A5004048477- Hydrology and Watershed Management Studies
- Plant Water Relations and Carbon Dynamics
- Soil erosion and sediment transport
- Hydrology and Sediment Transport Processes
- Meteorological Phenomena and Simulations
- Climate variability and models
- Hydrology and Drought Analysis
- Landslides and related hazards
- Soil Moisture and Remote Sensing
- Flood Risk Assessment and Management
- Precipitation Measurement and Analysis
- Soil and Unsaturated Flow
- Water resources management and optimization
- Remote Sensing in Agriculture
- Groundwater flow and contamination studies
- Hydrological Forecasting Using AI
- Atmospheric aerosols and clouds
- Cryospheric studies and observations
- Complex Systems and Time Series Analysis
- Land Use and Ecosystem Services
- Soil Geostatistics and Mapping
- Plant responses to water stress
- Advanced Thermodynamics and Statistical Mechanics
- Irrigation Practices and Water Management
- Tree Root and Stability Studies
Georgia Institute of Technology
2016-2025
Massachusetts Institute of Technology
2004-2024
Samueli Institute
2008-2020
University of California, Irvine
2008-2020
Groupe d'Analyse et de Théorie Economique Lyon St Etienne
2020
University of Illinois Urbana-Champaign
2020
Planetary Science Institute
2020
Goodman Research Group (United States)
2020
University of Utah
2018
Saint Anthony College of Nursing
2017
Abstract Channel networks with artibtrary drainage density or resolution can be extracted from digital elevation data. However, for data derived to useful they have at the correct length scale density. Here we suggest a criterion determining appropriate which extract The is basically highest (highest density) network that satisfies scaling laws traditionally been found hold channel networks. Procedures use this are presented and tested on 21 sets well distributed throughout U.S.
This paper presents a model of the long‐term evolution catchments, growth their drainage networks, and changes in elevations within both channels hillslopes. Elevation are determined from continuity equations for flow sediment transport, with transport being related to discharge slope. The central feature is that it explicitly differentiates between behavior hillslopes on basis observed physics, channel network extension results solely physically based interactions difference one most...
Catchment morphology and drainage density are strongly influenced by hillslope processes. The consequences of several different process laws explored in a series experiments with numerical model basin evolution. Five models considered, including simple diffusive‐advective transition, runoff generation threshold, an erosion two types threshold‐activated landsliding. These processes alter both the visual appearance landscape predicted relationship between slope contributing area. On basis...
Ever since Mandelbrot (1975, 1983) coined the term, there has been speculation that river networks are fractals. Here we report analyses done on to determine their fractal structure. We find network as a whole, although composed of nearly linear members, is practically space filling with dimension near 2. The empirical results backed by theoretical analysis based long‐standing hydrologic concepts describing geometric similarity networks. These advance our understanding geometry and composition
The water cycle regulates and reflects natural variability in climate at the regional global scales. Large‐scale human activities that involve changes land cover, such as tropical deforestation, are likely to modify through cycle. In order understand, hopefully be able predict, extent of these potential changes, we need first understand how works. past, most research hydrology focused on branch cycle, with little attention given atmospheric branch. study precipitation recycling, which is...
Abstract Precipitation recycling is the contribution of evaporation within a region to precipitation in that same region. The rate diagnostic measure potential for interactions between land surface hydrology and regional climate. In this paper we present model describing seasonal spatial variability process. ratio, ρ, basic variable process, ρ fraction at certain location time which contributed by under study. applied studying hydrologic cycle Amazon basin. It estimated about 25% all rain...
The results from an application of a conceptual hydrologic model, combined with filtering and statistical estimation methods, to real‐time forecasting river discharges are very encouraging. use feedback significantly improves the overall capability model even when input error statistics not perfectly known. Identification these through adaptive techniques is practical further performance model. Comparison simple linear ‘black box’ favorable for especially forecast lead times comparably...
We develop a simple stochastic theory for erosion and sediment transport, based on the Poisson pulse rainfall model, in order to analyze how variability runoff influences drainage basin evolution. Two cases are considered: transport by rills channels particle detachment from bedrock or cohesive soils. Analytical numerical results show that under some circumstances, can have an impact equal greater than of mean amount. The predicted sensitivity is greatest when (1) thresholds generation...
