Central Asia including Kyrgyzstan is a disaster prone area,suffering from snow avalanches,landslides and flooding.Within the Tyan- Shan region,a mountainous region in Southern Kyrgyzstan,there is an increasing number ...Central Asia including Kyrgyzstan is a disaster prone area,suffering from snow avalanches,landslides and flooding.Within the Tyan- Shan region,a mountainous region in Southern Kyrgyzstan,there is an increasing number of natural hazards over the last years.One of the possible causes of the increase in natural disasters in the region is the deterioration of the Juniper forests in the region.Juniper forests have a large economical and ecological importance for Kyrgyzstan.However,the conditions worsened for these juniper forests.Since 1980 approximately 20% of the juniper forests were lost due to intensive deforestation,forest fires and excessive cattle grazing and possibly also climate changes are affecting the juniper trees and their soil properties.The aim of this study is to investigate the impact of the juniper forest on the local hydrology and to characterize the water protective properties.展开更多
This paper presents a preliminary assessment of the hydrogeological characteristics of a karst mountainous catchment, the Suoi Muoi River catchment, in the northwest of Vietnam. The catchment is located at 600–700 m ...This paper presents a preliminary assessment of the hydrogeological characteristics of a karst mountainous catchment, the Suoi Muoi River catchment, in the northwest of Vietnam. The catchment is located at 600–700 m a.s.l. and covers an area of 284 km. Exposed limestone occupies 32% of the total catchment area. Various types of assessments have been carried out, including geological and hydrogeological field surveys, cave surveys, dye-tracer tests, meteorological and surface water monitoring. Geological studies and cave surveys have identified the most important active cave/conduit systems within the catchment. Although these data are essential, they are insufficient to make a comprehensive appraisal of the hydrologic nature of the catchment under interest. An attempt was made to calculate a global water balance of the catchment, based on short-term (15 months) meteorological and streamflow records. The results show that, despite the existence of a number of substantial cavern conduit systems, the groundwater system of the catchment is governed by the fracture/fissure matrix. The cavern conduit systems only collect groundwater from the adjacent fracture matrix and/or connect topographically isolated surface watercourses. The groundwater storage of the cavern conduit systems appears to be regionally insignificant in comparison with the governed fracture matrix groundwater system.展开更多
The article considers the issues of methodology and development of optimal model adapted for the ＂forest-water＂ system, for forecasting the rate of stream flow and for preventing mudflows, flood flows and soil flows...The article considers the issues of methodology and development of optimal model adapted for the ＂forest-water＂ system, for forecasting the rate of stream flow and for preventing mudflows, flood flows and soil flows in juniper forests of Kyrgyzstan, and also shows the dynamics of ecosystems＇ progress.展开更多
Landslide is one of the major natural disasters which cause extensive loss of life and property. During the last three decades, different researchers have developed different methodologies to prepare landslide suscept...Landslide is one of the major natural disasters which cause extensive loss of life and property. During the last three decades, different researchers have developed different methodologies to prepare landslide susceptibility mapping and hazard assessment in the world. The main goal of this paper is to apply a fuzzy logic approach to landslide susceptibility mapping in the Garuwa sub-basin area, East Nepal. Eight different causative factors are considered： slope angle, slope aspect, slope shape, relative relief, distance from drainage, land use, geology, and distance from active faults. Likelihood ratios are obtained for each class of causative factors by comparison with past landslide occurrences. Then, the likelihood ratios are normalized between zero and one to obtain fuzzy membership values. Next, different fuzzy operators are applied to generate landslide susceptibility maps. Compar- ison with the landslide inventory map reveals that the fuzzy gamma （γ） operator with a y-value of 0.70 yields the best prediction accuracy which is then used to produce the final landslide susceptibility zonation map.展开更多
基金Supported by the the International Cooperation Department of the Ministry of Science & Technology of China(2010DFB90240)
文摘Central Asia including Kyrgyzstan is a disaster prone area,suffering from snow avalanches,landslides and flooding.Within the Tyan- Shan region,a mountainous region in Southern Kyrgyzstan,there is an increasing number of natural hazards over the last years.One of the possible causes of the increase in natural disasters in the region is the deterioration of the Juniper forests in the region.Juniper forests have a large economical and ecological importance for Kyrgyzstan.However,the conditions worsened for these juniper forests.Since 1980 approximately 20% of the juniper forests were lost due to intensive deforestation,forest fires and excessive cattle grazing and possibly also climate changes are affecting the juniper trees and their soil properties.The aim of this study is to investigate the impact of the juniper forest on the local hydrology and to characterize the water protective properties.
文摘This paper presents a preliminary assessment of the hydrogeological characteristics of a karst mountainous catchment, the Suoi Muoi River catchment, in the northwest of Vietnam. The catchment is located at 600–700 m a.s.l. and covers an area of 284 km. Exposed limestone occupies 32% of the total catchment area. Various types of assessments have been carried out, including geological and hydrogeological field surveys, cave surveys, dye-tracer tests, meteorological and surface water monitoring. Geological studies and cave surveys have identified the most important active cave/conduit systems within the catchment. Although these data are essential, they are insufficient to make a comprehensive appraisal of the hydrologic nature of the catchment under interest. An attempt was made to calculate a global water balance of the catchment, based on short-term (15 months) meteorological and streamflow records. The results show that, despite the existence of a number of substantial cavern conduit systems, the groundwater system of the catchment is governed by the fracture/fissure matrix. The cavern conduit systems only collect groundwater from the adjacent fracture matrix and/or connect topographically isolated surface watercourses. The groundwater storage of the cavern conduit systems appears to be regionally insignificant in comparison with the governed fracture matrix groundwater system.
基金Supported by the International Cooperation Department of the Ministry of Science&Technology of the People's Republic of China(2010DFB90240)
文摘The article considers the issues of methodology and development of optimal model adapted for the ＂forest-water＂ system, for forecasting the rate of stream flow and for preventing mudflows, flood flows and soil flows in juniper forests of Kyrgyzstan, and also shows the dynamics of ecosystems＇ progress.
文摘Landslide is one of the major natural disasters which cause extensive loss of life and property. During the last three decades, different researchers have developed different methodologies to prepare landslide susceptibility mapping and hazard assessment in the world. The main goal of this paper is to apply a fuzzy logic approach to landslide susceptibility mapping in the Garuwa sub-basin area, East Nepal. Eight different causative factors are considered： slope angle, slope aspect, slope shape, relative relief, distance from drainage, land use, geology, and distance from active faults. Likelihood ratios are obtained for each class of causative factors by comparison with past landslide occurrences. Then, the likelihood ratios are normalized between zero and one to obtain fuzzy membership values. Next, different fuzzy operators are applied to generate landslide susceptibility maps. Compar- ison with the landslide inventory map reveals that the fuzzy gamma （γ） operator with a y-value of 0.70 yields the best prediction accuracy which is then used to produce the final landslide susceptibility zonation map.
