scholarly journals  the Impact of Watershed Land Use on River Water Quality: Implication for Planning in the Case of Kebena River Watershed, Addis Ababa, Ethiopia

2020 ◽  
Author(s):  
Kalkidan Asnake ◽  
Hailu Worku ◽  
Mekuria Argaw

Abstract Background: The impact of watershed land-use on surface water quality, especially in urbanized areas, has been investigated in numerous studies in developed countries, however, the issue is one of the under researched areas in developing cities of Africa. To study the impact of watershed land-use on surface water quality, we used the main land use types of the Kebena watershed from aerial photograph and collected river water samples during the dry and wet seasons for two consecutive years at different points from the river course. We calculated the share of each land use using ArcGIS and tested the water quality during each season. The variations in water quality parameters relating to the different land use types of the sub-watersheds were analyzed using ANOVA. Results: Kebena watershed is mainly covered by 39.14% forest, 32.51% built-up area and 27.25% cultivated land. At sub-catchment level, Denkaka, (agriculture dominated) sub-catchment with 44.90 % cultivated land, Little Kebena, (forest dominated) sub-catchment, with 60.87% forest cover and Ginfle (urban dominated) sub-catchment with 90.44% built-up area were identified. The variations in water quality parameters relating to the different land use types of Kebena watershed revealed the significantly high seasonal relationship between the concentration of the water quality indicators during the dry season at (P<0.001, P<0.05). Furthermore, there is a strong positive relationship between the urban and forest dominated sub-catchments and water quality indicators during both the wet and dry seasons than agriculture dominated sub-catchment.Conclusion: Integrating watershed planning with land use planning, therefore, becomes one of the vital tools to address water quality problems in a holistic manner to further prioritize restoration and protection strategies for specific sub-catchments. Thus, in the urban dominated sub-catchment, relocating riverfront communities, providing a well-designed sewage system, applying appropriate storm water management schemes, are some of the important measures while providing wide river buffers with various vegetation cover are necessary to minimize pollutants influx to the river from the agriculture dominated sub-catchment. Furthermore, in the forested sub-catchment, applying preventive measures to retain and enhance connectivity of the existing natural green spaces through open space planning, development and management schemes is crucial.

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Kalkidan Asnake ◽  
Hailu Worku ◽  
Mekuria Argaw

Abstract Background The impact of watershed land-use on surface water quality is one of the under researched areas in mega cities of the developing countries like Addis Ababa. The study examined the impact of watershed land uses on the Kebena river water quality within its seasonal and spatial variation and assessed the relationship between river water pollution and dominant land-use types in the sub-watersheds. Method The main land use types in the sub-watersheds were digitized from aerial photograph of 2016, and quantified for water quality impact analysis. Water samples were collected from the main Kebena river and the three sub-watersheds source and outlet points. A total of 128 samples were collected during the dry and wet seasons of 2016 and 2017 and analyzed for various water quality parameters. The study employed ANOVA, independent t-tests and multiple regression analysis to examine variations in water quality and assess the influence of the different land uses on water quality. Results Forest, built-up area and cultivated lands are the three major land use types in the Kebena watershed accounting for 39.14, 32.51 and 27.25% of the total area, respectively. Kebena catchment is drained by three sub-watersheds namely, Denkaka (44.9% cultivated land), Little-Kebena (60.87% forested) and Ginfle (90.44% urban land). The concentration of pollutants in the Kebena river was significantly higher (P < 0.001) in the dry season than in the wet season. However, when compared to surface water quality standards, both the dry and wet season water quality records are exceptionally high. The urban and forest dominated sub-watersheds contribute significantly high amount of (P < 0.001) pollutant loads to the river which is associated with high runoff from impervious surfaces and sewerage discharge to the river from nearby urban settlements. Conclusion Integrating watershed planning with land use planning is of paramount importance to address water quality problems in urban areas. Thus, in the urban dominated sub-catchment, land-use planning should aim to relocating river front communities, providing sufficient river buffer-zones and forwarding appropriate storm water management schemes. In the forested sub-catchment, planning should protect, retain and enhance the existing natural green spaces through open space planning, and management schemes while providing wide river-buffer with natural vegetation cover to minimize pollution load to urban rivers from agriculture dominated sub-watershed.


2021 ◽  
Vol 933 (1) ◽  
pp. 012010
Author(s):  
S A Nurhayati ◽  
M Marselina ◽  
A Sabar

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.


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.


2021 ◽  
Vol 43 (10) ◽  
pp. 664-678
Author(s):  
Hyeon Woo Go ◽  
Jin Chul Joo ◽  
Dong Hwi Lee ◽  
Chae Min Ahn ◽  
Sun Hwa Choi ◽  
...  