This study explores various aspects of catchment hydrology based on a mechanistic modeling distributed watershed processes. A new physics‐based, distributed‐parameter hydrological model that uses an irregular spatial discretization is introduced. The accounts, continuous basis, for the processes rainfall interception, evapotranspiration, moisture dynamics in unsaturated and saturated zones, runoff routing. Simulations several mid‐ to large‐sized watersheds (∼10 3 km 2 ) highlight dynamic...
This paper describes the first major attempt to compare seven different inverse approaches for identifying aquifer transmissivity. The ultimate objective was determine which of several geostatistical techniques is better suited making probabilistic forecasts potential transport solutes in an where spatial variability and uncertainty hydrogeologic properties are significant. Seven methods (fast Fourier transform (FF), fractal simulation (FS), linearized cokriging (LC), semianalytical )LS),...
Topography acts as a template for numerous landscape processes that include hydrologic, ecologic, and biologic phenomena. These not only interact with each other but also contribute to shaping the they influence geomorphic processes. We have investigated effects of vegetation on thresholds channel initiation landform evolution using both analytical numerical approaches. Vegetation is assumed form uniform ground cover. Runoff erosion modeled based power function excess shear stress, in which...
Three principles of optimal energy expenditure are used to derive the most important structural characteristics observed in drainage networks: (1) principle minimum any link network, (2) equal per unit area channel anywhere and (3) total network as a whole. Their joint application results unified picture empirical facts which have been dynamics its three‐dimensional structure. They also process runoff production basin with network.
This paper explores the similarities of digital elevation maps (DEMs) natural river basins and optimal channel network (OCN) configurations obtained minimizing total rate energy expenditure in system as a whole its parts. Striking are observed for networks their fractal aggregation structure certain multifractal structures found to be characteristic basins. Our results suggest, upon critical assessment reliability identification attractor underlying dynamics implied by our optimality...
Optimal channel networks (OCN's) obtained by minimizing the local and global rates of energy expenditure evolve automatically from arbitrary initial conditions to network configurations exhibiting fractal multifractal statistics indistinguishable those observed in nature. It is suggested that OCN's are spatial models self-organized criticality natural structures like river may arise as a joint consequence optimality randomness.
River networks constitute dissipative systems with many spatial degrees of freedom. Previous work by Mandelbrot (1983) and Bak et al. (1987, 1988, 1990) suggests that such will follow power law distributions in their mass energy characteristics. It is shown this the case for river where exponent β distribution, P [ X > x ] ∝ −β , approximately equal to 0.45 0.90 discharge respectively several analyzed North America when these variables are calculated each individual link throughout...
Abstract This paper briefly describes a model of the erosional development catchments and their channel networks. The differentiates between dominant transport processes in hillslope channels. channels hillslopes occurs an integrated manner as function physically observable mechanisms. growth river basin is qualitatively described. concepts are used to study during periods (transient periods), well dynamic equilibrium. leads hypotheses about relationship slopes, relief, tectonic uplift,...
Vegetation, particularly its dynamics, is the often‐ignored linchpin of land‐surface hydrology. This work emphasizes coupled nature vegetation‐water‐energy dynamics by considering linkages at timescales that vary from hourly to interannual. A series two papers presented. dynamic ecohydrological model [tRIBS + VEGGIE] described in this paper. It reproduces essential water and energy processes over complex topography a river basin links them basic plant life regulatory processes. The framework...
Hydrologic research at the interface between atmosphere and land surface is undergoing a dramatic change in focus, driven by new societal priorities, emerging technologies, better understanding of earth system. In this paper an agenda for hydrology proposed order to open debate more comprehensive prioritization science application activities hydrologic sciences. Sets priority questions are posed strategies achieving progress identified. The also coupled with ongoing international data...
The instantaneous unit hydrograph is conceived as a random function of climate and geomorphology varying with the characteristics rainfall excess. probability density functions peak time to IUH are analytically derived basin geomorphological parameters. main these pdf's studied, new approach hydrologic similarity initiated under concept geomorphoclimatic IUH. For given set geomorphologic particular intensity duration rainfall, corresponding those values can be easily estimated.