The study of lakes dynamic change based on RS and GIS –Take DaLiNuoEr Lake as an example

AbstractIn the study, TM images in eight periods was the data source, adopted RS and GIS technology, threshold value method, deference value and other methods,Statistics the water area of Dalinor from 1995 to 2009 in past 15 years. By establishing lake's Digital Elevation Model (DEM), it was analyzed dynamic change of Dalinor lakes volume in nearly 15 years. In this 15years, Dalinor lake's area narrowed from 246.7km2 in 1995 to 218 km2 in 2009, Lake area reduced 28.7km2, The average decrease speed was 2.05 km2 / a. The total volume narrowed from 4359821563.03 m3 in 1995 to 3889917491.37 m3 in 2009, the total volume reduced 469904071.66 m3, the average decrease speed was 33564576.55 m3 / a. Lake area and volume declined sharply

The biophysical effects of potential changes in irrigated crops on diurnal land surface temperature in Northeast China

Irrigated crops have experienced a significant global expansion. The biophysical response of climate change to irrigated crop expansion in different regions, particularly in terms of monitoring the influence mechanism of nighttime land surface temperature (LST) change, however, remains insufficiently explored. Taking the three northeastern provinces of China as our study area, we apply window analysis, partial correlation analysis, and geographical detector to quantitatively characterize the spatial and temporal distribution pattern of daytime and nighttime LST (diurnal LST) and biophysical parameters, and the main driving mechanism of diurnal LST change. The results showed that irrigated crop expansion led to asymmetric changes in daytime (−2.11 ± 0.2°C, 97.4%) and nighttime (0.64 ± 0.2°C, 79.9%) LST. ΔLSTDT had a negative correlation with ΔLE (63%), but a positive correlation with ΔSSR and ΔH (91% and 77%). This revealed that the cooling effect caused by the superposition of the output latent heat flux and the absorbed solar shortwave radiation was greater than its heating effect. ΔLSTNT and ΔLE had a positive connection across 69% of the region. ΔLSTNT demonstrated a negative correlation with ΔSSR and ΔH in 82% and 75% of the regions, respectively. At this time, the superposition of latent heat flux and heating potential term produces a greater heating effect. The explanatory power of the single factor (the mean of q<0.50) of biophysical parameters for diurnal LST variation was significantly smaller than that of the interaction factor (the mean of q>0.50, p<0.01). This study shows more detailed dynamic information of diurnal LST and biophysical parameters from 8day scale. The findings highlighted the critical role of asymmetric changes in the diurnal surface thermal environment caused by irrigated crop expansion in the global climate from a land surface hydrothermal energy balance perspective

Assessing the implications of temperature extremes during the period 1959-2014 on the Inner Mongolia Plateau to sustainable development

The study sought to foster a better understanding of the nature of extreme temperature events and variations, and their implications to sustainable development, based on 16 indices of extreme temperature obtained from 43 meteorological stations on the Inner Mongolia Plateau (IMP). By using linear trend and Mann-Kendall abrupt change tests to investigate temporal variation trends, coupled with spatial distribution patterns and abrupt changes of extreme temperature events, the study revealed that the IMP has experienced extreme warming during 1959–2014 with warm extremes increasing significantly (p < 0.01) and cold extremes apparently decreasing (p < 0.01). The most significant increasing trends of warm extreme indices occurred in the desert steppe area (DSA) and sand desert area (SDA), suggesting that warming trends for night-time indices were larger than for daytime indices, while the most significant decreases in cold extreme indices were detected in forest area (FA) and forest steppe area (FSA). In addition, the significant cold day and cold night indices showed a decreasing trend, while warm day and warm night indices showed an increasing trend across the entire study area. Moreover, the study identified that topography has a large impact on the spatial distribution of extreme temperature indices, as does the type of grassland, and the ubiquity of the heat island effect in constructed urban regions. Finally, the study posits that to mitigate the effects of extreme temperatures, it is imperative to foster adaptive actions based on the principles of sustainable development

