scholarly journals Drivers of Watershed Degradation and its Implications on Potable Water Supply in the Menchum River Basin of Cameroon

2019 ◽  
Vol 6 (4) ◽  
pp. p483
Author(s):  
Cordelia Givecheh Kometa
Keyword(s):  
Land Use ◽  
River Basin ◽  
Potable Water ◽  
Overland Flow ◽  
Planning Process ◽  
Global Climate ◽  
Population Pressure ◽  
Anthropogenic Factors ◽  
Water Yield ◽  
Watershed Degradation

Current anthropogenic stresses on natural systems in the Menchum River Basin of Cameroon have remained the major contributors to watershed degradation in the region. This study examines the various drivers of watershed degradation in the basin and their implications for potable water supplies. It gives an assessment of the spatio-temporal changes in land use and its effect on water yield and erosion rates, and also assesses the probable interaction of global climate change and anthropogenic factors on water yield. The study employed a combination of field observations, informal interviews and the consultation of secondary data to investigate these drivers. The data obtained were analysed using descriptive statistical techniques, and presented in both qualitative and quantitative terms. A series of maps and photographs were used to portray land use and land cover changes in the basin. It was observed that population pressure and incompatible land use changes account for watershed degradation in the basin. The implications have been increased runoff and surface overland flow, a reduction in potable water quality and quantity resulting to frequent water cuts. The paper recommends the sustainable management of watersheds whereby, all critical components need to be included into the planning process for the watercourses and their catchments.

scholarly journals Estimating Soil Water Susceptibility to Salinization in the Mekong River Delta Using a Modified DRASTIC Model

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1636
Author(s):  
Thanh N. Le ◽  
Duy X. Tran ◽  
Thuong V. Tran ◽  
Sangay Gyeltshen ◽  
Tan V. Lam ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Water ◽  
Management Practices ◽  
Global Climate ◽  
Anthropogenic Activities ◽  
Rapid Development ◽  
Anthropogenic Factors ◽  
Drastic Model ◽  
River Catchment ◽  
Modified Drastic

Saltwater intrusion risk assessment is a foundational step for preventing and controlling salinization in coastal regions. The Vietnamese Mekong Delta (VMD) is highly affected by drought and salinization threats, especially severe under the impacts of global climate change and the rapid development of an upstream hydropower dam system. This study aimed to apply a modified DRASTIC model, which combines the generic DRASTIC model with hydrological and anthropogenic factors (i.e., river catchment and land use), to examine seawater intrusion vulnerability in the soil-water-bearing layer in the Ben Tre province, located in the VMD. One hundred and fifty hand-auger samples for total dissolved solids (TDS) measurements, one of the reflected salinity parameters, were used to validate the results obtained with both the DRASTIC and modified DRASTIC models. The spatial analysis tools in the ArcGIS software (i.e., Kriging and data classification tools) were used to interpolate, classify, and map the input factors and salinization susceptibility in the study area. The results show that the vulnerability index values obtained from the DRASTIC and modified DRASTIC models were 36–128 and 55–163, respectively. The vulnerable indices increased from inland districts to coastal areas. The Ba Tri and Binh Dai districts were recorded as having very high vulnerability to salinization, while the Chau Thanh and Cho Lach districts were at a low vulnerability level. From the comparative analysis of the two models, it is obvious that the modified DRASTIC model with the inclusion of a river or canal network and agricultural practices factors enables better performance than the generic DRASTIC model. This enhancement is explained by the significant impact of anthropogenic activities on the salinization of soil water content. This study’s results can be used as scientific implications for planners and decision-makers in river catchment and land-use management practices.

scholarly journals Analysis of the Changes in the Water Yield Coefficient over the Past 50 Years in the Huang-Huai-Hai River Basin, China

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Xiaoqing Shi ◽  
Tianling Qin ◽  
Denghua Yan ◽  
Ruochen Sun ◽  
Shuang Cao ◽  
...  
Keyword(s):  
Land Use ◽  
River Basin ◽  
Vegetation Index ◽  
Yellow River ◽  
Rate Of Change ◽  
Vegetation Coverage ◽  
Water Yield ◽  
Yield Coefficient ◽  
Positive Trend ◽  
Land Use Types

