Jürgen Hofmann

Integrated water resources management in central Asia: nutrient and heavy metal emissions and their relevance for the Kharaa River Basin, Mongolia

Within the framework of Integrated Water Resources Management (IWRM) the nutrient and heavy metal levels within the Kharaa river basin were investigated. By the application of the MONERIS model, which quantifies nutrient emissions into river basins, various point and diffuse pathways, as well as nutrient load in rivers, could be analysed. Despite seasonal variations and inputs of point sources (e.g. Wastewater Treatment Plant Darkhan) the nutrient concentrations in most of the subbasins are on a moderate level. This shows evidence for a nutrient limited ecosystem as well as dilution effects. However, in the middle and lower reaches heavy metal concentrations of arsenic and mercury, which are linked to mining activities in many cases, are a point of concern. Thus measures are necessary to protect the valuable chemical and ecological status of the Kharaa River and its tributaries. As a result of the growing economic pressure Mongolia will enhance the agricultural production by irrigation. Until 2015 about 60% of the agricultural land shall be irrigated. In addition the gold mining activities shall increase by 20% a year. Both sectors have a high demand for water quantity and quality. The model MONERIS allows the assessment of measures which are inevitable to protect the water quality under shrinking water availability.

Groundwater quality under stress: contaminants in the Kharaa River basin (Mongolia)

Abstract Groundwater quality in Mongolia is increasingly endangered by expanding mining and industrial activities, urbanization and intensified land-use for agriculture. In the framework of the research project Integrated Water Resources Management in Central Asia: Model Region Mongolia (MoMo) project, groundwater and surface water quality has been monitored since 2007 throughout the Kharaa River basin, which includes the second largest city of Mongolia, Darkhan. In order to investigate the potential impacts of human activities, groundwater samples have been collected at 40 locations and were analyzed for heavy metals, electrical conductivity, chloride and boron. The initial characterization of all groundwater bodies in the river basin was an important prerequisite for the assessment of groundwater quality. Our results show impacts especially in the lower and middle reaches of the Kharaa River basin including the city of Darkhan and the smaller towns Khongor, Salkhit, Zuunkharaa and Baruunkharaa. Particularly in Khongor, significantly high values of electrical conductivity, chloride and boron were detected, indicating serious pollution by domestic and industrial wastewater. Furthermore, elevated concentrations of heavy metals, especially arsenic, lead, zinc, nickel, iron and manganese, were found in the vicinity and downstream of mining areas whereby in some cases the maximum contaminant level of the Mongolian drinking water guideline was exceeded. The findings of this study illustrate explicitly the stress on groundwater quality and its vulnerability in the Kharaa River basin. A sustainable water resources management needs to be urgently implemented to avoid potential public health impacts.

INTEGRATING MULTI-SCALE DATA FOR THE ASSESSMENT OF WATER AVAILABILITY AND QUALITY IN THE KHARAA—ORKHON—SELENGA RIVER SYSTEM

The environmental and socio-enonomic impacts of water pollution are particularly severe in regions with relatively limited water resources [WWAP, 2012]. Water quantity and quality are closely interlinked aspects which are relevant for surface water ecology, water use, and integrated management approaches. However, an intensive monitoring of both is usually prohibitive for very large areas, particularly if it includes the investigation of underlying processes and causes. For the Kharaa - Orkhon - Selenga River system, this paper combines results from the micro (experimental plots, individual point data), meso (Kharaa River Basin) and macro (Selenge River Basin) scales. On the one hand, this integration allows an interpretation of existing data on surface water quantity and quality in a wider context. On the other hand, it empirically underpins the complimentary character of intensive monitoring in selected model regions with more extensive monitoring in larger areas.

Modular Concept for Municipal Water Management in the Kharaa River Basin, Mongolia

Mongolia is a country with limited water resources but a rising water consumption due to an increasing population, urbanization and economic growth, which is largely driven by a booming mining sector. These processes do not only lead to greater water abstractions, but also contribute to water quality and aquatic ecosystem deterioration. Urban areas play a key role in this context, since water abstractions and waste water generation are concentrated here. However, there are considerable disparities between urban centers with centralized water supply and sewage infrastructures and peri-urban regions. Where existant, infrastructures for drinking water supply and wastewater collection and treatment are often in a poor state of maintenance, leading to the contamination of groundwater and surface water bodies with pathogens, nutrients, and other chemical substances. This paper presents components of a modular concept for urban water management at the example of Darkhan Uul Aimag, which were developed and pilot-tested in the context of a project aiming at the development and implementation of an integrated water resources management (IWRM) for the North Mongolian Kharaa River Basin. It is discussed how solutions were adapted to local situations, considering both sustainable resource utilization and local acceptance.

Agriculture in Mongolia Under Pressure of Agronomic Nutrient Imbalances and Food Security Demands: A Case Study of Stakeholder Participation for Future Nutrient and Water Resource Management

To gain independence from food imports, Mongolia’s agricultural system is facing significant changes with respect to land-use intensification and an expansion of arable land. The resulting depletion of nutrient resources was analyzed on the regional scale in a 3-year field study (2010–2012) in the Kharaa River basin in north central Mongolia. With a share of 20 % of the national crop yield of wheat, the Kharaa River basin is an important part of the national “breadbasket”. The results of soil surface nutrient balance for the agriculturally sown areas in eleven municipalities (sums) showed a significant negative balance for nitrogen and phosphorus (period 2008–2010). The average deficit for nitrogen is approximately −20 kg ha year−1, and for phosphorus, this value is approximately −4 kg ha year−1. The reason for these deficits is that the nutrients, which are primarily lost due to crop harvest, are neither replaced by natural input sources nor by the application of chemical fertilizer. Thus, a nutrient imbalance between rural and urban areas can be confirmed: area-specific nutrient emissions indicate that urban areas are “hot spots”, characterized by the accumulation of nutrients, whereas agricultural areas show negative N-balances with a continuously decreasing trend. With respect to future fertilizer demands, the identification of a sustainable land and fertilizer management practices is of high priority in order to achieve the demanded crop yields. To facilitate integration and inclusion of farmer perspectives, we conducted a participatory approach that also included the national and regional government levels. Several options for integrated nutrient-cycling strategies of cities and agricultural production will be presented and discussed.