Disaster Control Research Articles

Roof-cutting and energy-absorbing method for dynamic disaster control in deep coal mine

Deep mining roadways are often under high-stress conditions and strong mining-induced disturbances. In the traditional longwall mining method, stress concentration and energy accumulation take place in the surrounding rock of the roadway, often causing dynamic disasters. To this end, the roof-cutting and energy-absorbing (RCEA) control method is proposed. Directional roof presplitting is used to transfer the roof stress and release the energy accumulated in the rock. Importantly, a roadway is automatically formed and coal pillars are eliminated. Moreover, new constant resistance energy-absorbing bolt and cable with high prestress and high elongation are used to control the roadway roof, which are independently developed. As a result, the self-supporting capacity of the rock is improved, and the energy released by the rock deformation is effectively absorbed by the support system. To verify the fidelity of the RCEA method, the numerical comparison test between the automatically formed roadway (AFR) method and the gob side entry driving method is carried out. Compared with the latter, the energy per unit length of AFR is reduced by 4.59*10 6 J, and the maximum energy density is reduced by 36.6%, which shows that AFR has profound effect on the energy release. Subsequently, the mechanical tests on the new bolt (cable) are carried out. The forces at fracture of the new bolt and cable are 1.63 times and 2.80 times that of the common bolt, and the maximum energy absorbed per unit length are 3.05 times and 2.89 times that of the common bolt. The new bolt (cable) has characteristics of high strength and high energy absorption. Finally, the strength-energy combined support design method and the field application are carried out. Field monitoring results show that the RCEA method can effectively release the energy accumulated in the rock and ensure the safety and stability of the roadway.

Study on Creep Characteristics of Water Saturated Phyllite

Phyllite is affected by its own bedding, stress environment and water-saturated conditions. There are great differences in its deformation and failure in engineering, and its creep characteristics are an important basis for evaluating the long-term stability of phyllite engineering. Therefore, this study carried out creep tests of water-saturated phyllite under different bedding angles and confining pressures, studied the coupling effect of factors that affect the creep characteristics of phyllite, and investigated and analyzed the deformation characteristics of a phyllite roadway support on site to provide basic support for phyllite roadway mine disaster control and collaborative mining research. The results showed the following: (1) When the bedding dip angle was 30~60°, under the control of the bedding, the sliding deformation along the bedding suddenly increased under the low-stress condition and the specimen did not undergo structural damage. It could continuously bear multi-level stress and generated creep deformation. In this case, a phyllite roadway should adopt the support method of combining flexibility and rigidity. (2) In the process of multi-stage stress loading, the creep instantaneous stress was directly proportional to the initial stress. When the stress was loaded to 50% of the failure strength, the instantaneous stress tended to be stable and maintained a linear, slightly increasing relationship with the stress. When the bedding angle was 30~60°, the creep deformation accounted for more than 50% of the total deformation. The bedding angles of 0° and 90° were dominated by the instantaneous strain during the stress loading process. For the flexible support of the roadway, the deformation caused by disturbance stress should be fully considered. (3) The uniaxial creep specimen mainly displayed compression shear tensile failure, with a small number of parallel cracks along the main fracture surface. The triaxial creep fracture mode changed to single shear failure. The confining pressure showed greater inhibition of the creep of the specimen with a bedding inclination of 0° and 90°. The strength design of the rigid support should refer to the original rock stress value of the roadway. The creep deformation and failure of the specimen with a bedding inclination of 30~60° were mainly controlled by the bedding. The included angle between the bedding dip angle and the maximum principal stress should be kept within 30~60° as far as possible in the roadway layout.

