scholarly journals Empirical Modeling of Stream Nutrients for Countries without Robust Water Quality Monitoring Systems

Environments ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 129
Author(s):  
Ismael Díaz ◽  
Paula Levrini ◽  
Marcel Achkar ◽  
Carolina Crisci ◽  
Camila Fernández Nion ◽  
...  

Water quality models are useful tools to understand and mitigate eutrophication processes. However, gaining access to high-resolution data and fitting models to local conditions can interfere with their implementation. This paper analyzes whether it is possible to create a spatial model of nutrient water level at a local scale that is applicable in different geophysical and land-use conditions. The total nitrogen and phosphorus concentrations were modeled by integrating Geographical Information Systems, Remote Sensing, and Generalized Additive and Land-Use Changes Modeling. The research was based on two case studies, which included 204 drainage basins, with nutrient and limnological data collected during two seasons. The models performed well under local conditions, with small errors calculated from the independent samples. The recorded and predicted concentrations of nutrients indicated a significant risk of water eutrophication in both areas, showing the impact of agricultural intensification and population growth on water quality. The models are a contribution to the sustainable land-use planning process, which can help to prevent or promote land-use transformation and new practices in agricultural production and urban design. The ability to implement models using secondary information, which is easily collected at a low cost, is the most remarkable feature of this approach.

Author(s):  
Carmelo Maria Torre ◽  
Pierluigi Morano ◽  
Francesco Tajani

Our work is regarding the analysis of land use changes, in the light of “saving soil” against the expansion due to unearned plus value of land: The loss of natural and agricultural surface in front of the expanding urban environment is a critical aspect of unsustainability of urban development, especially in the way it was carried out in the past decades. The measure of the physical transition of land use and characters from a more natural condition of land surface to a new artificial one, joint with a parallel analysis of the increase of land value due to such change is nowadays a major land-policy tool. The interplay of urban economics regulation with planning, reveals new key issues in urban governance and environmental preservation. In this paper it will be shown some experiment about the impact assessment of soil take, related with the seek of valorization of property inside the planning process. Our paper reports as well about the experimental activity carried out inside the MITO Lab of the Polytechnic of Bari, where reports about property values and environmental values have been produced, specially looking at the reality of the Apulia, a southern Italian Region, that is rich of farmlands and coastlines, often invaded by constructions with a severe loss of nature, landscape and ecosystems services.


2015 ◽  
Vol 20 (2) ◽  
pp. 54-60 ◽  
Author(s):  
S. Gyawali ◽  
K. Techato ◽  
S. Monprapusson

The study investigated the linkages between land uses and water quality in U-tapao river basin, Thailand, in order to examine the impact of land use changes on full -basin, sub-watershed and buffer zone scales (1000m, 500m and 200m) on river water quality through Geographical Information Systems (GIS) and statistical analyses. Correlation and regression analysis were applied for ten water quality parameters. In scale analysis, in the most cases, the sub-watershed scale showed the clear relationship between land use water quality rather than full-basin and buffer zone scales. This indicates that the level of relationship between land use and water quality depends upon scale therefore the relationship between water quality parameters and land uses should be studied in multiple scales and it helps to develop effective river basin management in future.Journal of Institute of Science and Technology, 2015, 20(2): 54-60


2019 ◽  
Vol 8 (1) ◽  
pp. 87-91
Author(s):  
Bhanu Priya Chouhan ◽  
Monika Kannan

The world is undergoing the largest wave of urban growth in history. More than half of the world’s population now lives in towns and cities, and by 2030 this number will swell to about 5 billion. ‘Urbanization has the potential to usher in a new era of wellbeing, resource efficiency and economic growth. But due to increased population the pressure of demand also increases in urban areas’ (Drakakis-Smith, David, 1996). The loss of agricultural land to other land uses occasioned by urban growth is an issue of growing concern worldwide, particularly in the developing countries like India. This paper is an attempt to assess the impact of urbanization on land use and land cover patterns in Ajmer city. Recent trends indicate that the rural urban migration and religious significance of the place attracting thousands of tourists every year, have immensely contributed in the increasing population of city and is causing change in land use patterns. This accelerating urban sprawl has led to shrinking of the agricultural land and land holdings. Due to increased rate of urbanization, the agricultural areas have been transformed into residential and industrial areas (Retnaraj D,1994). There are several key factors which cause increase in population here such as Smart City Projects, potential for employment, higher education, more comfortable and quality housing, better health facilities, high living standard etc. Population pressure not only directly increases the demand for food, but also indirectly reduces its supply through building development, environmental degradation and marginalization of food production (Aldington T, 1997). Also, there are several issues which are associated with continuous increase in population i.e. land degradation, pollution, poverty, slums, unaffordable housing etc. Pollution, formulation of slums, transportation congestion, environmental hazards, land degradation and crime are some of the major impacts of urbanization on Ajmer city. This study involves mapping of land use patterns by analyzing data and satellite imagery taken at different time periods. The satellite images of year 2000 and 2017 are used. The change detection techniques are used with the help of Geographical Information System software like ERDAS and ArcGIS. The supervised classification of all the three satellite images is done by ERDAS software to demarcate and analyze land use change.


