University Stormwater Management within Urban Environmental Regulatory Regimes: Barriers to Progressivity or Opportunities to Innovate?

U.S. public university campuses are held directly responsible for compliance with many of the same federal- and state-level environmental regulations as cities, including stormwater management. While operating as 'cities within cities' in many respects, campuses face unique constraints in achieving stormwater regulatory compliance. To compare the abilities of campuses to comply with stormwater regulations to municipalities, we conduct mixed-methods research using primary data from five University of California (UC) campuses. Public universities constituted over 20% of California's "nontraditional" permittees under the municipal separate storm sewer system (MS4) regulation regime in 2013. We utilize semi-structured interviews with campus and regulatory officials, a survey of campus students and staff around support and willingness to pay for innovative stormwater management, and content analysis of campus stormwater management documents to examine challenges to public university stormwater compliance. We find that, despite their progressive environmental practices in other areas like energy and water conservation, even as compared to cities, stormwater management practices on the evaluated campuses are constrained by several factors: infrastructure financing limitations, lack of transparent and coordinated decision-making, a lack of campus resident involvement, and regulatory inflexibility. Our study provides new insights, both for understanding campuses as sustainable 'cities within cities' and more broadly for urban environmental compliance regimes globally

University Stormwater Management within Urban Environmental Regulatory Regimes: Barriers to Progressivity or Opportunities to Innovate?

U.S. public university campuses are held directly responsible for compliance with many of the same federal- and state-level environmental regulations as cities, including stormwater management. While operating as 'cities within cities' in many respects, campuses face unique constraints in achieving stormwater regulatory compliance. To compare the abilities of campuses to comply with stormwater regulations to municipalities, we conduct mixed-methods research using primary data from five University of California (UC) campuses. Public universities constituted over 20% of California's "nontraditional" permittees under the municipal separate storm sewer system (MS4) regulation regime in 2013. We utilize semi-structured interviews with campus and regulatory officials, a survey of campus students and staff around support and willingness to pay for innovative stormwater management, and content analysis of campus stormwater management documents to examine challenges to public university stormwater compliance. We find that, despite their progressive environmental practices in other areas like energy and water conservation, even as compared to cities, stormwater management practices on the evaluated campuses are constrained by several factors: infrastructure financing limitations, lack of transparent and coordinated decision-making, a lack of campus resident involvement, and regulatory inflexibility. Our study provides new insights, both for understanding campuses as sustainable 'cities within cities' and more broadly for urban environmental compliance regimes globally

Denser and greener cities: Green interventions to achieve both urban density and nature

Abstract Green spaces in urban areas—like remnant habitat, parks, constructed wetlands, and street trees—supply multiple benefits. Many studies show green spaces in and near urban areas play important roles harbouring biodiversity and promoting human well‐being. On the other hand, evidence suggests that greater human population density enables compact, low‐carbon cities that spare habitat conversion at the fringes of expanding urban areas, while also allowing more walkable and livable cities. How then can urban areas have abundant green spaces as well as density? In this paper, we review the empirical evidence for the relationships between urban density, nature, and sustainability. We also present a quantitative analysis of data on urban tree canopy cover and open space for United States large urbanized areas, as well as an analysis of non‐US Functional Urban Areas in OECD countries. We found that there is a negative correlation between population density and these green spaces. For Functional Urban Areas in the OECD, a 10% increase in density is associated with a 2.9% decline in tree cover. We argue that there are competing trade‐offs between the benefits of density for sustainability and the benefits of nature for human well‐being. Planners must decide an appropriate density by choosing where to be on this trade‐off curve, taking into account city‐specific urban planning goals and context. However, while the negative correlation between population density and tree cover is modest at the level of US urbanized areas (R2 = 0.22), it is weak at the US Census block level (R2 = 0.05), showing that there are significant brightspots, neighbourhoods that manage to have more tree canopy than would be expected based upon their level of density. We then describe techniques for how urban planners and designers can create more brightspots, identifying a typology of urban forms and listing green interventions appropriate for each form. We also analyse policies that enable these green interventions illustrating them with the case studies of Curitiba and Singapore. We conclude that while there are tensions between density and urban green spaces, an urban world that is both green and dense is possible, if society chooses to take advantage of the available green interventions and create it. Read the free Plain Language Summary for this article on the Journal blog

Probing the depths of the India-Asia collision : U-Th-Pb monazite chronology of granulites from NW Bhutan

Rocks metamorphosed to high temperatures and/or high pressures are rare across the Himalayan orogen, where peak metamorphic conditions recorded in the exposed metamorphic core, the Greater Himalayan Sequence (GHS), are generally at middle to upper amphibolite facies. However, mafic garnet-clinopyroxene assemblages exposed at the highest structural levels in Bhutan, eastern Himalaya, preserve patchy textural evidence for early eclogite-facies conditions, overprinted by granulite-facies conditions. Monazite hosted within the leucosome of neighboring granulite-facies orthopyroxene-bearing felsic gneiss yields LA-MC-ICP-MS U-Th-Pb ages of 13.9 ± 0.3 Ma. Monazite associated with sillimanite-grade metamorphism in granulite-hosting migmatitic gneisses yields U-Th-Pb rim ages between 15.4 ± 0.8 Ma and 13.4 ± 0.5 Ma. Monazite associated with sillimanite-grade metamorphism in gneiss at structurally lower levels yields U-Pb rim ages of 21–17 Ma. These data are consistent with Miocene exhumation of GHS material from a variety of crustal depths at different times along the Himalayan orogen. We propose that these granulitized eclogites represent lower crustal material exhumed by tectonic forcing over an incoming Indian crustal ramp and that they formed in a different tectonic regime to the ultrahigh-pressure eclogites in the western Himalaya. Their formation and exhumation in the Miocene therefore do not require diachroneity in the timing of the initial India-Asia collision

Retention of Sm-Nd isotopic ages in garnets subjected to high-grade thermal reworking: implications for diffusion rates of major and rare earth elements and the Sm-Nd closure temperature in garnet

Accepted: 21 June 2009. Published online: 10 July 2009Garnet is a vital mineral for determining constrained P–T–t paths as it can give both the P–T and t information directly. However, estimates of the closure temperature of the Sm–Nd system in garnet vary considerably leading to significant uncertainties in the timing of peak conditions. In this study, five igneous garnets from an early Proterozoic 2414 ± 6 Ma garnet—cordierite bearing s-type granite—which was subjected to high-T reworking have been dated to examine their diffusional behaviour in the Sm–Nd system. Garnets 8, 7, 6 and 2.5 mm in diameter were compositionally profiled and then dated, producing two-point Sm–Nd isochron ages of 2412 ± 10, 2377 ± 5, 2370 ± 5 and 2365 ± 8 and 2313 ± 11 Ma, respectively. A direct correlation exists between grain size and amount of resetting highlighting the effect of grain size on closure temperature. Major element EMPA and LA-ICPMS REE traverses reveal homogenous major element profiles and relict igneous REE profiles. The retention of REE zoning and homogenisation of major element zoning suggest that diffusion rates of REEs are considerably slower than that of the major cations. The retention of REE zoning and the lack of resetting in the largest grains suggest that Sm–Nd closure temperature in garnet is a function of grain size, thermal history and REE zoning in garnetRian Dutch and Martin Han