Water2016, 8(9), 373; doi:10.3390/w8090373 (registering DOI) - published 31 August 2016 Show/Hide Abstract
Abstract: Meteorological drought monitoring is important for drought early warning and disaster prevention. Regional meteorological drought can be evaluated and analyzed with standardized precipitation index (SPI). Two main processing schemes are frequently adopted: (1) mean of all SPI calculated from precipitation at individual stations (SPI-mean); and (2) SPI calculated from all-station averaged precipitation (precipitation-mean). It yet remains unclear if two processing schemes could make difference in drought assessment, which is of significance to reliable drought monitoring. Taking the Poyang Lake Basin with monthly precipitation recorded by 13 national stations for 1957–2014, this study examined two processing schemes. The precipitation mean and SPI mean were respectively calculated with the Thiessen Polygon weighting approach. Our results showed that the two SPI series individually constructed from two schemes had similar features and monitoring trends of regional meteorological droughts. Both SPI series had a significantly positive correlation (p < 0.005) with the number of precipitation stations. The precipitation-mean scheme reduced the extent of precipitation extremes and made the precipitation data more clustered in some certain, it made less precipitation deviate from the precipitation-mean series farther when less precipitation occurred universally, which would probably change the drought levels. Alternatively, the SPI-mean scheme accurately highlighted the extremes especially for those with wide spatial distribution over the region. Therefore, for regional meteorological drought monitoring, the SPI-mean scheme is recommended for its more suitable assessment of historical droughts.
Water2016, 8(9), 376; doi:10.3390/w8090376 (registering DOI) - published 31 August 2016 Show/Hide Abstract
Abstract: Thresholds based on critical combinations of amount/duration of precipitation and flood events were estimated for the Corgo hydrographic basin, in northern Portugal. Thirty-one flood events in the Corgo basin were identified between 1865 and 2011 from a database of hydrometeorological disasters in Portugal. The minimum, maximum, and pre-warning thresholds that define the boundaries for flood occurrence were determined. The results show that the ratio between the total number of floods and precipitation events exceeding the minimum threshold denotes a relatively low probability of successful forecasting. This result may be due to the reduced number of flooding events in the floods database, which only include floods that caused damage as reported by the media. The estimated maximum threshold is not adequate for use in floods, since the majority of true positives are below this limit. However, and more interestingly, the retrospective verification of the estimated thresholds suggests that the minimum and pre-warning thresholds are well adjusted. Therefore, the application of these precipitation thresholds may contribute to minimize possible situations of pre-crisis or immediate crisis by reducing the flood consequences and the resources involved in emergency response to flood events.
Water2016, 8(9), 374; doi:10.3390/w8090374 (registering DOI) - published 31 August 2016 Show/Hide Abstract
Abstract: The European Mediterranean coastline has experienced major tourism-related urbanization since 1960. This is a dynamic that has led to increased spending on water consumption for urban and tourism-related uses. The objective of this paper is to define and to analyze how domestic water consumption in the city of Alicante evolved between 2000 and 2013. Real billing figures for individual households were analyzed according to the type of housing and the income level of the occupants. The conclusions drawn show that consumption fell over the period studied, and that there are different patterns in water expenditure depending on the type of housing and the inhabitants.
Water2016, 8(9), 375; doi:10.3390/w8090375 (registering DOI) - published 31 August 2016 Show/Hide Abstract
Abstract: To better understand farmers’ refusal to pay agricultural water fees under the current policy in rural China and their corresponding negative emotions, this paper applies mental accounting, a behavioral economics framework, to explore how the governmental policies of reform of rural taxes and fees, direct agricultural subsidy programs, and agricultural water fees individually influence farmers’ decisions in paying the agricultural water fees. Using fieldwork data from 577 farmers and 20 water managers in Sichuan, we explore farmers’ information processing regarding paying agricultural water fees via three sequential mental accounting processes, with the associated underlying principles and measures behind each process. We find that the information processing in three mental accounting scenarios related to the agricultural water fee elucidates farmers’ observed behaviors in rural China. Generally, in the three mental accounting scenarios, two conditional intuitive expectations and nine conditional intuitive preferences are formed; however, the conditions of those expectations or preferences cannot be matched with the facts due to the reform of rural taxes and fees, the direct agricultural subsidy programs, and the internal attributes of agricultural water fee, which interpret those negative behaviors in rural China. Additionally, this paper offers a view into how previous policies create negative psychological externalities (such as farmers’ psychological dependence on the government) through mental accounting to negatively influence agents’ subsequent decision-making; it highlights the significance of underlying mental factors and information processing of negative behaviors in policymaking for managing or conserving common pool resources.
Water2016, 8(9), 371; doi:10.3390/w8090371 - published 30 August 2016 Show/Hide Abstract
Abstract: Nitrogen losses in the form of Nitrate (N-NO3) from point and diffuse sources of pollution are recognized to be the leading cause of water body impairment throughout Europe. Implementation of conservation programs is perceived as being crucial for restoring and protecting the good ecological status of freshwater bodies. The success of conservation programs depends on the efficient identification of management solutions with respect to the envisaged environmental and economic objectives. This is a complex task, especially considering that costs and effectiveness of conservation strategies depend on their locations. We applied a multi-objective, spatially explicit analysis tool, the R-SWAT-DM framework, to search for efficient, spatially-targeted solution of Nitrate abatement in the Upper Danube Basin. The Soil Water Assessment Tool (SWAT) model served as the nonpoint source pollution estimator for current conditions as well as for scenarios with modified agricultural practices and waste water treatment upgrading. A spatially explicit optimization analysis that considered point and diffuse sources of Nitrate was performed to search for strategies that could achieve largest pollution abatement at minimum cost. The set of optimal spatial conservation strategies identified in the Basin indicated that it could be possible to reduce Nitrate loads by more than 50% while simultaneously provide a higher income.
Water2016, 8(9), 372; doi:10.3390/w8090372 - published 30 August 2016 Show/Hide Abstract
Abstract: Channel reservoirs have the characteristics of both rivers and lakes, in which hydrodynamic conditions and the factors affecting the eutrophication process are complex and highly affected by weather conditions. Water age at any location in the reservoir is used as an indicator for describing the spatial and temporal variations of water exchange and nutrient transport. The hyper-eutrophic Changtan Reservoir (CTR) in Southern China was investigated. Three weather conditions including wet, normal, and dry years were considered for assessing the response of water age by using the coupled watershed model Soil Water Assessment Tool (SWAT) and the three-dimensional hydrodynamic model Environmental Fluid Hydrodynamic Code (EFDC). The results showed that the water age in CTR varied tremendously under different weather conditions. The averaged water ages at the downstream of CTR were 3 d, 60 d, and 110 d, respectively in the three typical wet, normal, and dry years. The highest water ages at the main tributary were >70 d, >100 d, and >200 d, respectively. The spatial distribution of water ages in the tributaries and the reservoir were mainly affected by precipitation. This paper provides useful information on water exchange and transport pathways in channel reservoir, which will be helpful in understanding nutrient dynamics for controlling algal blooms.