Evaluating the Impacts of Agriculture Conservation on Water Quantity and Quality Through Trend, Predictability, and...

We investigated the potential of nature-based solutions within the context of agriculture conservation practices (ACPs) that impact watershed hydrology and water quality in Shell Creek, Nebraska, USA. This region serves as an example of a successful watershed conversion driven by the collaboration of local stakeholders and government agencies, which also offers valuable solutions for addressing future climate challenges. We utilized a high-resolution remote sensing data covering a wide range of attributes, including continuous land cover, winter vegetation health, and summer cropping, and supplemented it with hydrometeorological and water quantity and quality data. The implementation patterns of ACPs and changes in water quantity and quality were studied using trend analysis. The data were then analyzed using explainable Artificial Intelligence and causal inference techniques to understand how ACPs lead to changes in water quantity and quality attributes. In addition, we carried out flood frequency analysis to assess the impact of ACPs on extreme flows. The findings suggested that winter cover cropping has extensively increased over the past 30 years. The health of winter vegetation also significantly improved, although there was an intensification in summer cropping. In the context of water quantity, extreme flood events have become less frequent. Results also showed a noticeable decrease in turbidity, total suspended solids concentration, and total phosphorus concentration. However, these changes were not statistically significant. The overall findings suggest that different nature-based solutions have increased in recent decades and have contributed to improvements in water quality and reductions in flood frequency in the watershed.