Modeling of runoff pollution load in a data scarce situation using swat, Sondu watershed, Lake Victoria Basin

Cheruiyot, CK; Muhandiki, VS

doi:10.4314/ejesm.v8i5.3

Cited by 3 publications

(7 citation statements)

References 10 publications

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“…The values of both cases are significantly lower than reported in the current study (Table 1). The value of R 2 obtained by Cheruiyot and Muhandiki [30] was 0.67 and 0.21, respectively, for TN and TP simulation results, which is also lower than those obtained in this study (see Table 2).…”

Section: Rationality Of Simulation Resultscontrasting

confidence: 87%

“…In the Simiyu catchment, the model simulation results show that the TN and TP loads range from 1.369 to 19.295 kg/ha•yr and 0.161~6.653 kg/ha•yr, respectively (calculated from Figure 8). They are essentially comparable to the TN and TP loads with ranges of 0.851~18.548 kg/ha•yr and 0.585~9.358 kg/ha•yr for the Sondu watershed reported by Cheruiyot and Muhandiki [30].…”

Section: Rationality Of Simulation Resultssupporting

confidence: 82%

“…For example, Kimwaga et al [55] reported the value of E ns for hydrologic simulation results to be 0.345 and 0.301, respectively, during calibration periods and validation periods in the same Simiyu catchment. Also, Cheruiyot and Muhandiki [30] reported the E ns value in the Sondu catchment of Kenya to be 0.46 and −4.45, respectively. The values of both cases are significantly lower than reported in the current study (Table 1).…”

Section: Rationality Of Simulation Resultsmentioning

confidence: 99%

“…The results from the study indicated an underestimation of the sediment production because only seven sediment monitoring data were used to calibrate the SWAT parameters, which were insufficient. Another study from Cheruiyot and Muhandiki [30] failed to obtain ideal simulation results of the NPS in the Sondu watershed in Kenya due to less and discontinuous water quality data. As a result, obtaining reliable simulation results with insufficient data has become a central challenge to researchers trying to simulate current or future NPS in the Lake Victoria Basin.…”

Section: Introductionmentioning

confidence: 99%

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Integrated Application of SWAT and L-THIA Models for Nonpoint Source Pollution Assessment in Data Scarce Regions

Zhang,

Chen,

Dai

et al. 2024

Water

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Nonpoint source pollution (NPS) has become the most important reason for the deterioration of water quality, while relevant studies are often limited to African river and lake basins with insufficient data. Taking the Simiyu catchment of the Lake Victoria basin as the study area, we set up a NPS model based on the soil and water assessment tool (SWAT). Furthermore, the rationality of this model is verified with the field-measured data. The results manifest that: (1) the temporal variation of NPS load is consistent with the variation pattern of rainfall, the average monthly output of total nitrogen (TN) and total phosphorus (TP) in the rainy season was 1360.6 t and 336.2 t, respectively, while in the dry season was much lower, only 13.5 t and 3.0 t, respectively; (2) in view of spatial distribution among 32 sub-basins, TN load ranged from 2.051 to 24.288 kg/ha with an average load of 12.940 kg/ha, and TP load ranged from 0.263 to 8.103 kg/ha with an average load of 3.321 kg/ha during the 16-month study period; (3) Among the land use types, the cropland contributed the highest proportion of TN and TP pollution with 50.28% and 76.29%, respectively, while the effect of forest on NPS was minimal with 0.05% and 0.02% for TN and TP, respectively. (4) Moreover, the event mean concentration (EMC) values of different land use types have been derived based on the SWAT model, which are key parameters for the application of the long-term hydrological impact assessment (L-THIA) model. Therefore, this study facilitates applying the L-THIA model to other similar data-deficient catchments in view of its relatively lower data requirement.

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Section: Rationality Of Simulation Resultscontrasting

confidence: 87%

Section: Rationality Of Simulation Resultssupporting

confidence: 82%

Section: Rationality Of Simulation Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Integrated Application of SWAT and L-THIA Models for Nonpoint Source Pollution Assessment in Data Scarce Regions

Zhang,

Chen,

Dai

et al. 2024

Water

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“…Aquatic insect samples were obtained from Winam Gulf of Lake Victoria (Figure 1). Te gulf is a semienclosed bay, with an area of 1400 km 2 on the Kenyan side of the lake [62], which connects to the main lake trough Rusinga channel and extends as a shallow indented bay with a depth of 2-4 m eastwards to Kisumu [63]. Te shoreline is approximately 500 km long with fat sandy or muddy areas, the latter being predominant in sheltered bays.…”