Satellite imagery evidence for a multiannual water level decline in Hulun Lake, China, with suggestions to future policy making responses

Lakes are ecosystems characterised by a substantial vulnerability to climate change. Their geomorphological features mean that they are particularly exposed to extreme events, which are known to put a significant pressure on fauna, flora and human populations. An example of the impacts of climate change on lakes canbe taken from Hulun Lake, China, whose water levels have changed over time due to the combined impact of climate extremes and anthropogenic activities. There is a limited amount of literature on Hulun Lake and a perceived need to monitor, document and disseminate information on how water level changes influence suchecosystems. This paper attempts to address the current information needs by reporting on a study, which lists the pressures and stressors Hulan Lake is exposed to and considers the role of policy-making in addressing them. The methods used  in this paper and the results obtained may serve the purpose of encouraging similarstudies elsewhere

Detection and classification of Brandt’s vole burrow clusters utilizing GF-2 satellite imagery and faster R-CNN model

Most small rodent populations worldwide exhibit fascinating population dynamics, capturing the attention of numerous scholars due to their multiyear cyclic fluctuations in population size and the astonishing amplitude of these fluctuations. Hulunbuir steppe stands as a crucial global hub for livestock production, yet in recent decades, the area has faced recurring challenges from steppes rodent invasions, with Brandt’s vole (Lasiopodomys brandtii, BV) being particularly rampant among them. They not only exhibit seasonal reproduction but also strong social behavior, and are generally considered pests, especially during population outbreak years. Prior studies suggest that BV population outbreaks tend to occur across a wider geographic area, and a strong indicator for identifying rodent outbreaks is recognizing their burrow clusters (burrow systems). Hence, this paper conducts target object detection of BV burrow clusters in the typical steppes of Hulunbuir using two GF-2 satellite images from 2021 (the year of the BV outbreak). This task is accomplished by incorporating the Faster R-CNN model in combination with three detection approaches: object-based image classification (OBIC), based on vegetation index classification (BVIC), and based on texture classification (BTC). The results indicate that OBIC demonstrated the highest robustness in BV burrow cluster detection, achieving an average AP of 63.80% and an F1 score of 0.722 across the two images. BTC exhibited the second-highest level of accuracy, achieving an average AP of 55.95% and an F1 score of 0.6660. Moreover, this approach displayed a strong performance in BV burrow clusters localization. In contrast, BVIC achieved the lowest level of accuracy among the three methods, with an average AP of only 29.45% and an F1 score of 0.4370. Overall, this study demonstrates the crucial role of utilizing high-resolution satellite imagery combined with DL-based object detection techniques in effectively monitoring and managing the potential outbreaks of steppe rodent pests across larger spatial extents

Scenario-based hazard analysis of extreme high-temperatures experienced between 1959 and 2014 in Hulunbuir, China

Purpose - Extreme high temperatures are a significant feature of global climate change and have become more frequent and intense in recent years. These pose a significant threat to both human health and economic activity, and thus are receiving increasing research attention. Understanding the hazards posed by extreme high temperatures are important for selecting intervention measures targeted at reducing socioeconomic and environmental damage. Design/methodology/approach - In this study, detrended fluctuation analysis is used to identify extreme high-temperature events, based on homogenized daily minimum and maximum temperatures from nine meteorological stations in a major grassland region, Hulunbuir, China, over the past 56 years. Findings - Compared with the commonly used functions, Weibull distribution has been selected to simulate extreme high-temperature scenarios. It has been found that there was an increasing trend of extreme high temperature, and in addition, the probability of its indices increased significantly, with regional differences. The extreme high temperatures in four return periods exhibited an extreme low hazard in the central region of Hulunbuir, and increased from the center to the periphery. With the increased length of the return period, the area of high hazard and extreme high hazard increased. Topography and anomalous atmospheric circulation patterns may be the main factors influencing the occurrence of extreme high temperatures. Originality/value - These results may contribute to a better insight in the hazard of extreme high temperatures, and facilitate the development of appropriate adaptation and mitigation strategies to cope with the adverse effects

