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1.
Nedim Özdemir Ahmet Demirak Feyyaz Keskin 《Environmental monitoring and assessment》2014,186(12):8463-8472
A thorough investigation of the impact of rainbow trout (Oncorhynchus mykiss) cultivation on surface water quality in the area known as Bereket HES IV Dam Lake was conducted. Water samples were collected from October 2009 to June 2010 from four stations in the Dam Lake and analyzed for water temperature, pH, dissolved oxygen, electrical conductivity, nitrite nitrogen, nitrate nitrogen, and orthophosphate. Surface water quality was then evaluated based on the comparison of samples collected from three stations located near fish cages to those collected from a reference station outside the cultivation area as well as by the comparison with standards specified in the Water Pollution Registration Act. According to the Water Pollution Registration Act, the surface water quality of the Dam Lake was class I. Additionally, there were no significant differences in water quality within the Dam Lake among any of the sampling stations, including the reference station. Overall, these findings indicate that cage cultivation of rainbow trout may have a negative impact on the entire Dam Lake. 相似文献
2.
Stefan Löfgren Neil Cory Therese Zetterberg 《Environmental monitoring and assessment》2010,166(1-4):609-624
The negative effects of elevated concentrations of inorganic aluminium on aquatic organisms are well documented. Acid deposition is often cited as a main driver behind the mobilisation and speciation of aluminium in soils and surface waters. In the study, we tested the hypothesis that sulphur deposition is the main driver for elevated concentrations of inorganic aluminium in 114 base poor, boreal Swedish streams. However, the deposition of anthropogenic sulphate has decreased substantially since it peaked in the 1970s, and at the current deposition levels, we hypothesise that local site parameters play an important role in determining vulnerability to elevated concentrations of inorganic aluminium in boreal stream waters. Presented here are the results of a principal components analysis of stream water chemistry, acid deposition data and local site variables, including forest composition and stem volume. It is shown that the concentrations of both organic and inorganic aluminium are not explained by either historical or current acid deposition, but are instead explained by a combination of local site characteristics. Sites with elevated concentrations of inorganic aluminium were characterised by small catchments (<500 ha) dominated by mature stands of Norway spruce with high stem volume. Using data from the Swedish National Forest Inventory the area of productive forest land in Sweden with a higher vulnerability for elevated inorganic aluminium concentrations in forests streams is approximately 1.5 million hectares or 7% of the total productive forest area; this is higher in the south of Sweden (10%) and lower in the north (2%). A better understanding of the effects of natural processes and forest management in controlling aquatic inorganic aluminium concentrations is therefore important in future discussions about measures against surface water acidification. 相似文献
3.
Megan MH Nash MS Neale AC Pitchford AM 《Environmental monitoring and assessment》2007,124(1-3):141-156
The objective of this study was to assess the applicability of using landscape variables in conjunction with water quality
and benthic data to efficiently estimate stream condition of select headwater streams in the Mid-Atlantic Coastal Plains.
Eighty-two streams with riffle sites were selected from eight-two independent watersheds across the region for sampling and
analyses. Clustering of the watersheds by landscape resulted in three distinct groups (forest, crop, and urban) which coincided
with watersheds dominant land cover or use. We used non-parametric analyses to test differences in benthos and water chemistry
between groups, and used regression analyses to evaluate responses of benthic communities to water chemistry within each of
the landscape groups. We found that typical water chemistry measures associated with urban runoff such as specific conductance
and dissolved chloride were significantly higher in the urban group. In the crop group, we found variables commonly associated
with farming such as nutrients and pesticides significantly greater than in the other two groups. Regression analyses demonstrated
that the numbers of tolerant and facultative macroinvertebrates increased significantly in forested watersheds with small
shifts in pollutants, while in human use dominated watersheds the intolerant macroinvertebrates were more sensitive to shifts
in chemicals present at lower concentrations. The results from this study suggest that landscape based clustering can be used
to link upstream landscape characteristics, water chemistry and biotic integrity in order to assess stream condition and likely
cause of degradation without the use of reference sites. Notice: Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency
policy. 相似文献
4.