Section: Study Areamentioning

confidence: 99%

Spatial Variations in Aquatic Insect Community Structure in the Winam Gulf of Lake Victoria, Kenya

Misiko,

Bere,

Andika

et al. 2023

International Journal of Ecology

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Background. Aquatic insect community structure is dynamic due to threats by anthropogenic activities coupled with changing climatic conditions. The insect’s survival is dependent on the substrate, water quality, and environmental effects. The changes in water quality influence their distribution and abundance and are reflected in spatial and temporal trends. This study sought to document the effects of spatial variation on aquatic insects in Winam Gulf of Lake Victoria, Kenya. Materials and Methods. Systematic random design was used in sampling, and water quality parameters were assessed. Insects were sampled by profundal lake procedure, pooled, sorted, and identified based on the morphological approach and diversity indices analyzed. The relationship between insects and water quality was established. Results. Statistical homogeneity in water quality parameters was documented with the exception of nitrates, nitrites, soluble reactive phosphorus, ammonium, and silicates, which displayed significant variation at p < 0.05 . A total of 383 individual insects representing 19 species, 19 genera, 16 families, and six orders were obtained from Winam Gulf. Hemiptera, Ephemeroptera, and Diptera were the most predominant orders, respectively. Chironomus spp. and Ablebesmyia spp. were representatives of the Chironomidae family. Species distribution and water quality were determined using cluster analysis (CA) and conical correspondence analysis (CCA). Conclusion. The findings of this study demonstrated that spatial variations were associated with change in water quality and had a corresponding influence on insect community structure.

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Spatial distribution of non-point source pollution from total nitrogen and total phosphorous in the African city of Mwanza (Tanzania)

Zong

Chen

Kattel

et al. 2023

Front. Environ. Sci.

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Rapid urbanization has caused widespread environmental pollution in Africa, restricting sustainable development programs. Today, non-point source pollution has become a major threat to many African cities. In this study, we have classified urban land use followed by the identification of urban functional areas based on multi-source data. We have then evaluated non-point source pollution based on nitrogen and phosphorus loads at a spatial scale in Mwanza city (Tanzania). We have estimated the spatial distribution of total nitrogen (TN) and total phosphorus (TP) loads at a scale of 1 square kilometer grid. The results show that ① the built-up area of the city was identified as 28.9 km2, accounting for 6.8% of the total area of the city. The area of informal settlements was 56.9 km2, accounting for 13.4% of the total area of the city. About 90.38% of 2.41×105 kg of the total TN load and 87.23% of 4.00×104 kg of the total TP load in the city were derived from the informal settlements alone in 2020. ② The average load intensities of TN and TP in Mwanza city were 6.90 kg·hm-2·yr-1 and 1.14 kg·hm-2·yr-1, respectively. The average TN and TP intensities in Mwanza city were slightly higher than the average TN and TP load intensities in the Lake Victoria basin. However, given the high population density of the Mwanza city area, the average TN and TP intensities were found to be consistent. ③ The TN and TP pollution loads were relatively concentrated in the inner urban area, including the lower reaches of the Mirongo River basin, the eastern side of the Nyamagana Peninsula, and the lakeside area extending north and south from the peninsula, and gradually decreased toward the city’s outskirts. We propose that the identified riparian areas in our study should be prioritized as potentially key construction zones for pollution treatment plant facilities and urban renewal pilot programs for restraining the widespread informal settlements. This study contributes to the development of an innovative urban non-point source pollution control measure, which may be applicable to low-income countries in Africa and elsewhere.

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Modeling of runoff pollution load in a data scarce situation using swat, Sondu watershed, Lake Victoria Basin

Abstract: Sondu watershed is one of the major rivers flowing to Winam Gulf on the Kenyan side of Lake

Cited by 3 publications

References 10 publications

Integrated Application of SWAT and L-THIA Models for Nonpoint Source Pollution Assessment in Data Scarce Regions

Integrated Application of SWAT and L-THIA Models for Nonpoint Source Pollution Assessment in Data Scarce Regions

Spatial Variations in Aquatic Insect Community Structure in the Winam Gulf of Lake Victoria, Kenya

Spatial distribution of non-point source pollution from total nitrogen and total phosphorous in the African city of Mwanza (Tanzania)

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