Research And Application On The Coupled Method Of Remote-Sensing And Ground-Monitoring Of Reservoir Storage Capacity

Reservoir storage capacity monitoring is the basis of reservoir operation. The relationship curves of reservoir water level-area and water level-capacity are the significant parameters of storage capacity calculation. With the long-term operation, both on the bottom and bank of the reservoir have erosion and deposition, causing the relationship of water level-area and level-storage changes, which leads to inaccuracy of reservoir storage capacity calculation with the original curves. It is costly to revise the curves of reservoir water level-area and water level-capacity by ground measurement termly. A coupled Method of Remote-sensing and Ground-monitoring of Reservoir Storage Capacity is proposed in this paper. Based on coupled data of satellite image of the reservoir water-area monitoring and the ground water-level monitoring on the same day, the relationship curves of reservoir water level-area and water level-capacity are updated, the calculation accuracy of reservoir storage capacity is improved. The Gangnan Reservoir is taken as an example for this research. 10 HJ-satellite images are used for revising the curve of reservoir water level-area and water level-capacity. The reservoir storage capacity differences between original and revised curves are analyzed and turned out to be reasonable

The Research And Application Of Remote Sensing Monitoring Method Of Actual Irrigated Area

The value of actual irrigated area is an important indicator of irrigation water management, but due to wide space range of irrigated district, ground manual monitoring is very difficult to achieve. Remote sensing methods have a wide rapid coverage, high efficiency, real-time, objective and other advantages, which can be used to solve the difficulties in monitoring irrigated area. In this paper, a remote sensing monitoring method of irrigated area based on modified perpendicular drought index (MPDI) is researched and the differential thresholds for distinguishing irrigation are analyzed and proposed. The method was applied to 5 rounds of actual irrigated area monitoring in Hetao irrigated district, inner Monglia, China., using the satellite images of HJ1A/1B CCD, China, and verified by ground tests. The results show that the method is of high precision, and can provide help for enhancing the management level of irrigated districts

Multiple Precast Component Orders Acceptance and Scheduling

Precast components manufacturer generally operates under limited production capacity and produces products of one order which may delay another. This paper develops a precast component order acceptance and scheduling model that aims to maximize the total profit in a stochastic multiple orders environment. In that model, the increasing of the overall profit of the precast component manufacturer is achieved by using a heuristic algorithm and a dynamic order acceptance heuristic. Results of numerical examples indicate the proposed model realizes the increasing total profit in most cases comparing to accept all of the orders. Besides, this study tested three order acceptance criteria and found that the profit-based criterion is to be more stable in terms of maximum total profit. This approach is anticipated to provide support to precast component manufacturers when faced with multiple orders in long-term production

Continuous Daily Evapotranspiration Estimation at the Field-Scale over Heterogeneous Agricultural Areas by Fusing ASTER and MODIS Data

Continuous daily evapotranspiration (ET) monitoring at the field-scale is crucial for water resource management in irrigated agricultural areas in arid regions. Here, an integrated framework for daily ET, with the required spatiotemporal resolution, is described. Multi-scale surface energy balance algorithm evaluations and a data fusion algorithm are combined to optimally exploit the spatial and temporal characteristics of image datasets, collected by the advanced space-borne thermal emission reflectance radiometer (ASTER) and the moderate resolution imaging spectroradiometer (MODIS). Through combination with a linear unmixing-based method, the spatial and temporal adaptive reflectance fusion model (STARFM) is modified to generate high-resolution ET estimates for heterogeneous areas. The performance of this methodology was evaluated for irrigated agricultural fields in arid and semiarid areas of Northwest China. Compared with the original STARFM, a significant improvement in daily ET estimation accuracy was obtained by the modified STARFM (overall mean absolute percentage error (MAP): 12.9% vs. 17.2%; root mean square error (RMSE): 0.7 mm d−1 vs. 1.2 mm d−1). The modified STARFM additionally preserved more spatial details than the original STARFM for heterogeneous agricultural fields, and provided field-to-field variability in water use. Improvements were further evident in the continuous daily ET, where the day-to-day dynamics of ET estimates were captured. ET data fusion provides a unique means of monitoring continuous daily crop ET values at the field-scale in agricultural areas, and may have value in supporting operational water management decisions

Multi-Site Statistical Downscaling Method Using GCM-Based Monthly Data for Daily Precipitation Generation

Global Climate Models (GCMs) can provide essential meteorological data as inputs for simulating and assessing the impact of climate change on catchment hydrology. However, downscaling of GCM outputs is often required due to their coarse spatial and temporal resolution. As an effective downscaling method, stochastic weather generators can reproduce daily sequences with statistically similar statistical characteristics. Most weather generators can only simulate single-site meteorological data, which are spatially uncorrelated. Therefore, this study introduces a method for multi-site precipitation downscaling based on a combination of a single-site stochastic weather generator, CLIGEN (CLImate GENerator), and a modified shuffle procedure constrained with multi-model ensemble GCM monthly precipitation outputs. The applicability of the downscaling method is demonstrated in the Huangfuchuan Basin (arid to semi-arid climate) for a historical period (1976–2005) and a projection period (2021–2070, historical, the representative concentration path (RCP) 2.6, RCP4.5, RCP4.8 scenarios) to generate spatially correlated daily precipitation. The results show that the proposed downscaling method can accurately simulate the mean of daily, monthly and annual precipitation and the wet spell lengths, and the inter-station correlation among 10 sites in the basin. In addition, this combination method generated the projected precipitation and showed an increasing trend for future years. These findings could help us better cope with the potential risks of climate change

Study on the Unconventional Water Subsidy Policy in the Arid Area of Northwest China

The arid regions of Northwest China are facing water shortages and ecological fragility. Making full use of unconventional water is one of the effective ways of solving water issues and achieving high-quality regional development. The high cost of unconventional water utilization is the main obstacle to its utilization and technological development, and the subsidy policy may become a breaking point. Taking Ningdong Energy and Chemical Industry Base (NECI Base) as a case study, the article proposes raising the Yellow River water price to subsidize the utilization of mine water. The development and utilization of mine water can be effectively improved. Considering the optimal allocation of multiple water sources and the substitution relationship between the Yellow river water and mine water, this paper extends the water resources module (WRM) of the Computable General Equilibrium (CGE) model. The model can reflect the substitution of water sources and the linkage between water prices and the economy. Ten different subsidy policy scenarios are simulated through the extended CGE model, and the laws and mechanisms of the subsidy policy on the economy and water usage are summarized. The results show that increasing the price of Yellow River water by 8% to subsidize the mine water will achieve optimal socio-economic output. Under this scenario, the industrial value added (IVA) is basically unaffected, the water-use efficiency (WUE) is significantly improved, and the affordability of the enterprise is satisfied. The Yellow River water usage decreased from 319.03 million (M)m³ to 283.58 Mm³ (11.1% saving), and mine water usage increased from 27.88 Mm³ to 47.15 Mm³ (69.1% increase)

Current Study on Estuarine Coastal Ecological Environment and Its Development

AbstractThe paper, referring to the documents on estuarine coastal ecological problems at home and abroad, states the researches on coastal erosion recovery, water quality of estuarine areas, and the recovery and reconstruction of estuarine wetland, and, according to the study situation and real demands of Chinese estuarine coastal researches, analyzes several future popular focuses on estuarine coastal ecological researches, including researches on sediment flux, water quality and wetland protection