Elucidating the distribution of the grazing pressure requires an understanding of the grazing activities.In this study,we analyzed the grazing behavior of yaks in Three-RiverSource Region(TRSR)and identified the main ...Elucidating the distribution of the grazing pressure requires an understanding of the grazing activities.In this study,we analyzed the grazing behavior of yaks in Three-RiverSource Region(TRSR)and identified the main factors influencing the distribution of grazing intensity(GI)using trajectory data and remote sensing datasets.Our results revealed that a semi-resident transhumance strategy is employed in this region.The average grazing time(GT)of four GPS collars over the year was 11.84 h/day(N6),11.01 h/day(N11),9.25 h/day(N18),and 11.61 h/day(N24).GT was generally higher in warm seasons(summer and autumn)than in cold seasons(spring and winter).The average daily moving speed was found to be closely related to the pasture size of different herders and the seasons.Geodetector analysis identified the distance to camp(DOC)as the most important single factor influencing the distribution of GI,explaining up to 52%of the GI variations.However,relying solely on this factor may not accurately depict the actual GI distribution.When pairwise factors interacted,the explanatory power of the model increased,ranging from 34.55%to 63.26%.Our study highlights the importance of considering multiple factors when predicting grazing intensity,as grazing activities tend to cluster near settlements,but other factors may also be influential.展开更多
Myanmar is a country with an economy based on agriculture.It has rich agricultural resources and great potential for development.The development of agriculture in Myanmar is becoming increasingly important to internat...Myanmar is a country with an economy based on agriculture.It has rich agricultural resources and great potential for development.The development of agriculture in Myanmar is becoming increasingly important to international food security.Assessments of agricultural land resources in Myanmar are the basis for the country's agricultural development and for food security evaluations.In this paper we used the MaxEnt model to analyze the relationship between the suitability of land for agricultural reclamation and the main environmental variables in Myanmar,and then constructed a model to comprehensively evaluate the suitability of land for agriculture in Myanmar.The results show that:1)the overall accuracy of the MaxEnt model is high (AUC>0.8),which means there is a high correlation between the database of selected environmental indicators and the true distribution of cultivated land in Myanmar.2)Soil depth is the most important factor affecting the suitability of land for agriculture in Myanmar When the thickness of soil layer is less than 100 cm,the suitability of land for agriculture is low.With respect to topographic conditions,slope is the main factor affecting suitability.When the slope is greater than 20 degrees,the suitability of land for agriculture is low.With respect to climate conditions,precipitation is the main influencing factor. There is a positive correlation between river network density and land suitability.3)Currently,400000 km^2 of the land resources in Myanmar are suitable for agriculture,and of this amount 290000km^2 are highly suitable,accounting for nearly 40% of the country's land area.The highly suitable land is distributed mainly in Magway,Sagaing,Ayeyarwady and Yangon provinces.The provinces are also important grain production areas in Myanmar,and this serves to validate the effectiveness of the method used in this paper.展开更多
Gandaki River Basin(GRB) is part of the central Himalayan region, which provides habitat for numerous wild species. However, due to changes in climate and land cover, the habitats of many protected species are at risk...Gandaki River Basin(GRB) is part of the central Himalayan region, which provides habitat for numerous wild species. However, due to changes in climate and land cover, the habitats of many protected species are at risk. Based on the maximum entropy(MaxEnt) model, coupled with bioclimatic layers, land cover and DEM data, the impacts of environmental factors on habitat suitability of Himalayan Monal(Lophophorus impejanus), a national bird of Nepal, was quantified. This study further assessed the present and future habitat and distribution of the Himalayan Monal in the context of climate and land cover changes. The results of this study show that the highly suitable habitat of Himalayan Monal presently occupies around 749 km^2 within the northern, eastern and western parts, particularly protected areas such as Langtang National Park, Manaslu Conservation Area and Annapurna Conservation Area, while it is likely to decrease to 561 km^2 by 2050, primarily in the northern and northwestern parts(i.e., Chhyo, Tatopani, Humde and Chame). These expected changes indicate increasing risk for Himalayan Monal due to a decline in its suitable habitat area.展开更多
Against the background of rapid climate warming,frequent and severe flooding disasters significantly impact socio-economic development and human life.In 2023,due to the northward movement of Typhoon Doksuri,extreme pr...Against the background of rapid climate warming,frequent and severe flooding disasters significantly impact socio-economic development and human life.In 2023,due to the northward movement of Typhoon Doksuri,extreme precipitation occurred in northern China,which resulted in a massive flood event in the Haihe River basin.Seven flood detention basins(FDBs)in North China were successfully implemented to effectively alleviate the downstream flood pressure.Leveraging all available Chinese satellite data,we monitored the flooding process daily,focusing on reviewing the flooding in the Dongdian FDB.The results indicate that since the activation of Dongdian FDB on August 1,the flood reached the urban area of Tianjin in just nine days and inundated the entire detention basin.Flooding persisted in the detention basin for about a week before gradually receding.The total maximum inundated area in the whole region was 307.5 km^(2),including 240.5 km^(2)of arable land,7.0 km^(2)of greenhouse land,and 9.7 km^(2)of built-up land,with an average inundation duration of 19 days.The total cumulative inundated arable land area was 240.5 km^(2),with an average inundation time of 21 days.This study shows that multi-source Chinese satellite data can provide comprehensive information and adequate references for post-disaster assessments.展开更多
基金The Second Tibetan Plateau Scientific Expedition and Research,No.2019QZKK0603Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA20040201National Natural Science Foundation of China,No.41671104。
文摘Elucidating the distribution of the grazing pressure requires an understanding of the grazing activities.In this study,we analyzed the grazing behavior of yaks in Three-RiverSource Region(TRSR)and identified the main factors influencing the distribution of grazing intensity(GI)using trajectory data and remote sensing datasets.Our results revealed that a semi-resident transhumance strategy is employed in this region.The average grazing time(GT)of four GPS collars over the year was 11.84 h/day(N6),11.01 h/day(N11),9.25 h/day(N18),and 11.61 h/day(N24).GT was generally higher in warm seasons(summer and autumn)than in cold seasons(spring and winter).The average daily moving speed was found to be closely related to the pasture size of different herders and the seasons.Geodetector analysis identified the distance to camp(DOC)as the most important single factor influencing the distribution of GI,explaining up to 52%of the GI variations.However,relying solely on this factor may not accurately depict the actual GI distribution.When pairwise factors interacted,the explanatory power of the model increased,ranging from 34.55%to 63.26%.Our study highlights the importance of considering multiple factors when predicting grazing intensity,as grazing activities tend to cluster near settlements,but other factors may also be influential.
