The DCHM (Duke Coupled surface-subsurface Hydrology Model) is a research model that is freely available to all interested scientists. Due to the lack of appropriate funding, the model is documented in the literature, but a User’s Manual and FAQ documentation are not maintained and regularly updated. Therefore, interested users should plan to spend time in-residence at Duke toward hands-on orientation and applications using the model.
The overarching research objective of this research is to investigate aerosol-cloud-rainfall interactions in the Central Himalayas with a focus on elucidating the impact of anthropogenic aerosols on cloudiness, the space-time variability of precipitation, and ultimately the regional water cycle in the northern Indian subcontinent, and in particular the Ganges river basin.
Understanding how landform and landcover modulate the spatial and temporal variability of orographic clouds and precipitation
The objective of this project is to investigate whether and how landform and landcover modulate the spatial and temporal variability of orographic clouds and precipitation in a high priority area for biodiversity conservation and human water supply. The central research hypothesis is that evapotranspiration is a critical source of moisture to the atmospheric boundary layer (ABL) either locally and, or remotely via moist transport by diurnal mountain-valley circulations, lowering the cloud base at high elevations during the afternoon, and enhancing thermodynamic instability at locations in the landscape where precipitable water and CAPE (Convective Available Potential Energy) attain collocated night-time maxima. Spatial patterns in the organization of convective initiation are proposed to be explained by the spatial variability of vegetation and soil moisture patterns on altitudinal gradients, and by how this translates into the spatial variability of the diurnal cycle of latent heating fluxes between the land surface and the lower troposphere.
Vulnerability of Water Resources in Southern Africa: Elucidating the Role of the Angola High Plateau in the Water Cycle of Upper Zambezi River Basin Using Models and Remote Sensing Observations
The headwaters of major rivers in Southern Africa including the Cunene, the Okavango and the Zambezi are located on the Angola High Plateau (AHP). The plateau is dominated by woodland savanna and tropical montane forests and grasslands, a complex transitional ecosystem between the Congo tropical rainforest to the north and the Kalahari Desert to the south. The Northern Kalahari Aquifer system underlies the southern-facing slopes of AHP, and the ubiquity of gleysols, histosols and fluvisols suggests that soil moisture dynamics is a key process in regional hydroecology. Despite its central role in the partitioning of freshwater resources among different key basins, the hydroclimatology of the AHP and its role in the regional water cycle have not been investigated previously. This is the overarching goal of the proposed research.
This research addresses the question of whether this challenge can be addressed by factoring the opportunity costs of environmental constraints, and economic value of conservation strategies into hydro economic assessments of water allocation policy at the basin level.
Characterization of the Physical Properties of the Snowpack at Very High Resolution using RF Wireless Grid and Downscaling of Satellite-Based Estimates of Snow Water Equivalent
This summarizes the laboratory experiments using current 5 RF sensors. During the second year, reliability testing of 5 RF sensors was conducted using 20 dB attenuators. Next, a second set of experiments was designed to simulate the snowpack under laboratory conditions.
Characterizing the Spatial and Temporal Structure of Orographic Precipitation and its Relationship to Hydrologic Extremes in Mountain Landscapes
The research approach includes maintaining a science-grade orographic precipitation observing system in the Southern Appalachians, developing precipitation downscaling models conditional on orographic precipitation regimes, and process studies through data analysis and the integration of atmospheric and hydrologic models and ground-based observations and satellite products.
The Integrated Precipitation and Hydrology Experiment (IPHEx) centered in the Southern Appalachians and spanning into the Piedmont and Coastal Plain regions of North Carolina seeks to characterize warm season orographic precipitation regimes, and the relationship between precipitation regimes and hydrologic processes in regions of complex terrain.
MODIS satellite images show that the Himalayas act as a barrier for the aerosols being transported from the Indian Gangetic Plains (IGP). This accumulation of aerosols during the pre-monsoon season not only affects the radiation budget, but can also have a profound impact on the evolution of orographically induced clouds and the local hydrological cycle.
The Barros research group has installed a research-grade precipitation monitoring network in the Pigeon River Basin (PRB) in Western North Carolina. One meteorological tower and 32 rain gauges are currently deployed at high-elevation locations along ridgelines. In addition to collecting data from these instruments, which have been in the field for as long as three years, the group has conducted several Intensive Observation Periods (IOPs), at Purchase Knob, a central location along the Cataloochee Ridge in the PRB.
Using Satellite Data to Characterize the Role of Tropical Cyclones in the Ecohydrology of the Southeast United States
Tropical cyclones (TCs) are well known for hazardous aspects due to the damage and loss of life they cause along their track. Beyond this common association, hurricanes and tropical cyclones provide an important amount of freshwater to the landscape in a short time period. This significant input of freshwater is necessary for the recharge of surface and subsurface reservoirs for several regions of the world.