scholarly journals Event-based runoff and sediment yield dynamics and controls in the sub-humid headwaters of the Blue Nile, Ethiopia

2021 ◽  
Author(s):  
Habtamu Assaye Deffersha ◽  
Jan Nyssen ◽  
Jean Poesen ◽  
Hanibal Lemma ◽  
Derege Meshesha ◽  
...  
Keyword(s):  
Land Use ◽  
Land Management ◽  
Sediment Yield ◽  
Management Practices ◽  
Sediment Concentration ◽  
Rock Fragment ◽  
Grazing Land ◽  
The Mean ◽  
The Impact ◽  
Runoff And Sediment Yield

Land degradation due to soil erosion presents a challenge for sustainable development. We investigated the impact of land use type and land management practices on runoff and sediment yield dynamics in the northwestern highlands of Ethiopia. The study area included 14 zero-order catchments with a surface area ranging from 324 m2 to 1715 m2. V-notch weirs produced from plastic jars were introduced as measuring alternatives that met local constraints. Runoff depth at the weir was registered at 5-min intervals during two rainy seasons in 2018 and 2019. Rainfall was measured using tipping-bucket rain gauges. Runoff samples were collected in 1-L bottles and suspended sediment concentration (SSC) was determined. The mean event runoff coefficient ranged from 3% for forests to 56% for badlands. Similarly, the mean annual sediment yield (SY) was lowest for forests (0.8 Mg ha-1 yr-1) and highest for badlands (43.4 Mg ha-1 yr-1), with significant differences among land use types (14.8 Mg ha-1 yr-1 in cropland, 5.7 Mg ha-1 yr-1 in grazing land, and 2.9 Mg ha-1 yr-1 in plantations). Soil organic matter (SOM) reduced runoff and SY, necessitating the consideration of agronomic and land management practices that enhance SOM. Annual SY decreased exponentially with the rock fragment cover (RFC). In fields where RFC was less than 20%, collecting rock fragments for installing stone bunds resulted in a net increase in SY. Rehabilitating badlands and enhancing SOM content in croplands can substantially reduce catchment SY and, hence considerably contribute to the sustainability of this type of environment.

Canadian agricultural land-use and land management data for Kyoto reporting

2006 ◽  
Vol 86 (3) ◽  
pp. 431-439 ◽  
Author(s):  
T. Huffman ◽  
R. Ogston ◽  
T. Fisette ◽  
B. Daneshfar ◽  
P-Y. Gasser, L. White ◽  
...  
Keyword(s):  
Land Use ◽  
Land Management ◽  
Management Practices ◽  
Agricultural Land ◽  
Spatial Scales ◽  
Satellite Image ◽  
Data Sources ◽  
Land Use And Management ◽  
National Analysis ◽  
The Impact

The land use and management data requirements for assessing, monitoring and reporting on the impact of agricultural production practices on the environment, especially in a country as large as Canada, are considerable. In view of the fact that environmental assessments are a relatively new phenomenon, data collection activities targeted toward these needs are not widespread. As a result, we find it necessary to acquire and integrate a variety of data sources with differing time lines, spatial scales and sampling frameworks. This paper uses our current activities with respect to Kyoto reporting as a focus to present and discuss the types of data required and the spatial analysis and integration procedures being developed to provide them. The essential data for this activity include the area of crop and land use types, land use changes since 1990, farm and land management practices and biomass production. The spatial framework selected for national analysis is the Soil Landscapes of Canada, and the primary existing data sources are the Census of Agriculture, sample-derived yield estimates and satellite-based land cover products. These are supplemented with detailed, multi-season, multi-year satellite image interpretations conducted at an ecologically and statistically stratified sample of sites across the country. The use of these data in preparing an account of greenhouse gas sources and sinks identified a number of gaps and problems, and a brief outline of future work designed to improve the data inputs is presented. Key words: Kyoto reporting, data integration, land use and management, greenhouse gases, carbon sequestration

scholarly journals Modeling runoff response to land-use changes using the SWAT model in the Mundaú watershed, Brazil

2020 ◽  
Vol 5 (2) ◽  
pp. 194-206
Author(s):  
Carolyne Wanessa Lins de Andrade Farias ◽  
Suzana Maria Gico Lima Montenegro ◽  
Abelardo Antônio de Assunção Montenegro ◽  
José Romualdo de Sousa Lima ◽  
Raghavan Srinivasan ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Sediment Yield ◽  
Surface Runoff ◽  
Assessment Tool ◽  
Swat Model ◽  
Land Use Changes ◽  
Water Yield ◽  
Grazing Land ◽  
Runoff And Sediment Yield