An evaluation of benthic macroinvertebrate biomass methodology 总被引:2,自引:0,他引:2
William T. Mason Jr. Philip A. Lewis Cornelius I. Weber 《Environmental monitoring and assessment》1985,5(4):399-422
This study shows that biological assessments of water quality status using biomass estimates of wet, dry, and ash-free dry weights and counts of individual organisms from a small, headwater stream in southwestern Ohio provide essentially similar results concerning the impact of a sewage treatment plant discharge. Of the indices of biotic status for the stream segment employed for data evaluation; Diversity Index (D), Community Diversity Index (d), Trophic Condition Index (TCI), and Empirical Biotic Index (EBI), the latter two provided evaluations most consistent with benchmark water chemistry and physics information concerning the trophic status of the stream. In addition, the percent composition of macro-invertebrate taxa by pollutional category; clean water, facultative, and pollution tolerant, as ascribed using TCI and EBI ranges for individual taxa collected in combination of Ekman grab, rock-filled basket sampler and drift net samples, proves adequate for interpretation of biotic status. 相似文献
5.
Chitrini Mozumder N. K. Tripathi Taravudh Tipdecho 《Environmental monitoring and assessment》2014,186(11):7909-7927
The unprecedented urban growth especially in developing countries has laid immense pressure on wetlands, finally threatening their existence altogether. A long-term monitoring of wetland ecosystems is the basis of planning conservation measures for a sustainable development. Deepor Beel, a Ramsar wetland and major storm water basin of the River Brahmaputra in the northeastern region of India, needs particular attention due to its constant degradation over the past decades. A rule-based classification algorithm was developed using Landsat (2011)-derived indices, namely Normalised Difference Water Index (NDWI), Modified Normalised Difference Water Index (MNDWI), Normalised Difference Pond Index (NDPI), Normalised Difference Vegetation Index (NDVI) and field data as ancillary information. Field data, ALOS AVNIR and Google Earth images were used for accuracy assessment. A fuzzy accuracy assessment of the classified data sets showed an overall accuracy of 82 % for MAX criteria and 90 % for RIGHT criteria. The rules were used to classify major wetland cover types during low water season (January) in 1989, 2001 and 2012. The statistical analysis of the classified wetland showed heavy manifestation in aquatic vegetation and other features indicating severe eutrophication over the past 23 years. This degradation was closely related to major contributing anthropogenic factors, such as a railway line construction, growing croplands, waste disposal and illegal human settlements in the wetland catchment. In addition, the landscape development index (LDI) indicated a rapid increase in the impact of the surrounding land use on the wetland from 1989 to 2012. The techniques and results from this study may prove useful for top-down landscape analyses of this and other freshwater wetlands. 相似文献
6.
Dynamic response of the scenic beauty value of different forests to various thinning intensities in central eastern China 总被引:1,自引:0,他引:1
Songqiu Deng Na Yin Qingwei Guan Masato Katoh 《Environmental monitoring and assessment》2014,186(11):7413-7429
Forest management has a significant influence on the preferences of people for forest landscapes. This study sought to evaluate the dynamic effects of thinning intensities on the landscape value of forests over time. Five typical stands in Wuxiangsi National Forest Park in Nanjing, China, were subjected to a thinning experiment designed with four intensities: unthinned, light thinning, moderate thinning, and heavy thinning. People’s preferences for landscape photographs taken in plots under various thinning intensities were assessed through scenic beauty estimation (SBE) at 2 and 5 years after thinning. The differences in scenic beauty value between different thinning intensities were then analyzed with a paired samples t test for the two periods. The results indicated that the landscape value of all of the thinned plots significantly exceeded that of the unthinned plots 2 years after thinning (p?0.01) and that the heavily thinned plots were most appreciated, showing an average improvement of 9.71 % compared with the control plots. Additionally, the heavily thinned plots were judged to be more beautiful than the lightly thinned and moderately thinned plots, whereas there was no significant difference between moderate thinning and light thinning. At 5 years after thinning, however, the moderately thinned plots received the highest preference scores among the four intensities, displaying an average improvement of 11.32 % compared with the unthinned plots. A multiple linear regression (MLR) model indicated that landscape value improved with increases in the average diameter at breast height (DBH) and with the improvement of environmental cleanliness in the stand, whereas the value decreased with an increasing stem density, species diversity, litter coverage, and canopy density. In addition, we found that the performance of a neural network model based on a multilayer perception (MLP) algorithm for predicting scenic beauty was slightly better than that of the MLR model. The findings of our study suggest that moderate to heavy thinning should be recommended to manage forests for the improvement of forest landscape value. 相似文献
7.
