Design and Implementation of a Wireless Sensor Network-Based Remote Water-Level Monitoring System

The proposed remote water-level monitoring system (RWMS) consists of a field sensor module, a base station module, adata center module and aWEB releasing module. It has advantages in real time and synchronized remote control, expandability, and anti-jamming capabilities. The RWMS can realize real-time remote monitoring, providing early warning of events and protection of the safety of monitoring personnel under certain dangerous circumstances. This system has been successfully applied in Poyanghu Lake. The cost of the whole system is approximately 1,500 yuan (RMB)

The impact of agricultural activities on water quality: A case for collaborative catchment-scale management using integrated wireless sensor networks

The challenge of improving water quality is a growing global concern, typified by the European Commission Water Framework Directive and the United States Clean Water Act. The main drivers of poor water quality are economics, poor water management, agricultural practices and urban development. This paper reviews the extensive role of non-point sources, in particular the outdated agricultural practices, with respect to nutrient and contaminant contributions. Water quality monitoring (WQM) is currently undertaken through a number of data acquisition methods from grab sampling to satellite based remote sensing of water bodies. Based on the surveyed sampling methods and their numerous limitations, it is proposed that wireless sensor networks (WSNs), despite their own limitations, are still very attractive and effective for real-time spatio-temporal data collection for WQM applications. WSNs have been employed for WQM of surface and ground water and catchments, and have been fundamental in advancing the knowledge of contaminants trends through their high resolution observations. However, these applications have yet to explore the implementation and impact of this technology for management and control decisions, to minimize and prevent individual stakeholder’s contributions, in an autonomous and dynamic manner. Here, the potential of WSN-controlled agricultural activities and different environmental compartments for integrated water quality management is presented and limitations of WSN in agriculture and WQM are identified. Finally, a case for collaborative networks at catchment scale is proposed for enabling cooperation among individually networked activities/stakeholders (farming activities, water bodies) for integrated water quality monitoring, control and management

Using motes for high resolution hydrological measurement

Low cost, low power wireless sensors (motes) promise to revolutionize environmental data collection, but are they currently refined enough for widespread use by hydrologists? Their viability as a replacement for traditional data collection techniques was investigated in a 7 ha forested watershed in south-western British Columbia. The watershed included 41 instrument clusters measuring air and soil temperature, humidity, throughfall, soil moisture content, overland flow and groundwater head. The foundation of each cluster was a data box containing a MDA300 data acquisition board and a MICA2 processor board from Crossbow Technologies, Inc.™ that allowed for short range wireless data collection. The 41 motes each recorded data every 15 minutes from July, 2006, to April, 2007. In addition to reporting on the reliability of the motes and sensors during the 10 months deployment, the high spatial and temporal resolution data collected by this study gave the opportunity for many analyses of catchment processes. As soil moisture and throughfall are two influential processes in the exchange of water between the earth and the atmosphere, these were the focus of the data analysis. The first analysis was a resampling experiment on seven different events selected from the full data set. Comparing 100 different subsamples each of 5, 10 and 20 points for throughfall and soil moisture showed if increasing the sample size eventually produced diminishing returns in the ability to reproduce the true catchment mean. With significant differences in prediction ability for both soil moisture and throughfall at times of differing hydrologic activity, this analysis provides further support for the theories of changing moisture states of soil moisture and threshold values for throughfall. The second analysis described how the organization of soil moisture and throughfall changed during a range of weather conditions and timescales. Spatial representation of normalized values and Pearson correlation coefficients showed that there were distinct differences between wet and dry periods for soil moisture and between long and short analysis periods for throughfall.Forestry, Faculty ofGraduat

Hydrometeorology and streamflow response during rain-on-snow events in a coastal mountain region

Rain-on-snow, in which rainfall occurs upon a previously existing snowpack, complicates runoff response to rain events. In some situations the snowpack absorbs rainfall; in others, runoff is enhanced by significant snowmelt. Rain-on-snow has generated major floods around the world, particularly in coastal, mountainous regions such as southwestern British Columbia, where the rugged topography can cause rapid and varying transitions between rainfall and snowfall within the same watershed, and warm, subtropical storms known as atmospheric rivers can deliver large quantities of precipitation. This thesis sought to further the understanding of rain-on-snow at the regional scale, including its role in runoff response to a wide spectrum of rain-on-snow events. Tools were developed and assessed to help achieve this goal and for use by others. First, the hydrologic utility of output from a regional weather reanalysis model was tested. Results showed air temperature and vapour pressure were likely to be useful, whereas other variables were not accurate enough to be of use. Air temperature, in particular, showed potential ability for more accurate specification of temperature gradients for hydrologic forecasting of rain-on-snow runoff. An analysis of rain-on-snow events across five automated snow pillow sites over 10 years illustrated the importance of understanding the amount of rainfall occurring at high elevations during rain-on-snow, and the relatively consistent enhancement of water available for runoff (WAR) by 25-30% due to snowmelt during large rain-on-snow events. For smaller events, a range of antecedent and meteorological factors influenced WAR generation, particularly the antecedent liquid water content of the snowpack. A probabilistic method for infilling cloud obscured pixels in optical remotely sensed snow cover imagery showed strong performance compared to more standard methods, and illustrated spatial changes in snow cover during the largest flood event within the analysis period. This method was developed to maximize information gain from satellite snowcover imagery while minimizing the transfer of disinformation. Finally, high elevation rainfall during atmospheric river events was found to be the dominant predictor of runoff response in six study catchments in the region. Antecedent snowcover provided only minimal increases in the ability to predict runoff during these events compared to rainfall alone.Arts, Faculty ofGeography, Department ofGraduat