scholarly journals Evaluation of the impacts of land use/cover changes on water balance of Bilate watershed, Rift valley basin, Ethiopia

2021 ◽  
Author(s):  
Mulatu Abayicho Sulamo ◽  
Asfaw Kebede Kassa ◽  
Negash Tessema Roba
Keyword(s):  
Land Use ◽  
Water Balance ◽  
Surface Runoff ◽  
Base Flow ◽  
Decision Makers ◽  
Environmental Response ◽  
Watershed Hydrology ◽  
Design Strategies ◽  
Policy Makers ◽  
Urban Planning And Management

Abstract Land use/cover change is one of the responsible factors for changing the water balance of the watershed by altering the magnitude of surface runoff, interflow, base flow, and evapotranspiration. This study was aimed at evaluating the impacts of land use/cover change on the water balance of Bilate watershed between 1989, 2002, and 2015. The water balance simulation model (WaSiM) was used to access the impacts of land use/cover change on water balance. The model was calibrated (1989–2003) and validated (2007–2015) using the streamflow of at Bilate Tena gauging station. The result of land-use dynamics showed land use/cover change has a significant impact on the water balance of the watershed like on runoff production, base flow, interflow, evapotranspiration, and total simulation flow. In the study watershed, the change in total simulated flow increased by 77.83%, and surface runoff, interflow, and base flow increased by 80.23%, 75.69%, and 87.79% respectively and evapotranspiration decreased by 6% throughout the study period (1989–2015). The results obtained from this study revealed that the watershed is under the land/cover change that shows its impacts on hydrological processes and water balance. Thus, effective information regarding the environmental response of land use/cover, change is important to hydrologists, land-use planners, watershed management, and decision-makers for sustainable water resource projects and ecosystem services. Therefore, the policy-makers, planners, and stakeholders should design strategies to ensure the sustainability of the watershed hydrology for the sake of protecting agricultural activities, and urban planning and management systems within the watershed area.

scholarly journals Effect of deforestation on watershed water balance: hydrological modelling-based approach / Vplyv odlesnenia na vodnú bilanciu povodia: prístup na báze hydrologického modelovania

2015 ◽  
Vol 61 (2) ◽  
pp. 89-100 ◽  
Author(s):  
Tomáš Hlásny ◽  
Dušan Kočický ◽  
Martin Maretta ◽  
Zuzana Sitková ◽  
Ivan Barka ◽  
...  
Keyword(s):  
Land Cover ◽  
Water Balance ◽  
Surface Runoff ◽  
Forest Cover ◽  
Base Flow ◽  
Peak Discharge ◽  
Precipitation Event ◽  
Total Precipitation ◽  
Watershed Hydrology ◽  
Water Balance Components

Abstract Changes in land cover, including deforestation, can have significant effect on watershed hydrology. We used hydrological model with distributed parameters to evaluate the effect of simulated deforestation on water balance components in the watershed Ulička (97 km2, 84.3% forest cover) located in the eastern Slovakia. Under the current land cover, average interception accounted for 21.1% of the total precipitation during the calibration period 2001-2013. Most of the precipitation (77%) infiltrated into the soil profile, and less than half of this amount percolated into the ground water aquifer. The surface runoff accounted for 1.2% of the total precipitation only, while the interflow accounted for ca. 12%. The largest proportion of the precipitation contributed to the base flow (23%). Watershed`s deforestation induced significant decrease in the interception and evapotranspiration (by 76% and 12%, respectively). At the same time, total runoff, surface runoff, interflow and base flow increased by 20.4, 38.8, 9.0 and 25.5%, respectively. Daily discharge increased by 20%. The deforestation significantly increased peak discharge induced by a simulated extreme precipitation event with the recurrence interval of 100 years. In the deforested watershed, the peak discharge was higher by 58% as compared with the current land cover. Peak discharge occurred in 432 minutes with the current land cover and in 378 minutes with deforestation, after the precipitation event had started. The presented assessment emphasized the risk of adverse effect of excessive deforestation on watershed hydrology. At the same time, the developed model allows testing the effect of other land cover scenarios, and thus supports management in the investigated watershed.

scholarly journals Modelling monthly runoff generation processes following land use changes: groundwater–surface runoff interactions

2004 ◽  
Vol 8 (5) ◽  
pp. 903-922 ◽  
Author(s):  
M. Bari ◽  
K. R. J. Smettem
Keyword(s):  
Land Use ◽  
Water Balance ◽  
Surface Runoff ◽  
Land Use Changes ◽  
Annual Rainfall ◽  
Rainfall Runoff ◽  
Runoff Generation ◽  
Mean Annual Rainfall ◽  
Monthly Runoff ◽  
Stream Bed