Objectives : In this study, the characteristics of stormwater runoff from agricultural nonpoint pollution sources investigated under various experimental conditions were evaluated among different land use types (e.g., paddy, field, field (alpine), and vinyl house), and event mean concentrations (EMCs) for each water quality parameter were statistically analyzed. These results can be used in calculating the contribution of stormwater runoff to water quality of receiving water body by performing quantitative and qualitative analysis. The unit loads calculated were compared with Ministry of Environment TMDL (2019) to secure the reliability of the calculated unit loads.Methods : EMCs and unit loads investigated in various studies were classified in terms of paddy, field, field (alpine), and vinyl house. Among various land use types, EMCs and unit loads were statistically analyzed quantitatively and qualitatively. For EMCs, a null hypothesis is that ‘EMCs of water quality parameters among different land use types are not different at a statistically significant level (α=0.05)’. Based on the results of statistical analysis, heteroscedasticity (p<0.05) and Welch-test method were consequently applied, and post hoc test was performed using the Games-Howell method. Finally, unit loads was compared and reviewed against the TMDL (2019) unit loads of the Ministry of Environment.Results and Discussion : Various EMCs in all water quality parameters were found among different land use types (i.e., paddy, field, field (alpine) and vinyl house). For most water quality parameters, EMCs tended to decrease in the order of field (alpine) > field > vinyl house > paddy. The coefficient of variance (CV) values of all water q uality parameters were 0.5 or greater. Based on these results, EMCs in agricultural nonpoint source pollution are very diverse and deviated due to the combination of natural and artificial factors. Post hoc test results indicated different statistical significance among all water quality parameters. In addition to the land use types, both natural factors (i.e., season, rainfall, antecedent rainfall day, and, rainfall runoff rate) and artificial factors (i.e., cultivator manipulation, emission route, type of crop, and amount of compost) affect the characteristics of stormwater runoff. In particular, in the case of field (alpine) with prominent topographical feature of slope, and EMCs were statistically greater than those from other land use types in all water quality categories (p<0.05).Conclusions : Countermeasures for field (alpine)with greater EMCs than paddy, field and vinyl house, should be performed priority. EMCs were affected by a complex interaction between natural factors (i.e., season, rainfall, antecedent rainfall day, and, rainfall runoff rate) and artificial factors (i.e., cultivator manipulation, emission route, type of crop, and amount of compost), and additional data and research are required for further study to elucidate these complex interactions.


Author(s):  
Mandla Dlamini ◽  
George Chirima ◽  
Nebo Jovanovic ◽  
Elhadi Adam

This study investigated the impacts of cultivation on water and soil quality in the lower uMfolozi floodplain system in KwaZulu-Natal province, South Africa. We did this by assessing seasonal variations in purposefully selected water and soil properties in these two land-use systems. The observed values were statistically analysed by performing Student’s paired t-tests to determine seasonal trends in these variables. Results revealed significant seasonal differences in chloride and sodium concentrations and electrical conductivity (EC) and the sodium adsorption ratio (SAR) with cultivated sites exhibiting higher values. Most of the analyzed chemical parameters were within acceptable limits specified by the South African agricultural-water-quality (SAWQ) water quality guidelines for irrigation except for sodium adsorption ratio (SAR), chloride, sodium and EC. EC, pH and nitrate content which were higher than the specified SAWQ limits in cultivated sites. Quantities of glyphosate, ametryn and imidacloprid could not be measured because they were below detectable limits. The study concludes that most water quality parameters met SAWQ’s standards. These results argue for concerted efforts to systematically monitor water and soil quality characteristics in this environment to enhance sustainability by providing timely information for management purposes.


InterConf ◽  
2021 ◽  
pp. 413-421
Author(s):  
Jingyao Su ◽  
Simon Courtenay

Teck's Castle Project is the largest coal mine project to be mined in Canada. This article is an environmental assessment of Teck's Castle Project based on five valued ecosystem components (VECs) including: Surface Water Quality, Fish and Fish habitat, Vegetation, Local Employment, and Land Use. I proposed to use a surface water quality model to detect the degree of pollution of the water quality of the surrounding rivers and use an economic multiplier to measure the impact on local economic employment. Through research, I found that the water treatment facilities used by Teck Coal Limited can effectively alleviate the impact of the project on the water quality of the surrounding rivers, and I recommended that Teck Coal Limited wear protective equipment to protect their health when working.


2017 ◽  
Vol 21 (3) ◽  
pp. 1593-1609 ◽  
Author(s):  
Mark Honti ◽  
Nele Schuwirth ◽  
Jörg Rieckermann ◽  
Christian Stamm

Abstract. The design and evaluation of solutions for integrated surface water quality management requires an integrated modelling approach. Integrated models have to be comprehensive enough to cover the aspects relevant for management decisions, allowing for mapping of larger-scale processes such as climate change to the regional and local contexts. Besides this, models have to be sufficiently simple and fast to apply proper methods of uncertainty analysis, covering model structure deficits and error propagation through the chain of sub-models. Here, we present a new integrated catchment model satisfying both conditions. The conceptual iWaQa model was developed to support the integrated management of small streams. It can be used to predict traditional water quality parameters, such as nutrients and a wide set of organic micropollutants (plant and material protection products), by considering all major pollutant pathways in urban and agricultural environments. Due to its simplicity, the model allows for a full, propagative analysis of predictive uncertainty, including certain structural and input errors. The usefulness of the model is demonstrated by predicting future surface water quality in a small catchment with mixed land use in the Swiss Plateau. We consider climate change, population growth or decline, socio-economic development, and the implementation of management strategies to tackle urban and agricultural point and non-point sources of pollution. Our results indicate that input and model structure uncertainties are the most influential factors for certain water quality parameters. In these cases model uncertainty is already high for present conditions. Nevertheless, accounting for today's uncertainty makes management fairly robust to the foreseen range of potential changes in the next decades. The assessment of total predictive uncertainty allows for selecting management strategies that show small sensitivity to poorly known boundary conditions. The identification of important sources of uncertainty helps to guide future monitoring efforts and pinpoints key indicators, whose evolution should be closely followed to adapt management. The possible impact of climate change is clearly demonstrated by water quality substantially changing depending on single climate model chains. However, when all climate trajectories are combined, the human land use and management decisions have a larger influence on water quality against a time horizon of 2050 in the study.


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


Sign in / Sign up

Export Citation Format

Share Document