C. M. Pilgrim E. A. Mikhailova C. J. Post J. J. Hains 《Environmental monitoring and assessment》2014,186(11):7617-7630
Monitoring changes in land cover and the subsequent environmental responses are essential for water quality assessment, natural resource planning, management, and policies. Over the last 75 years, the Lake Issaqueena watershed has experienced a drastic shift in land use. This study was conducted to examine the changes in land cover and the implied changes in land use that have occurred and their environmental, water quality impacts. Aerial photography of the watershed (1951, 1956, 1968, 1977, 1989, 1999, 2005, 2006, and 2009) was analyzed and classified using the geographic information system (GIS) software. Seven land cover classes were defined: evergreen, deciduous, bare ground, pasture/grassland, cultivated, and residential/other development. Water quality data, including sampling depth, water temperature, dissolved oxygen content, fecal coliform levels, inorganic nitrogen concentrations, and turbidity, were obtained from the South Carolina (SC) Department of Health and Environmental Control (SCDHEC) for two stations and analyzed for trends as they relate to land cover change. From 1951 to 2009, the watershed experienced an increase of tree cover and bare ground (+17.4 % evergreen, +62.3 % deciduous, +9.8 % bare ground) and a decrease of pasture/grassland and cultivated land (?42.6 % pasture/grassland and ?57.1 % cultivated). From 2005 to 2009, there was an increase of 21.5 % in residential/other development. Sampling depth ranged from 0.1 to 0.3 m. Water temperature fluctuated corresponding to changing air temperatures, and dissolved oxygen content fluctuated as a factor of water temperature. Inorganic nitrogen content was higher from December to April possibly due to application of fertilizers prior to the growing season. Turbidity and fecal coliform bacteria levels remained relatively the same from 1962 to 2005, but a slight decline in pH can be observed at both stations. Prior to 1938, the area consisted of single-crop cotton farms; after 1938, the farms were abandoned, leaving large bare areas with highly eroded soil. Starting in 1938, Clemson reforested almost 30 % of the watershed. Currently, three fourths of the watershed is forestland, with a limited coverage of small farms and residential developments. Monitoring water quality is essential in maintaining adequate freshwater supply. Water quality monitoring focuses mainly on the collection of field data, but current water quality conditions depend on the cumulative impacts of land cover change over time. 相似文献
8.
Sohyun Park Çiğdem C. Hepcan Şerif Hepcan Edward A. Cook 《Environmental monitoring and assessment》2014,186(10):6301-6318
Although ecological connectivity conservation in urban areas has recently been recognized as an important issue, less is known about its relationship to urban form and landscape pattern. This study investigates how urban morphology influences regional ecosystem pattern and landscape connectivity. Two metropolitan landscapes, Phoenix, AZ, USA, and Izmir, Turkey, were compared, both of which are fast-growing regions in their national context. A wide range of variables were considered for identifying natural and urban properties. The natural characteristics include typology of urban ecosystems, urban to natural cover ratio, dominant habitat type, urban biodiversity, landscape context, and connectivity conservation efforts. Urban parameters examine urban form, urban extent, urban cover proportion, growth rate, populations, urban gradient, major drivers of urbanization, urban density, and mode/approach of urban development. Twelve landscape metrics were measured and compared across the natural patches. Results show that there is little difference in landscape connectivity in the rural zones of Phoenix and Izmir, although Phoenix has slightly higher connectivity values. The connectivity variance in urbanized areas, however, is significantly dependent on the region. For example, Phoenix urban zones have substantially lower connectivity than either urban or suburban zones in Izmir. Findings demonstrate that small and compact urban settlements with more dense populations are more likely to conserve landscape connectivity compared to multiple-concentric but amalgamated urban form spreading all over the landscape (aka urban sprawl). 相似文献
9.