Abstract. A conceptual water balance model is presented to represent changes in monthly water balance following land use changes. Monthly rainfall–runoff, groundwater and soil moisture data from four experimental catchments in Western Australia have been analysed. Two of these catchments, "Ernies" (control, fully forested) and "Lemon" (54% cleared) are in a zone of mean annual rainfall of 725 mm, while "Salmon" (control, fully forested) and "Wights" (100% cleared) are in a zone with mean annual rainfall of 1125 mm. At the Salmon forested control catchment, streamflow comprises surface runoff, base flow and interflow components. In the Wights catchment, cleared of native forest for pasture development, all three components increased, groundwater levels rose significantly and stream zone saturated area increased from 1% to 15% of the catchment area. It took seven years after clearing for the rainfall–runoff generation process to stabilise in 1984. At the Ernies forested control catchment, the permanent groundwater system is 20 m below the stream bed and so does not contribute to streamflow. Following partial clearing of forest in the Lemon catchment, groundwater rose steadily and reached the stream bed by 1987. The streamflow increased in two phases: (i) immediately after clearing due to reduced evapotranspiration, and (ii) through an increase in the groundwater-induced stream zone saturated area after 1987. After analysing all the data available, a conceptual monthly model was created, comprising four inter-connecting stores: (i) an upper zone unsaturated store, (ii) a transient stream zone store, (ii) a lower zone unsaturated store and (iv) a saturated groundwater store. Data such as rooting depth, Leaf Area Index, soil porosity, profile thickness, depth to groundwater, stream length and surface slope were incorporated into the model as a priori defined attributes. The catchment average values for different stores were determined through matching observed and predicted monthly hydrographs. The observed and predicted monthly runoff for all catchments matched well with coefficients of determination (R2) ranging from 0.68 to 0.87. Predictions were relatively poor for: (i) the Ernies catchment (lowest rainfall, forested), and (ii) months with very high flows. Overall, the predicted mean annual streamflow was within ±8% of the observed values. Keywords: monthly streamflow, land use change, conceptual model, data-based approach, groundwater

scholarly journals Land Use Projections Under Alternative Policies: A Transition Matrix Approach

1979 ◽  
Vol 8 (2) ◽  
pp. 87-99 ◽  
Author(s):  
Bruce E. Lindsay ◽  
Daniel L. Dunn
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Land Use Planning ◽  
Current Trend ◽  
Land Use Policy ◽  
Decision Makers ◽  
Policy Makers ◽  
The Past ◽  
Accelerated Growth ◽  
Insight Into

As a result of accelerated growth during the past decade, land use change over time and its accompanying problems represents a policy area germane to New Hampshire. Accurate projections of the future pattern of land use would be helpful to decision makers responsible for land use policy. Such projections could assist policy makers either directly in formulating land use plans or indirectly in justifying the need (or lack of need) for overt land use planning. Future projections, based upon various alternative land use policy scenarios, will increase the quantitative supply of information to decision makers in a two-fold manner. First, such estimates provide an insight into the current trend in land use mix and, secondly, give an overview of what impacts various policies directly have upon land use change.

scholarly journals Impact of Arable Land to Grassland Conversion on the Vegetation-period Water Balance of a Small Agricultural Catchment (Němčický Stream)

2010 ◽  
Vol 5 (No. 4) ◽  
pp. 128-138 ◽  
Author(s):  
P. Kovář ◽  
D. Vaššová
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Water Balance ◽  
Surface Runoff ◽  
Arable Land ◽  
Vegetation Period ◽  
Water Balance Components ◽  
Total Runoff ◽  
Grassland Conversion ◽  
Pronounced Reduction

This paper presents results of decadal (10-day) water balance simulations for the vegetation periods (April to October) of 2001 (normal year), 2002 (wet year) and 2003 (dry year) in the Němčick&yacute; Stream experimental catchment (3.52 km<sup>2</sup>). The catchment is a typical agricultural area with a large extent of arable land. This paper shows that the model used (WBCM) is capable of reliably simulating decadal water balance components for the actual land use. The same model is then used to estimate water balance changes brought about when 10% of arable land has been transformed into permanent grassland. It is shown that this land use change results in a pronounced reduction of surface runoff and an increase in subsurface storage over the vegetation periods of all three years. The vegetation period groundwater runoff was only enhanced in the wet year, while the total runoff was reduced in all three years.&nbsp;

scholarly journals Land Use/Cover Change and their Impacts on Streamflow in Kikuletwa Catchment of Pangani River Basin, Tanzania

