This study aimed to locate areas along the Debretabor-Alember route segment in northern Ethiopia that are susceptible landslides. Geospatial tools, specifically frequency ratios (FR) and information values (IV), were used develop landslide susceptibility maps (LSMs). A comprehensive on-site investigation analysis of Google Earth imagery conducted, resulting detection 89 landslides, including current historical events. The dataset for validation comprised 78% previously documented whereas...

The study area (Enfraz to Addis Zemen) is located in northwestern Ethiopia, which frequently experiences landslides, causing damage farmland, engineering structures, infrastructures, and villages, as well animal human fatalities. To manage this catastrophic hazard, a comprehensive GIS-based frequency ratio model (FR) was applied produce landslide susceptibility map. In study, 134 landslides were identified from detailed fieldwork Google Earth imagery analysis, split into 70% develop the 30%...

Abstract The flood is one of the frequently occurring natural hazards within sub-basin Lake Tana. hazard Tana causes damage to cropland, properties, and a fatality every season. Therefore, susceptibility modeling in this area significant for reduction management purposes. Thus, analytical hierarchy process (AHP), bivariate (information value [IV] frequency ratio [FR]), multivariate (logistic regression [LR]) statistical methods were applied. Using an intensive field survey, historical...

Knowledge of the sensitivity performance and other related dependent furrow-irrigation parameters, in quantitative terms, to variations field, design, management variables can help save a considerable amount cost, time, effort spent field data collection. A univariate analysis, based on concept relative sensitivity, was used quantify seven irrigation parameters ( E , r R D U cc ℓr, t ) 13 co S0 σ1, σ2, ρ1, ρ2, n k c ℓ, q0 Z ). Three different sets, representative wide range conditions have...

The effect of specific initial and boundary conditions is generally not considered when applying the Kostiakov infiltration functions. A methodology developed to account for changes in water levels soil moisture. First, Richards' equation solved numerically generate a database one-dimensional values, with varying (water content or pressure head) (ponding depth) three contrasting soils. These are then used calibrate corresponding coefficients modified models and, by considering linear...

Surface fertigation is widely practiced in irrigated crop production systems. Lack of design and management tools limits the effectiveness surface practices. The availability a process-based coupled surface–subsurface hydraulic solute transport model can lead to improved management. This paper presents development model. A described previous by writers provided hydrodynamic basis for presented here. numerical solution area averaged advection–dispersion equation, based on split-operator...

The availability of a process-based coupled surface-subsurface model can lead to improved surface irrigation/fertigation management practices. In this study, one-dimensional zero-inertia is with unsaturated zone water-flow model: HYDRUS-1D. A driver program used effect internal iterative coupling the and subsurface flow models. Flow depths calculated using surface-flow are as Dirichlet boundary conditions for subsurface-flow model, infiltration amounts by in turn mass balance calculations....

Cumulative infiltration was computed as a function of time-varying ponded water depths using Green and Ampt analysis. The input were field-measured values from two irrigation events on Superstition sand, one basin border. For both types irrigation, the cumulative at given measuring station nearly same whether variable head or constant (average) during time opportunity. As an example, first measurement for event, depth went 0 to 9 cm over 2–12 min. introduced into basin; this followed by...

This study addresses infiltration from furrows or narrow channels. The basic approach is to develop the two-dimensional as a combination of corresponding one-dimensional vertical and an edge effect. idea borrowed previous applications for disc strip sources. assumption tested directly with numerical experiments using four representative soils three furrow shapes (triangular, rectangular, parabolic). effect difference between cumulative per unit adjusted wetting perimeter infiltration. A...

Moment analysis techniques are applied to describe the spatial and temporal subsurface wetting patterns resulting from furrow infiltration redistribution. These adapted previous work with drip irrigation. The water added is considered as a "plume" zeroth moment representing total volume of domain. first moments lead location center plume, second relate amount spreading about mean position. Using moments, any fraction its extent, defined by an ellipse, can be related "probability" curve....

Droplet dynamics simulations are key to predicting sprinkler irrigation precipitation patterns. This paper includes derivations of equations describing droplet motion through a steady, uniform horizontal airflow (wind). The assumptions on which is based stated, and the limitations they entail highlighted. droplets treated as an impulsively started accelerated rigid spheres, originating at nozzle with known initial conditions, involving no interactions between themselves. following steps used...

Application efficiency (Ea) is the primary criterion for border irrigation design and management. The objectiveof this study to analyze behavior of application function with respect length(L) unit inlet flow rate (qo), given a target minimum depth. results show that efficiencyfunction unimodal L qo. Optimality conditions are derived both Ea(L) Ea(qo) functions, basedon which simple rules reduce management procedure into series one-dimensional optimizationproblems qo developed. proposed has...

The application of N fertilizers mixed with a surface irrigation stream (surface fertigation) is widely practiced in the southwestern United States. Procedures for optimal design and management fertigation systems are needed. purpose this work to identify define set performance indices that can be used assess relative merits alternative scenarios. Equations solutions quantifying proposed. Sample calculations presented field experiment which bromide ion was as tracer simulate movement nitrate...

The development of a coupled surface–subsurface solute transport model for surface fertigation management is presented in companion paper (Part I). This discusses an evaluation the model. numerical solution pure advection stream was evaluated using test problems with steep concentration gradients. result shows that can simulate without diffusion and oscillations, important problem advection–dispersion equation dominated transport. In addition, close match obtained between one-dimensional...