Influence of Water Injection Pressure on Methane Gas Displacement by Coal Seam Water Injection

It is of great significance to study the pattern of displacing methane gas with water in the coal seam water injection process for the prevention and control of gas disasters. A two-phase displacement test device was used to conduct experiments on the water injection of coal samples to displace methane gas under different water injection pressures, and the influence of the water injection pressure on the displacement was analyzed. The test results show that with the same displacement time, the ratio of displaced methane increases with the increase in the water injection pressure. The displacement rate increases with the increase in the water injection pressure at the stage without water discharge, while the water displacement rate under different water injection pressures differed slightly; in the later displacement stage, a higher water injection pressure of the coal sample results in a faster attenuation of the displacement rate and water displacement rate due to the decrease in the methane content in the coal sample. There is a critical water injection pressure to displace methane gas. When the critical water injection pressure is exceeded, the displacement time does not change appreciably. Flowing water can displace a large amount of methane gas in coal, and the methane displacement rate increases with the increase in the water injection pressure. The high solubility of methane in water is the reason for the high methane displacement rate. The results of this study can provide theoretical guidance for coal seam water injection to control gas disasters.

Assessment of building reliability in the Gedung Kuliah Bersama (GKB) of State Polytechnic Fakfak West Papua

The engineer must pay attention to strength, comfort, frugality, and impact on the environment in the building planning both in multi-storey or non-storey. Those aspects must be carefully planned and taken into a capable management system in it and to comply the comfort aspect in the building, hence disaster risk management such as fire prevention is needed. The purpose of this research is to evaluate the fire prevention and control system based on Minister of Public Works Regulation No.26/PRT/M/2008 and Indonesian National Standart 03-6574-2001, analyze the building reliability, and provide alternative solutions for the fire disaster control system in the college building of Fakfak State Polytechnic. The result of check list observation showed the average suitability was . The calculation result of Value of the Building Safety System Components using the Pd-T-11-2005-c guideline based on <em>Analytical Hierarchy Process</em> (AHP) was 64.23 % < 80%. It was classified into GOOD ENOUGH. From the results, alternative solution that can be proposed for college building at Fakfak State Polytechnic is to establish fire prevention.

Causality Analysis and Risk Assessment of Haze Disaster in Beijing

Due to the lack of training data and effective haze disaster prediction model, the research on causality analysis and the risk prediction of haze disaster is mainly qualitative. In order to solve this problem, a nonlinear dynamic prediction model of Beijing haze disaster was built in this study. Based on the macroscopic evaluation of multiple influencing factors of haze disaster in Beijing, a causality model and flow diagrams of the Beijing crude oil consumption system, Beijing coal consumption system, Beijing urban greening system and sulfur dioxide emission system in Hebei and Tianjin were established. The risk prediction of Beijing haze disaster was simulated at different conditions of air pollutant discharge level for the Beijing–Tianjin–Hebei region. Compared with the governance strategies of vehicle emission reduction, petrochemical production emission reduction, coal combustion emission reduction, greening and reducing dust and collaborative governance policy, the Beijing–Tianjin–Hebei cross-regional collaborative governance policy was more effective in controlling the haze disaster of Beijing. In the prediction, from 2011 to 2017, the air quality of Beijing changed from light pollution to good. By 2017, the PM2.5 of Beijing reduced to 75 µg/m3. From 2017 to 2035, the control effect of urban haze disaster for Beijing further strengthened. By 2035, the PM2.5 of Beijing reduced to 35 μg/m3. Finally, the PM2.5 of Beijing continued to reduce from 2035 to 2050. The speed of reduction for PM2.5 in Beijing slowed down. Meanwhile, the achievements of haze control in Beijing were consolidated. By 2050, the risk of haze disaster for Beijing was basically solved. The nonlinear dynamic prediction model in this study provides better promise toward the future control and prediction of global haze disaster under the condition of limited data.

