Capture & Recharge Strategies

Urban and Natural Landscape Strategies

We are investigating the impact of land management practices on the hydrologic cycle using a combination of empirical analyses, remote sensing, and publicly available models. Specifically, models such as SnowPALM, ECOSTRESS, and Noah-MP are used along with empirical analyses and remote sensing to investigate the impact of forest thinning, wildfires, and stream channel management on hydrologic components (evapotranspiration, soil moisture, runoff, etc.) that affect recharge in natural areas. Empirical analyses and models such as KINEROS2 and HYDRUS 1-D are combined with machine learning to evaluate recharge strategies such as retention/detention basins and drywells in urban areas. 

There is a wide array of capture and recharge strategies available to natural resource managers, some of which are common practice and others that are innovative ideas that are not well-recognized or investigated. Our project has focused on identifying and evaluating a broad range of options for urban, rural, and wildland applications through the development of a capture and recharge opportunities and constraints matrix (currently in progress).

Publications

Forest Patch Geometry and Climate Regulate the Impact of Forest Thinning on Snowpack in the Southwest United States

Broxton, P. D., Biederman, J. A., Dwivedi, R., van Leeuwen, W. J. D., Sankey, T. Ts., Woolley, T., & Svoma, B. M. (2025). Forest Patch Geometry and climate regulate the impact of forest thinning on snowpack in the Southwest United States. Ecohydrology, 18(6). https://doi.org/10.1002/eco.70111 

Abstract: Despite having important implications for water resources, the climatic dependence of forest thinning impacts on snowpack is poorly quantified. In this study, we used a high-resolution snow model to understand the impact of forest thinning on snowpack in Arizona under contrasting climate conditions, leading to ephemeral vs. seasonal snowpack conditions. The model is evaluated using a spatiotemporally extensive set of snowpack measurements and is run for the same set of pre- and post-thinning forest patch geometry using two meteorological forcing datasets representing locally mid- and high-elevation climate conditions. Although the high-elevation climate is only 1°C cooler and has 20% more winter precipitation, it leads to markedly different snowpack conditions, i.e., twice as long-lasting snowpack, less mid-winter ablation events and ~60% larger at its peak. For both climates, forest thinning increased peak snow water equivalent (SWE) and liquid water input (LWI), but it decreased snow cover duration (SCD) only for the high-elevation climate. Total sublimation losses decreased from ~35% of wintertime precipitation pre-thinning to ~25% post-thinning for the high-elevation climate and from ~25% to ~15% for the mid-elevation climate. Generally, a 10% reduction in canopy cover resulted in ~4.5% more snowfall reaching the ground, and a 10-day decrease in SCD reduced the fraction of winter precipitation lost to snowpack sublimation by ~2%. Post-thinning changes in forest patch geometry were also important as larger canopy gaps had more LWI, and areas with warmer canopy edges had lower peak SWE and SCD.

ECOSTRESS-derived semi-arid forest temperature and evapotranspiration estimates demonstrate drought and thinning impacts

Sankey, T. T., Kyaw, T. Y., Tatum, J., Koch, G. W., Kolb, T., Lewis, R., Poulos, H. M., Barton, A. M., LaSala, B., & Thode, A. (2025). Ecostress‐derived semi‐arid forest temperature and evapotranspiration estimates demonstrate drought and thinning impacts. Remote Sensing in Ecology and Conservation. https://doi.org/10.1002/rse2.70026 

Abstract: Southwestern US forests are experiencing increasing wildfire activity, and land managers are implementing large-scale forest thinning treatments. We investigated semi-arid ponderosa pine forest thinning treatment and regional drought impacts on ECOSTRESS land surface temperature (LST) and evapotranspiration (ET). Our study period at a northern Arizona study site included an average precipitation year, 2019, a regional drought period of 2020–2022, and a record winter snowfall year 2023. We examined ECOSTRESS LST and ET during spring seasons when the region experiences an annual dry period, and plant water stress is heightened. Our results indicate that ECOSTRESS LST data are sensitive to forest thinning, regional drought and their interaction. Consistent with high-resolution UAV images, ECOSTRESS LST data indicate the thinned forest had significantly greater temperature across years, regardless of precipitation patterns. During drought, ECOSTRESS LST increased in both thinned and non-thinned forests (by up to 10°C) and then declined in 2023. ECOSTRESS ET was similarly sensitive to forest thinning and regional drought. Consistent with in situ ET measurements, ECOSTRESS ET was significantly greater in the non-thinned forest compared to the thinned forest. ECOSTRESS ET significantly decreased during drought in both forests. Our analysis of EMIT data indicates that EMIT trends are not consistent with ground-based hyperspectral data that documented thinned forest moisture content is greater than that of the non-thinned forest. While quality filtering reduces ECOSTRESS data temporal resolution, both ECOSTRESS LST and ET data can be used across large spatial extents to examine impacts of regional drought and management treatments in semi-arid ponderosa pine forests.

Stormwater capture as a pathway to enhance groundwater recharge: A potential assessment in arid to semi-arid urban landscapes

Su, X., Dai, Q., Yao, C., Gupta, N., Korgaonkar, Y., Milczarek, M., Tong, D., & Xu, T. (2025). Stormwater capture as a pathway to enhance groundwater recharge: A potential assessment in arid to semi-arid urban landscapes. City and Environment Interactions, 26, 100190. https://doi.org/10.1016/j.cacint.2025.100190

Abstract: In semi-arid to arid regions, urban stormwater management practices (SMPs) can be used to capture runoff and enhance local groundwater recharge. This study develops a novel, transferable, easy-to-implement method that utilizes open public records and LiDAR data to quantify stormwater runoff captured by SMPs. The novel approach is demonstrated using the Phoenix Active Management Area (Phoenix AMA), a large metropolitan region in semi-arid to arid central Arizona. We employ a spatially distributed approach to analyse stormwater runoff capture under a portfolio of historical and future (1992–2058) climate and urbanization scenarios, with a focus on drywells and retention/detention ponds. It was found that existing drywell installations captured approximately 7.2 % of the total runoff in the Phoenix AMA during 2010–2020, or an average annual volume of 19,300 acre-ft (2.38 × 107m3). Retention/detention ponds are estimated to capture 82,900 acre-ft (1.02 × 108m3) annually during 2010–2019, or 28.4 % of the total runoff. Projections suggest that over 45,000 acre-ft (5.55 × 107m3) of more runoff could be captured per year under future climate and urbanization scenarios by 2058, with most of the increase attributed to urbanization. The results highlight the significant role of SMPs in mitigating stormwater runoff and improving local groundwater recharge. Our approach is transferable to other regions sharing the need for stormwater capture yet lacking detailed infrastructure data.