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Using combined sewer systems to handle excess stormwater runoff is common in older urban areas. Combined sewer overflow (CSO) events occur when hydraulic capacity is exceeded, and untreated wastewater discharges to surface waters. As urban population density increases, and more demand is placed on infrastructure, CSO events happen more often and cause serious environmental problems and public-health risks. Recently, green infrastructure (GI) has been integrated with existing gray infrastructure (GrayI) to reduce CSO events. However, there lacks a goal-oriented planning framework for eliminating CSOs at a watershed/sewershed scale. Moreover, existing stormwater simulations based on catchments or other geographic units, do not consider spatial variation within the unit, such as distribution, attribution, ownership, and management of GI. We propose a scenario-based Stormwater Management Planning Support System for CSOs (SMPSS-CSO) to provide a platform for reducing CSO events by coordinating parcel-based installations of GI. We applied the SMPSS-CSO to a sewershed with a single CSO location in Cincinnati, Ohio and developed four scenarios representing increased use of GI (rain barrels, green roofs, porous pavements, and detention basin) based on its cost, difficulty of installation, and property ownership. Runoff quantity, time of concentration, and peak flow rate were simulated using the curve number method. Our analysis shows a 41% reduction in stormwater runoff is necessary to eliminate CSO events for a two-year rainfall, required 97.25% of private and 27.59% of public parcels to install GI. GI alone cannot eliminate CSO events in this sewershed and must be incorporated with additional GrayI (e.g., storage tanks, pipes). The SMPSS-CSO has the potential for including multiple stakeholders' preferences and concerns in the searching for preferable scenarios.

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Conservation efforts and cooperation from major stakeholders are critical factors for cultural heritage (e.g., historical landmarks) sustainability. Although landscape planners provide professional knowledge and intended designs for sustainable management of cultural heritage sites, the active effort and participation of local residents or communities are the decisive facts of whether relevant preservation actions can be successfully implemented. Traditional village landscapes in Qing Mu Chuan, China, were selected as the study area. We used photo questionnaires to explore the preferences, value perceptions, and preservation attitudes toward traditional village landscapes of landscape professionals and local residents. The results revealed large differences in the perceptions and preservation attitudes toward traditional village landscapes between the two groups. The most unexpected finding was that the local residents showed much stronger preferences and preservation willingness toward traditional village landscapes with cultural elements than the professionals. In addition, the local residents’ preservation attitudes were mainly affected by their perception of economic benefits and daily utility values, rather than cultural values. Meanwhile, the preservation of professionals’ attitudes was significantly related to recreational and cultural value perceptions. These findings will direct the participatory planning process to provide appropriate incentives for developing the preservation attitudes of local residents. They will also support the implementation of participatory planning to promote the positive collaboration of local residents and landscape planners toward cultural heritage sustainability.

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