Land-use change has a significant influence on runoff process of any watershed, and the deepening of this theme is essential to assist decision making, within the scope of water resources management. The study was conducted for Mundaú River Basin (MRB) using the Soil and Water Assessment Tool (SWAT) model. The study aims to assess the issue of land-use change and its effect on evapotranspiration, surface runoff, and sediment yield. Input data like land use, topography, weather, and soil data features are required to undertake watershed simulation. Two scenarios of land use were analyzed over 30 years, which were: a regeneration scenario (referring to use in the year 1987) and another scene of degradation (relating to use in the year 2017). Land use maps for 1987 and 2017 were acquired from satellite images. Overall, during the last three decades, 76.4% of forest was lost in the MRB. The grazing land increased in 2017 at a few more than double the area that existed in 1987. Changes in land use, over the years, resulted in an increase of about 37% in the water yield of MRB. Changes have led to increased processes such as surface runoff and sediment yield and in the decrease of evapotranspiration. The spatial and temporal distribution of land use controls the water balance and sediment production in the MRB.

scholarly journals Sediment load estimation in the Mellegue catchment, Algeria

2016 ◽  
Vol 31 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Kaouther Selmi ◽  
Kamel Khanchoul
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Sediment Yield ◽  
Agricultural Land ◽  
Water Discharge ◽  
Sediment Concentration ◽  
Sediment Loads ◽  
Recorded Data ◽  
The Mean ◽  
The Impact

AbstractSoil erosion by water and the impact of sediment transport on lakes and streams, can seriously degrade soil and create problems for both agricultural land and water quality. The present study has been carried out to assess suspended sediment yield in Mellegue catchment, northeast of Algeria. Regression analysis was used to establish a relationship between the instantaneous water discharge (Q) and the instantaneous suspended sediment concentration (C) based on all recorded data and seasonal ratings for the period 1970–2003. The regression technique used in this paper involved a division of data into discharge – based classes, the mean concentrations and discharges of which are used to develop power regressions, according to single and season ratings, through log-transformation. Sediment loads estimated by stratified rating curves reduced underestimations to a range from 2 to 4%. The mean annual sediment yield during the 34 years of the study period was 589.23 t·km−2·y−1. Sediment transport is dominated by fall rainstorms accounting for 41% of the annual load. The big supply of sediment during this season confirms the intense geomorphic work by fall storms caused by high intensity rainfall and low vegetation cover.

Modeling the impact of land use changes on runoff and sediment yield in the Le Sueur watershed, Minnesota using GeoWEPP

CATENA ◽  
2013 ◽  
Vol 107 ◽  
pp. 35-45 ◽  
Author(s):  
Fukhrudin K. Maalim ◽  
Assefa M. Melesse ◽  
Patrick Belmont ◽  
Karen B. Gran
Keyword(s):  
Land Use ◽  
Sediment Yield ◽  
Land Use Changes ◽  
The Impact ◽  
Runoff And Sediment Yield

scholarly journals Modeling Impact of Land Use Dynamics on Hydrology and Sedimentation of Megech Dam Watershed, Ethiopia

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Abebe Tarko Assfaw
Keyword(s):  
Land Use ◽  
Sediment Yield ◽  
Surface Runoff ◽  
Hydrological Modeling ◽  
Plantation Forest ◽  
Dam Reservoir ◽  
Land Use Dynamics ◽  
The Mean ◽  
The Government ◽  
Runoff And Sediment Yield

Land use/land cover dynamics change the hydrology and sediment yield of the watershed. This research on how land use dynamics alters catchment hydrology and reservoir sedimentation aids the government to implement appropriate response strategies to minimize undesirable future impacts on the upper Megech dam reservoir. For this study, the impacts were quantified and analyzed through hydrological modeling (SWAT). The overall analysis was performed by using 1998 historical and 2016 recent land use satellite images. The analysis has shown that the cultivated land has increased from 60.69% to 67.17% and urban land from 2.3% to 3.36% between 1998 and 2016. Whereas the grassland area has decreased from 11.42% to 5.33%, plantation forest from 1.84% to 0.9%, and bareland from 3.58% to 2.56%. A comparison of the simulated outputs of the model shows that the mean annual surface runoff for 1998 land use was 251.3 mm and had changed to 316.7 mm in 2016 land use. The mean annual streamflow changed from 150.3 m3/sec to 165.6 m3/sec for 1998 and 2016 land uses, respectively. Similarly, 10.23 t/ha mean annual sediment load gets into Megech dam reservoir in 1998 LULC and was changed to 13.61 t/ha in 2016 LULC. This shows that streamflow, surface runoff, and sediment yield increases by 10.2%, 26.03%, and 33.3% in 2016 land use as compared with 1998 land use. Finally, the most dynamic subbasins that have a significant impact on streamflow and sediment yield were identified. Based on this, subbasins 13, 17, 19, 20, 23, 24, and 25 were found to be the most dynamic and change sensitive subbasins that have a significant contribution to the increment of runoff and sediment yield in Megech dam watershed.

scholarly journals Analyzing Factors Affecting the Sustainability of Land Management Practices in Mecha Woreda, Northwestern Ethiopia

