Landscape Architecture & Environmental Planning

Significant wetland losses and continuing threats to remnant habitats have motivated extensive restoration efforts in the San Francisco Bay–Delta estuary of California, the largest in the western United States. Consistent monitoring of ecological outcomes from this restoration effort would help managers learn from past projects to improve the design of future endeavors. However, budget constraints and challenging field conditions can limit the scope of current monitoring programs. Geospatial tools and remote sensing data sets could help complement field efforts for a low-cost, longer, and broader monitoring of wetland resources. To understand where geospatial tools could best complement current field monitoring practices, we reviewed the metrics and monitoring methods used by 42 wetland restoration projects implemented in the estuary. Monitoring strategies within our sample of monitoring plans relied predominantly on field surveys to assess key aspects of vegetation recovery while geospatial data sets were used sparingly. Drawing on recent publications that focus on the estuary and other wetland systems, we propose additional geospatial applications to help monitor the progress made toward site-specific and regional goals. These include the use of ecological niche models to target on-the-ground monitoring efforts, the up-scaling of field measurements into regional estimates using remote sensing data, and the analysis of time-series to detect ecosystem shifts. We discuss challenges and limitations to the broad-scale application of remote sensing data in wetland monitoring. These notably include the need to find a venue to store and share computationally intensive data sets, the often cumbersome pre-processing effort needed for long-term analyses, and multiple confounding factors that can obscure the signal of remote sensing data sets.

Large-scale ecosystem restoration projects seldom undergo comprehensive evaluation to determine project effectiveness. Consequently, there are missed opportunities for learning and strategy refinement. Before our study, monitoring information from California’s middle Sacramento River had not been synthesized, despite restoration having been ongoing since 1989. Our assessment was based on the development and application of 36 quantitative ecological indicators. These indicators were used to characterize the status of terrestrial and floodplain resources (e.g., flora and fauna), channel dynamics (e.g., planform, geomorphology), and the flow regime. Indicators were also associated with specific goal statements of the CALFED Ecosystem Restoration Program. A collective weight of evidence approach was used to assess restoration success. Our synthesis demonstrates good progress in the restoration of riparian habitats, birds and other wildlife, but not in restoration of streamflows and geomorphic processes. For example, from 1999 to 2007, there was a > 600% increase in forest patch core size, and a 43% increase in the area of the river bordered by natural habitat > 500 m wide. Species richness of landbirds and beetles increased at restoration sites, as did detections of bats. However, degraded post-Shasta Dam streamflow conditions continued. Relative to pre-dam conditions, the average number of years that pass between flows that are sufficient to mobilize the bed, and those that are of sufficient magnitude to inundate the floodplain, increased by over 100%. Trends in geomorphic processes were strongly negative, with increases in the amount of bank hardened with riprap, and decreases in the area of floodplain reworked. Overall the channel simplified, becoming less sinuous with reduced overall channel length. Our progress assessment presents a compelling case for what needs to be done to further advance the ecological restoration of the river. The most important actions to be taken relate to promoting river meander and floodplain connectivity, and restoring components of the natural flow regime.

Hydropower, although an attractive renewable energy source, can alter the flux of water, sediments, and biota, producing detrimental impacts in downstream regions. The Mekong River illustrates the impacts of large dams and the limitations of conventional dam regulating strategies. Even under the most optimistic sluicing scenario, sediment load at the Mekong Delta could only recover to 62.3 ± 8.2 million tonnes (1 million tonnes = 109 kilograms), short of the (100 to 160)-million tonne historical level. Furthermore, unless retrofit to reroute sediments, the dams are doomed to continue trapping sediment for at least 170 years and thus starve downstream reaches of sediment, contributing to the impending disappearance of the Mekong Delta. Therefore, we explicitly challenge the widespread use of large dead storages-the portion of the reservoirs that cannot be emptied-in dam designs. Smaller dead storages can ease sediment starvation in downstream regions, thereby buffering against sinking deltas or relative sea level rises.

WILDERNESS / UX - DESIGN RESEARCH “Design & Planning Opportunities for the Big Sur Region” THIS RESEARCH WAS SUPPORTED BY THE PEDER SATHER CENTER FOR ADVANCED STUDY AT UC BERKELEY LANDSCAPE ARCHITECTURE AND ENVIRONMENTAL PLANNING UC BERKELEY LDARCH 203 - FALL 2023 Isaiah Rapko Olivia Jones Lynsey Coke-Ferreira Aishwarya Dharmarajan Eli Demosthenes Lulu Liu Dongni Ma Luis Lu Jie Han Aishvarya Dubey Alex Jordan Claudia Lamberty Instructor: Richard

Modernist ontologies of water physically materialise in Phoenix’s landscape: over 100 miles of canals convey water to the suburban grid, where thousands of gallons are piped into backyard swimming pools. The canal and pool are thus joined in architectural folly to move, hold, and control water in the service of sustaining the belief that dry ecologies are but supply chain problems in need of engineering solutions. These typologies reveal longstanding entanglements between the promises of modernity and aridland urbanism; and they further amplify the immense challenge of transitioning away from modern water infrastructure in the face of climate change. By using the canal and the pool as signifiers of the insidious entanglements between modernity, growth, and aridland urbanism, this article advances an historical examination of Phoenix that destabilises tropes of water scarcity as a problem to be solved but which has also created cultural perceptions of abundant water.

The climate resilience of river deltas is threatened by rising sea levels, accelerated land subsidence, and reduced sediment supply from contributing river basins. Yet, these uncertain and rapidly changing threats are rarely considered in conjunction. Here we provide an integrated assessment, on basin and delta scales, to identify key planning levers for increasing the climate resilience of the Mekong Delta. We find, first, that 23 to 90% of this unusually productive delta might fall below sea level by 2100, with the large uncertainty driven mainly by future management of groundwater pumping and associated land subsidence. Second, maintaining sediment supply from the basin is crucial under all scenarios for maintaining delta land and enhancing the climate resilience of the system. We then use a bottom-up approach to identify basin development scenarios that are compatible with maintaining sediment supply at current levels. This analysis highlights, third, that strategic placement of hydropower dams will be more important for maintaining sediment supply than either projected increases in sediment yields or improved sediment management at individual dams. Our results demonstrate 1) the need for integrated planning across basin and delta scales, 2) the role of river sediment management as a nature-based solution to increase delta resilience, and 3) global benefits from strategic basin management to maintain resilient deltas, especially under uncertain and changing conditions.