A Systematic Review of Methodological Tools for Evaluating the Water, Energy, Food, and One Health Nexus in Transboundary Water Basins.

Water plays a vital role in human socioeconomic development and overall well-being, making its effective management essential in achieving the Sustainable Development Goals. The close interlinkage between water, other environmental resources, and socioeconomic development have prompted the emergence and adoption of holistic and trans-sectoral concepts such as integrated water resources management and, more recently, the resource nexus. However, even such holistic approaches often exclude the one health approach, particularly at the transboundary water basins (TWBs), which not only dominate 40% of the earth but are vital in environmental and human sustainability. This review aimed to understand, evaluate, and compare assessment tools for water, energy, food, and one health (WEF + H) nexus management in TWBs. The review applied the systematic review guidelines for articles published in the Scopus database. The inclusion criteria encompassed English-language articles featuring case studies, meta-studies, or review articles with no less than three nexus resources. The review categorized the article based on criteria that focused on identifying tools capable of analyzing scenarios and policies for WEF + H in TWBs and their accessibility and easiness of implementation in case studies. Of the eighteen analyzed tools, 13 (72%) had limitations in their application at various geographical scales. Additionally, they could not integrate one health into the nexus or analyze policies through running scenarios. On the contrary, the Bayesian networks, system dynamics, agent-based models, life-cycle assessments, and input-output tools were highly accessible for efficiently conducting scenario-based WEF + H nexus assessments in TWBs.

Green water appropriation of the cropland ecosystem in China.

Despite the awareness that green water is the main source of water to produce food, studies on green water use in cropland ecosystems are still rather limited, and almost no research has so far explored the relationship between green water utilization and socioeconomic development. In this study, with the help of CropWat 8.0, the green water footprint (GWF) of main crops in China was estimated from 1979 to 2016. On this basis, a novel concept, i.e., green water appropriation rate (GWar), was introduced to reveal the relationship between GWF and precipitation. Then, for the first time, the center of gravity trajectory of the GWar and the correlation between GWar and socioeconomic factors were further investigated. The results show that the provinces with the largest increases of GWF were Inner Mongolia (223%), Xinjiang (127%), and Ningxia (123%), while the GWF of 11 provinces has decreased, and 9 of them were municipalities or coastal areas. Generally, the GWar in the eastern and central provinces was higher than that in the western provinces. The center of gravity of the GWar has always been in Henan Province, but it has moved westward from Kaifeng City in 1979 to Sanmenxia City in 2016 and may further move to Shanxi Province soon. The total power of agricultural machinery and the effective irrigation rate had a positive correlation with the GWar, while the agricultural GDP was negatively correlated with the GWar. It is expected that the results will explicitly provide a scientific basis for the development of water-appropriate agriculture and the full utilization of rainwater.

Hydro-social dynamics of miningscapes: Obstacles to implementing water protection legislation in Mongolia.

Waterscapes with mining activities are often sites of water resource degradation and contestation. To prevent this, policy-makers deploy an increasing number of measures that purportedly align the interests of different water users. In Mongolia, mining-related protests led to the prohibition of mining in and close to rivers. However, implementation of these regulations has been slow. In this paper, we investigate why that is the case, drawing on an extended elaboration of the Institutional Analysis and Development (IAD) framework to disentangle the web of formal and informal rules, incentive structures, discourses, and other elements that characterize Mongolian miningscapes. We find that i) a combination of insufficient resources for lower-level actors, large areas to cover and high mobility of extractive operations, ii) a lack of information among implementing entities, combined with time pressure on decision-making and a lack of involvement of local actors, and iii) cultural norms and political context conditions that privilege the pursuit of private interests are key obstacles. Irrespective of these challenges, the prohibition of mining in riverbeds entrenches a social imaginary in the Mongolian governance framework that prioritizes water resources protection over resource extraction, offering a counterweight to dominant discourses that cast mining as a necessary requirement for social and economic development. Our analysis illustrates the usefulness of looking at implementation processes through the lens of mining- and waterscapes to identify how social power is embedded in social-political artifacts and impacts hydro-social outcomes. Strong discrepancies between the formal description of governance processes and interactions on the ground support the need to look at how processes play out in practice in order to understand implementation obstacles.

Arsenic distribution and pathway scenarios for sediments and water in a peri-urban Mongolian small-scale coal mining area (Nalaikh District, Ulaanbaatar).