Mark Gabriel Chris Knightes Robin Dennis Ellen Cooter 《Environmental Modeling and Assessment》2014,19(6):451-465
There has been extensive analysis of Clean Air Act Amendment (CAAA) regulation impacts to changes in atmospheric nitrogen deposition; however, few studies have focused on watershed nitrogen transfer particularly regarding long-term predictions. In this study, we investigated impacts of CAAA NOx emissions on the fate and transport of nitrogen for two watersheds in the Neuse River Basin. We applied the Soil and Water Assessment Tool (SWAT) using simulated deposition rates from the Community Multiscale Air Quality (CMAQ) model. Two scenarios were investigated: one that considered CAAA emission controls in CMAQ simulation (with) and a second that did not (without). By 2020, results showed a 70 % drop in nitrogen discharge for the Little River watershed and a 50 % drop for the Nahunta watershed from 1990 levels under the with-CAAA scenario. Denitrification and plant nitrogen uptake played important roles in nitrogen discharge from each watershed. Nitrogen watershed response time to a change in atmospheric nitrogen deposition was 4 years for Nahunta and 2 years for Little River. We attribute these differences in nitrogen response time to contrasts in agricultural land use and diversity of crop types. Soybean, hay, and corn land covers had comparatively longer response times to changes in atmospheric deposition. The studied watersheds demonstrate relatively large nitrogen retention: ≥80 % of all delivered nitrogen. 相似文献
10.
Spatiotemporal distribution pattern of cyanobacteria community and its relationship with the environmental factors in Hongze Lake,China 总被引:1,自引:0,他引:1
Ying Ren Haiyan Pei Wenrong Hu Chang Tian Daping Hao Jielin Wei Yawei Feng 《Environmental monitoring and assessment》2014,186(10):6919-6933
Hongze Lake, located in the east route of the South-to-North Water Diversion Project (SNWDP), is a potential drinking water source for the residents along this water diversion project. Based on a monthly sampling at 11 stations in three regions of Hongze Lake, the spatiotemporal distribution pattern of cyanobacteria community was comprehensively investigated from March 2011 to February 2013. A total of 23 cyanobacterial species which belong to 16 genera were identified, and Microcystis was the most predominant cyanobacterial genus mainly composed of Microcystis wesenbergii in Hongze Lake. The cyanobacterial abundance ranged from 0 to 2.6?×?107 cells/L, and the average cyanobacteria abundance of Northern region was significantly higher than those of Western region and Eastern region in the 2-year study. The total cyanobacteria abundance and the Microcystis abundance both took on a similar seasonal regularity in the three regions. The results of correlation analysis indicated that Microcystis abundance was correlated with water temperature, chemical oxygen demand (COD)Mn, nitrate (NO3-N), and total nitrogen (TN)/total phosphorus (TP) mass ratio, among which water temperature had the highest correlation coefficient. In summer, cyanobacteria blooms may take place under suitable environmental conditions at some special areas in Hongze Lake, especially where the concurrence of slow water exchange and steady wind direction exists. 相似文献
11.
