Assessing the Hydrology of a Data-Scarce Tropical Watershed Using the Soil and Water Assessment Tool: Case of the Little Ruaha River Watershed in Iringa, Tanzania

Mbungu, Winfred; Kashaigili, Japhet J.

doi:10.4236/ojmh.2017.72004

Cited by 21 publications

(11 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was found that the runoff Soil Conservation Service runoff curve number (CN2) was the most sensitive parameter followed by Available Water Capacity of the Soil Layer (SOL_AWC), Threshold depth of water in the shallow aquifer required for return flow to occur (GWQWN), Groundwater Delay Time (GW_DELAY), Base Flow Alpha Factor (ALPHA_BF) and Soil Evaporation Compensation Factor (ESCO). These results are in agreement with the study reported by [11] that mentioned parameters are most sensitive to flow prediction. The most sensitive parameters were then considered for model calibration.…”

Section: Sensitive Parameterssupporting

confidence: 94%

Impact of Land Use and Land Cover Changes on Surface Runoff and Sediment Yield in the Little Ruaha River Catchment

Chilagane¹,

Kashaigili²,

Mutayoba³

et al. 2021

OJMH

Self Cite

View full text Add to dashboard Cite

Little Ruaha River catchment (6370 Km 2 ) in the Southern Agricultural Growth Corridor of Tanzania (SAGCOT), is one of the country's most significant waterways due to its ecological composition and economic value. Regardless of its ecological and economical value, the regional hydrologic condition has been tremendously affected due to land uses alteration, influenced by different socio-economic factors. This study aimed to understand the associated impacts of the present Land Use Land Cover (LULC) change on the surface runoff and sediment yield in the Little Ruaha River Catchment. Hydrological modelling using Soil and Water Assessment Tool (SWAT Model) was done to quantify the impact of land use and land cover dynamics on catchment water balance and sediment loads. The calibration and validation of the SWAT model were performed using sequential uncertainty fitting (SUFI-2). The results showed that, for the given LULC change, the average annual surface runoff increased by 2.78 mm while average annual total sediment loading increased by 3.56 t/ha, the average annual base flow decreased by 2.68 mm, ground water shallow aquifer recharge decreased from 2.97 mm and a slight decrease in average annual ground water deep aquifer recharge by 0.14 mm. The model predicts that in the future, there will be a further increase in both surface runoff and sediment load. Such changes, increased runoff generation and sediment yield with decreased base flow have implications on the sustenance flow regimes particularly the observed reduced dry season river flow of the Little Ruaha River, which in turn cause adverse impacts to the biotic component of How to cite this paper: Chilagane, N.A.,

show abstract

Section: Sensitive Parameterssupporting

confidence: 94%

Impact of Land Use and Land Cover Changes on Surface Runoff and Sediment Yield in the Little Ruaha River Catchment

Chilagane¹,

Kashaigili²,

Mutayoba³

et al. 2021

OJMH

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is worth to note that the surface flow contributions of the Great Ruaha, Little Ruaha and Kisigo rivers to the total inflow to the Mtera reservoir are estimated as 56%, 18% and 26%, respectively (Kashaigili et al, 2005). Also, Mbungu and Kashaigili (2017) revealed reduction and changes of streamflows with time and therefore more water shortages are expected on the planned water development and related ecosystems in the Little Ruaha catchment. Moreover, Munkyala (2017) indicated that irrigation is the big water user in the Ndembera catchment, which accounts for about 77% of the all water demands in the catchment.…”

Section: Discussionmentioning

confidence: 97%

Assessment of Surface Water Resources in Great Ruaha River Sub-Basin Tanzania: Application of WEAP Model for Water Allocation and Utilization Impacts Analysis

Gervas

Mulungu

Nobert

2019

TJET

View full text Add to dashboard Cite

The Great Ruaha River (GRR) sub-basin is one of the most important waterways in Tanzania as it supports important economic activities. The sub-basin is progressively faced with an inevitable situation of increasing water demand among competing users while the quantity and quality of water is diminishing. The focus of this study was to assess allocation of existing (2012) and future (up to 2025) quantities of surface water in the GRR sub-basin with consideration of priorities given in the Tanzania Water Resources Management Act, 2009 in the order: domestic, environment, agriculture, livestock and non-domestic. Simulation of water allocation scenarios of irrigation expansion (IE) and implementation of environmental flow requirements (EWD) and their impacts on met demands was done by using WEAP model. Results showed that under current and future conditions, available streamflows are sufficient for the first two water use priorities. Implementation of EWD and IE scenarios will change demands in comparison with reference scenario by 80%, -38% and 45% and shortages by 147%, 123% and 13% in Little Ruaha, Ndembera and Kisigo catchments respectively. To eliminate water shortages, construction of reservoirs, use of alternative supply sources (especially in agriculture) and water demand management measures are recommended.

show abstract

“…The average annual precipitation is around 685 mm (Hijmans et al 2005). The mean annual temperature in the scene ranges from 18°C at higher altitudes to 28°C (Mbungu and Kashaigili 2017). Elevation ranges from 698 m to over 2300 m (Mbungu and Kashaigili 2017).…”

Section: Methodsmentioning

confidence: 99%

Environmental controls on Landsat‐derived phenoregions across an East African megatransect

2020

View full text Add to dashboard Cite

Semiarid and savanna‐type (SAST) ecosystems in East Africa have unique plant species compositions and characteristics that make quantifying this biome's seasonality and interannual variability difficult. Phenoregion classification offers a way to use seasonality of vegetation growth to help understand the phenological spatial patterns of complex landscapes. Here, we used Normalized Difference Vegetation Index (NDVI) time series from Landsat 8 to map phenoregions in scenes centered around national parks from Mt. Kenya National Park (Kenya) to Limpopo National Park (Mozambique). We then assessed whether landscape‐scale controls on phenology are consistent across the region or whether they vary across this latitudinal gradient. We compared our phenoregion maps to MODIS Land Cover and geology, and we used multinomial logistic regression to determine the role that elevation, slope, aspect, and geology play in driving phenological differences. The sites' phenoregions showed no unique land cover composition, suggesting that MODIS land cover does not capture the subtle variations identified in phenoregion analysis. Multinomial logistic regression showed that geographic trend (x‐ and y‐directions) was a strong predictor in four of the five landscapes and that, depending on the scene, geology, elevation, or aspect was a strong secondary predictor. Using seasonality of the NDVI time series to generate phenoregions provides different and, in some cases, more ecologically relevant information, compared to vegetation maps that use only land cover from a single season or time period to generate ecoregions. With a significant population of humans and animals that live in and depend on SAST ecosystems, it is important to better understand vegetation processes and factors that affect them as climate change becomes an increasingly pertinent issue in dry systems.

show abstract

Assessing the Hydrology of a Data-Scarce Tropical Watershed Using the Soil and Water Assessment Tool: Case of the Little Ruaha River Watershed in Iringa, Tanzania

Cited by 21 publications

References 47 publications

Impact of Land Use and Land Cover Changes on Surface Runoff and Sediment Yield in the Little Ruaha River Catchment

Impact of Land Use and Land Cover Changes on Surface Runoff and Sediment Yield in the Little Ruaha River Catchment

Assessment of Surface Water Resources in Great Ruaha River Sub-Basin Tanzania: Application of WEAP Model for Water Allocation and Utilization Impacts Analysis

Environmental controls on Landsat‐derived phenoregions across an East African megatransect

Contact Info

Product

Resources

About