulnerable areas and further limit the effectiveness of the drainage system. Local configurations are investigated to categorize the influence of the local geological and geomorphological structures and upscale it at the regional scale.</p>


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 964 ◽  
Author(s):  
Andrzej Bogdał ◽  
Andrzej Wałęga ◽  
Tomasz Kowalik ◽  
Agnieszka Cupak

The aim of the study was to determine the impact of natural and anthropogenic factors on the values of 22 quality indicators of surface waters flowing out of two small catchments differing in physiographic parameters and land use, in particular forest cover and urbanization of the area. The research was carried out in the years 2012–2014 at four measurement-control points located on the Chechło river and the Młoszówka stream (Poland), which are the main tributaries of the retention reservoir. Basic descriptive statistics, statistical tests, as well as cluster analysis and factor analysis were used to interpret the research results. The water that outflowed from the forestry-settlement catchment of the Młoszówka stream contained higher concentrations of total phosphorus, phosphates, nitrite, and nitrate nitrogen and salinity indicators than outflow from the Chechło river. Water from the Młoszówka stream was characterized by more favourable oxygen conditions. Higher oxygen concentration in the catchment influenced a large slope of the watercourse and thus higher water velocity, which is promoted by the mixed process. In the case of the forest catchment of the Chechło river, the water quality was generally better than in the Młoszówka stream, mainly in cases of total suspended solids TSS, total phosphorus TP, phosphates PO43−, total nitrogen TN, nitrite N–NO2−, nitrate N–NO3−, and salinity parameters. Despite it being a short section of the river taken into the study, favourable self-purification processes like mixed, nitrification, and denitrification were observed in its water. The research shows that forest areas have a positive effect on the balance of most substances dissolved in water, and natural factors in many cases shape the quality and utility values of surface waters on an equal footing with anthropogenic factors. In the case of a large number of examined parameters and complex processes occurring in water, the interpretation of the results makes it much easier by applying multivariate statistical methods.


2014 ◽  
Vol 61 (3-4) ◽  
pp. 141-162 ◽  
Author(s):  
Borys Olechnowicz ◽  
Katarzyna Weinerowska-Bords

AbstractThis paper deals with the impact of different forms of urbanization on the basin outflow. The influence of changes in land cover/use, drainage system development, reservoirs, and alternative ways of stormwater management (green roofs, permeable pavements) on basin runoff was presented in the case of a small urban basin in Gdansk (Poland). Seven variants of area development (in the period of 2000-2012) - three historical and four hypothetical - were analyzed. In each case, runoff calculations for three rainfall scenarios were carried out by means of the Hydrologic Modeling System designed by Hydrologic Engineering Center of the U.S. Army Corps of Engineers (HEC-HMS). The Soil Conservation Service (SCS) Curve Number (CN) method was used for calculations of effective rainfall, the kinematic wave model for those of overland flow, and the Muskingum-Cunge model for those of channel routing. The calculations indicated that urban development had resulted in increased peak discharge and runoff volume and in decreased peak time. On the other hand, a significant reduction in peak values was observed for a relatively small decrease in the normal storage level (NSL) in reservoirs or when green roofs on commercial centers were present. The study confirmed a significant increase in runoff as a result of urbanization and a considerable runoff reduction by simple alternative ways of stormwater management.


2020 ◽  
Author(s):  
Johannes Teuchies ◽  
Tom J.S. Cox ◽  
Katrien Van Itterbeeck ◽  
Filip J.R. Me ◽  
Ronny Blust

