This article studies the soil moisture conditions of 30 years artificial Robinia pseudoacacia in the north of Shaanxi under different climate conditions in order to explore the relationship between soil moisture and i...This article studies the soil moisture conditions of 30 years artificial Robinia pseudoacacia in the north of Shaanxi under different climate conditions in order to explore the relationship between soil moisture and impact factor of Robinia pseudoacacia in this area,and variation characteristics of soil moisture in the Loess Plateau region. The results show that soil moisture content decreases with increase of soil depth, and in 40- 50 cm depth the jump point of moisture reduction appears significantly. Soil moisture was lower than the growth critical moisture in 5 samples to the north of Chunhua,and has different degrees of deficit. Soil moisture deficit degree was more than 50% in sandy loam and light loam soils such as Yulin,Shenmu and Suide. With the increasing of latitude,both of soil accumulative storage and net rainfall tends to decrease,but the relationship between them is significant correlation,indicating that that climate conditions are the major factors causing significant difference of soil moisture.展开更多
Freshwater is recharged mainly by rainfall and stored inland for a period of time,which is directly affected by its storage capability.The storage capability of river basins has different spatiotemporal features that ...Freshwater is recharged mainly by rainfall and stored inland for a period of time,which is directly affected by its storage capability.The storage capability of river basins has different spatiotemporal features that are important for the predictability of freshwater resources.However,the estimation of freshwater storage capability(FSC)remains a challenge due to the lack of observations and quantification indices.Here,we use a metric that characterizes hydrological“inertia”after rainfalls to analyze FSC over the 194 largest global major river basins based on satellite observations from the Gravity Recovery and Climate Experiment(GRACE)and simulations from the Community Land Model version 5(CLM5).During 2003–16,the global land was observed to retain 28%of precipitation after one month based on GRACE observations,and the simulation depicts that the retained proportions decrease from 42%after one day to 26%after one month,with smaller FSC partly attributed to wetter conditions and higher vegetation densities.The root zone contributes about 40%to the global land FSC on daily to monthly time scales.As the time scale increases,the contribution from the surface soil decreases from 26%to 14%,while the contribution from the deep soil increases from 4%to 10%.Snow contributes over 20%of land FSC,especially over high latitudes.With six decades of CLM5 long-term simulations,it is revealed that the change of FSC in most basins is related to internal climate variability.The FSC of river basins which displays the proportion of precipitation retained on land is worthy of further attention regarding the predictability of water resources.展开更多
We studied the variation of soil moisture as well as its regularity over the irrigation cycle at shelterbelts along the Tarim Desert Highway at different site types and different planting years. The results show that:...We studied the variation of soil moisture as well as its regularity over the irrigation cycle at shelterbelts along the Tarim Desert Highway at different site types and different planting years. The results show that: (1) There is an obvious temporal variation of soil moisture within a typical irrigation period in shelterbelts along the Tarim Desert Highway, and the soil water storage varied linearly with the number of days after irrigation. Along the direction perpendicular to the soil top, the soil profile can be divided into four layers and each shows different dynamics of soil moisture variation, including the quickly changing layer (0—20 cm), the active layer (20—60 cm), the weakly layer (60—100 cm), and the regulated layer (under 100 cm). (2) Both the soil moisture and soil water content decreased gradually with the number of planting year, while the soil water deficit increased. It indicates that shelterbelts along the Tarim Desert Highway can retain the water accumulated from previous years. (3) The soil water storage of harden sand is the maximum among all types of sites. Specifically, it is about 1.58 times higher than that of longitudinal dune, 1.15 times higher than clay, and 1.43 times higher than flat sand. Its soil water deficit was over 900 mm.展开更多
文摘This article studies the soil moisture conditions of 30 years artificial Robinia pseudoacacia in the north of Shaanxi under different climate conditions in order to explore the relationship between soil moisture and impact factor of Robinia pseudoacacia in this area,and variation characteristics of soil moisture in the Loess Plateau region. The results show that soil moisture content decreases with increase of soil depth, and in 40- 50 cm depth the jump point of moisture reduction appears significantly. Soil moisture was lower than the growth critical moisture in 5 samples to the north of Chunhua,and has different degrees of deficit. Soil moisture deficit degree was more than 50% in sandy loam and light loam soils such as Yulin,Shenmu and Suide. With the increasing of latitude,both of soil accumulative storage and net rainfall tends to decrease,but the relationship between them is significant correlation,indicating that that climate conditions are the major factors causing significant difference of soil moisture.
基金the National Key R&D Program of China(2018YFA0606002)the National Natural Science Foundation of China(41875105)the Startup Foundation for Introducing Talent of NUIST(2018r078)。
文摘Freshwater is recharged mainly by rainfall and stored inland for a period of time,which is directly affected by its storage capability.The storage capability of river basins has different spatiotemporal features that are important for the predictability of freshwater resources.However,the estimation of freshwater storage capability(FSC)remains a challenge due to the lack of observations and quantification indices.Here,we use a metric that characterizes hydrological“inertia”after rainfalls to analyze FSC over the 194 largest global major river basins based on satellite observations from the Gravity Recovery and Climate Experiment(GRACE)and simulations from the Community Land Model version 5(CLM5).During 2003–16,the global land was observed to retain 28%of precipitation after one month based on GRACE observations,and the simulation depicts that the retained proportions decrease from 42%after one day to 26%after one month,with smaller FSC partly attributed to wetter conditions and higher vegetation densities.The root zone contributes about 40%to the global land FSC on daily to monthly time scales.As the time scale increases,the contribution from the surface soil decreases from 26%to 14%,while the contribution from the deep soil increases from 4%to 10%.Snow contributes over 20%of land FSC,especially over high latitudes.With six decades of CLM5 long-term simulations,it is revealed that the change of FSC in most basins is related to internal climate variability.The FSC of river basins which displays the proportion of precipitation retained on land is worthy of further attention regarding the predictability of water resources.
基金Supported by Major Orientation Foundation of the CAS Innovation Program (Grant No. KZCX3-SW-342)CAS Action-Plan for West Development (Grant No. KZCX2- XB2-13)+2 种基金Major Scientific and Technological Special of Xinjiang Uygur Autono-mous Region (Grant No. 200733144-3)National Natural Science Foundation of China (Grant No. 40701098)the research projects of the Tarim Branch of Pet-roChina Company Limited (Grant Nos. 971008090016 and 971008090017)
文摘We studied the variation of soil moisture as well as its regularity over the irrigation cycle at shelterbelts along the Tarim Desert Highway at different site types and different planting years. The results show that: (1) There is an obvious temporal variation of soil moisture within a typical irrigation period in shelterbelts along the Tarim Desert Highway, and the soil water storage varied linearly with the number of days after irrigation. Along the direction perpendicular to the soil top, the soil profile can be divided into four layers and each shows different dynamics of soil moisture variation, including the quickly changing layer (0—20 cm), the active layer (20—60 cm), the weakly layer (60—100 cm), and the regulated layer (under 100 cm). (2) Both the soil moisture and soil water content decreased gradually with the number of planting year, while the soil water deficit increased. It indicates that shelterbelts along the Tarim Desert Highway can retain the water accumulated from previous years. (3) The soil water storage of harden sand is the maximum among all types of sites. Specifically, it is about 1.58 times higher than that of longitudinal dune, 1.15 times higher than clay, and 1.43 times higher than flat sand. Its soil water deficit was over 900 mm.
