scholarly journals Topography Impacts Hydrology in the Sub-Humid Ethiopian Highlands

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 196
Author(s):  
Demesew A. Mhiret ◽  
Minychl G. Dersseh ◽  
Christian D. Guzman ◽  
Dessalegn C. Dagnew ◽  
Wubneh B. Abebe ◽  
...  
Keyword(s):  
Water Table ◽  
Surface Runoff ◽  
Management Practices ◽  
Infiltration Rate ◽  
Watershed Hydrology ◽  
Ethiopian Highlands ◽  
Topographic Position ◽  
Tropical Highlands ◽  
Average Water ◽  
The Relationship

Understanding the relationship between topography, hydrological processes, and runoff source areas is essential in engineering design, such as predicting floods and implementing effective watershed management practices. This relationship is not well defined in the highlands with a monsoon climate and needs further study. The objective of this study is to relate topographic position and hydrological response in tropical highlands. The research was conducted in the Debre Mawi watershed in the northwest sub-humid Ethiopian highlands. In the monsoon rain phase of 2017 and 2018, groundwater depth, infiltration rate, and surface runoff were monitored at the upslope, midslope, and downslope positions. Surface runoff rates were measured in farmer fields through distributed V-notch weirs as estimates of positional runoff. Average water table depths were 30 cm deep in the downslope regions and 95 cm in the upslope position. The water table depth affected the steady-state infiltration rate in the rain phase. It was high upslope (350 mm h−1), low midslope (49 mm h−1), and zero downslope. In 2017, the average runoff coefficients were 0.29 for the upslope and midslope and 0.73 downslope. Thus, topographic position affects all aspects of the watershed hydrology in the humid highlands and is critical in determining runoff response.

scholarly journals Effect of Slope on Infiltration Capacity and Erosion of Mount Merapi Slope Materials

2020 ◽  
Vol 1000 (1000) ◽  
Author(s):  
Adam Pamudji Rahardjo
Keyword(s):  
Surface Runoff ◽  
Erosion Rate ◽  
Soil Surface ◽  
Infiltration Rate ◽  
Infiltration Capacity ◽  
Erosion Rates ◽  
Slope Steepness ◽  
Balance Principle ◽  
Exponential Equations ◽  
The Relationship

 Infiltration which occurs on slope has a specific behavior that can be parameterized. One of the reasons is because the slope generates less ponding on the sloping soil surface. This condition affects infiltration rate and surface runoff proportion of water from any kind of rainfall distribution in time. Since surface runoff tends to be higher, erosion rate is also to be higher on slope. The slope steepness is the most important parameter of a slope. In this study, the effect of slope steepness on infiltration capacity and erosion rate of Mount Merapi bare slope material were tested in a laboratory using rainfall simulator. Three values of slope steepness of 36%, 47%, and 58% were used. The rainfall intensity was set constant and was found has rate of 116,312 mm/hour. The infiltration rate was measured by volumetric balance principle and the erosion rates were measured by collecting the eroded grains at the downstream end tank. Infiltration rate was evaluated by using Horton method and the average erosion were analyzed from the eroded grain data for each test. After fitting the recorded infiltration rate data to the Horton equation, the infiltration capacity was obtained. The results were the relationship between slope steepness and the affected the infiltration capacity and erosion for each test. Infiltration capacity is found to increase and the decrease with the increase of slope steepness while erosion rate is found to increase on the steeper slope. The increase of erosion range is between 15% to 33% for each 1o increase of slope steepness. In addition, polynomial and exponential equations were developed to express the relationship between slope steepness and infiltration capacity and also the erosion rate.

Integrated Soil, Crop and Water Management System to Abate Herbicide and Nitrate Contamination of the Great Lakes

1993 ◽  
Vol 28 (3-5) ◽  
pp. 497-507 ◽  
Author(s):  
C. S. Tan ◽  
C. F. Drury ◽  
J. D. Gaynor ◽  
T. W. Welacky
Keyword(s):  
Water Table ◽  
Surface Runoff ◽  
Management System ◽  
Management Practices ◽  
Drainage Water ◽  
Tile Drainage ◽  
Nitrate Contamination ◽  
Runoff Water ◽  
Runoff Events ◽  
Water Table Control