This study analysed the temporal and spatial changes in the water yield coefficient (WYC), which represents the ratio of the gross amount of water resources to precipitation. Factors such as precipitation, rainstorm days, rainless days, vegetation cover change, and land use/cover change were considered to determine the causes of these changes. The results led to the following conclusions: (1) The average annual WYC of the Huang-Huai-Hai River Basin is between 0.03 and 0.58, with an average value of 0.17, which is smaller than the national average WYC of 0.4. (2) Temporally, the WYC varied slightly, with the western part showing a negative trend and the eastern part showing a positive trend. The WYC is positively correlated with precipitation, rainstorm days, and the normalized difference vegetation index (NDVI) and negatively correlated with rainless days. However, a slower change in NDVI produced a faster change in WYC. In areas with land use types exhibiting a large evapotranspiration decrease, the rate of change in the WYC increased. (3) Spatially, the distribution is fairly regular, exhibiting a gradual increase from the northern part of the Yellow River Basin (WYC < 0.1) to the surrounding areas. When the WYC is correlated with precipitation, rainstorm days, rainless days, and NDVI, the R2 values of the linear fitting results are 0.98, 0.91, 0.96, and 0.73, respectively. The WYC is positively correlated with precipitation, rainstorm days, and vegetation coverage and negatively correlated with rainless days, but the correlation coefficient is greatly influenced by the precipitation characteristics and land use types. In areas featuring high proportions of land use types associated with high evapotranspiration, the average WYC is low.

scholarly journals Application of SWAT model to Assess Land Use and Climate Changes Impacts on Hydrology of Nam Rom River Basin in Vietnam

2020 ◽  
Author(s):  
Son Ngo ◽  
Huong Hoang ◽  
Phuong Tran ◽  
Loc Nguyen
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Ground Water ◽  
River Basin ◽  
Climate Changes ◽  
Swat Model ◽  
Land Use Changes ◽  
Hydrological Processes ◽  
Water Yield ◽  
Hydrological Process

Land use/land cover (LULC) and climate changes are two main factors directly affecting hydrologic conditions. However, very few studies in Vietnam have investigated changes in hydrological process under the impact of climate and land use changes on a basin scale. The objective of this study is to assess the individual and combined impacts of land use and climate changes on hydrological processes for the Nam Rom river basin, Northwestern Viet Nam using Remote Sensing (RS) and Soil and Water Assessment Tools (SWAT) model. SWAT model was used for hydrological process simulation. Results indicated that SWAT proved to be a powerful tool in simulating the impacts of land use and climate change on catchment hydrology. The change in historical land use between 1992 and 2015 strongly contributed to increasing hydrological processes (ET, percolation, ground water, and water yield), whereas, climate change led to significant decrease of all hydrological components. The combination of land use and climate changes significantly reduced surface runoff (-16.9%), ground water (-5.7%), water yield (-9.2%), and sediment load (-4.9%). Overall climatic changes had more significant effect on hydrological components than land use changes in the Nam Rom river basin during the 1992&ndash;2015. Under impacts of projected land use and climate change scenarios in 2030 on hydrological process of the upper Nam Rom river basin indicate that ET and surface flow are more sensitive to the changes in land use and climate in the future. In conclusion, the findings of this study will basic knowledge of the effects of climate and land-use changes on the hydrology for future development of integrated land use and water management practices in Nam Rom river basin.

scholarly journals Modeling the supply, demand, and stress of water resources using ecosystem services concept in Sirvan River Basin (Kurdistan-Iran)

2021 ◽  
Author(s):  
Jahanbakhsh Balist ◽  
Bahram Malekmohammadi ◽  
Hamid Reza Jafari ◽  
Ahmad Nohegar ◽  
Davide Geneletti
Keyword(s):  
Land Use ◽  
Ecosystem Services ◽  
Water Resources ◽  
River Basin ◽  
Water Scarcity ◽  
Supply And Demand ◽  
Stress Index ◽  
Water Yield ◽  
Yield Model ◽  
Software Environment

Abstract Water resources modeling can provide valuable information to planners. In this respect, water yield is an ecosystem service with significant roles in the sustainability of societies and ecosystems. The present study aimed to model the supply and demand of water resources and identify their scarcity and stress in the Sirvan river basin. For this purpose, we employed the ecosystem services concept as new thinking in earth sciences and using soil, climate, and land use data. Firstly, the Landsat satellite images of 2019 were prepared after different corrections, and the land use map was produced. Then, precipitation, evapotranspiration, root restricting layer depth, and evapotranspiration coefficients of the land uses were prepared and modeled in InVEST 3.8.9 software environment. The findings indicated that the water yield in this river basin is 5,381 million m3, with sub-basins 5, 11, and 1 having the highest water yield per year and sub-basin 2 having the lowest water yield. Moreover, sub-basins 5 and 11 had the highest water consumption. Based on the estimated water scarcity and stress index, sub-basin 8 has experienced water scarcity and sub-basin 4 water stress. We conclude that applying the InVEST Water Yield model to assess water resource status at the basin and sub-basins level can provide suitable results for planning.

scholarly journals The effects of rainfall characteristics and land use and cover change on runoff in the Yellow River basin, China

2021 ◽  
Vol 69 (1) ◽  
pp. 29-40
Author(s):  
CaiHong Hu ◽  
Guang Ran ◽  
Gang Li ◽  
Yun Yu ◽  
Qiang Wu ◽  
...  
Keyword(s):  
Land Use ◽  
River Basin ◽  
Yellow River ◽  
Yellow River Basin ◽  
Vegetation Coverage ◽  
Water Yield ◽  
The Yellow River ◽  
Rainfall Events ◽  
The Yellow River Basin ◽  
The Impact