2019 ◽  
Vol 38 (2) ◽  
pp. 171-192
Author(s):  
Upendo E. Msovu ◽  
Deogratias M.M. Mulungu ◽  
Joel K. Nobert ◽  
Henry Mahoo
Keyword(s):  
Land Use ◽  
Assessment Tool ◽  
Landsat Imagery ◽  
Swat Model ◽  
Base Flow ◽  
Percentage Increase ◽  
Policy Makers ◽  
Future Prediction ◽  
Water Assessment

Streamflow perturbation is highly prevalent in Kikuletwa catchment. However, little is known concerning land use/cover change (LULCC) with regard to streamflow perturbation in the catchment. This study aims to detect the historical and predict future LULCC and assess their impacts on streamflow amounts using the Soil and Water Assessment Tool (SWAT) model. Supervised classification of Landsat imagery data for 1985, 2000 and 2015 years was done in ERDAS 14 Imagine software. Future prediction of LULCC was done using Module for Land Use Change Evaluation (MOLUSCE) tool, a QGIS plug-in. An accuracy ranging from 79% to 82% was obtained for all steps. The results revealed that, from 1985 to 2000; 1985 to 2015; 1985 to 2030 and 1985 to 2050 the percentage of area change in cultivated land is +21.1%; +29.2%; +38.2% and +42.7%, respectively; forest is - 2.3%, -3.1%, -3.8% and -5.8%, respectively; and shrubland is -6.3%, -10%, -15.7% and - 16%, respectively. The performance of SWAT model during calibration were 0.74, 0.75, 0.51 and -0.5% for NSE, R2, RSR and PBIAS, respectively. The impacts of LULCC indicated that, between 1985 to 2000; 1985 to 2015; 1985 to 2030 and 1985 to 2050, the percentage increase in average simulated annual flow is 4.7%, 6.8%, 12.6% and 19.3%, respectively. Surface runoff increased from 25.2 mm (baseline) to 34.5 mm (36.9%); 36.2 mm (42.4%); 41.4 mm (64.3%) and 47.6 mm (88.9%), respectively. Base flow decreased marginally from 82.2 mm (baseline) to 79 mm (-3.8%); 77.8 mm (5.4%); 75.4 mm (-8.3%) and 73.9 mm (- 10.1%), respectively. Thus, apart from climate effects, streamflow perturbation in the catchment is also related to disturbances of catchment influences such as LULCC as revealed in this study. The study is useful for land planners and water resources managers and policy makers in managing resources sustainably. 

scholarly journals A daily salt balance model for representing stream salinity generation process following land use change

2005 ◽  
Vol 2 (4) ◽  
pp. 1147-1183
Author(s):  
M. A. Bari ◽  
K. R. J. Smettem
Keyword(s):  
Land Use ◽  
Water Balance ◽  
Surface Runoff ◽  
Preferential Flow ◽  
Water Movement ◽  
Water Balance Model ◽  
Salt Flux ◽  
Balance Model ◽  
Generation Process ◽  
Salt Balance

Abstract. We developed a coupled salt and water balance model to represent the stream salinity generation process following land use changes. The conceptual model consists of three main components with five stores: (i) Dry, Wet and Subsurface Stores, (ii) saturated Groundwater Store and (iii) a transient Stream zone Store. The Dry and Wet Stores represent the salt and water movement in the unsaturated zone and also the near-stream dynamic saturated areas, responsible for the generation of salt flux associated with surface runoff and interflow. The unsaturated Subsurface Store represents the salt bulge and the salt fluxes. The Groundwater Store comes into play when the groundwater level is at or above the stream invert and quantifies the salt fluxes to the Stream zone Store. In the stream zone module, we consider a "free mixing" between the salt brought about by surface runoff, interflow and groundwater flow. Salt accumulation on the surface due to evaporation and its flushing by initial winter flow is also incorporated in the Stream zone Store. The salt balance model was calibrated sequentially following successful application of the water balance model. Initial salt stores were estimated from measured salt profile data. We incorporated two lumped parameters to represent the complex chemical processes like diffusion-dilution-dispersion and salt fluxes due to preferential flow. The model has performed very well in simulating stream salinity generation processes observed at Ernies and Lemon experimental catchments in south west of Western Australia. The simulated and observed stream salinity and salt loads compare very well throughout the study period. The model slightly over predicted annual stream salt load by 6.2% and 6.8%, with R2 of 0.95 and 0.96 for Ernies and Lemon catchment, respectively.