2021 ◽  
Vol 13 (13) ◽  
pp. 7007
Author(s):  
Habtamu Nebere ◽  
Degefa Tolossa ◽  
Amare Bantider
Keyword(s):  
Decision Making ◽  
Land Management ◽  
Land Degradation ◽  
Quantitative Data ◽  
Management Practices ◽  
Short Term ◽  
Factors Affecting ◽  
Decision Making Processes ◽  
Household Heads ◽  
The Impact

In Ethiopia, the practice of land management started three decades ago in order to address the problem of land degradation and to further boost agricultural production. However, the impact of land management practices in curbing land degradation problems and improving the productivity of the agricultural sector is insignificant. Various empirical works have previously identified the determinants of the adoption rate of land management practices. However, the sustainability of land management practices after adoption, and the various factors that control the sustainability of implemented land management practices, are not well addressed. This study analyzed the factors affecting the sustainability of land management practices after implementation in Mecha Woreda, northwestern Ethiopia. The study used 378 sample respondents, selected by a systematic random sampling technique. Binary logistic regression was used to analyze the quantitative data, while the qualitative data were qualitatively and concurrently analyzed with the quantitative data. The sustained supply of fodder from the implemented land management practices, as well as improved cattle breed, increases the sustainability of the implemented land management practices. While lack of agreement in the community, lack of enforcing community bylaws, open cattle grazing, lack of benefits of implemented land management practices, acting as barrier for farming practices, poor participation of household heads during planning and decision-making processes, as well as the lack of short-term benefits, reduce the sustainability of the implemented land management practices. Thus, it is better to allow for the full participation of household heads in planning and decision-making processes to bring practical and visible results in land management practices. In addition, recognizing short-term benefits to compensate the land lost in constructing land management structures must be the strategy in land management practices. Finally, reducing the number of cattle and practicing stall feeding is helpful both for the sustainability of land management practices and the productivity of cattle. In line with this, fast-growing fodder grass species have to be introduced for household heads to grow on land management structures and communal grazing fields for stall feeding.

scholarly journals Rural Roads Are Paving the Way for Land-Use Intensification in the Uplands of Laos

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 330
Author(s):  
Jean-Christophe Castella ◽  
Sonnasack Phaipasith
Keyword(s):  
Land Use ◽  
Management Practices ◽  
Management Strategies ◽  
Farming Systems ◽  
Long Term Effects ◽  
Group Discussions ◽  
Rural Roads ◽  
External Resources ◽  
Hybrid Maize ◽  
The Impact

Road expansion has played a prominent role in the agrarian transition that marked the integration of swidden-based farming systems into the market economy in Southeast Asia. Rural roads deeply altered the landscape and livelihood structures by allowing the penetration of boom crops such as hybrid maize in remote territories. In this article, we investigate the impact of rural road developments on livelihoods in northern Laos through a longitudinal study conducted over a period of 15 years in a forest frontier. We studied adaptive management strategies of local stakeholders through the combination of individual surveys, focus group discussions, participatory mapping and remote-sensing approaches. The study revealed the short-term benefits of the maize feeder roads on poverty alleviation and rural development, but also the negative long-term effects on agroecosystem health and agricultural productivity related to unsustainable land use. Lessons learnt about the mechanisms of agricultural intensification helped understanding the constraints faced by external interventions promoting sustainable land management practices. When negotiated by local communities for their own interest, roads may provide livelihood-enhancing opportunities through access to external resources, rather than undermining them.

scholarly journals Assessment of alternative land management practices using hydrological simulation and a decision support tool: Arborea agricultural region, Sardinia

2007 ◽  
Vol 11 (6) ◽  
pp. 1811-1823 ◽  
Author(s):  
P. Cau ◽  
C. Paniconi
Keyword(s):  
Decision Support ◽  
Land Management ◽  
Quantitative Methods ◽  
Management Practices ◽  
Water Movement ◽  
Agricultural Practices ◽  
Treated Wastewater ◽  
Hydrological Simulation ◽  
Support Tool ◽  
The Impact

Abstract. Quantifying the impact of land use on water supply and quality is a primary focus of environmental management. In this work we apply a semidistributed hydrological model (SWAT) to predict the impact of different land management practices on water and agricultural chemical yield over a long period of time for a study site situated in the Arborea region of central Sardinia, Italy. The physical processes associated with water movement, crop growth, and nutrient cycling are directly modeled by SWAT. The model simulations are used to identify indicators that reflect critical processes related to the integrity and sustainability of the ecosystem. Specifically we focus on stream quality and quantity indicators associated with anthropogenic and natural sources of pollution. A multicriteria decision support system is then used to develop the analysis matrix where water quality and quantity indicators for the rivers, lagoons, and soil are combined with socio-economic variables. The DSS is used to assess four options involving alternative watersheds designated for intensive agriculture and dairy farming and the use or not of treated wastewater for irrigation. Our analysis suggests that of the four options, the most widely acceptable consists in the transfer of intensive agricultural practices to the larger watershed, which is less vulnerable, in tandem with wastewater reuse, which rates highly due to water scarcity in this region of the Mediterranean. More generally, the work demonstrates how both qualitative and quantitative methods and information can assist decision making in complex settings.

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