Human-scale surface energy budget and ground thermal responses to soil moisture and vegetation change in flat and complex terrain
Abstract
The spatio-temporal distribution of both Surface Energy Budget (SEB) and Soil Temperature Profile (STP) at the scale of the human activities is significantly impacted by heterogeneities in soil water content, vegetation cover and activity, and the intricacies resulting from different soil materials, weather forcing and complex topography. Furthermore, seasonal or abrupt changes in vegetation and moisture induce transient states to the land surface-atmosphere processes, the surface energy and water budgets and the way ground surface stores and conducts energy. Little is still known about the SEB and the STP when water moves to and from shallow soil depths and when seasonal or abrupt changes in vegetation occur, as the processes are so dynamic in time that an analytical steady-state approach s not appropriate for an accurate, transient assessment. The goal of the proposed work is to improve our understanding of the soil moisture and vegetation controls on the human-scale surface energy budget and soil temperature distribution across different soil types and terrain conditions. The research hypotheses will be tested at four distinct-vegetation, strategic regions of the U.S. southwest and southcentral that experienced human-induced disturbance regimes in recent years. Our scientific objectives are to: (l) Characterize the cross-site and temporal variability of SEB and STP at the stationÕs footprint and catchment scales; (2) Analyze the event and seasonal scale evolution of the catchmentsÕ SEB and STP in response to soil moisture changes: (3) Conduct simulation experiments to reproduce seasonal and abrupt changes in vegetation to quantify anomalies in ground thermal properties and energy distribution in light of ground-truth observations; and (4) Synthetize the numerical modeling results to provide broader knowledge on the influence of soil moisture and vegetation shifts on regional surface energy patterns and their relation with terrain complexity, vegetation type and cover, meteorological conditions and soil material type. A key aspect of the proposed study is the use of (1) a set of micrometeorological tower sites that use radiometers, weather, soil and eddy flux sensors to estimate energy, water and carbon fluxes: (2) a hyper-resolution, parallelized, process-based simulator that resolves the energy and water balance equations and soil heat transport across Triangular Irregular Networks (TIN); and (3) an adaptive visualization tool for immersive display decision making. Expected results can be summarized as (1) A reference data base with all micro-meteorological and soil monitoring information used for cross-site comparison model validation and calibration. (2) A set of model inputs including remotely sensed data across all four regional catchments topography, soils, vegetation, weather and radiation forcing, and model outputs, including soil moisture, net radiation, sensible, latent, ground heat fluxes, soil surface temperatures and variation with depth. (3) A characterization of the observed effects of vegetation seasonality and abrupt changes on the SEB and STP through observed and modeled anomalies and the mechanics through which these anomalies are produced. And (4) an end-user decision making tool for the Army s use in replicating the projected simulations, developing additional synthetic change scenarios and evaluating modeling results. The new knowledge produced from this project will be transferable to similar eco-regions and with natural or human-induced perturbations (e.g. fire. logging). Results will positively impact key ArmyÕs activities and factors that affect its systems and operations, spanning from operational mobility, detection of landmines and unexploded ordinance, natural material penetration/excavation, military engineering activities, blowing dust and sand, catchment responses and flooding, performance of optical and infrared sensors as well as acoustic detection systems.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2018
- Source ID
- W911NF1810007
Entities
People
- Hernan Moreno Ramirez
Organizations
- Army Contracting Command
- United States Army
- University of Oklahoma