[Objective] Saline-alkali wasteland is a kind of land use type that formed by soil salinization and secondary salinization. To study the causes of spatial distri- bution of saline-alkali wasteland could be used as ref...[Objective] Saline-alkali wasteland is a kind of land use type that formed by soil salinization and secondary salinization. To study the causes of spatial distri- bution of saline-alkali wasteland could be used as reference for the amelioration and is significant for developing the reserved land with great potential. [Method] The re- search set a total of 1 729 sampling points in the study area of 34 433 hm2. Spa- tial analyses were used to find out the causes of saline-alkali wasteland in Datong basin from four factors： topography, geology, hydrology and soil. DEM and land use data were used to calculate distribution index of topography, and distribution of the total salinity （TS） and pH was analyzed by means of IDW interpolation. [Result] The results showed that saline-alkali wasteland was distributed on flat and low-lying ter- rains with poor drainage, which led to salt accumulation. 87% of saline-alkali wasteland was distributed on Quaternary Holocene alluvium whose performance of soil hydraulic conductivity was poor. TS value distribution was that in midstream re- gion was the highest, less in upstream region and the least in downstream region along the rivers, and TS value decreased when distance between saline-alkali wasteland and rivers increased. The major soil types in Datong basin were fluvo- aquic soil and saline soil. Both of the two soil types were of high TS value and pH value, and heavily salinized and strongly alkalized. [Conclusion] High groundwater table and the existence of two salt accumulation centers are the two causes of saline-alkali wasteland in Datong basin. The key to ameliorate saline-alkali waste- land is to descend the groundwater table and lessen salt accumulation.展开更多
文摘[Objective] Saline-alkali wasteland is a kind of land use type that formed by soil salinization and secondary salinization. To study the causes of spatial distri- bution of saline-alkali wasteland could be used as reference for the amelioration and is significant for developing the reserved land with great potential. [Method] The re- search set a total of 1 729 sampling points in the study area of 34 433 hm2. Spa- tial analyses were used to find out the causes of saline-alkali wasteland in Datong basin from four factors： topography, geology, hydrology and soil. DEM and land use data were used to calculate distribution index of topography, and distribution of the total salinity （TS） and pH was analyzed by means of IDW interpolation. [Result] The results showed that saline-alkali wasteland was distributed on flat and low-lying ter- rains with poor drainage, which led to salt accumulation. 87% of saline-alkali wasteland was distributed on Quaternary Holocene alluvium whose performance of soil hydraulic conductivity was poor. TS value distribution was that in midstream re- gion was the highest, less in upstream region and the least in downstream region along the rivers, and TS value decreased when distance between saline-alkali wasteland and rivers increased. The major soil types in Datong basin were fluvo- aquic soil and saline soil. Both of the two soil types were of high TS value and pH value, and heavily salinized and strongly alkalized. [Conclusion] High groundwater table and the existence of two salt accumulation centers are the two causes of saline-alkali wasteland in Datong basin. The key to ameliorate saline-alkali waste- land is to descend the groundwater table and lessen salt accumulation.
