Journal of Contemporary Water Research & Education最新文献

The increased incidences of pipe breaks worldwide are posing a serious threat to potable water security in urban communities. The consequences may involve water loss and service interruptions, compromised water quality, infrastructure disruptions, and loss of revenue. Thus, creating failure assessment models is quite crucial to sustain water distribution networks (WDNs) and to optimize maintenance spending. This research paper aims at developing an assessment framework for water systems, as well as modeling the failure phenomena toward sustainable management of underground infrastructure. The city of El Pedregal in Peru was chosen to exemplify the methodology of the research due to the rapid pace of urbanization and growing economic activities in the region, which make water infrastructure even more critical. The framework is based on the application of modeling techniques stemming from statistical regression analysis (RA) and 3D schematic representation. First, the influential factors that lead to the deterioration of the WDNs are determined. Second, the RA technique is leveraged to evaluate and model the failure rate through consecutive simulation operations and a 3D surface plot. Finally, the efficacy of the model is investigated using different performance metrics, in conjunction with a residual analysis scheme. The validation results revealed the robustness of the model with R-squared (R²) and the sum of squares error (SSE) of 0.9767 and 0.0008, respectively. The developed model is a predictive tool that can be used by municipal engineers as a preemptive measure against future pipeline bursts or leaks.

Seated at the foot of the Misti volcano in an area prone to intense seasonal rains and earthquakes, the city of Arequipa is highly vulnerable to natural disasters. During the rainy season, intense storms create large volumes of runoff that rush through the city's ephemeral streams, known locally as torrenteras. Episodic flows in these torrenteras have caused flooding, damage to bridges, homes, and other infrastructure, and caused many deaths. In recent years, while unprecedented rain events have caused extreme disasters, the city's population has continued to expand into these channels by creating informal or illegal settlements. Currently, detailed hazard maps of flood-prone areas surrounding the torrenteras are not available to stakeholders in Arequipa. In this study, hydrologic and hydraulic models were combined to assess flash flood hazards, including inundation, velocity hazards, and slope instability hazards. Hydrologic models were created using satellite precipitation data and terrain-sensitive, gridded climate maps to characterize flow within six torrenteras in Arequipa. These flows were used in conjunction with elevation data and data collected in the field using an online mobile application system to develop a hydraulic model of these flood events. Hydraulic model outputs were used to determine flood hazards related to inundation, velocity affecting human stability, and slope instability in case study areas of the torrenteras. We then discuss how this information can be used by disaster risk management groups, water authorities, planners and municipalities, and community groups.

The confluence of the Little Colorado and Colorado Rivers is an Indigenous socio-ecological landscape, revolving in large part around water resources. Substantial surface and groundwater use within the Little Colorado River (LCR) basin threatens the water sources of the confluence, springs in the LCR basin, and specifically the Hopi Sipapuni—a sacred site of cultural emergence. To address concerns about diminished flows of sacred springs, we engaged in praxis through collaborative, reciprocal, community-based research processes. Through the lens of anticolonial theory, we ask: Can federal policies be employed in an anticolonial pursuit of water and sacred site protection? How do Indigenous grassroots organizers envision protection and work to re-Indigenize water management? Semi-structured interviews with Indigenous community organizers and federal land managers were coupled with policy analysis of the National Historic Preservation Act/Traditional Cultural Properties, the ongoing LCR Adjudication, and the Treaty of Guadalupe Hidalgo. Findings point to multifaceted, complex, and contradictory themes that elucidate the continued influence of colonization on water governance and the degree to which protection solutions can be anticolonial. Criteria were generated for anticolonial protective pathways that highlight the centrality of reciprocal relationships, Indigenous Knowledges, and meaningful inclusion. While details about protection pathways for the confluence and Sipapuni are many, the salient finding is that the struggle for water protection in the LCR is the struggle for protection of inherent Indigenous rights.

The Portage Waterway in Michigan's Upper Peninsula supports traditional Anishnaabe walleye (or ogaawag in the Anishnaabe language) spear-harvesting for the Keweenaw Bay Indian Community (KBIC). Through reserved Indian treaty fishing rights, KBIC is highly involved in the waterway's stewardship and annual community spear-harvest. Tribal leadership and fisheries personnel have long documented that annual harvests are far below sustainable quotas. The objectives of this research were to 1) understand the values and concerns of KBIC tribal members on Anishnaabe walleye (ogaawag) spear-harvesting, 2) examine water temperature patterns during the spring 2018 harvest to seek insight on how harvests may be optimized, and 3) integrate Anishinaabe gikendaasowin or traditional knowledge with science and education. We conducted an online survey in February 2018, containing 27 questions, to gain preliminary insight on KBIC's perspectives of the annual walleye (ogaawag) spear-harvest. Nearly all respondents highly value the spear-harvest tradition personally and on behalf of the community. Similarly, nearly all agreed that it is important for the KBIC to manage its own fishery resources, and that the Tribe's Natural Resources Department effectively does so. Respondents also expressed concerns about factors that could impact their harvests, including environmental changes and confrontations with non-Native residents. From May 1 to May 19, 2018, we deployed 13 Onset HOBO Pro V2 temperature dataloggers across the Portage Waterway to measure spring warming patterns in locations popular for spear-fishing. This period encompassed the entire KBIC spear-harvest season, with dataloggers recording water temperature every two hours. Temperature data show that management of the harvest season may need revision, as embayments and sloughs where spear-fishing largely occurs warmed significantly earlier than other parts of the waterway. As the presence of walleye (ogaawag) in shallow waters depends on temperature, some parts of the waterway should be opened for harvesting earlier. Our findings will be prepared in a formal recommendation for KBIC leadership in efforts to increase harvests for the Tribal community that rely on walleye (ogaawag) as a sacred and traditional food source.

Emerging contaminants in Tribal water have been unexplored until implementation of the Unregulated Contaminant Monitoring Rule (UCMR) campaigns, which mandated the analysis of up to 30 new contaminants in drinking water every five years. As additions to the Safe Water Drinking Act (SDWA), the UCMR1 – 3 were created to assess contaminants which have not yet been assigned a maximum contaminant level (MCL) but may be regulated in the future to protect human health. While a handful of Tribes (n = 6) participated in UCMR1, public water systems (PWS) within reservation boundaries were intentionally included in representative nation-wide sampling beginning with UCMR2 after a period of Tribal consultation. Still, less than 3% of Tribal PWS were surveyed. The results from UCMR2 revealed that samples from all surveyed Tribal PWS fell below the method detection limits. Target analytes shifted to metals, perfluorinated chemicals, hormones, volatile organic compounds (VOCs), dioxane, and chlorate under UCMR3. Detectable levels of metals (chromium, hexavalent chromium, strontium, and vanadium), chlorate, and dioxane were observed, and in some cases, at concentrations greater than the U.S. Environmental Protection Agency's (EPA's) recommended health reference limit (HRL). The presence of elevated levels of vanadium, strontium, 1,4-dioxane, perfluorooctanesulfonate (PFOS), and chlorate defines a new set of emerging contaminants that needs to be considered with regards to risk, reporting and monitoring, and water treatment in Tribal drinking water.