scholarly journals Towards the response of water balance to sugarcane expansion in the Rio Grande Basin, Brazil

2013 ◽  
Vol 10 (5) ◽  
pp. 5563-5603 ◽  
Author(s):  
F. F. Pereira ◽  
M. Tursunov ◽  
C. B. Uvo
Keyword(s):  
Land Use ◽  
Water Balance ◽  
Surface Runoff ◽  
Satellite Images ◽  
Hydrological Model ◽  
Agricultural Research ◽  
Rio Grande ◽  
Land Use Classification ◽  
Rio Grande Basin

Abstract. This study explores the short-, medium- and long-term impacts of expansion of the sugarcane plantation on the water balance of the Rio Grande Basin, Brazil, as estimated by changes in evapotranspiration, soil moisture content and surface runoff calculated by a hydrological model. Twenty years of simulation are made using three different land use scenarios that include the basin area planted with sugarcane in 1993, 2000 and 2007 as estimated from satellite images. Complementary, it is used a scenario for sugarcane plantation defined by the Brazilian Institute for Agricultural Research (EMPRAPA) as all areas suitable for sugarcane cultivation within the Rio Grande Basin. In addition, parameters for sugarcane fields were specifically defined via calibration and validation of the hydrological model for all growth phases based on the annual cycle of sugarcane phenology in the Rio Grande Basin. According to results from the land use classification of satellite images, the expansion of sugarcane fields mostly replaced pasture lands. Modelling results for short-, medium- and long-term clarify that impacts of this expansion depended not only on the amount of areas planted with sugarcane, but also the type of land use replaced, location of the expansion within the basin and regional soil properties. Largest impacts on the water balance are observed if areas located close to headwaters with low soil water capacity are planted with sugarcane. In case all areas suitable for sugarcane plantation, as defined by EMBRAPA will actually be planted, simulations showed that the annual accumulated values of evapotranspiration increase up to 180% while surface runoff is reduced to 20% of the values calculated using a land use scenario from 1993.

scholarly journals Impacts of forestation on the annual and seasonal water balance of a tropical catchment under climate change

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hero Marhaento ◽  
Martijn J. Booij ◽  
Noorhadi Rahardjo ◽  
Naveed Ahmed
Keyword(s):  
Climate Change ◽  
Water Balance ◽  
Surface Runoff ◽  
Assessment Tool ◽  
Swat Model ◽  
Base Flow ◽  
Hydrological Processes ◽  
Severe Drought ◽  
Seasonal Temperature ◽  
The Mean

Abstract Background This study aims to assess the effects of a forestation program and climate change on the annual and seasonal water balance of the Bogowonto catchment (597 km2) in Java, Indonesia. The catchment study is rare example in Indonesia where forestation has been applied at the catchment level. However, since the forestation program has been initiated, evaluations of the program only focus on the planting area targets, while the environmental success e.g., impacts on the hydrological processes have never been assessed. This study used a calibrated Soil and Water Assessment Tool (SWAT) model to diagnose the isolated and combined effects of forestation and climate change on five water balance components, namely streamflow (Q), evapotranspiration (ET), surface runoff (Qs), lateral flow (Ql) and base flow (Qb). Results The results show that from 2006 to 2019, forest cover has increased from 2.7% to 12.8% of the total area, while in the same period there was an increase in the mean annual and seasonal temperature, rainfall, and streamflow. Results of SWAT simulations show that changes in the mean annual and seasonal water balance under the forestation only scenario were relatively minor, while changes were more pronounced under the climate change only scenario. Based on the combined impacts scenario, it was observed that the effects of a larger forest area on the water balance were smaller than the effects of climate change. Conclusions Although we found that forestation program has minor impacts compared to that of climate change on the hydrological processes in the Bogowonto catchment, seasonally, forestation activity has decreased the streamflow and surface runoff during the wet season which may reduce the risk of moderate floods. However, much attention should be paid to the way how forestation may result in severe drought events during the dry season. Finally, we urge the importance of accounting for the positive and negative effects in future forestation programs.

scholarly journals Impact of land-use change on catchment water balance: a case study in the central region of South Africa