Prasad VK Ortiz A Stinner B McCartney D Parker J Hudgins D Hoy C Moore R 《Environmental monitoring and assessment》2005,110(1-3):141-169
Ohio is typical among the Midwestern and Eastern United States with high levels of water pollutants, the main sources being
from agriculture. In this study, we used a digital elevation model in conjunction with hydrological indices to determine the
role of landscape complexity affecting the spatial and temporal variation in pollutant levels, in one of the most impaired
headwater streams in Ohio. More than eighty five percent of the study area is dominated by agriculture. Spatial distribution
of slope (S), altitude and wetness index along with other watershed parameters such as flow direction, flow accumulation,
stream networks, flow stream orders and erosion index were used within a Geographic Information Systems framework to quantify
variation in nitrate and phosphate loads to headwater streams. Stream monitoring data for nutrient loads were used to correlate
the observed spatial and temporal patterns with hydrological parameters using multiple linear regressions. Results from the
wetness index calculated from a digital elevation model suggested a range of 0.10–16.39, with more than 35% having values
less than 4.0. A Revised Universal Soil Loss Equation (RUSLE) predicted soil loss in the range of 0.01–4.0 t/ha/yr. Nitrate
nitrogen levels in the study area paralleled precipitation patterns over time, with higher nitrate levels corresponding to
high precipitation. Atmospheric deposition through precipitation could explain approximately 35% of total nitrate levels observed
in streams. Among the different topographic variables and hydrological indices, results from the step-wise multiple regression
suggested the following best predictors, (1) elevation range and upstream flow length for nitrate, (2) flow direction and
upstream flow length for ammonia-nitrogen and slope, and (3) elevation range for phosphate levels. Differences in the landscape
models observed for nitrate, phosphate and ammonia-nitrogen in the surface waters were attributed partly to differences in
the chemical activity and source strengths of the different forms of these nutrients through agricultural management practices.
The results identify geomorphologic and landscape characteristics that influence pollutant levels in the study area. 相似文献
12.
Ingrid Jüttner P. James Chimonides Steve J. Ormerod 《Environmental monitoring and assessment》2010,162(1-4):47-65
Periphytic diatoms were studied to evaluate the water quality of a newly created lake, formed by the enclosure of the formerly tidal Cardiff Bay (Wales, UK), and the effects of two inflowing rivers which drain densely populated and industrialised catchments. Seven sites in Cardiff Bay and two locations on the inflowing rivers were monitored for diatoms and water chemistry over 2 years. Water quality was assessed using a revised UK trophic diatom index (TDI) and new methods to determine ecological quality ratios and ecological status classes as required by the EU Water Framework Directive. Diatom assemblages reflected spatiotemporal variations in environmental conditions between the rivers and Cardiff Bay and within the bay. In the bay, diatoms reflected differences in river quality and possibly local pollution in certain areas of the lake. High values of the TDI indicated eutrophic to hypertrophic conditions in both rivers and in the bay and diatoms indicated poor ecological status. 相似文献
13.
Simone G. Varandas Rui Manuel Vitor Cortes 《Environmental monitoring and assessment》2010,166(1-4):201-221
A procedure to select the most relevant metrics for assessing the ecological condition of the Douro basin (north Portugal) was developed based upon a set of 184 benthic community metrics. They were grouped into 16 biological categories selected from literature using data collected over 2 years from 54 sites along 31 rivers covering the whole perceived range of human disturbance. Multivariate analyses were carried out to identify the main trends in the macroinvertebrate data, to select reference versus impaired sites, to avoid multicolinearity between metrics, and to identify those that were clearly independent from natural stream typology. Structural metrics, adaptation metrics, and tolerance measures most effectively responded across a range of human influence. We find these attributes to be ecologically sound for monitoring Portugal’s lotic ecosystems and providing information relevant to the Water Framework Directive, which asserts that the definition of water quality depends on its “ecological status”, independent of the actual or potential uses of those waters. 相似文献
14.
Kagalou I 《Journal of environmental monitoring : JEM》2010,12(12):2207-2215
The European Water Framework Directive (WFD) establishes a framework for the protection of water bodies. The aim of the Water Framework Directive (WFD) is to ensure sustainable management of groundwater, freshwater and marine water in the European Union, such that a minimum "good ecological status" will be obtained by 2015. We used background morphometric, hydrologic, physico-chemical and biological data, in order to highlight the ecological status of the natural Greek lakes using also the Driving-Pressure-State-Impact-Response (DPSIR) approach in order to link the driving forces and further the pressures with the present state of the lakes' ecosystems. In addition detailed biodiversity and habitat typology data are provided. The assessment of the DPSIR approach under the view of WFD provided a quite clear identification of pressures and the subsequent impacts of the qualitative status of the Greek lakes. 相似文献
15.