Abstract Background: The International Maritime Organization (IMO) has set limits on sulphur content in fuels for marine transport. However, vessels continue to use these residual high sulphur fuels in combination with exhaust gas cleaning systems (EGCS or scrubbers). Next to high sulphur, combustion of these fuels also results in higher emissions of contaminants including metals and PAHs. In scrubbers, exhaust gases are sprayed with water in order to remove SOx, resulting in acidic washwater with elevated contaminant concentrations discharged in the aquatic ecosystem. The number of vessels with scrubbers is increasing rapidly, but knowledge on washwater quality and impact are limited. Results: The scrubber washwater is found to be acidic with elevated concentrations of e.g. zinc, vanadium, copper, nickel, phenanthrene, naphthalene, fluorene and fluoranthene. Model calculations on the effects of scrubber discharge under scenario HIGH (20% of vessels, 90th percentile concentrations) on the water quality in harbor docks showed a decrease in pH of 0.015 units and an increase in surface water concentrations for e.g. naphthalene (189% increase) and vanadium (46% increase). Conclusions: The IMO established sulphur regulations to mitigate the impact of high sulphur emissions of the maritime sector. However, the use of open loop scrubbers as an abatement technology will not reduce their contribution to ocean acidification. In addition, different types of scrubbers discharge washwater that is acute toxic for aquatic organisms. However, washwater is diluted and the compounds for which a large increase in surface water concentrations was calculated in the Antwerp (Belgium) harbour docks (Naphthalene > Phenanthrene > Fluorene > Acenaphthene > Vanadium) were not the compounds that already exceed their respective Water Quality Standards (WQS). Nevertheless, the WQS of several ‘priority hazardous substances’ (Water Framework Directive) are already exceeded in the docks and the Scheldt estuary. Since these hazardous substances are also identified in the washwater, scrubber washwater discharge should be discouraged in coastal waters and estuaries with large ecological value.


2021 ◽  
Vol 6 (2) ◽  
pp. 1-12
Author(s):  
Emeka Anyanwu ◽  
◽  
Onyinyechi Adetunji ◽  
Solomon Umeham ◽  
◽  
...  

Aquatic ecosystems respond differently to diverse anthropogenic activities in their watersheds. Phytoplankton is sensitive to their environment and is used to monitor anthropogenic impacts. A study was carried out in a South-eastern Nigerian River between December 2017 and November 2018 in 6 stations; to assess the phytoplankton community, water quality, and anthropogenic impacts. Sand mining was a major activity in the river among others. The phytoplankton was sampled with the filtration method while water was collected and analyzed using standard methods. A total of 36 phytoplankton species were recorded with Chlorophyceae being the most abundant group. The most abundant species - Melosira granulata is a pollution indicator. The water quality and phytoplankton structure showed that the water was tending towards eutrophication. This is attributed to the observed anthropogenic activities and cumulative impacts of all the activities in the watershed. The impact of sand mining activities was observed more in the downstream stations (4 – 6) while perturbation from swimming children and related activities was observed in station 1. The community structure reflected the impacts of the activities while CCA showed the major water quality parameters that influenced the phytoplankton community structure.


2004 ◽  
Vol 57 (10) ◽  
pp. 951
Author(s):  
Paul L. Brown ◽  
John M. Ferris

The Dawesley Creek–Bremer River drainage system, in South Australia, is affected by the potentially costly problem of acid drainage from the Brukunga mine site. This paper contrasts geochemical model predictions of water quality with detailed measurement of water chemistry in the field. This information is also used in the ecological risk assessment code, AQUARISK, to predict the degree of ecological detriment. These predictions are then assessed against independent, field-based biomeasures of algal and bacterial communities to test the performance of the code. The study demonstrates that the assessment of ecological risk obtained using AQUARISK, when coupled with geochemical modelling, accords quite well with the independent data from the biomeasures. Results from the study also suggest that only a single water-quality guideline value is required for aluminium, the major toxicant in the Dawesley Creek–Bremer River system.


2017 ◽  
Vol 03 (04) ◽  
pp. 1750006 ◽  
Author(s):  
Travis Warziniack ◽  
Chi Ho Sham ◽  
Robert Morgan ◽  
Yasha Feferholtz

