Study on drying bamboo shoots by Sasaki heat pump drying technology

The study was conducted to investigate the effects of blanching regimes at the salt concentration and drying temperature using Sasaki heat pump drying technology on the quality of dried bamboo shoots to create a product that can be kept color, flavour, and quality. Fresh bamboo shoots were cut into slices with a thickness of 6 mm, boiled in hot saltwater at 100oC at different concentrations (0, 1, 3, 5%) for 15 minutes. Then, they were dried in the temperature setting differences (30, 40, 50oC) by Sasaki dryers and tested for moisture, color, cyanide content, microorganisms, water compensation capacity, and product sensory quality. Fresh bamboo shoots were boiled in hot saltwater at 100oC, 3% salt concentration for 15 minutes, and dried at 40oC by Sasaki drier for the best quality. This treatment mode provides the lowest color variation and the best water compensation compared to other treatment modes. Dried bamboo shoots are bright yellow, uniform color, characteristic odour, toughness with little deformation, low cyanide content, and microbiological content below the threshold of food hygiene and safety.

Evaluation of Physical and Economic Water-Saving Efficiency for Virtual Water Flows Related to Inter-Regional Crop Trade in China

If products were traded from regions with relatively high water productivity to regions with relatively low water productivity, water saving could be achieved. In this study, two indices—physical water-saving efficiency (volume of water savings per cubic meter of virtual water flows) and economic water-saving efficiency (value of water savings per cubic meter of virtual water flows considering water right trading)—were proposed to analyze the efficiency of inter-regional virtual water flows related to crop trade in China. Results indicated that the volume of inter-regional virtual water flows was 1.61 × 109 m3, more than 90% of which was occupied by oil-bearing crops, cereals, and beans. In terms of physical efficiency, only cereals and vegetables presented negative values. All kinds of crop trades were economically efficient, while most crops’ economic water-saving efficiency was less than 10 × 103 Yuan/m3. The application of advanced water-saving technologies, the cultivation of new crop varieties, the adjustment of regional cropping patterns, or consumption and trade patterns, could contribute to more water savings and higher physical water-saving efficiency, while the possible social, economic, and environmental tradeoffs should be considered simultaneously. Water right trading and virtual water compensation could contribute to sustainable water consumption, and full-cost pricing should be adapted in the future.

Impoundment Impact of the Three Gorge Reservoir on the Hydrological Regime in the Lower Han River, China

Reservoir regulation has been playing an increasingly important role in water resources development and its influence on the hydrological processes of downstream tributaries has attracted much attention. The lower Han River is selected as a case study to examine the hydrological and hydraulic influence of the upstream flow regulation of the Three Gorges Reservoir (TGR) in the middle Yangtze River, China. Based on a hydrodynamic model and the observed data, the hydrological processes in the lower Han River were simulated and their changes were analyzed under the impoundment influences of the TGR. The results indicated that there were obviously hydrological changes in the lower Han River after the TGR operation. The decreased stage downstream the TGR during the impounding periods of the TGR resulted in an increase in the stage difference, current speed, hydraulic gradient and the discharge ratio. In addition, the stage difference between the two rivers was decreased during the periods of water compensation from the TGR, which led to the outflow congestion in the lower Han River. The hydrological changes in the lower Han River were the response to the flow regulation of the TGR and the inflow of the two rivers. The variation in the rating curve in the lower Han River mainly resulted from the stage difference between the two rivers during the dispatching periods of the TGR. These results help to explain the hydrological variability under the impounding influence of the TGR for the lower Han River and they can be extended to other river tributaries downstream to the reservoirs.

Water Compensation and Its Implication of the Three Gorges Reservoir for the River-Lake System in the Middle Yangtze River, China

Dam construction is an important means to improve water use efficiency and the aquatic environment. However, the flow regulation of the Three Gorges Reservoir (TGR) in the middle Yangtze River has attracted much attention because the severe drought occurred in the river-lake system downstream of the TGR. In this paper, the Dongting Lake was selected as a case study in order to detect the possible relationship between the flow regulation of the TGR and the extreme drought in the river-lake system based on a coupled hydrodynamic model. The results not only confirmed the significant role of the TGR to relieve drought in the river-lake system, but also indicated that the outflow of the TGR and the hydraulic gradient between the Zhicheng to Chenglingji stations were the crucial factors to affect the water exchange between the rivers and the Dongting Lake. The adjustment of hydraulic gradient within a proper range during the water compensation of the TGR will be an effective measure to improve the water exchange and water environment in the river-lake system. These findings present the quantitative influence of these important factors on the water exchange between rivers and lakes and provide a scientific reference for environmental and ecological management of other river-lake systems.

Integrating a mini catchment with mulching for soil water management in a sloping jujube orchard on the semiarid Loess Plateau of China

Conserving more soil water is of great importance to the sustainability of arid and semiarid orchards. Here we integrated fish-scale pits, semicircular mini-catchments for hill slope runoff collection, with mulches to test their effects on soil water storage in a 12-year-old dryland jujube orchard on the Loess Plateau of China, by using soil water measurements from April 2013 to November 2014. This experiment included four treatments: fish-scale pits with branch mulching (FB), fish-scale pits with straw mulching (FS), fish-scale pits without mulching (F), and bare land treatment (CK). Soil water was measured using the TRIME®-IPH time-domain reflectometer (TDR) tool in 20 cm intervals down to a depth of 180 cm, and was measured once every 2 weeks in the 2013 and 2014 growing seasons. The results showed that fish-scale pits with mulching were better in soil water conservation. Average soil water storage (SWS, for short) of FB at soil layer depths of 0–180 cm increased by 14.23 % (2013) and 21.81 % (2014), respectively, compared to CK, but only increased by 4.82 % (2013) and 5.34 % (2014), respectively, for the F treatment. The degree of soil water compensation, WS, was employed here to represent to what extent soil water was recharged from precipitation at the end of the rainy season relative to that at the beginning of the rainy season. A positive (negative) WS larger (lower) soil water content at the end of rainy season than at the beginning. For the treatment of FB, the values of WS over the entire soil profile were greater than 0; for the treatment of F, negative values of WS were observed in depths of 60–100 cm in both years. However, the bare land treatment showed negative values in depths of 40–180 cm. This indicated that integrating fish-scale pits with mulching could significantly increase soil water storage by increasing infiltration and decreasing evaporation, and it showed greater soil water storage and degree of soil water compensation compared to fish-scale pits alone. Since the branches used for mulching here were trimmed jujube branches, the cost of mulching materials was largely reduced. Therefore, integration of fish-scale pits with branch mulching is recommended in orchards for soil water conservation on the Loess Plateau and potentially for other regions.

Water Resources Compensation Policy and Application on Differential Empowerment System

Through the water compensation models, the article studies the effect of water resources compensation policy on the upstream and downstream areas under differential empowerment systems. Study finds that difference in water resources utilization efficiency is the precondition of water resources compensation policy implementation. With changes of water resources utilization efficiency, the compensation price changes in the same direction and the compensation amount changes in the opposite direction. Finally, water resources compensation policy will improve the welfare of both areas, which is highly consistent with Coase theorem.