基金The Key Research Program of the Chinese Academy of Sciences(ZDRW-ZS-2016-6-4)Strategic Priority Research Program of Chinese Academy of Sciences(XDA20040200)+1 种基金National Natural Science Foundation of China(41761144081 41671104)
文摘Myanmar is a country with an economy based on agriculture.It has rich agricultural resources and great potential for development.The development of agriculture in Myanmar is becoming increasingly important to international food security.Assessments of agricultural land resources in Myanmar are the basis for the country's agricultural development and for food security evaluations.In this paper we used the MaxEnt model to analyze the relationship between the suitability of land for agricultural reclamation and the main environmental variables in Myanmar,and then constructed a model to comprehensively evaluate the suitability of land for agriculture in Myanmar.The results show that:1)the overall accuracy of the MaxEnt model is high (AUC>0.8),which means there is a high correlation between the database of selected environmental indicators and the true distribution of cultivated land in Myanmar.2)Soil depth is the most important factor affecting the suitability of land for agriculture in Myanmar When the thickness of soil layer is less than 100 cm,the suitability of land for agriculture is low.With respect to topographic conditions,slope is the main factor affecting suitability.When the slope is greater than 20 degrees,the suitability of land for agriculture is low.With respect to climate conditions,precipitation is the main influencing factor. There is a positive correlation between river network density and land suitability.3)Currently,400000 km^2 of the land resources in Myanmar are suitable for agriculture,and of this amount 290000km^2 are highly suitable,accounting for nearly 40% of the country's land area.The highly suitable land is distributed mainly in Magway,Sagaing,Ayeyarwady and Yangon provinces.The provinces are also important grain production areas in Myanmar,and this serves to validate the effectiveness of the method used in this paper.
基金Chinese Academy of Sciences-The World Academy of Sciences(CAS-TWAS)President's Fellowship Program for PhD Study。
文摘Gandaki River Basin(GRB) is part of the central Himalayan region, which provides habitat for numerous wild species. However, due to changes in climate and land cover, the habitats of many protected species are at risk. Based on the maximum entropy(MaxEnt) model, coupled with bioclimatic layers, land cover and DEM data, the impacts of environmental factors on habitat suitability of Himalayan Monal(Lophophorus impejanus), a national bird of Nepal, was quantified. This study further assessed the present and future habitat and distribution of the Himalayan Monal in the context of climate and land cover changes. The results of this study show that the highly suitable habitat of Himalayan Monal presently occupies around 749 km^2 within the northern, eastern and western parts, particularly protected areas such as Langtang National Park, Manaslu Conservation Area and Annapurna Conservation Area, while it is likely to decrease to 561 km^2 by 2050, primarily in the northern and northwestern parts(i.e., Chhyo, Tatopani, Humde and Chame). These expected changes indicate increasing risk for Himalayan Monal due to a decline in its suitable habitat area.
基金The Research and Development Program of China(2021YFB3901205)。
文摘Against the background of rapid climate warming,frequent and severe flooding disasters significantly impact socio-economic development and human life.In 2023,due to the northward movement of Typhoon Doksuri,extreme precipitation occurred in northern China,which resulted in a massive flood event in the Haihe River basin.Seven flood detention basins(FDBs)in North China were successfully implemented to effectively alleviate the downstream flood pressure.Leveraging all available Chinese satellite data,we monitored the flooding process daily,focusing on reviewing the flooding in the Dongdian FDB.The results indicate that since the activation of Dongdian FDB on August 1,the flood reached the urban area of Tianjin in just nine days and inundated the entire detention basin.Flooding persisted in the detention basin for about a week before gradually receding.The total maximum inundated area in the whole region was 307.5 km^(2),including 240.5 km^(2)of arable land,7.0 km^(2)of greenhouse land,and 9.7 km^(2)of built-up land,with an average inundation duration of 19 days.The total cumulative inundated arable land area was 240.5 km^(2),with an average inundation time of 21 days.This study shows that multi-source Chinese satellite data can provide comprehensive information and adequate references for post-disaster assessments.