Ensemble stacking rockburst prediction model based on Yeo–Johnson, K-means SMOTE, and optimal rockburst feature dimension determination

Rockburst forecasting plays a crucial role in prevention and control of rockburst disaster. To improve the accuracy of rockburst prediction at the data structure and algorithm levels, the Yeo–Johnson transform, K-means SMOTE oversampling, and optimal rockburst feature dimension determination are used to optimize the data structure. At the algorithm optimization level, ensemble stacking rockburst prediction is performed based on the data structure optimization. First, to solve the problem of many outliers and data imbalance in the distribution of rockburst data, the Yeo–Johnson transform and k-means SMOTE algorithm are respectively used to solve the problems. Then, based on six original rockburst features, 21 new features are generated using the PolynomialFeatures function in Sklearn. Principal component analysis (PCA) dimensionality reduction is applied to eliminate the correlations between the 27 features. Thirteen types of machine learning algorithms are used to predict datasets that retain different numbers of features after dimensionality reduction to determine the optimal rockburst feature dimension. Finally, the 14-feature rockburst dataset is used as the input for integrated stacking. The results show that the ensemble stacking model based on Yeo–Johnson, K-means SMOTE, and optimal rockburst feature dimension determination can improve the accuracy of rockburst prediction by 0.1602–0.3636. Compared with the 13 single machine learning models without data preprocessing, this data structure optimization and algorithm optimization method effectively improves the accuracy of rockburst prediction.

Development Law of Mining Fracture and Disaster Control Technology under Hard and Thick Magmatic Rock

Hard and thick magmatic rocks are widely distributed in many mining areas in China. Their fracture migration could cause mechanical effects such as the evolution of overburden structure, the sudden change of surface subsidence, and the transformation of accumulated elastic properties, inducing strong dynamic phenomena and even coupled geo dynamic disasters. In this study, by means of theoretical analysis and similar material simulation testing, the fracture of hard thick magmatic rock and the fracture development characteristics of stope are analyzed, and the following research results are obtained: (1) the mechanical model of an elastic foundation beam is established, and it is found that the bending moment in the middle of hard thick magmatic rock is greater than the bending moment at the end, and the magmatic rock first produces fractures in the middle, and then the initial fracture occurs. (2) The existence of hard thick magmatic rock blocks the development of fractures in the longitudinal direction. The bed separation and fracture undergo three processes of generation, development and closure. When the working face advances 160 m, 200 m and 270 m, the maximum bed separation shape on the strike section experiences triangle trapezoid crescent shape. (3) A ladder type fissure channel is formed above the working face side and the open cut hole side. When the working face is advanced 160 m, the ladder type fissure channel develops to the bottom of the hard thick rock layer, providing a ladder type channel for gas flow. After the hard thick rock layer is broken, a large number of elastic properties are released, which produces a strong impact force on the gas rich area of the bed separation, and also causes a sharp rise in the gas pressure of the bed separation at the bottom of the magmatic rock. A large amount of high-pressure gas in the bed separation space flows reversely to the working face along the ladder type gas channel, which can easily induce a gas outburst, coal and gas outburst or other disasters. (4) The correctness of the similar simulation experiment is verified by the field data. Technical measures for preventing gas outbursts in bed separation by surface drilling and pressure relief gas extraction are put forward. The research results have a certain guiding role for the prevention and control of dynamic disasters and the design of roadway support under the condition of a hard and thick key stratum overlying the working face.

Technical Analysis of Drilling Fluid System for Water Disaster Control in Jiaozuo Mining Area

Technical Analysis of Drilling Fluid System for Water Disaster Control in Jiaozuo Mining Area

