北部引嫩扩建工程防治土壤盐碱措施

北部引嫩工程位于黑龙江省松嫩平原,哈大齐东北振兴工业基地的中心地带,七十年初为解决石化工业、灌溉、病改用水的需要,便无坝兴建了引嫩江水的工程,但起到的作用并不明显,在枯水年甚至引不进嫩江水。随着嫩江干流尼尔基水库与北引渠首拦江闸于21世纪初建成,为北部引嫩工程扩建创造了很好的环境条件,扩建工程全部完工后,产油区地下水下降漏斗得以恢复地下水位,农田草原灌溉可达460余万亩。由于本区本来就是苏打盐碱化土壤分布集中的地区,随着大量水的引入,防治土壤盐碱化措施必须采取对策,根据国内外的经验,都将能否防治土壤盐碱化作为引水工程成败的关键。

Variation characteristics of aquifer parameters induced by groundwater source heat pump operation under variable flow

The variation characteristics of aquifer parameters,induced by groundwater source heat pump(GWSHP) operation under variable flow,were theoretically analyzed through a case study,in which the characteristics of building air conditioning load were considered.The results,compared with the constant flow operation,indicate that the influence on the variations of porosity,hydraulic conductivity and confined water head is decreased by 48%,51% and 71%,respectively,under variable flow operation.The security of variable flow operation is superior to that of constant flow.It is also concluded that the climate region and function of the buildings are primary factors which affect the suitability of variable flow operation in GWSHP.

Underwater Terrain-Aided Navigation Based on Multibeam Bathymetric Sonar Images

Underwater terrain-aided navigation is used to complement the traditional inertial navigation employed by autonomous underwater vehicles during lengthy missions. It can provide fixed estimations by matching real-time depth data with a digital terrain map, This study presents the concept of using image processing techniques in the underwater terrain matching process. A traditional gray-scale histogram of an image is enriched by incorporation with spatial information in pixels. Edge comer pixels are then defined and used to construct an edge comer histogram, which employs as a template to scan the digital terrain map and estimate the fixes of the vehicle by searching the correlation peak. Simulations are performed to investigate the robustness of the proposed method, particularly in relation to its sensitivity to background noise, the scale of real-time images, and the travel direction of the vehicle. At an image resolution of 1 m2/pixel, the accuracy of localization is more than 10 meters.

Numerical Modeling of Shallow Water Table Behavior with Lisse Effect

Air entrapment is an important consideration in environments with shallow water tables and sandy soil, like the condition of highly conductive sandy soils and flat topography in Florida, USA. It causes water table rises in soils, which are significantly faster and higher than those in soils without air entrapment. Two numerical models, Integrated Hydrologic Model (IHM) and HYDRUS-1D (a single-phase, one-dimensional Richards′ equation model) were tested at an area of west central Florida to help further understanding the shallow water table behavior during a long term air entrapment. This investigation employed field data with two modeling approaches to quantify the variation of air pressurization values. It was found that the air pressurization effect was responsible at time up to 40 cm of water table rise being recorded by the observation well for these two models. The values of air pressurization calculated from IHM and HYDRUS-1D match the previously published values. Results also indicated that the two numerical models did not consider air entrapment effect (as the predictive parameters remain uncertain) and thus results of depth to water table from these models did not compare to the observations for these selected periods. Incorporating air entrapment in prediction models is critical to reproduce shallow water table observations.

Hydrochemical Control of Groundwater in an Administrative Area of Mamou

The potability of water wells, drilling and tap water is the determining factor for the quality management of health of the urban and rural population. This study has been done on the basis of monitoring aspect such as pH, content ammonium, nitrate, nitrite and chloride from a physico chemical point of view. This study allowed the chemical and bacteriological analysis of samples, based on the result obtained, and the potability of water was defined. The bacteriological analysis was carried out taking account of the total flora, coliforms and Escherichia coll. This work gave rise to analyze 36 samples of water from wells, eight samples of drilling water and nine samples of water taps from municipalities such as Mamou, Dalaba and Pita. Water wells represent 90% of water supplies in drinking water to the population. In this research, collection of samples was very important. This study shows that 16 samples from 52 are potable, therefore, it is urgent to focus on the treatment of sewage in order to ensure better health for the population from administrative region of Mamou.

Trophallaxis network control approach to formation flight of multiple unmanned aerial vehicles

A novel network control method based on trophaUaxis mechanism is applied to the formation flight problem for multiple un- manned aerial vehicles （UAVs）. Firstly, the multiple UAVs formation flight system based on trophallaxis network control is given. Then, the model of leader-follower formation flight with a virtual leader based on trophallaxis network control is pre- sented, and the influence of time delays on the network performance is analyzed. A particle swarm optimization （PSO）-based formation controller is proposed for solving the leader-follower formation flight system. The proposed method is applied to five UAVs for achieving a ＇V＇ formation, and a series of experimental results show its feasibility and validity. The proposed control algorithm is also a promising control strategy for formation flight of multiple unmanned underwater vehicles （UUVs）, unmanned ground vehicles （UGVs）, missiles and satellites.