A Novel Intravital Method to Evaluate Cerebral Vasospasm in Rat Models of Subarachnoid Hemorrhage: A Study with Synchrotron Radiation Angiography

Precise in vivo evaluation of cerebral vasospasm caused by subarachnoid hemorrhage has remained a critical but unsolved issue in experimental small animal models. In this study, we used synchrotron radiation angiography to study the vasospasm of anterior circulation arteries in two subarachnoid hemorrhage models in rats. Synchrotron radiation angiography, laser Doppler flowmetry-cerebral blood flow measurement, [125I]N-isopropyl-p-iodoamphetamine cerebral blood flow measurement and terminal examinations were applied to evaluate the changes of anterior circulation arteries in two subarachnoid hemorrhage models made by blood injection into cisterna magna and prechiasmatic cistern. Using synchrotron radiation angiography technique, we detected cerebral vasospasm in subarachnoid hemorrhage rats compared to the controls (p<0.05). We also identified two interesting findings: 1) both middle cerebral artery and anterior cerebral artery shrunk the most at day 3 after subarachnoid hemorrhage; 2) the diameter of anterior cerebral artery in the prechiasmatic cistern injection group was smaller than that in the cisterna magna injection group (p<0.05), but not for middle cerebral artery. We concluded that synchrotron radiation angiography provided a novel technique, which could directly evaluate cerebral vasospasm in small animal experimental subarachnoid hemorrhage models. The courses of vasospasm in these two injection models are similar; however, the model produced by prechiasmatic cistern injection is more suitable for study of anterior circulation vasospasm

Combined Effects of Hillslope-Concentrated Flows and Riverine Stream Waves on Soil Erosion in the Reservoir Riparian Zone

During the exposed season, the water level fluctuation zone of the Three Gorges Reservoir has suffered from hillslope-concentrated flows and riverine stream waves, which considerably complicates the processes and magnifies the rate of bank erosion. This study depicts the forms and patterns of integrated bank erosion in this reservoir marginal landscape, decouples the evolutionary processes involved, explores the underlying mechanisms, and quantifies the magnitude through a case study on a fine-grained sandy bank. Hillslope-concentrated flows over rainfall storm events developed continuous gullies starting from uplands and extending throughout the entire slope of the reservoir bank, characterized by relatively larger depths and widths compared with discontinuous gullies on the lower slope developed by riverine stream waves

Simulation and Prediction of Land Use/Cover Changes Based on CLUE-S and CA-Markov Models: A Case Study of a Typical Pastoral Area in Mongolia

Modeling and predicting land use/cover change (LUCC) and identifying its drivers have been a focus of research over the past few decades. In order to solve the problem of land resource degradation in typical pastoral areas, reveal the temporal and spatial evolution characteristics of LUCC, and the contradiction between man and land in sustainable development, we analyze the Gurvanbulag area of Bulgan province, Mongolia, where grassland degradation is relatively serious. The LUCC data in 2000, 2010 and 2019 were obtained through interpreting human-computer interaction. On this basis, the same binary logistic regression (BLR) results were input into the multi-criteria evaluation analytic hierarchy process (MCE_AHP) of CLUE-S and CA_Markov models. The Current Trends (CT) and Ecological Protection (EP) development scenarios were used to predict the temporal and spatial evolution characteristics of LUCC in 2030 and 2040. The results show: (1) both models can effectively simulate the LUCC in 2019, and the CLUE-S model was significantly better than the CA_Markov model. (2) From 2000 to 2019, the LUCC in this region was dominated by a decrease in water and the growth of grassland and other land, indicating that the region is at the risk of land resource degradation. (3) In a multi-scenario development study, by 2030 and 2040, both models predicted that the EP development scenario is more effective in protecting the local ecological environment and it is easier to achieve the sustainability of land resources, than the CT development scenario. Combined with local policy demands and the prediction results of restraining land resource degradation, CLUE-S was significantly higher than the CA_Markov model, indicating that in typical pastoral areas, the former is more in line with the need for sustainable development of the local ecological environment than the latter