Scientific challenges in disaster risk reduction for the Sichuan–Tibet Railway

Traversing the Qinghai–Tibetan Plateau, the Sichuan–Tibet Railway is by far the most difficult railway project in the world. The Qinghai–Tibetan Plateau features the most active crustal dynamics on earth, the strongest coupling effects of endogenic and exogenic dynamics, and the environment most sensitive to global climate change. The project area is characterized by extremely cold climate, high elevation and relief, high seismic intensity, high geothermal activity, and high tectonic stress. Consequently, the threat of various disaster risks is ever-present at different stages of the entire life cycle of the Sichuan–Tibet Railway. There is urgent need to systematically study these problems at various levels from the fundamental science to the development of key technologies. This article investigates the different disaster risks recognized during the various stages of construction of the Sichuan–Tibet Railway project, and summarizes the scientific challenges and technical problems faced in relation to disaster risk prevention and control. This work also introduces the scientific deployment and relevant research progress of the Sichuan–Tibet Fund special project initiated by the National Natural Science Foundation of China. Here, we also aim to solve the major fundamental scientific challenges in terms of long-term risk prevention and control during the construction of the Sichuan–Tibet Railway, and lay a theoretical foundation to promote breakthroughs in the bottleneck of key technologies. The scientific challenges addressed in the study of disaster risk associated with the Sichuan–Tibet Railway include the following: The quantitative assessment of the activity of deep-large faults and strong earthquake prediction, the evolution of physical fields in areas of strong tectonic activity, the development mechanisms of tunnel hazards, the slope evolution processes under coupled endogenic and exogenic dynamics in alpine gorges, the impact of climate change on the formation and evolution of surface hazards, and the evolution of extreme wind fields in deep-cut canyons. The technical problems faced in disaster risk prevention and mitigation in relation to the Sichuan–Tibet Railway are as follows: Advanced identification, monitoring, and early warning of geological disasters in mountainous areas with steep and complex terrain; risk analysis, prevention, and control of railway engineering disasters based on their dynamic processes; tunnel engineering hazard monitoring, early warning, risk analysis, prevention, and control technologies; key technologies for emergency response; and the green and resilient railway system and lifecycle risk management. The Sichuan–Tibet Fund special project will include five key research topics: (1) the interior geological structure and dynamic evolution of the eastern plateau; (2) the hazard-inducing mechanisms of coupled internal and external forces in canyons and gullies within plateaus; (3) the cataclysm mechanics of deeply buried long-distance tunnel engineering; (4) risk identification and projection of major disasters affecting the railway; and (5) the integrated management of scientific innovations and super large-scale railway construction. Systematic research is expected to reveal the evolution of earth surface movements and coupled engineering-disturbance related disasters. It will also enable the formation of a comprehensive risk analysis method for major engineering disasters, and promote the development of green, safe, efficient, and resilient engineering disaster risk reduction technologies that will support the disaster risk management during the entire lifecycle of the Sichuan–Tibet Railway.

Spatio-temporal assessment of rainfall erosivity in Ecuador based on RUSLE using satellite-based high frequency GPM-IMERG precipitation data

Soil erosion caused by rainfall is one of the main soil degradation problems in Ecuador and has major implications on conservation and management of water and soil resources, disaster control, agricultural protection and other applications in the Ecuadorian territory. Extensive precipitation time series are required to estimate the rainfall erosivity as a triggering element of soil erosion, however, meteorological stations distribution in Ecuador is not homogeneous over the national territory (greater concentration in coastal basins) and present high lack of data, generating an incorrect rainfall distribution that requires resorting to other types of available information. The objective of this work was to analysis the spatio-temporal distribution of potential soil erosion through rainfall erosivity in Ecuador, through an innovative method based on the Revised Universal Soil Loss Equation (RUSLE) employing GPM-IMERG rainfall data. Our methodology considered the delimitation and evaluation of the watersheds environmental characteristics, GPM-IMERG, GPCC and ERG-data evaluation as providers of rainfall databases, and calculation of the erosive force of the rain (R-Factor) over the period 2001–2020. Basins delimitation and layers of environmental characteristics were obtained from regional literature; GPM-IMERG and GPCC from web servers; ERG-data from INAMHI-Ecuador; R-Factor (30 min) calculation was made from GPM-IMERG parameters and its was validated with RIST software using a representative subset of pixels, revealing an excellent compatibility of almost 1% average difference. New information was obtained from spatial, interannual and seasonal R-Factor distribution considering environmental characteristics, even though the satellite image products (GPM-IMERG) still underestimate the high values of R-Factor compared to Literature. New models for Ecuador have been established to estimate the R-Factor from annual rainfall, which allow it to be calculated since the beginning of the last century as well as generate projections of future soil erosion. This helps territory managers to take new measures to deal with soil loss.