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yali E. Woyessa ◽  
Worku A. Welderufael
Keyword(s):  
South Africa ◽  
Land Use ◽  
Water Balance ◽  
Central Region ◽  
Surface Runoff ◽  
Catchment Area ◽  
Forest Cover ◽  
Water Yield ◽  
Climatic Data ◽  
The Mean

AbstractAn assessment study on the impact of land use change through afforestation on catchment water balance was carried out in one of the semi-arid quaternary catchments (C52A) of the Modder River Basin located in the central region of South Africa. The study used ArcGIS and the Soil and Water Assessment Tool (SWAT) to create scenarios of forest cover areas and to simulate the water balance of C52A, respectively. Climatic data from 1993 to 2020 were used to simulate the catchment water balance. The climatic data from 2011 to 2020 were generated using SWAT weather generator while the rest was obtained from South Africa Weather Service at three weather stations located within C52A catchment. In the C52A quaternary catchment it was envisaged to increase forest cover by considering afforestation on pastureland that is found on slopes > 8% and > 3% which created two forest scenarios. The baseline land use [Land use 2000 (LU2000)] which is taken as the base scenario in this study has about 84% of the catchment area covered with pasture. The two forest scenarios created were: forest scenario1 (FRSE1), i.e. conversion of pastureland on slope > 8% to forest, and forest scenario2 (FRSE2), i.e. conversion of pastureland on slope > 3% to forest. The type of forest considered in these scenarios is an evergreen tree, acronym as FRSE by SWAT land use classification. The conversion increased forest cover by 8.3% and 30.5% on FRSE1 and FRSE2, respectively. The result of the water balance of the catchment based on the land use scenarios were compared with the baseline land use scenario (LU2000). The result obtained showed that FRSE1 produced a non-significant change both on the mean monthly surface runoff and water yield compared to LU2000. On the other hand, FRSE2 showed 30% decrease on the mean monthly surface runoff, but increased the mean monthly lateral flow and base flow by 110% and 254%, respectively compared to the LU2000. Thus, in the overall water balance, the mean monthly water yield of the catchment increased by 171% on FRSE2 compared to the LU2000. Although there are considerable number of research reports on the negative effect of forest on catchment water yield, this study showed a significant water yield increase when approximately 30% of the C52A catchment area, which lay on slopes > 3% and covered by grass, was converted to evergreen forest land. The result showed that having a forest cover on a suitable slope range can bring about a positive effect on the total water yield of a catchment. Therefore, this finding is important for catchment management stakeholders and policy-makers when devising land use and water resources management strategies in a catchment.

scholarly journals Analisis Respons Hidrologi untuk Mendukung Perencanaan Pengelolaan Sub-DAS Opak Hulu, Daerah Istimewa Yogyakarta

2020 ◽  
Vol 25 (4) ◽  
pp. 503-514
Author(s):  
Nicko Widiatmoko ◽  
Suria Darma Tarigan ◽  
Enni Dwi Wahjunie
Keyword(s):  
Land Use ◽  
Watershed Management ◽  
Water Conservation ◽  
Surface Runoff ◽  
Swat Model ◽  
Base Flow ◽  
Soil And Water Conservation ◽  
Hydrological Response ◽  
Management Planning ◽  
Soil And Water

Land use change is one of the causes of the decreasing of hydrological function that affects the hydrological response of a watershed. Planning of watershed management needs to be conducted to improve the hydrological function of the watershed. This study aims to determine the hydrological response in supporting watershed management planning in Opak Hulu Watershed. This research was conducted using the Soil and Water Assessment Tool (SWAT) hydrological modeling. The method used included data collection, processing of input data, running of SWAT model, calibration, validation, and the decision of the best watershed management scenarios. The results of the analysis of land use changes in the Opak Hulu Watershed in 2012–2017 had a significant increase in mixed upland agriculture (3.21%) and shrubs (1.43%). Meanwhile, open field (2,31%) and dry land agriculture (1.71%) decreased significantly. Based on the analyzed hydrological scenario, Soil and Water Conservation techniques can decrease the surface runoff and increase the lateral flow and base flow. The scenario is able to decrease the surface runoff by 542.22 mm (27.09%). It increases lateral flow and base flow by 321.82 mm (13.15%) and 797.28 mm (18.32%), respectively. The best watershed management planning with Soil and Water Conservation technique is able to reach Annual Flow Coefficient value to 0,33 (moderate) and 69,85 (moderate) for Flow Regime Coefficient. Keywords: land use, soil and water conservation techniques, SWAT model, watershed

Sign in / Sign up

Export Citation Format

Share Document