This paper studies the relationship between forest cover and drinking water chemical treatment costs using land use data and a survey by the American Water Works Association (AWWA). The survey gathers cost and water quality data from 37 treatment plants in forested ecoregions of the United States. We model the effect of forest conversion on the cost of water treatment using a two-step process. First, we examine the effect of changes in land use on water quality through an ecological production function. Second, we examine the effect of changes in water quality on cost of treatment through an economic benefits function. We find a negative relationship between forest cover and turbidity, but no relationship between forest cover and total organic carbon (TOC). Increasing forest cover in a watershed by 1% reduces turbidity by 3%, and increasing development by 1% in a watershed increases turbidity by 3%. The impact of development is more consistent across models than the impact of forest cover. We also find a large impact on turbidity from grazing in the watershed. Our economic benefits function shows a 1% increase in turbidity increases water treatment costs by 0.19%, and 1% increase in TOC increases water treatment costs by 0.46%. TOC has a clearer impact on costs than turbidity, which becomes insignificant when we omit one of our observations with high turbidity.


2019 ◽  
Author(s):  
Lilia Serrano-Grijalva ◽  
Raul Ochoa-Hueso ◽  
Raquel Sánchez-Andrés ◽  
Santos Cirujano ◽  
Salvador Sánchez-Carrillo

Wetlands provide a great variety of environmental services to society, but they are currently globally threatened by human activities. We evaluated the effects of anthropogenic disturbances on the ecological quality of semiarid wetlands from central Spain (La Mancha Húmeda) through the natural abundance of isotopes (13C and 15N) of aquatic plants. We measured water quality and also compiled historical information about land-use and socioeconomic characteristics at local (100 m around the lagoon) and regional (sub-basin) scales. We then related this information to isotopic signatures of three types of aquatic plants: (i) charophytes, (ii) marginal aquatic macrophytes and (iii) vascular plants. Aquatic plants exposed to high levels of nitrogen showed very low δ13C values, consistent with negative physiological effects. Vascular aquatic plants were the group that best reflected the effects of nutrient enrichment in wetlands and lagoons through significant correlations between their δ15N values and total nitrogen and phosphorus concentrations in water. Demographic factors did not exert a clear influence on aquatic plant isotopic signatures, although we observed inverse correlations between the coverage of natural vegetation at regional scale and δ13C of marginal plants and δ15N of vascular plants. Furthermore, the isotopic signatures of Phragmites australis, present in 96% of the studied la-goons, were not significantly correlated with any of the environmental quality variables evaluated. Although δ13C signatures of Typha dominguensis and Cladium mariscus increased significantly due to changes in water quality, their narrow isotopic variability at the regional scale limits their use as a bioindicators of environmental changes in this wetland system. Finally, we propose the use of δ15N measured in the vascular plant Salicornia sp. as the most suitable bio-indicator of anthropogenic impacts in La Mancha Húmeda region, a highly emblematic system of semiarid Mediterranean wetlands that is unique in the Mediterranean region of Europe.


2015 ◽  
Vol 12 (13) ◽  
pp. 4085-4098 ◽  
Author(s):  
R. Aguilera ◽  
R. Marcé ◽  
S. Sabater

Abstract. Attributing changes in river water quality to specific factors is challenging because multiple factors act at different temporal and spatial scales, and it often requires examining long-term series of continuous data. Data consistency is sometimes hindered by the lack of observations of relevant water quality variables and the low and uneven sampling frequency that characterizes many water quality monitoring schemes. Nitrate and dissolved phosphate concentration time series (1980–2011) from 50 sampling stations across a large Mediterranean river basin were analyzed to disentangle the role of hydrology, land-use practices, and global climatic phenomena on the observed nutrient patterns, with the final aim of understanding how the different aspects of global change affected nutrient dynamics in the basin. Dynamic factor analysis (DFA) provided the methodological framework to extract underlying common patterns in nutrient time series with missing observations. Using complementary methods such as frequency and trend analyses, we sought to further characterize the common patterns and identify the drivers behind their variability across time and space. Seasonal and other cyclic patterns were identified as well as trends of increase or decrease of nutrient concentration in particular areas of the basin. Overall, the impact of global change, which includes both climate change and anthropogenic impacts, on the dynamics of nitrate concentration across the study basin was found to be a multifaceted process including regional and global factors, such as climatic oscillations and agricultural irrigation practices, whereas impacts on phosphate concentration seemed to depend more on local impacts, such as urban and industrial activities, and less on large-scale factors.


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