Brief Discussion on Prevention and Control of Mine Geological Disasters and Protection of Geological Environment

Brief Discussion on Prevention and Control of Mine Geological Disasters and Protection of Geological Environment

Coupling Mechanism of Coal Body Stress–Seepage around a Water Injection Borehole

In China, coal seam water injection technology is widely used in the prevention and control of mine gas and dust disasters. The evolution law of stress–seepage field in the range of hydraulic influence in the process of coal seam water injection is the most basic theoretical problem in coal seam water injection technology. Therefore, this paper first uses the radial seepage experimental system to test the permeability of raw coal samples, and then numerically inverts the stress–seepage evolution law of the coal body around the water injection hole. The results show that the coal seam permeability decreases exponentially with the increase in the experimental overburden pressure. The dynamic water intrusion causes the pressure relief area and the stress concentration area to transfer to the deep part of the coal body, and abnormal stress occurs near the water injection hole wall. The composite stress area formed by the superposition of stress and pore water pressure reduces the permeability of the hole wall. During the radial development of water injection, the pore water pressure dropped sharply and eventually tended to zero, while Darcy’s velocity decreased significantly (within the pressure relief zone, it rapidly decreased from 7.26 × 10−3 m s−1 to 2.5 × 10−3 m s−1 (by 65.56%)). Near the initiation point, the maximum step-down height of Darcy’s velocity decreased from 6.73 × 10−3 m s−1 to 5.27 × 10−3 m s−1 (by 22.73%). This can make it clear that the seepage velocity presents a non-Darcy seepage phenomenon under the influence of pore pressure.

Mining Subsidence Prediction Model and Parameters Inversion in Mountainous Areas

Coal mining in mountainous areas is general in China, especially in Shanxi Province. Under the influence of topography in mountainous areas, surface collapses and landslides caused by underground mining happen at a certain frequency and threaten human lives and assets. Accurate prediction of the movement and deformation of mining subsidence in mountainous areas facilitates the prevention and control of geological disasters. The probability integral method is an official prediction method for mining subsidence prediction in China, while it is lacking in the prediction accuracy in mountainous areas due to the inherent topography. Therefore, a practical prediction model based on slopes slip combined parameters optimization was proposed in this study. The slip subsidence and slip horizontal movement were deduced based on the probability integral method considering the topography (slope angle α < 30°) and geological conditions (loess covered) to build the prediction model. The dynamic step fruit fly optimization algorithm (DSFOA) was applied for parameters inversion about the probability integral method in the proposed prediction model, while the other parameters in the proposed model were determined by mechanics analysis based on the nature of losses. The determination of parameters is more efficient, objective and reasonable, so that the prediction accuracy can be improved. The measured data of the working panel 22,101 located in Taiyuan, Shanxi Province was verified by this practical model, and the result shows that the mean square error of subsidence and the horizontal movement was decreased to 71 mm and 276 mm, respectively, hence, the applicability of the proposed mining subsidence prediction model in mountainous areas is verified. This work will contribute to a comprehensive understanding on the law of surface movement and provide theoretical guidance for surface damage prevention and control in mountainous mining areas.

Failure analysis and countermeasures of a tunnel constructed in loose granular stratum by shallow tunnelling method

