Ground, Proximal, and Satellite Remote Sensing of Soil Moisture

Soil moisture (SM) is a key hydrologic state variable that is of significant importance for numerous Earth and environmental science applications that directly impact the global environment and human society. Potential applications include, but are not limited to, forecasting of weather and climate variability; prediction and monitoring of drought conditions; management and allocation of water resources; agricultural plant production and alleviation of famine; prevention of natural disasters such as wild fires, landslides, floods, and dust storms; or monitoring of ecosystem response to climate change. Because of the importance and wide‐ranging applicability of highly variable spatial and temporal SM information that links the water, energy, and carbon cycles, significant efforts and resources have been devoted in recent years to advance SM measurement and monitoring capabilities from the point to the global scales. This review encompasses recent advances and the state‐of‐the‐art of ground, proximal, and novel SM remote sensing techniques at various spatial and temporal scales and identifies critical future research needs and directions to further advance and optimize technology, analysis and retrieval methods, and the application of SM information to improve the understanding of critical zone moisture dynamics. Despite the impressive progress over the last decade, there are still many opportunities and needs to, for example, improve SM retrieval from remotely sensed optical, thermal, and microwave data and opportunities for novel applications of SM information for water resources management, sustainable environmental development, and food security

Bulk Density Optimization to Determine Subsurface Hydraulic Properties in Rocky Mountain Catchments Using the GEOtop Model

Integrated watershed models can be used to calculate streamflow generation in snow‐dominated mountainous catchments. Parameterization of water flow is often complicated by the lack of information on subsurface hydraulic properties. In this study, bulk density optimization was used to determine hydraulic parameters for the upper and lower regolith in the GEOtop model. The methodology was tested in two small catchments in the Dry Creek Watershed in Idaho and the Libby Creek Watershed in Wyoming. Modelling efficiencies for profile‐average soil–water content for the two catchments were between 0.52 and 0.64. Modelling efficiencies for stream discharge (cumulative stream discharge) were 0.45 (0.91) and 0.54 (0.94) for the Idaho and Wyoming catchments, respectively. The calculated hydraulic properties suggest that lateral flow across the upper–lower regolith interface is an important driver of streamflow in both the Idaho and Wyoming watersheds. The overall calibration procedure is computationally efficient because only two bulk density values are optimized. The two‐parameter calibration procedure was complicated by uncertainty in hydraulic conductivity anisotropy. Different upper regolith hydraulic conductivity anisotropy factors had to be tested in order to describe streamflow in both catchments

Modeling the Water and Energy Balance of Vegetated Areas with Snow Accumulation

The ability to quantify soil-atmosphere water and energy exchange is important in understanding agricultural and natural ecosystems, as well as the earth\u27s climate. We developed a one-dimensional vertical model that calculates solar radiation, canopy energy balance, surface energy balance, snowpack dynamics, soil water flow, and snow–soil–bedrock heat exchange, including soil water freezing. The processes are loosely coupled (solved sequentially) to limit the computational burden. The model was applied to describe water and energy dynamics for a northeast-facing mountain slope in the Dry Creek Experimental Watershed near Boise, ID. Calibration was achieved by optimizing the saturated soil hydraulic conductivity. Validation results showed that the model can successfully calculate seasonal dynamics in snow height, soil water content, and soil temperature. Both the calibration and validation years confirmed earlier results that evapotranspiration on the northeast-facing slope consumes approximately 60% of yearly precipitation, while deep percolation from the soil profile constitutes about 40% of yearly precipitation

Fractionated 5-aminolevulinic acid photodynamic therapy after partial debulking versus surgical excision for nodular basal cell carcinoma: A randomized controlled trial with at least 5-year follow-up

Background: Although effective in superficial basal cell carcinoma (BCC), the treatment effect of photodynamic therapy (PDT) in nodular BCC (nBCC) is still questionable. The relation between tumor thickness and PDT failure is unclear. Objective: We sought to compare long-term effectiveness of fractionated 20% 5-aminolevulinic acid (ALA)-PDT with prior partial debulking versus surgical excision in nBCC. The effect of tumor thickness on ALA-PDT failure was analyzed. Methods: 173 primary, histologically proven nBCCs in 151 patients were randomized to fractionated ALA-PDT (n = 85) or surgical excision (n = 88). Two PDT illuminations were performed with a 1-hour interval. Follow-up was at least 5 years posttreatment. Clinical recurrences were confirmed histologically. Results: A total of 171 nBCCs were treated and had a median follow-up of 67 months (range 0-106). At 60 months, 23 tumors had recurred in the ALA-PDT group and 2 tumors in the surgical excision group. Cumulative recurrence probabilities 5 years posttreatment were 30.7% (95% confidence interval [CI] 21.5%-42.6%) for ALA-PDT and 2.3% (95% CI 0.6%-8.8%) for surgical excision (P <.0001). Two tumors in the ALA-PDT group recurred at 72 and 91 months posttreatment. Cumulative probability of recurrence-free survival post-PDT was 65.0% (95% CI 51%-76%) for nBCC measuring greater than 0.7 mm in thickness and 94.4% (95% CI 67%-99%, P = .018) for tumors less than or equal to 0.7 mm. Limitations: Tumor thickness on punch biopsy specimen might differ from the total lesion thickness. Conclusions: In nBCC, 5-year cumulative probability of recurrence after surgical excision is lower than after fractionated ALA-PDT with prior debulking. Although surgical excision remains the gold standard of treatment, PDT might be an alternative for inoperable patients with thin