Search

In order to study the determination methods of "three major elevations" in the design of underground water sealed caverns, including the elevation of the groundwater level, the elevation of the water curtain system, and the elevation of the oil storage caverns, a method for determining the "three major elevations" from the perspective of water sealing effect on the bases of a certain cavern project was proposed. The water sealing evaluation was also conducted. The analysis results indicated that the regional groundwater drainage datum plane can be taken as the design groundwater level. The design elevations of the water curtain system and the main caverns need to be determined based on a comprehensive consideration of the water sealing effect, the thickness of the "water cover layer" formed above the storage caverns, and the amount of inflow toward the caverns from the surrounding rocks. According to the calculation model established based on the cavern project, the elevation of the designed groundwater level was 25 meters above the water curtain system, and the water curtain system was 25 meters above the storage caverns. The numerical simulation results showed that it has a good water sealing effect, and small adjustments to these elevation parameters can also ensure water sealing. The "three major elevations" are both the key parameters in storage caverns design and the key factors affecting water sealing. [ABSTRACT FROM AUTHOR]

A dynamic global vegetation model based on the annual land- use change data was used to quantify water conservation capacity with respect to grassland changes in the Yellow River above Lanzhou between 1980 and 2020 using different scenario simulations. The results showed that the average annual water conservation in this region was approximately 24. 21 billion cubic meters, with grassland ecosystems contributing approximately 20. 28 billion cubic meters, accounting for 83. 8% of the total water conservation. Before 2002, the water conservation capacity exhibited a decline trend (- 0. 51 billion cubic meters per year). However, an increasing trend was observed after 2002 (0. 35 billion cubic meters per year). Changes in the grassland in the Yellow River above Lanzhou, while having negligible negative impacts and no discernible regional differences, resulted in an annual reduction of 0. 67 billion cubic meters in the regional water conservation volume between 2015 and 2020. Simulations were performed under scenarios representing different degrees of grassland degradation. The results showed that mild degradation caused changes in the components of grassland evapotranspiration, which in turn led to a slight increase in the regional water conservation volume; however, this effect decreased significantly as the degree of degradation increased. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Through the analysis of existing measurement technology, this article screens a single well metering technology which is suitable for screw pump and rodless pump oil production metering, and develops a new type of liquid water automatic metering skid. After a series strict indoor experiments and field tests, metering skid has shown reliable performance and has high measurement accuracy, liquid volume measurement error is within ± 10 %, moisture content is within ± 5 %, which meet the requirements of oil and gas field surface engineering oil and gas gathering and processing technology design specifications. Research and application of automatic measurement of liquid production and moisture content, can simplify oilfield gathering and transportation process, reduce ground construction costs, and solve the problem that there is no effective single well online metering method for oil production methods such as screw pumps and rodless pumps, filling the technology gap. [ABSTRACT FROM AUTHOR]

Rational water price policy is of great significance for the efficient use of water resources. However, development processes of water price policy are mostly subjective and few methods are suitable to quantify policy effects. In this study, we focused on irrigation areas with multiple water sources and irrigation techniques. A method based on positive mathematical programming (PMP) was proposed to simulate the impacts of agricultural water price policy on economic benefits of water use, irrigation water consumption, planting land occupation and water-saving irrigation area. This method was applied to address a case in Minqin County, Gansu Province. Under the current water price policy of the study area, the model was calibrated with the actual data in 2015, the absolute value of the difference between the optimal solution of the calibrated model and the actual planting area in the base year didn’t exceed 1.3×10-3 hm2, indicating that the model was reliable to simulate the effect of water price policy. Subsequently, the model was used to simulate the change trend of index with the rise of water price under the volumetric water price policy, the 2-part water price policy and the differential water price policy. The simulation results showed that with the rise of water price, the change trend of index under 3 water price policy was similar: the farmer income reduced, the irrigation water consumption and planting area reduced first and then stabilized, the water-saving irrigation area increased, and the benefit per cubic meter of water increased first and then decreased. Simultaneously, in response to rising water price, farmers tended to reduce the planting area of food crops first and then the area of cash crops to alleviate the loss of income. Based on the simulation results, the water price threshold under different policies and the scope of application of various policies were further analyzed, and the following conclusions were drawn. Under the volumetric water price and the 2-part water price policy, the water price should be between 0.24 yuan/m3-2.10 yuan/m3; under the differential water price policy, the water price should be between 0.24-1.50 yuan/m3; when the metering part of the water price was lower than 2.10 yuan/m3 or higher than 6 yuan/m3, the comprehensive benefit of the differential water price policy was the highest; when the metering part of the water price was between 2.10 yuan/m3 and 6 yuan/m3, the volumetric water price policy was the most ideal; when the differential water price policy was implemented and the metering part of the water price was 1.50 yuan/m3, the benefit per cubic meter of water was the highest. This paper confirmed that the steady increase of water price would not reduce the comprehensive benefits of water use, but increase the benefit per cubic meter of water. The differential water price policy currently implemented in Minqin County was appropriate. In the future, in Minqin County, the water price under the differential water price policy should be increased within the range of 0.24-1.50 yuan/m3. Moreover, during the course of water price rising in the study area, special attentions should be paid to increase investment in water-saving irrigation projects and farmer income subsidy policies should be established under local contexts. Based on the conclusions of this study, various local factors and evaluation indexes such as current water price, farmers' willingness to pay, government financial subsidies, and income from water supply projects, could be comprehensively considered to obtain detailed implementation plan of water price policy. Finally, the method established in this paper was also applicable to other areas with similar problems. [ABSTRACT FROM AUTHOR]