William S. Fisher Leska S. Fore Leah M. Oliver Charles Lobue Robert Quarles Jed Campbell Peggy Harris Becky Hemmer Sherry Vickery Mel Parsons Aaron Hutchins Kent Bernier Danny Rodriguez Patricia Bradley 《Environmental monitoring and assessment》2014,186(11):7165-7181
States may protect coral reefs using biological water quality standards outlined by the Clean Water Act. This requires biological assessments with indicators sensitive to human disturbance and regional, probability-based survey designs. Stony coral condition was characterized on a regional scale for the first time in the nearshore waters of the US Virgin Islands (USVI). Coral composition, abundance, size, and health were assessed at 66 stations in the St. Croix region in fall 2007 and at 63 stations in the St. Thomas and St. John region in winter 2009. Indicators were chosen for their sensitivity to human disturbance. Both surveys were probability-based (random) designs with station locations preselected from areas covered by hardbottom and coral reef substrate. Taxa richness was as high as 21 species but more than half the area of both regions exhibited taxa richness of <10 species in the 25 m2 transect area. Coral density was as high as 5 colonies m?2 but more than half the area of both regions had <2 colonies m?2. Both regions showed similar dominant species based on frequency of occurrence and relative abundance. Because of large colony sizes, Montastrea annularis provided more total surface area and live surface area than more abundant species. The surveys establish baseline regional conditions and provide a foundation for long-term regional monitoring envisioned by the USVI Department of Planning and Natural Resources. The probabilistic sampling design assures the data can be used in Clean Water Act reporting. 相似文献
16.
Ourania Tzoraki Nikolaos P. Nikolaidis David Cooper Elissavet Kassotaki 《Environmental monitoring and assessment》2014,186(4):2243-2257
We estimate the nutrient budget in a temporary Mediterranean river basin. We use field monitoring and modelling tools to estimate nutrient sources and transfer in both high and low flow conditions. Inverse modelling by the help of PHREEQC model validated the hypothesis of a losing stream during the dry period. Soil and Water Assessment Tool model captured the water quality of the basin. The ‘total daily maximum load’ approach is used to estimate the nutrient flux status by flow class, indicating that almost 60 % of the river network fails to meet nitrogen criteria and 50 % phosphate criteria. We recommend that existing well-documented remediation measures such as reforestation of the riparian area or composting of food process biosolids should be implemented to achieve load reduction in close conjunction with social needs. 相似文献
17.
Application of Qual2Kw model as a tool for water quality management: Cértima River as a case study 总被引:1,自引:0,他引:1
Oliveira B Bola J Quinteiro P Nadais H Arroja L 《Environmental monitoring and assessment》2012,184(10):6197-6210
Modelling can be a useful management tool because models allow the understanding of water body response to different pollution pressure scenarios which may help on the decision-making process and in prosecuting the Water Framework Directive objectives. This study aims to evaluate the usage of simple water quality models (Qual2Kw) applied to small river basins in order to better understand the response of a river to different loads of nitrogen and phosphorus. Qual2Kw model was applied to Cértima River (Portugal), a small river that ends in a shallow lake called Pateira Fermentelos and represents a very important ecosystem to the local community. Along its pathway, Cértima River has a significant enrichment in nutrients due to agriculture, livestock, domestic sewage and industrial effluents discharged into the river. In case of nitrogen, the highest loads are from domestic (44%) and diffuse (35%) sources. The main sources of phosphorous are domestic (46%), livestock (24%) and diffuse sources (20%). Cértima River is strongly enriched with nutrients, and neither nitrogen nor phosphorous is limiting the algal growth. According to the criterion of Dodds et al. (Water Res, 32(5):1455-1462, 1998), the river is classified as eutrophic. By comparing in stream measurements with Qual2Kw simulations, it can be concluded that it would be necessary to decrease the actual pollutants loads of nitrogen and phosphorous 5 and 10 times, respectively, in order to change Cértima River classification from eutrophic to mesotrophic. 相似文献
18.