2021 ◽  
Vol 13 (19) ◽  
pp. 11067
Author(s):  
Kaige Lei ◽  
Yifan Wu ◽  
Feng Li ◽  
Jiayu Yang ◽  
Mingtao Xiang ◽  
...  

Understanding the relationship between land use/cover pattern and water quality could provide guidelines for non-point source pollution and facilitate sustainable development. The previous studies mainly relate the land use/cover of the entire region to the water quality at the monitoring sites, but the water quality at monitoring sites did not totally reflect the water environment of the entire basin. In this study, the land use/cover was monitored on Google Earth Engine in Tang-Pu Reservoir basin, China. In order to reflect the water quality of the whole study area, the spatial distribution of the determinants for water quality there, i.e., the total nitrogen and total phosphorus (TN&TP), were simulated by the Soil and Water Assessment Tool (SWAT). The redundancy analysis explored the correlations between land use/cover pattern and simulated TN&TP. The results showed that: (1) From 2009 to 2019, forest was the dominant land cover, and there was little land use/cover change. The landscape fragmentation increased, and the connectivity decreased. (2) About 25% TP concentrations and nearly all the TN concentrations at the monitoring points did not reach drinking water standard, which means nitrogen and phosphorus pollution were the most serious problems. The highest output per unit TN&TP simulated by SWAT were 44.50 kg/hm2 and 9.51 kg/hm2 and occurred in areas with highly fragile landscape patterns. (3) TN&TP correlated positively with cultivated and construction land but negatively with forest. The correlation between forest and TN&TP summited at 500–700-m buffer and construction land at 100-m buffer. As the buffer size increased, the correlation between the cultivated land, and the TN weakened, while the correlation with the TP increased. TN&TP correlated positively with the Shannon’s Diversity Index and negatively with the Contagion Index. This study provides a new perspective for exporting the impact of land use/cover pattern on water quality.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karina A. Chavarria ◽  
Kristin Saltonstall ◽  
Jorge Vinda ◽  
Jorge Batista ◽  
Megan Lindmark ◽  
...  

AbstractLand use is known to affect water quality yet the impact it has on aquatic microbial communities in tropical systems is poorly understood. We used 16S metabarcoding to assess the impact of land use on bacterial communities in the water column of four streams in central Panama. Each stream was influenced by a common Neotropical land use: mature forest, secondary forest, silvopasture and traditional cattle pasture. Bacterial community diversity and composition were significantly influenced by nearby land uses. Streams bordered by forests had higher phylogenetic diversity (Faith’s PD) and similar community structure (based on weighted UniFrac distance), whereas the stream surrounded by traditional cattle pasture had lower diversity and unique bacterial communities. The silvopasture stream showed strong seasonal shifts, with communities similar to forested catchments during the wet seasons and cattle pasture during dry seasons. We demonstrate that natural forest regrowth and targeted management, such as maintaining and restoring riparian corridors, benefit stream-water microbiomes in tropical landscapes and can provide a rapid and efficient approach to balancing agricultural activities and water quality protection.


Author(s):  
Peixuan Cheng ◽  
Fansheng Meng ◽  
Yeyao Wang ◽  
Lingsong Zhang ◽  
Qi Yang ◽  
...  

The relationships between land use patterns and water quality in trans-boundary watersheds remain elusive due to the heterogeneous natural environment. We assess the impact of land use patterns on water quality at different eco-functional regions in the Songhua River basin during two hydrological seasons in 2016. The partial least square regression indicated that agricultural activities associated with most water quality pollutants in the region with a relative higher runoff depth and lower altitude. Intensive grazing had negative impacts on water quality in plain areas with low runoff depth. Forest was related negatively with degraded water quality in mountainous high flow region. Patch density and edge density had major impacts on water quality contaminants especially in mountainous high flow region; Contagion was related with non-point source pollutants in mountainous normal flow region; landscape shape index was an effective indicator for anions in some eco-regions in high flow season; Shannon’s diversity index contributed to degraded water quality in each eco-region, indicating the variation of landscape heterogeneity influenced water quality regardless of natural environment. The results provide a regional based approach of identifying the impact of land use patterns on water quality in order to improve water pollution control and land use management.


Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 724 ◽  
Author(s):  
Pankaj Kumar ◽  
Rajarshi Dasgupta ◽  
Brian Johnson ◽  
Chitresh Saraswat ◽  
Mrittika Basu ◽  
...  

Rapid changes in land use and land cover pattern have exerted an irreversible change on different natural resources, and water resources in particular, throughout the world. Khambhat City, located in the Western coastal plain of India, is witnessing a rapid expansion of human settlements, as well as agricultural and industrial activities. This development has led to a massive increase in groundwater use (the only source of potable water in the area), brought about significant changes to land management practices (e.g., increased fertilizer use), and resulted in much greater amounts of household and industrial waste. To better understand the impacts of this development on the local groundwater, this study investigated the relationship between groundwater quality change and land use change over the 2001–2011 period; a time during which rapid development occurred. Water quality measurements from 66 groundwater sampling wells were analyzed for the years 2001 and 2011, and two water quality indicators (NO3− and Cl− concentration) were mapped and correlated against the changes in land use. Our results indicated that the groundwater quality has deteriorated, with both nitrate (NO3−) and chloride (Cl−) levels being elevated significantly. Contour maps of NO3− and Cl− were compared with the land use maps for 2001 and 2011, respectively, to identify the impact of land use changes on water quality. Zonal statistics suggested that conversion from barren land to agricultural land had the most significant negative impact on water quality, demonstrating a positive correlation with accelerated levels of both NO3− and Cl−. The amount of influence of the different land use categories on NO3− increase was, in order, agriculture > bare land > lake > marshland > built-up > river. Whereas, for higher concentration of Cl− in the groundwater, the order of influence of the different land use categories was marshland > built-up > agriculture > bare land > lake > river. This study will help policy planners and decision makers to understand the trend of groundwater development and hence to take timely mitigation measures for its sustainable management.


2018 ◽  
Vol 47 (5) ◽  
pp. 745-758
Author(s):  
Adekunle Moruf Alabi ◽  
Mubarak Olatunji Lasisi ◽  
Maryam Abimbola Azeez

Urban growth is one of the indicators that reflects human interaction with the environment and has a direct effect on land use change. Continuous demand for space in Nigeria’s urban markets to accommodate shops and other retail outlets used for informal economic activities is accompanied by a change of use. This study examined the impact of informal economic activities on change of use in Bola Ige International Market, Ibadan. The concept of informal economy and the bid rent theory provided the conceptual/theoretical framework for this study. Geographical Information System was used to capture the change of use between 2006 and 2016. Land used for informal economic activities increased from 39.45% in 2006 to 55.35% in 2016, signifying a 15.9% increase. This implies that other land uses have been illegally converted and encroached. Transportation land use decreased from 31.47% in 2006 to 30.28% in 2011 and to 28.73% in 2016. Land used for open space (including parking space, and open trading area) which was 26.7% in 2006 reduced to 20.24% and 11.05% in 2011 and 2016, respectively. Most of the green areas (62.1%) have been converted to informal trading spaces between 2006 and 2016. Illegal change of use was credited to harsh economic condition in the country, and the engagement of the unemployed and retirees in informal sector economic activities. It was suggested that urban managers in conjunction with informed activists, researchers and citizens need to formulate and implement planning regulations that will integrate informal economic activities.


Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 189 ◽  
Author(s):  
Matjaž Glavan ◽  
Sara Bele ◽  
Miha Curk ◽  
Marina Pintar

Intensive agriculture causes nutrient leaching and accelerates erosion processes, which threatens the good quality status of surface waters, as proposed by the European Union (EU) Water Framework Directive. The purpose of this study was to define the impact of two alternative agricultural land-use change scenarios defined in a Municipal Spatial Plan on surface water quality by using the Agricultural Policy/Environmental eXtender (APEX) model. As experimental area, we chose a small Kožbanjšček stream catchment (1464 ha) situated in the Goriška Brda region in Slovenia. The area, due to favorable conditions for vineyards, is facing increasing deforestation. The change of 66.3 ha of forests to vineyards would increase the sediment, nitrate, and phosphorus loads in the stream by 24.8%, 17.1%, and 10.7%, respectively. With the implementation of vegetative buffer strips as a mitigation measure of the current situation, we could reduce the sediment, nitrate, and phosphorus loads by 17.9%, 11.1%, and 3.1%, respectively, while a combination of the two land-use change scenarios would result in a slight increase of the above-mentioned loads, corresponding to 0.61%, 2.1%, and 6.6%, respectively, compared to the baseline situation. The results confirm that, as we can increase pollution levels with deforestation, we can also reduce water pollution by choosing proper types of land management measures.


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