The distribution of arsenic (As) in environmental compartments is investigated in the Nalaikh Depression of N-Mongolia. In Nalaikh, lignite coal is mined by artisanal small-scale mining (ASM) approaches. Because As is often associated with sulfuric minerals in coal, it was hypothesized that enrichment of As is related to coal ASM. A second hypothesis considered coal combustion in power plants, and stoves are a key source of As in the local environment. Three mobilization and distribution scenarios were developed for potential As pathways in this semiarid environment. About 43 soil and 14 water sites were analyzed for As concentrations and meaningful parameters in soil and water. About 28 topsoil samples were analyzed in surface-subsurface pairs in order to identify potential eolian surface enrichment. Additionally, fluvial-alluvial sediments and geogenic and anthropogenic deposits were sampled. Water was sampled as surface water, groundwater, precipitation, and industrial water. Results show that As does not pose a ubiquitous risk in the Nalaikh Depression. However, locally and specifically in water, As concentrations may exceed the WHO guideline value for drinking water by up to a factor of 10. A carefully selected sampling strategy allows the evaluation of the distribution scenarios, which reveals a combination of (a) geogenic As in groundwater and distribution via surface water with (b) anthropogenic As redistribution via eolian pathways. An immediate linkage between As redistribution and coal mining is not evident. However, As distribution in fly ash from coal combustion in the local power plant and yurt settlements is the most likely As pathway. Hence, the results indicate the potential influence of diffuse, low-altitude sources on As emission to the environment. As such, this study provides a good example for As distribution under semiarid climate conditions influenced by geogenic and anthropogenic factors.

Fish conservation in the land of steppe and sky: Evolutionarily significant units of threatened salmonid species in Mongolia mirror major river basins.

Mongolia's salmonids are suffering extensive population declines; thus, more comprehensive fisheries management and conservation strategies are required. To assist with their development, a better understanding of the genetic structure and diversity of these threatened species would allow a more targeted approach for preserving genetic variation and ultimately improve long-term species recoveries. It is hypothesized that the unfragmented river basins that have persisted across Mongolia provide unobstructed connectivity for resident salmonid species. Thus, genetic structure is expected to be primarily segregated between major river basins. We tested this hypothesis by investigating the population structure for three salmonid genera (Hucho, Brachymystax and Thymallus) using different genetic markers to identify evolutionarily significant units (ESUs) and priority rivers to focus conservation efforts. Fish were assigned to separate ESUs when the combined evidence of mitochondrial and nuclear data indicated genetic isolation. Hucho taimen exhibited a dichotomous population structure forming two ESUs, with five priority rivers. Within the Brachymystax genus, there were three B. lenokESUs and one B. tumensisESU, along with six priority rivers. While B. tumensiswas confirmed to display divergent mtDNA haplotypes, haplotype sharing between these two congeneric species was also identified. For T. baicalensis,only a single ESU was assigned, with five priority rivers identified plus Lake Hovsgol. Additionally, we confirmed that T. nigrescens from Lake Hovsgol is a synonym of T. baicalensis. Across all species, the most prominent pattern was strong differentiation among major river basins with low differentiation and weak patterns of isolation by distance within river basins, which corroborated our hypothesis of high within-basin connectivity across Mongolia. This new genetic information provides authorities the opportunity to distribute resources for management between ESUs while assigning additional protection for the more genetically valuable salmonid rivers so that the greatest adaptive potential within each species can be preserved.

Development and application of GIS-based assessment of land-use impacts on water quality: A case study of the Kharaa River Basin.

Effective analytical tools, such as geographical information systems (GIS) and multivariate analysis, help to deal with spatial data and complex interactions in watershed management. To investigate the impact of land-use on chemical water quality in the Mongolian Kharaa River Basin, the whole catchment and sub-catchments in relation to each sampling point were delineated. Chemical water quality over three seasons was assessed with GIS and RDA in a modeling approach with forward selection of variables and cluster analysis. The most powerful predictors of river water quality were altitude, settlements, forest, cropland, and distance to spring. In particular, this was true when instead of full sub-basins riparian buffer zones (max. 3 km) were considered. From a management perspective, this implies that the protection of riparian zones should be a priority in the Kharaa basin and similar river basins in Mongolia and Central Asia. Because of its positive effects on water quality, forest protection should be closely coupled with river basin management.

Chemical water quality gradients in the Mongolian sub-catchments of the Selenga River basin.

Even though the Selenga is the main tributary to Lake Baikal in Russia, the largest part of the Selenga River basin is located in Mongolia. It covers a region that is highly diverse, ranging from almost virgin mountain zones to densely urbanized areas and mining zones. These contrasts have a strong impact on rivers and their ecosystems. Based on two sampling campaigns (summer 2014, spring 2015), we investigated the longitudinal water quality pattern along the Selenga and its tributaries in Mongolia. While headwater regions typically had a very good water quality status, wastewater from urban areas and impacts from mining were found to be main pollution sources in the tributaries. The highest nutrient concentrations in the catchment were found in Tuul River, and severely elevated concentrations of trace elements (As, Cd, Cu, Cr, Fe, Mn, Ni, Pb, Zn), nutrients (NH4+, NO2-, NO3-, PO43-), and selected major ions (SO42-) were found in main tributaries of Selenga River. Moreover, trace element concentrations during spring 2015 (a time when many mines had not yet started operation) were markedly lower than in summer 2014, indicating that the additional metal loads measured in summer 2014 were related to mining activities. Nevertheless, all taken water samples in 2014 and 2015 from the main channel of the Mongolian Selenga River complied with the Mongolian standard (MNS 1998) for the investigated parameters.