节水工程技术改造研究——以河东区葛沟灌区为例

灌区节水改造是河东区葛沟节约水资源、提高粮食产量的重要手段.灌区节水改造对周边环境有一定的影响,而灌区节水改造环境效应评价就显得尤为重要.灌区节水改造的目的是改善灌区的灌溉条件以及提高灌区的农业生产的综合能力,当然在节水改造之前,对灌区节水改造的影响进行全面的分析、客观的评价,并指出相应的改善策略,提升灌区节水改造的综合效益.     

引黄灌区水资源调配模型及和谐评估

基于引黄灌区普遍特征及存在的水资源问题,构建考虑水资源、经济社会和生态环境多维目标的水资源优化调配模型,建立引黄灌区水资源和谐评估指标体系,并将模型和评估体系应用到赵口引黄灌区二期工程。基于模型解集中选取的4种代表性优化调配方案进行水资源、经济社会、生态环境的效益分析,选定P₄方案为赵口二期水资源多目标优化调度方案,并基于该方案开展和谐评估和多方案调控研究。结果表明：模型优化后灌区和谐度明显提高,通过对和谐度较低的地下水开采率、农业用水比例、城镇化率、人均粮食产量、绿化覆盖率等指标调控后,和谐度可进一步提高到0.790。     

Needle-type in situ water content sensor with polyethersulfone polymer membrane

A needle-type water content sensor with a polyethersulfone (PES, poly(4-phenoxy-co-4-benzensulfone)) polymer membrane is proposed for the low-invasive, direct in situ measurement of plant water content (PWC). When the PWC sensor is inserted into a plant, the electrical impedance of PES is determined by the amount of absorbed water, which indicates the PWC. In situ measurement of PWC was successfully demonstrated for a strawberry plant (Fragaria × ananassa) and the application feasibility of the sensor to in situ PWC measurement for irrigation agriculture was verified.     

Assessing the efficacy of pre-harvest,chlorine-based sanitizers against human pathogen indicator microorganisms and Phytophthora capsici in non-recycled surface irrigation water

Many factors must be considered in order to develop and implement treatment systems to improve the microbial quality of surface water and prevent the accidental introduction of plant and human pathogens into vegetable crops. The efficacy of chlorine gas (Cl_2(g)) and chlorine dioxide (ClO₂) injection systems in combination with rapid sand filtration (RSF) was evaluated in killing fecal indicator microorganisms in irrigation water in a vegetable-intensive production area. The efficacy of ClO₂ and Cl_2(g) was variable throughout the distribution systems and coliform bacteria never dropped below levels required by the United States Environmental Protection Agency for recreational waters. Sampling date and sampling point had a significant effect on the abundance of coliforms in Cl_2(g)- and ClO₂-treated water. Sampling date and sampling point also had a significant effect on the abundance of generic Escherichia coli in Cl_2(g) treated water but only sampling point was significant in ClO₂ treated water. Although the waterborne plant pathogen Phytophthora capsici was detected in five different sources of surface irrigation water using baiting and P. capsici-specific PCR, in vitro studies indicated that ClO₂ at concentrations similar to those used to treat irrigation water did not reduce mycelial growth or direct germination of P. capsici sporangia and reduced zoospore populations by less than 50%. This study concludes that injection of ClO₂ and Cl_2(g) into surface water prior to rapid sand filtration is inadequate in reducing fecal indicator microorganism populations and ClO₂ ineffectively kills infectious propagules of P. capsici. Additional research is needed to design a system that effectively targets and significantly reduces both plant and human pathogens that are present in surface irrigation water. A model for a multiple barrier approach to treating surface water for irrigation is proposed.     

OPTIMAL SIZING OF IRRIGATION DELIVERY SYSTEMS USING A TWO-STAGE STOCHASTIC PROGRAMMING APPROACH

In arid areas where the available water is limited and randomly changing with time, the surface irrigation might still be the best option due to economic and other considerations. Hence, the irrigation delivery system should be sized in such a way that the allocation of available surface water to different crops at any time yields maximum possible revenues. This can be ultimately achieved with the aid of a two-stage optimal formulation combining the present design stage with the future operational conditions. This work applies two stochastic mathematical techniques to determine the optimal sizes of a hypothetical surface irrigation delivery system subjected to varying deficit levels of available water and considering the uncertainties associated with the available water and the crop revenues. Canal sizes represented the first-stage decisions while the future water allocations were made in the second stage. The Regularized Stochastic Decomposition approach solved the case of stochastic available water present at the right hand side, while the L-Shaped method solved the case of stochastic second-objective coefficients associated with the crop selling prices. The L-Shaped method was also used to consider the problem of uncertain parameters in both the right hand side and the second-objective coefficients. The problem was investigated by considering a system of nine irrigation canals and six farms grown with different crops during a season of two distinctive irrigation periods. Results obtained from the stochastic formulation were compared with the corresponding ones obtained from an equivalent deterministic formulation. The comparison showed that the effect of parameter uncertainties on canal sizes and associated revenues increases with the increasing levels of deficit in water supply.     

