Mongolia is an example of a nation where the rapidity of mining development is outpacing capacity to manage the potential land and water resources impacts. Further, Mongolia has a particular social and economic reliance on traditional uses of land and water, principally livestock herding. While some mining operations are setting high standards in protecting the natural resources surrounding the mine site, others have less incentive and capacity to do so and therefore are having adverse effects on surrounding communities. The paper describes a case study of the Sharyn Gol Soum in northern Mongolia where a range of mining types, from artisanal, small-scale mining to a large coal mine, operate alongside traditional herding lifestyles. A multi-disciplinary approach is taken to observe and attribute causes to the water resources impacts in the area. Surveys of the herding household community, land use mapping, and monitoring the spatial variations in water quality indicate deterioration of water resources. Collectively, the different sources of evidence suggest that the deterioration is mainly due to small-scale gold mining. The evidence included the perception of 78% of the interviewed herders that water quality had changed due to mining; a change in the footprint of small-scale gold mining from 2.8 to 15.2km(2) during the period 1999 to 2015; and pH and sulphate values in 2015 consistently outside the ranges observed at a baseline site in the same region. It is concluded that the lack of baseline data and effective governance mechanisms are fundamental challenges that need to be addressed if Mongolia's transition to a mining economy is to be managed alongside sustainability of herder lifestyles.

Satellite-based estimates of rainfall are frequently used to complement scarce networks of gauges. Understanding uncertainties is an important step, but is often hindered by a lack of validation data or misrepresented by spatial scale-related uncertainties, which are especially important in spatially-variable regions such as mountains. This study evaluates the Integrated Multi-satellitE Retrievals for GPM (IMERG) V05B 30-minute estimates for all three runs (Early, Late, Final) over the high tropical Andes. A unique dataset containing 15 rain gauges located within one IMERG grid at elevations ranging from 3,800 to 4,600 metres, provides a first evaluation opportunity in this topographical context. The evaluation was based on categorical, statistical and graphical methods. Error dependencies on precipitation characteristics and data source of the IMERG estimate were investigated. We show that IMERG severely underdetects precipitation events, thus underestimating precipitation depths. Poor detection is partially attributable to the low-intensity nature of precipitation over the region. However, tracing the error to the data source highlights limitations in passive microwave retrievals over the full range of intensities. No IMERG run has best overall performance, emphasising that run suitability is application specific. The impact of gauge density on performance metrics was also evaluated, and showed that sub-daily IMERG accuracy is overestimated by sparse networks. A minimum of six gauges was required at the 30-minute increment so that performance metrics are within 0.1 points of their true scores. We provide the first comprehensive assessment of 30-minute IMERG in a mountainous setting, highlighting the importance of high-density networks for accurate sub-daily evaluations.

Setting limit on groundwater extractions is important to ensure sustainable groundwater management. Lack of extraction data can affect interpretations of historical pressure changes, predictions of future impacts, accuracy of groundwater model calibration, and identification of sustainable management options. Yet, many groundwater extractions are unmetered. Therefore, there is a need for models that estimate extraction rates and quantify model outputs uncertainties arising due to a lack of data. This paper develops such a model within the Generalized Linear Modeling (GLM) framework, using a case study of stock and domestic (SD) extractions in the Surat Cumulative Management Area, a predominantly cattle farming region in eastern Australia. Various types of extraction observations were used, ranging from metering to analytically-derived estimates. GLMs were developed and applied to estimate the property-level extraction amounts, where observation types were weighted by perceived relative accuracy, and well usage status. The primary variables found to affect property-level extraction rates were: yearly average temperature and rainfall, pasture, property area, and number of active wells; while variables most affecting well usage were well water electrical conductivity, spatial coordinates, and well age. Results were compared with analytical estimates of property-level extraction, illustrating uncertainties and potential biases across 20 hydrogeological units. Spatial patterns of mean extraction rates (and standard deviations) are presented. It is concluded that GLMs are well suited to the problem of extraction rate estimation and uncertainty analysis, and are ideal when model verification is supported by measurement of a random sample of properties.

The quantification of percolation processes and deep drainage rates in cracking clays is challenging due to the existence of multiple flow pathways, including desiccation crack networks, and the effect of variability in antecedent soil moisture and rain event properties. While most previous research on this topic focuses on long‐term average rates, this study focusses on inter‐event dynamics. The study uses data from soil moisture sensors distributed vertically down 4 m profiles of Vertosol and Chromosol soils across 13 sites over an area of approximately 20 km2. The objectives were to estimate the temporal and spatial variability of deep drainage rates and to investigate the effect of antecedent soil moisture conditions and rain event properties on deep drainage rates and percolation dynamics. 35 deep drainage events over a 40‐month period contributed 78 % of the total deep drainage of 254 mm at 4 m depth. Average deep drainage estimates were about 15 % (ranging from 0 – 80 % between sites) of total rainfall and irrigation in the Vertosol and 8% (0 – 24 %) in the Chromosol. The event water travel times at 4 m depth were 0.25 – 38 hr and 14 – 39 hr in the Vertosol and Chromosol respectively. The event deep drainage rates averaged across sites were associated with event rainfall volumes (linear regression R2 = 0.40), with the effect of antecedent conditions evident only when looking at inter‐site differences. The percolation response time was strongly associated with higher rainfall intensities (R2 = 0.33) with no evidence from the linear regression of an antecedent moisture effect.

Understanding the rate of extraction from bores (or wells) can be essential in estimating groundwater discharge at a regional scale and understanding pressures on sustainable use. The challenges in doing so include the impracticality of directly measuring extractions from all, or even a large proportion of, operating bores using flow meters, especially in rural and remote areas. This challenge may be addressed by metering a representative sample of bores and generalising results to develop estimation methods; however, even achieving this presents considerable obstacles. While the benefits of metering a subset of bores to progress groundwater science and management are recognised, the obstacles to implementing metering and guidance on overcoming them are not well documented. In the Surat Basin, Australia, most groundwater bores are used for stock watering and domestic purposes, with less than 0.1% metered. As part of a research program to understand regional groundwater extraction in this area, a voluntary bore metering program has been undertaken. In this paper the challenges that arose when recruiting participants, installing and maintaining flow metering equipment, and interpreting and using data collected are described. Lessons learnt during implementation of the program that can guide other voluntary metering of rural groundwater extractions are discussed.