Per Stålnacke Anders Grimvall Karin Sundblad Anders Wilander 《Environmental monitoring and assessment》1999,59(1):47-72
Concern about nitrogen loads in marine environments has drawn attention to the existence and possible causes of long-term trends in nitrogen transport in rivers. The present study was based on data from the Swedish environmental monitoring programme for surface water quality; the continuity of these data is internationally unique. A recently developed semiparametric method was employed to study the development of relationships between runoff and river transport of nitrogen since 1971; the observed relationships were then used to produce time series of flow-normalised transports for 66 sites in 39 river basins. Subsequent statistical analyses of flow-normalised data revealed only few significant downward trends (p 0.05) during the time period 1971–1994, and the most pronounced of these downward trends were caused by reduced point emissions of nitrogen. The number of significant upward trends was substantially larger (15 for total-N and 18 for NO3-N). Closer examination of obtained results revealed the following: (i) the most pronounced upward trends were present downstream of lakes, and (ii) observed increases in nitrogen transport coincided in time and space with reduced point emissions of phosphorus or organic matter. This indicated that changes in the retention of nitrogen in lakes were responsible for the upward nitrogen trends. The hypothesis that nitrogen saturation of forest soils has caused a general increase in the riverine export of nitrogen from forested catchments in Sweden was not confirmed. Neither did the results indicate that improved agricultural practices have reduced the export of nitrogen from agricultural catchments. 相似文献
19.
为精准治理流域非点源氮磷污染,基于SWAT模型,运用本地区第二次全国污染源普查数据和2000—2019年流域水文、水质数据,开展湘江永州流域非点源氮磷污染模拟。结果表明:湘江永州流域建立的SWAT模型具有较好的模拟效果,流域2005—2019年的总氮月均污染负荷为383.40~17 998.70 t/m;总磷月均污染负荷为64.62~567.86 t/m,总氮和总磷各月污染负荷均与各月降雨量呈显著相关关系;农田和林地是本流域总氮、总磷污染负荷总量最大的2种用地类型,但两者之间单位面积输出的污染负荷强度却相反,林地对流域水污染防控具有正面效应,农田种植面源污染是非点源氮磷污染治理的重点。 相似文献
20.
Cost-effectiveness and cost-benefit analysis of BMPs in controlling agricultural nonpoint source pollution in China based on the SWAT model 总被引:1,自引:0,他引:1
Ruimin Liu Peipei Zhang Xiujuan Wang Jiawei Wang Wenwen Yu Zhenyao Shen 《Environmental monitoring and assessment》2014,186(12):9011-9022
Best management practices (BMPs) have been widely used in managing agricultural nonpoint source pollution (ANSP) at the watershed level. Most BMPs are related to land use, tillage management, and fertilizer levels. In total, seven BMP scenarios (Reforest1, Reforest2, No Tillage, Contour tillage, and fertilizer level 1–4) that are related to these three factors were estimated in this study. The objectives were to investigate the effectiveness and cost-benefit of these BMPs on ANSP reduction in a large tributary of the Three Gorges Reservoir (TGR) in China, which are based on the simulation results of the Soil and Water Assessment Tool (SWAT) model. The results indicated that reforestation was the most economically efficient of all BMPs, and its net benefits were up to CNY 4.36×107 years?1 (about USD 7.08×106 years?1). Regarding tillage practices, no tillage practice was more environmentally friendly than other tillage practices, and contour tillage was more economically efficient. Reducing the local fertilizer level to 0.8-fold less than that of 2010 can yield a satisfactory environmental and economic efficiency. Reforestation and fertilizer management were more effective in reducing total phosphorus (TP), whereas tillage management was more effective in reducing total nitrogen (TN). When CNY 10,000 (about USD 162) was applied to reforestation, no tillage, contour tillage, and an 0.8-fold reduction in the fertilizer level, then annual TN load can be reduced by 0.08, 0.16, 0.11, and 0.04 t and annual TP load can be reduced by 0.04, 0.02, 0.01 and 0.03 t, respectively. The cost-benefit (CB) ratios of the BMPs were as follows: reforestation (207 %) > contour tillage (129 %) > no tillage (114 %) > fertilizer management (96 and 89 %). The most economical and effective BMPs can be designated as follows: BMP1 (returning arable land with slopes greater than 25° to forests and those lands with slopes of 15–25° to orchards), BMP2 (implementing no tillage on arable land with slopes less than 15°), and BMP5 (0.8-fold less than that of 2010). 相似文献