Relative Comparison of the Local Recalibration of the Temperature-Based Evapotranspiration Equation for the Korea Peninsula

It is well known that local calibration is subject to improving the performance of the temperature-based equation because that calibration includes the influence of the local climate characteristics. This paper evaluates different local recalibrations (the regression-based, one-parameter, and three-parameter methods) of the Hargreaves equation at 21 meteorological stations. The FAO-56 Penman-Monteith is used to describe the control condition against which each calibration method is then assessed. The one-parameter method provides the strength for inland areas, while it presents the worst performance for coastal areas. The regression-based calibration provides slightly better performance for coastal areas. It is true that the difference between the estimates of ETo using the different calibration methods is relatively small and that the difference does not provide the benchmark control that is desirable to demonstrate a significant difference. In relative terms, the regression-based and the three-parameter methods can be an alternative for both inland and coastal areas, giving similar level of accuracy. However, the one-parameter presents may be an alternative only for inland areas. This study can provide guidelines for crop production, water resources conservation, irrigation scheduling, and environmental assessment.     

On the role of individuals in models of coupled human and natural systems: Lessons from a case study in the Republican River Basin

In models of coupled human and natural systems (CHANS), the role of individuals and human behavior is often overlooked as data are scarce and assumptions hard to verify. To assess this role, we couple an agent-based model simulating farmers' behavior and a groundwater model and apply the models to the case of groundwater-fed irrigation in a river basin in the High Plains Aquifer region. Results show the crucial role of human behavior in driving the interactions between these coupled systems. Conversely, individuals are impacted by the systems’ dynamics in different ways depending on physical, economic and social characteristics. The findings provide implications for local policy making and education and demonstrate that assumptions on human behavior could be treated as an additional source of uncertainty. This work suggests that modeling individuals and human behavior can be an important step to simulate and understand the dynamics of CHANS in a holistic way.     

Fate of carbamazepine and anthracene in soils watered with UV-LED treated wastewaters

Water disinfection technologies based on ultraviolet (UV) radiations emitted by Light-Emitting Diodes (LED), as a wastewater tertiary treatment, have been shown to be promising for water reuse. Here, we assessed the fate of two ubiquitous pollutants, carbamazepine and anthracene, in soil watered with either UV-LED treated wastewaters or irrigation water. After 3 months, anthracene and carbamazepine were transformed two and three times faster respectively, in soils watered with UV-LED wastewater than in soils watered with tap water (probably because of the addition of organic matter by the effluent). Laccase activity was induced in the presence of the pollutants and anthraquinone was found as anthracene product of oxidation by laccases. Moreover, the addition of these pollutants into soil did not affect the functional diversity of autochthonous microbial communities assessed by Ecolog plates. Cellulase, protease and urease activities increased in soils watered with UV-LED treated wastewaters (UV-LED WW), showing transformation of organic matter from the effluent and lipase activity increased by anthracene addition, confirming the potential role of these enzymes as indicators of hydrocarbon contamination.     

长庆五蛟油田里74区高效开发技术研究

五蛟油田里74区为边底水油藏,2006年全面开发以来,因采油速度较高,部分井采液强度不合理,造成底水锥进和边水内推,区块含水上升。本文针对上述问题从注水时机选择、采液强度优化两个方面开展工作,并进行效果评价,摸索出区块最佳注水时机,油井生产的合理采液强度,对同类边底水油藏的开发有借鉴意义。     

Effect of Preharvest Deficit Irrigation on Second Crop Watermelon Grown in an Extremely Hot Climate

As a second crop, watermelons (Citrullus vulgaris, Crimson sweet) were grown in 2003 and 2004 in the Sanliurfa-Harran Plain in southeastern Turkey to determine the effect of preharvest water stress on fruit yield, quality (i.e., soluble solids contents and fruit size), leaf temperature, and some other physiological parameters. Preharvest drip irrigation treatments included (1) complete irrigation cutoff, dry (D); (2) full irrigation based on replenishment of soil water depleted from 0 to 90?cm soil profile (C); (3) 75% full irrigation (IR1); (4) 50% full irrigation (IR2); and (5) 25% full irrigation (IR3) with 3-day irrigation interval. Treatment plots received the same level of irrigation water until the fruit formation stage, except for Treatment D. Then, different water stress levels were imposed on treatment plots. Irrigation water applied to the five respective treatments were 636, 511, 395, 245, and 120?mm in 2003 and 648, 516, 403, 252, and 127?mm in 2004. Results indicated that fruit yield was significantly lowered by reduced water rates. The seasonal average yield response factor (ky) for both years was 1.0, but it was 0.97 for 2003 and 0.98 for 2004. The highest marketable fruit yield, obtained from treatment C, was 32.4?Mg?ha?1 in 2003 and 37.1?Mg?ha?1 in 2004. D, IR2, and IR3 treatments reduced most measured parameters, except for soluble solids contents (SSC). Both the fruit size and SSC were significantly affected by late-season irrigation management; individual fruit weights were significantly reduced, whereas SSC increased in the IR2 and IR3 treatments compared to the control values. The writers’ results clearly indicated that reduced preharvest irrigation was detrimental. Water use efficiency (WUE) was significantly affected by irrigation treatments. Even a 25% reduction in the irrigation amount caused a 15% reduction in marketable yield. This indicates that deficit irrigation in the ripening stage significantly increased water use efficiency. The study demonstrated that a moderate deficit irrigation, which is replenishment up to 50% of soil water depleted in the root zone, can be successfully used to improve WUE under semiarid climatic conditions.