Understanding hydrologic connectivity is essential for managing ephemeral headwater streams where upstream land use influences downstream aquatic habitats. This study relies on a field‐based approach to evaluate how precipitation and roads affect runoff generation in low‐order ephemeral streams of the U.S. Virgin Islands. Logistic regression analyses show that runoff delivery from unroaded catchments follows a water storage conceptual model typical for subsurface storm and saturation overland flow dominated settings. Without roads, runoff occurs only about four times per year in response to 10 and 78 mm of storm rainfall, depending on antecedent precipitation. In contrast, maximum fifteen‐minute rainfall intensities are a better predictor of runoff generation on unpaved roads than are total rainfall and antecedent conditions. Intensities surpassing ~10 mm hr^‐1 lead to road runoff and this occurs about 40 times per year. Road influenced streams represent an intermediate setting for which runoff generation depends on storm and antecedent rainfall, as well as the road surface area captured by drains and flow path distance. In our focus area, roads can provoke streams to deliver runoff to coral bearing waters 10 to 13 times every year as a response to 9.3 to 50 mm storms, depending on antecedent rainfall and road drain characteristics. These results highlight the sensitivity of road connectivity to specific road drain characteristics and display the potential for connectivity as a guiding watershed restoration principle.

Although agricultural intensification generally has homogenizing effects on landscapes that reduce crop diversity, the specific effects of different input strategies on crop diversity are unclear. This study examines the effects of irrigation inputs on crop species diversity in Mexico. We assess the richness and evenness diversity of 297 crop species across 2455 municipalities while controlling for environmental and socioeconomic factors and farm structural and functional characteristics. Using a quantile regression approach, we assess relationships across conditional quantiles of low-, medium-, and high-diversity farm regions. Results show irrigation level (% cropland irrigated) is a strong positive predictor of crop species richness and evenness diversity across all quantile regions. Moreover, the quantile effects of irrigation on evenness diversity are five times greater in low-diversity rather than high-diversity regions. With implications for agricultural water policy in Mexico, this study illustrates the potential benefits of sustainable irrigation expansion in water-rich but irrigation-poor farming regions. Specifically, by enhancing crop species diversity, carefully targeted irrigation expansion can support the transition to sustainable intensification.

In Nigeria, the widespread lack of access to water, sanitation, and hygiene (WASH) represents a critical public health challenge. Yet, the socioeconomic determinants of WASH access at the national level remain poorly understood. This study uses 2018 Nigeria Demographic and Health Surveys (NDHS) cross-sectional data to investigate the socioeconomic factors associated with WASH access. The majority of survey respondents lived in rural areas (57%); used an improved source of drinking water (73%) and an improved sanitation facility (55%); and did not treat their drinking water (92%). Binary logistic regression showed that Nigerians living in rural areas were less likely to have access to an improved water source (p < 0.001, OR = 0.42 [0.41, 0.44]) and less likely to have access to an improved sanitation facility (p < 0.001, OR = 0.79 [0.77, 0.81]). A sub-group regression analysis of respondents without access to improved WASH found that rural residence (OR = 0.84 [0.76, 0.93]), along with lower levels of education and wealth were associated with non-treatment of their unimproved drinking water. This study suggests that efforts are needed to increase WASH access in rural areas and to improve household water treatment in areas without access to improved water and sanitation.