[Objective] This study was to reveal the effect of different land use patterns on physical characteristics of soil water in the Yellow River wetland in Shaanxi Province.[Method]Taking Yellow River wetland in Shaanxi P...[Objective] This study was to reveal the effect of different land use patterns on physical characteristics of soil water in the Yellow River wetland in Shaanxi Province.[Method]Taking Yellow River wetland in Shaanxi Province as experimental plot,we compared the physical properties of the soil water under different land use patterns and studied the physical properties and the change law of soil water during the wetland degeneration process.[Result]Under different land use patterns,soil bulk density rose with the increase of soil depth.During the degeneration process of from river wetland to reclaimed wetland（paddy field）,finally to abandoned land owing to salinization,the mean soil bulk density reduced correspondingly from 1.474 to 1.522 g/cm3,finally to 1.593 g/cm3 when abandoned.Accompanying wetland degeneration,soil became compact increasingly,and the indicators of soil porosity（total porosity,capillary porosity,non-capillary porosity）were also reduced with the change of land use patterns,in which,capillary porosity and total porosity reached the extremely significant level with the change of land use patterns,and non-capillary porosity reached significant level.The changes of soil porosity condition accelerated the deterioration of wetland.Under different land use patterns,the maximum soil moisture capacity,capillary moisture capacity and minimum moisture capacity all showed a similar change law.Compared with wetland,the maximum soil moisture capacity of reclaimed land（paddy field）and salinized land respectively decreased by 5.7% and 22.3%,capillary moisture capacity by 0.2% and 19.4%,minimum moisture capacity by 2.7% and 15.9%.Of the three land use patterns,wetland displayed both higher water holding capacity and water drainage capacity over reclaimed land（paddy field）and salinized land.By comparison with wetland,the reclaimed land（paddy field）and salinized land respectively decreased by 12.4% and 15.2% in total water holding capacity,and by 2.7% and 15.9% in total water drainage capacity.[Conclusion]To conserve the water resource in Yellow River wetland,regulate the hydrological cycle and enhance drought and water logging resistances,it should be noted that reasonable countermeasures be taken to exploit the state-owned forest land and paddy field around the wetland and the related resources.展开更多
Palaeoflood hydrological study is a frontal subject of global change study. Using sedimentology, geomorphology and OSL dating methods, the typical palaeoflood slackwater deposits were studied in the Qishuihe River val...Palaeoflood hydrological study is a frontal subject of global change study. Using sedimentology, geomorphology and OSL dating methods, the typical palaeoflood slackwater deposits were studied in the Qishuihe River valley. The results showed that five flooding episodes with 21 palaeoflood events occurred during 4300-4250 a B.P., 4250-4190 a B.P., 4190-4100 a B.P., 4100-4000 a B.P. and 3100-3010 a B.P., respectively, during the Holocene period. The palaeoflood peak discharges were calculated with hydrological models. With a combination of the gauged flood, historical flood and palaeoflood hydrological data, the archives of flood events were extended to over 10,000 years in the Qishuihe River valley, and the flood frequency-peak discharge relationship curve was established accurately. These research results played important roles in mitigating flood hazard, hydraulic engineering and also the development of water resources in the semiarid Weihe River basin.展开更多
基金Supported by National Natural Science Foundation of China(40871119)Key Science and Technology Program of Shaanxi Province,China(2007K01-15-1)~~
文摘[Objective] This study was to reveal the effect of different land use patterns on physical characteristics of soil water in the Yellow River wetland in Shaanxi Province.[Method]Taking Yellow River wetland in Shaanxi Province as experimental plot,we compared the physical properties of the soil water under different land use patterns and studied the physical properties and the change law of soil water during the wetland degeneration process.[Result]Under different land use patterns,soil bulk density rose with the increase of soil depth.During the degeneration process of from river wetland to reclaimed wetland（paddy field）,finally to abandoned land owing to salinization,the mean soil bulk density reduced correspondingly from 1.474 to 1.522 g/cm3,finally to 1.593 g/cm3 when abandoned.Accompanying wetland degeneration,soil became compact increasingly,and the indicators of soil porosity（total porosity,capillary porosity,non-capillary porosity）were also reduced with the change of land use patterns,in which,capillary porosity and total porosity reached the extremely significant level with the change of land use patterns,and non-capillary porosity reached significant level.The changes of soil porosity condition accelerated the deterioration of wetland.Under different land use patterns,the maximum soil moisture capacity,capillary moisture capacity and minimum moisture capacity all showed a similar change law.Compared with wetland,the maximum soil moisture capacity of reclaimed land（paddy field）and salinized land respectively decreased by 5.7% and 22.3%,capillary moisture capacity by 0.2% and 19.4%,minimum moisture capacity by 2.7% and 15.9%.Of the three land use patterns,wetland displayed both higher water holding capacity and water drainage capacity over reclaimed land（paddy field）and salinized land.By comparison with wetland,the reclaimed land（paddy field）and salinized land respectively decreased by 12.4% and 15.2% in total water holding capacity,and by 2.7% and 15.9% in total water drainage capacity.[Conclusion]To conserve the water resource in Yellow River wetland,regulate the hydrological cycle and enhance drought and water logging resistances,it should be noted that reasonable countermeasures be taken to exploit the state-owned forest land and paddy field around the wetland and the related resources.
基金National Natural Science Foundation of China, No.40771018Natural Science Foundation of Shaanxi Prov-ince, No.2006D01Basic Research Fund of Shaanxi Normal University, No.200702001
文摘Palaeoflood hydrological study is a frontal subject of global change study. Using sedimentology, geomorphology and OSL dating methods, the typical palaeoflood slackwater deposits were studied in the Qishuihe River valley. The results showed that five flooding episodes with 21 palaeoflood events occurred during 4300-4250 a B.P., 4250-4190 a B.P., 4190-4100 a B.P., 4100-4000 a B.P. and 3100-3010 a B.P., respectively, during the Holocene period. The palaeoflood peak discharges were calculated with hydrological models. With a combination of the gauged flood, historical flood and palaeoflood hydrological data, the archives of flood events were extended to over 10,000 years in the Qishuihe River valley, and the flood frequency-peak discharge relationship curve was established accurately. These research results played important roles in mitigating flood hazard, hydraulic engineering and also the development of water resources in the semiarid Weihe River basin.