AbstractThe changes of runoff in the middle reaches of the Yellow River basin of China have received considerable attention owing to their sharply decline during recent decades. In this paper, the impacts of rainfall characteristics and land use and cover change on water yields in the Jingle sub-basin of the middle reaches of the Yellow River basin were investigated using a combination of statistical analysis and hydrological simulations. The Levenberg Marquardt and Analysis of Variance methods were used to construct multivariate, nonlinear, model equations between runoff coefficient and rainfall intensity and vegetation coverage. The land use changes from 1971 to 2017 were ascertained using transition matrix analysis. The impact of land use on water yields was estimated using the M-EIES hydrological model. The results show that the runoff during flood season (July to September) decreased significantly after 2000, whereas slightly decreasing trend was detected for precipitation. Furthermore, there were increase in short, intense, rainfall events after 2000 and this rainfall events were more conducive to flood generation. The “Grain for Green” project was carried out in 1999, and the land use in the middle reaches of the Yellow River improved significantly, which make the vegetation coverage (Vc) of the Jingle sub-basin increased by 13%. When Vc approaches 48%, the runoff coefficient decreased to the lowest, and the vegetation conditions have the greatest effect on reducing runoff. Both land use and climate can change the water yield in the basin, but for areas where land use has significantly improved, the impact of land use change on water yield plays a dominant role. The results acquired in this study provide a useful reference for water resources planning and soil and water conservation in the erodible areas of the middle reaches of the Yellow River basin.

scholarly journals Water Yield Variation due to Forestry Change in the Head-Water Area of Heihe River Basin, Northwest China

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Feng Wu ◽  
Jinyan Zhan ◽  
Jiancheng Chen ◽  
Chao He ◽  
Qian Zhang
Keyword(s):  
Land Use ◽  
Land Cover ◽  
River Basin ◽  
Heihe River Basin ◽  
Water Yield ◽  
Heihe River ◽  
Observation Data ◽  
Hydrological Process ◽  
Hydrological Simulation ◽  
Land Cover Data

Understanding the effects of forestation on the hydrological process is crucial to protecting water resources. In this study, the upstream Heihe River Basin is selected as the study area, which is the water source area of the whole basin. The grassland and forest are the main land use types, the proportion of which in the total land area is 21% and 50%, respectively. Firstly, a scenario of forestation was designed with the actual land cover data in 1980. Then a scenario with simulated land cover data in 1980 was established, in which the forest area increases by 12%. Thereafter a hydrological simulation was carried out with the actual and simulated land cover maps and the climate observation data during 1980–2010. The results suggested that the total water yield increased by 12.57 mm under the scenario with land use change during 1980–2010 compared with the simulation with the actual land cover in 1980. However, the results also indicated that the surface runoff reduced by 22.17 mm during the same period, indicating the forest land has “sponge” effects on the water resource in the mountainous watershed. These results may provide important information that supports operational practices, such as forest regeneration programs and watershed restoration.

scholarly journals River Basin Hydrological Balance Evaluation in Term of the Land Use Change Impact

2018 ◽  
Vol 21 (1) ◽  
pp. 5-9
Author(s):  
Beáta Novotná ◽  
Ján Čimo ◽  
Branislav Chvíla ◽  
Gabriela Pozníková
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Water Balance ◽  
River Basin ◽  
Slovak Republic ◽  
Vegetation Type ◽  
Global Climate ◽  
Climatic Conditions ◽  
Change Effect ◽  
Dry Conditions

Abstract Assessment of the land use impact on the processes of water balance in the river basin should be an indispensable part of integrated river basins management. This paper compares climatic conditions occurring during the long-term period (1951-1980), following the situation immediately after dry conditions (1993-1999) and extremely rainy dates (2009-2012) with emphasis to estimate the runoff components in the Žitava river basin: the Obyce sub-catchment, situated in its upper part (74.5 km2) in the Slovak Republic. Modelling of the land use change effect on the total hydrology balance of the river basin characteristics was performed using the hydrological model WaSiM-ETH. The model was applied to evaluate the vegetation type influence and the water balance change in the presently mostly forested river basin (1), altering its replacement by the permanent grasses (2) and bushes (3), with emphasis to different total water balance characteristics change. The present state land use data were taken from the Corine Land Cover of the Slovak Republic. Model results show that actual evapotranspiration would decrease from -1.3% in case of bushes in 2009 up to -32.5% in case of grass in 2011. However, 13.3% rise was considered for bushes in 2010. Total annual discharge shows its increment in all observed changes from 5.9% for bushes in 2010 up to 65.3% for grass in 2012. Only in case of bushes in 2011 there was observed slight decrease of about -3.1%. Regarding the very expected land use change, especially in connection with the ongoing global climate change, the estimation of the hydrology balance components is of utmost significance.

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