Corn management practices, incorporating annual ryegrass intercrop, conservation tillage and water table management, were evaluated to reduce herbicide and N0−3 losses through surface runoff and tile drainage. The integrated management system being developed at Harrow in S.W. Ontario reduced herbicide input 50% by banding the chemical over the seed row. Runoff events close to herbicide application contained high concentrations of atrazine, metribuzin and metolachlor. However, the volume of runoff was low during the 1991 growing season, therefore herbicide loss was low (<2% of applied). The three herbicides rapidly dissipated in the soil so that subsequent runoff events transported little herbicide in the runoff water. The total quantity of de-ethyl atrazine loss was lower from soil saver than moldboard plow. No water table control or intercrop effects were found in 1991 for herbicide loss because of the drought Tile drainage resulted in a greater volume of water and loss of N0−3 than with surface runoff. Consequently, over 97% of the total N0−3 loss occurred through tile drainage. The flow weighted N0−3 concentration in tile drainage water was 22.5 mg N L−1 for the drainage treatments and 15.1 mg N L−1 for the water table control treatments from Nov. 1, 1991 till April 30, 1992. During this time period, N0−3 loss through tile drainage was 57.8 kg N ha−1 from the drainage treatments and 36.3 kg N ha−1 from the water table control treatments. Therefore, the water table control treatment reduced the flow weighted N0−3 concentration in tile drainage water by 33% and total N0−3 loss by 37%. The water table control treatments combined with soil saver tillage resulted in lower concentrations and losses of N0−3 than with any other treatments.

scholarly journals Research on the Relationship between Shared Leadership and Individual Creativity-Qualitative Comparative Analysis on the Basis of Clear Set

2021 ◽  
Vol 13 (10) ◽  
pp. 5445
Author(s):  
Muyun Sun ◽  
Jigan Wang ◽  
Ting Wen
Keyword(s):  
Comparative Analysis ◽  
Environmental Factors ◽  
Shared Leadership ◽  
Management Practices ◽  
Qualitative Comparative Analysis ◽  
Necessary Condition ◽  
The Individual ◽  
The Impact ◽  
The Relationship ◽  
Sufficient And Necessary Condition

Creativity is the key to obtaining and maintaining competitiveness of modern organizations, and it has attracted much attention from academic circles and management practices. Shared leadership is believed to effectively influence team output. However, research on the impact of individual creativity is still in its infancy. This study adopts the qualitative comparative analysis method, taking 1584 individuals as the research objects, underpinned by a questionnaire-based survey. It investigates the influence of the team’s shared leadership network elements and organizational environmental factors on the individual creativity. We have found that there are six combination of conditions of shared leadership and organizational environmental factors constituting sufficient combination of conditions to increase or decrease individual creativity. Moreover, we have noticed that the low network density of shared leadership is a sufficient and necessary condition of reducing individual creativity. Our results also provide management suggestions for practical activities during the team management.

scholarly journals 395 Impact of pig mortality on U.S. pig producers

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 184-185
Author(s):  
Caleb M Shull
Keyword(s):  
Feed Efficiency ◽  
Management Practices ◽  
Production Systems ◽  
Research Priorities ◽  
Functional Approach ◽  
Production Cycle ◽  
Limiting Factor ◽  
Significant Challenge ◽  
The Relationship ◽  
Positive Step

Abstract Swine producers in the U.S. face a significant challenge. On top of the ever-changing market dynamics that lead to wide swings in profitability or loss, is an underlying issue of pig mortality that the industry must address. While significant improvements in total piglets born per litter have been achieved over the last 10 years, pig mortality has seen no improvement or has worsened (Figure 1). When expressed as a percentage of piglets born (excluding mummies), a total of 7.9% were recorded as stillborn and 13.4% died prior to weaning in 2019. Assuming a typical mortality range of 7–10% from weaning to harvest, a typical U.S. producer could expect to lose around 27–30% of all piglets born. In addition, the average producer had around 12% annual sow mortality (Figure 1). Litter size and post-weaning growth rate and feed efficiency will always factor heavily into research priorities due to the economic impact associated with those traits; however, the opportunity to drive value through reduction in pig losses across the production cycle is staggering. In defense of the industry, improving pig survival is not an easy task for a number of reasons. The sample size (i.e., number of pigs) required to do mortality research correctly is often a limiting factor for many production systems. Furthermore, a cross-functional approach is likely required to make significant improvements in mortality. Specifically, the relationship between genetics, health, and management practices warrant consideration. Recent collaboration across the industry to improve mortality is a positive step forward and this collaboration should continue moving forward.

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