The present impediments to the implementation of sustainable practices in residential and commercial structures in the United States, India and Afghanistan will be evaluated and compared in this study. This study intends to identify the barriers to sustainable development within the residential and commercial buildings creating a basis for the methods to address these issues. The selection of these three countries was based on taking the United States as a developed country, India as developing country and Afghanistan as an undeveloped country. Understanding the barriers studied will establish a path to overcoming them and allow the market to open up to the widespread implementation of sustainable practices. According to the survey conducted, about 91% of respondents in Afghanistan, about 71% in India and 32% of respondents in the USA have moderate to low knowledge on sustainable construction. Other barriers mentioned in the study include the high cost of materials, insufficient training, government policy, and so on.

Recent efforts to address flooding have explored incorporating flow-reduction capabilities into existing infrastructure. Roadside ditches have historically been viewed as an underutilized component of flood reduction, and a two-stage design has been proposed that modifies a conventional trapezoidal ditch by incorporating bench insets along the main channel. While it is expected that this second stage becomes inundated during storm events, resulting in flow attenuation, the exact impacts of this design are unknown. This study quantified the impact of the two-stage design by modeling a roadside ditch corridor in eastern Iowa. An existing single-stage ditch was converted to a two-stage design, and a HEC-RAS model was constructed to investigate the ditch’s impacts for four design storms (1-year, 2-year, 5-year, and 10-year). In the modeled results, peak flow rates were reduced by 22%, 21%, 7.5%, and 4.3%, respectively, while water volume reductions were near 6%. Maximum velocities throughout the ditch corridor also decreased, with reductions spanning 32% (1-year)–45% (10-year). These results indicate that increased travel times and infiltration associated with the two-stage design provide hydrologic and hydraulic benefits by lessening flood and erosion risk. While further study is needed to verify this behavior through monitoring and modeling at other locations, our findings suggest that two-stage ditches can be a useful best management practice for the transportation community.

Although grass waterways are an effective conservation practice to reduce soil erosion, less is known about their subsurface hydrogeology. New research is highlighting the potential for NO₃-N load reductions in waterways, but studies have not been done to characterize regional patterns. In this study, we used field investigation and numerical modeling to evaluate subsurface hydrogeological conditions beneath grass waterways found in major landform regions of Iowa. Our goal was to identify waterways that could be best utilized in a new conservation practice aimed at reducing tile NO₃-N export from cropped fields. Waterway stratigraphy consisted of a layer of fine-textured, nutrient-rich sediment overlying glacial or post-glacial parent material. The mean hydraulic conductivity (K) of the alluvial sediments reflected a dominantly silty matrix and it was highest in northeast Iowa where sand contents were higher. Groundwater was largely anaerobic in lowland waterway areas, where high water tables contributed to low dissolved oxygen and NO₃-N concentrations in shallow groundwater. Numerical modeling parameterized using the field data showed that in terms of annual water balance, more water is exported from grass waterways in surface runoff compared to subsurface tile and groundwater flow. In terms of subsurface flow, tile water yields were higher in smaller and steeper catchments and when the K of the waterway alluvium was higher. Based on regional patterns of sedimentology and landscape topography, smaller and steeper catchments within a landform region found in NE Iowa may be most appropriate to test a new conservation practice aimed to capture and remediate tile NO₃-N export from grass waterways.

Prairie strips are narrow bands of native vegetation embedded within row‐crop fields. They are a promising nature‐based measure for reducing field‐scale flood peaks. We evaluated their hydrologic performance and placement sensitivity using an integrated surface‐subsurface model for two comparable sub‐watersheds in the US Midwest: a treatment watershed (TRT, 48,900 m²) and a corn‐only control (CTRL, 42,800 m²). Calibration/validation performance using observed runoff was NSE = 0.87 and KGE = 0.65. In comparison to a corn‐only baseline simulation, introducing prairie strips in a moderate rainfall condition reduced event total runoff volume by 84% and peak discharge by 64% in the 10%‐area scenario, and consistently delayed time‐to‐peak. Placement mattered: single footslope strips lowered peaks by ≈41.4%, upper and mid‐slope placements by ≈32%–33%, a middle and footslope combination by ≈54.3%, and a distributed 10% layout achieved the largest attenuation (≈63.8%). We tested the strips peak flow attenuation potential for design storms with return periods of 10, 25, 50, and 100 years. Across design storms, the greatest total‐runoff reduction occurred for the 10‐year event (36.3%), with diminishing benefits at higher return periods as infiltration and storage were exceeded. Overall, prairie strips provide a practical, farm‐compatible, and cost‐effective option for managing frequent storms, with meaningful benefits even when less than 10% of the field can be allocated, especially when strips are targeted to footslope zones or stacked across slope positions.