To solve the failure problems encountered in the tunnels constructed by shallow tunnelling method in loose granular stratum, taking a tunnel construction project on the Sichuan-Tibet 318 Highway Line in China as an example. Failure phenomena, characteristics, and modes were systematically analyzed during tunnel construction. Then, the evolution at different failure modes was analyzed through DEM calculation and the prevention mechanism was discussed. Finally, corresponding construction countermeasures were put forward from the aspects of pre-support, excavation, bolt driving, and collapse prevention. The results show that: (1) The conventionally strong support system cannot play an active role in the tunnel. The core problems in construction are how to reduce the disturbance of excavation to surrounding rock and realize the restraint of the support system to the surrounding rock in the arch-foot area. (2) According to the loss of the surrounding rock, the failure modes can be divided into two types: Ⅰ-the rapid development failure from vault collapse and Ⅱ-the lag failure of ground cavity moving up. Construction optimization aims at avoiding the mode-Ⅰ and alleviating the mode-Ⅱ. (3) For the mode-Ⅰ, maintaining the stability of the initial ground-arch is the practical measure; For the mode-Ⅱ, when the cavity area is more significant than 5 m2, it must be filled in time. (4) The field deformation data of surrounding rock after treatment shows that the effect of the proposed countermeasures is remarkable, which can provide valuable references for the tunnel design, construction, and disaster control in a similar area.

Disaster talk: The increased knowledge of disaster management among a study group of students of Faculty X University Y

Indonesia has been known as a disaster-prone country. Disasters can occur due to several things, namely natural disasters, disasters due to technological failures, and also emerging risks. Disaster control can be done by knowing disaster management in an integrated and comprehensive manner. Providing information and increasing relevant knowledge about disasters is one of the implementations of the disaster management phase, namely the pre-disaster stage. University students are chosen as partners because they are agents of change who can play a significant role in society. The method of implementing community service is through online lectures and discussions. Pre and post-test were carried out to determine the comparison of knowledge in students. This activity succeeded in increasing students' knowledge about disaster management.

Numerical simulation of creep fracture evolution in fractured rock masses

The initiation, expansion, and penetration of microscopic cracks in rock is the macroscopic manifestation of creep. This paper investigates mechanical creep characteristics and fracture evolution processes in rock masses with different fracture angles, lengths, and rock bridge dip angles. Single fractures, dual parallel fractures, and fracture groups are considered. The approach comprises discrete element simulation based on continuum mechanics, utilizing the continuous and discontinuous software, GDEM. Single-fracture rock masses are characterized by a progressive fracture development mode dominated by tensile shear failure. The rate of creep and fracture magnitude both increase according to fracture length. With increasing fracture inclination angle, creep rate and fracture magnitude increase and decrease. The creep rate and degree of rupture are highest for fractures inclined at 30°. The dual-fracture rock mass exhibits both tensile crack failure and compressional shear failure. Creep rates are highest, and rupture effects are most apparent at rock bridge inclination angles of 90°. If the rock bridge is too long or too short, the stable creep stage is prolonged, but the creep acceleration stage intensifies due to interaction between fracture-bounded rock masses. The failure mode, in this case, involves collective failure by tension fractures and compressional shear. Creep rate and fracture magnitude increase with the number of fractures, which accelerates rock mass deformation to a certain extent. However, when the number of fractures reaches a certain threshold, a relatively stable structure may become established, slowing down the creep rate, especially during the creep acceleration stage. This study can provide a theoretical basis and reference for investigating the creep rupture law of rock mass engineering and the prevention and control of fractured rock mass geological disasters.

Numerical Simulation Analysis of the Formation and Morphological Evolution of Asymmetric Crescentic Dunes

Generally, typical crescentic dunes in the ideal state are symmetrical, but it is difficult to form crescentic dunes with two perfectly symmetrical horns under actual conditions. Among many environmental factors, bidirectional winds, the size of sand particles, topography, epiphyte vegetation, and dune collision are important reasons for the asymmetric evolution of sand dunes. Few existing studies have revealed the mechanism of the morphological evolution of asymmetric crescentic dunes, especially in regard to the role of wind in a complex dune’s morphology. In this study, we used the Reynolds Averaged Navier-Stokes (RANS) and mass balance models to simulate the asymmetric forms and flow fields of crescentic dunes and analyzed the potential causes of the asymmetry among the above aspects. The results showed that: (1) the angle of the bidirectional winds significantly changed the structure of vortices around the sand dune; (2) for crescentic dunes with coarser sand, the deposit continuity was better, the extension of the single horn was maintained for a long time, and the extended horn took longer to die out; (3) the crescentic dune deformed according to the direction of the inclination of the terrain, and the shear stress of a dune on a slope was related to the slope, width, or height; (4) whether there was epiphytic vegetation on a dune’s surface had a great impact on the dune’s migration; (5) the collision position of two dunes determined the shape of the two dunes after fusion. The simulation results indicated that the spatial–temporal differences in sand flux, caused by changes in flow fields that were induced by various factors, determined the evolutionary shape of crescentic dunes. These results can provide a reference for the study of the erosion of surface flow fields on various dunes and for the prevention and control of wind and sand disasters in the Gobi Desert area.

