Abstract: This paper reports a contingent valuation study on household kitchen waste separation (HKWS) services via willingness to pay (WTP) conducted in the Haidian and Dongcheng districts of Beijing city in 2013. This study focuses on a real program to understand households’ attitudes toward HKWS and to estimate the value of HKWS services. The results of this study revealed that 41.4% agreed to accept the proposed price of HKWS services, while 42.2% refused to pay, but with a positive attitude toward the HKWS program. In addition, respondents’ WTP for proposed HKWS services is significantly related to the level of bid price and their gender, age and education experience. Attitudinal factors that affect resident WTP were also found. For example, respondents who perceive themselves as having a higher ability to conduct HKWS at the source are more willing to pay for their HKWS services, while respondents who complain of the inconvenience of conducting HKWS show negative WTP. The results also showed that on average each household is willing to pay about US$1.44 per month for HKWS services, which is based on 327 respondents after excluding 64 (16.4% of all sample) who indicated complete opposition to the HKWS program.
Abstract: Historical aerial images are important to retain past ground surface information. The land-use land-cover change in the past can be identified using historical aerial images. Automatic historical image registration and stitching is essential because the historical image pose information was usually lost. In this study, the Scale Invariant Feature Transform (SIFT) algorithm was used for feature extraction. Subsequently, the present study used the automatic affine transformation algorithm for historical image registration, based on SIFT features and control points. This study automatically determined image affine parameters and simultaneously transformed from an image coordinate system to a ground coordinate system. After historical aerial image registration, the land-use land-cover change was analyzed between two different years (1947 and 1975) at the Tseng Wen River estuary. Results show that sandbars and water zones were transformed into a large number of fish ponds between 1947 and 1975.
Abstract: The change of nonpoint source and freshwater discharge as a result of land use change might affect the water quality in a river. In the current study, a coupled three-dimensional hydrodynamic and water quality model was created and applied to the Danshuei River estuarine system and its adjacent coastal ocean. The hydrodynamic and water quality models were validated using observations of water surface elevation, salinity distribution and water quality state variables. The predictions of hydrodynamics, salinity, dissolved oxygen and nutrients from the model simulation quantitatively agreed with the observational data. The validated model was then used to investigate the possible effects of the nonpoint source and freshwater discharge changes at the upstream reaches on water quality conditions in the Danshuei River estuarine system. Three scenarios were investigated to predict the dissolved oxygen using model simulations. The simulated results indicated that increasing nonpoint sources at the upstream reaches degraded the dissolved oxygen under low flow conditions. However, increasing freshwater discharges at the upstream reaches would overcome the loadings of the nonpoint source, which would result in increasing the dissolved oxygen in the tidal river estuary. The model can provide a useful tool for developing management practices for nonpoint sources to protect the water quality in the estuarine system.
Abstract: In this study, the impact of three different types of activated carbon (AC) on the bioaccessibility of 14C-phenanthrene in non-sterile and sterile soils was investigated. A single dose (1%) of each of the different AC (CB4, CP1 and AQ5000) was blended with soil spiked with 50 mg·kg−1 of 12C/14C-phenanthrene. The mineralisation of the 14C-phenanthrene was monitored over a 14 day incubation period by indigenous soil microflora and an enriched inoculum of Pseudomonas sp., while uptake in earthworms, Eisenia fetida, was measured after incubation for 10 days at 1, 25, 50 and 100 d. Bioaccessibility was assessed using hydroxypropyl-β-cyclodextrin (HPCD) solution. Results showed that the presence of AC had a significant effect upon the extents of mineralisation, earthworm uptake and HPCD extraction, when compared to the control. Aquasorb CB4 was the least effective amongst the different AC used. The characteristics of the different AC used was also seen to have a major influence on how each AC would have an effect on its use in soil remediation in reducing bioaccessibility, mobility and risk.
Abstract: Located in the west coast of Taiwan, Yunlin County is considered as one of the most industrialized counties. The impact of land use on the coastal zone is significantly high. The main objective of this study is to analyze the impact of coastal land use changes in Yunlin County between 1996 and 2011 on shoreline dynamics. Two sets of satellite images (SPOT and FORMOSAT-2) are used as major data sources, and all analyses are performed using Geographic Information Systems (GIS) techniques. Land use classification includes seven types. Their area changes and correlations with shoreline area changes are calculated. Results indicate that between 1996 and 2011, the Yunlin coastal zone has experienced substantial land use changes, with dramatic increase of industrial and residential area along with significant loss of sandy coast. For the last sixteen years, Yunlin shoreline has undergone both erosion and accretion position changes. However, accretion is more prominent and common in many places. The net shoreline change observed is an accretion area of 1.65 km2. Results also further reveal that area changes of agriculture, residential, abandoned and aquaculture lands have caused a negative impact on the shoreline, moving it landward. However, area changes of industrial land and the sandy coast have exerted a positive impact (shifting the shoreline towards the sea). This positive impact is mainly due to land reclamation projects and destruction of natural coasts. As such, this is not favorable for natural coastal environments. This study also clearly indicates that, human induced coastal land use changes do exist in Yunlin. These changes may have created long-term shoreline position shifts and significant impact on its coastal environment.
Abstract: This study proposes a framework for estimating pollutant flux in an estuary. An efficient method is applied to estimate the flux of pollutants in an estuary. A gauging station network in the Danshui River estuary is established to measure the data of water quality and discharge based on the efficient method. A boat mounted with an acoustic Doppler profiler (ADP) traverses the river along a preselected path that is normal to the streamflow to measure the velocities, water depths and water quality for calculating pollutant flux. To know the characteristics of the estuary and to provide the basis for the pollutant flux estimation model, data of complete tidal cycles is collected. The discharge estimation model applies the maximum velocity and water level to estimate mean velocity and cross-sectional area, respectively. Thus, the pollutant flux of the estuary can be easily computed as the product of the mean velocity, cross-sectional area and pollutant concentration. The good agreement between the observed and estimated pollutant flux of the Danshui River estuary shows that the pollutant measured by the conventional and the efficient methods are not fundamentally different. The proposed method is cost-effective and reliable. It can be used to estimate pollutant flux in an estuary accurately and efficiently.