Driving Effects and Spatial-Temporal Variations in Economic Losses Due to Flood Disasters in China

The economic loss caused by frequent flood disasters poses a great threat to China’s economic prosperity. This study analyzes the driving factors of flood-related economic losses in China. We used the extended Kaya identity to establish a factor decomposition model and the logarithmic mean Divisia index decomposition method to identify five flood-related driving effects for economic loss: demographic effect, economic effect, flash flood disaster control effect, capital efficiency effect, and loss-rainfall effect. Among these factors, the flash flood disaster control effect most obviously reduced flood-related economic losses. Considering the weak foundation of flash flood disaster prevention and control in China, non-engineering measures for flash flood prevention and control have been implemented since 2010, achieving remarkable results. Influenced by these measures, the loss-rainfall effect also showed reduction output characteristics. The demographic, economic, and capital efficiency effects showed incremental effect characteristics. China’s current economic growth leads to an increase in flood control pressure, thus explaining the incremental effect of the economic effect. This study discusses the relationship between flood-related economic loss and flash flood disaster prevention and control in China, adding value for the adjustment and formulation of future flood disaster prevention policies.

Analysis of the Influence of Agricultural Natural Disaster on Farmers’ Technology Adoption Decision

Xinjiang is the main cotton-producing area in China. However, its natural environment is special, and natural disasters frequently occur during the agricultural production process. Fortunately, the application of modern agricultural production technology provides a good tool for cotton farmers to reduce disaster losses. In order to analyze the impact of agricultural natural disasters on farmers’ adoption of agricultural production technology, based on the survey data of 216 cotton farmers in the main cotton production areas, this study uses a binary logistic model to analyze the impact of disaster types and stages on cotton farmers’ application of drip irrigation water-saving technology. The results show that hail, drought, and disease disasters have a significant impact on the application of drip irrigation water-saving technology, considering that the damage to equipment and technology’s control of disasters are the reasons behind; post-disaster remediation in the growth or maturity period also has a significant impact, which can reduce losses; and market price risk for cotton also has a significant impact.

Long range multi-step water quality forecasting using iterative ensembling

Real-life water quality monitoring applications such as aquaculture domains and water resource management need long range multi-step prediction for disaster control. However, prediction accuracy usually degrades gradually as the prediction target timepoint is further away from the current timepoint. To address this, recent water quality forecasting methods mostly rely on complex deep learning models. In this paper, we propose a simple time-variant iterative ensembling method that strives to significantly improve the performance of a given arbitrary long range multi-step time series predictor for water quality data with minimal increase in computational cost. With the given predictor, our proposed method iteratively uses ensembles of predicted values for preceding steps to improve the prediction accuracy for the succeeding steps. The iterative ensembling operation is performed on the trained model and only at the inference stage, and so does not need any further computing-intensive training for the performance improvement. We experimentally show that the proposed method is effective with 7 predictors and 9 water quality datasets of various types, and it outperforms the state-of-the-art results in those datasets by around 2%–29% in mean absolute error (MAE), root mean squared error (RMSE) and mean absolute percentage error (MAPE) metrics. Similar improvement has also been found in two other metrics such as normalized Nash–Sutcliffe model efficiency coefficient (NNSE) metric and Taylor diagram plot. Overall, the proposed iterative ensembling is a promising approach for multi-step long range water quality prediction for high-frequency water quality monitoring systems.