Hydrology and nutrient flux in an agrarian watershed of the Sikkim Himalaya
Hydrology and nutrient flux in an agrarian watershed of the Sikkim Himalaya
复制标题
锡金喜马拉雅农业流域的水文和养分通量
DOI：
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复制
发表时间：
1998
影响因子：
3.9
通讯作者：
E. Sharma
中科院分区：
文献类型：
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作者：
S. C. Rai;E. Sharma
摘要：在位于喜马拉雅山锡金的农业流域进行了水文研究。Mamlay流域海拔高度为300-2650米，总面积为3014公顷。流域水系为树枝状水系，高海拔处河流质地较细，河谷处逐渐变粗。流量在雨季最大，夏季最小。在雨季a：流域出口，记录的沉积物浓度为325 mg/i。地表径流量最大的是开放农业（种植）区（降水量的9.6%）和最小的豆蔻agroforcstry（2.17%）。在开放的农业区，土壤流失量为477公斤/公顷，而在茂密的温带混合天然林中，土壤流失量很低（6公斤/公顷）。与农林复合系统相比，开放农业区由于土壤侵蚀而损失了大量养分。应在采用开放农业做法的大多数地区推广农林系统。天然林和农林复合系统中不同途径的地表径流、土壤和养分流失以及降水分配表明，这些土地利用促进了土壤水分和养分的保持。
ABSTRACT: A hydrological study was carried out in an agrarian watershed located in the Sikkim Himalaya. The Mamlay watershed has an clevational range of 300-2650 m above msl with a total area of 3014 ha. The drainage of the watershed is dendritic type and the stream texture is fine on the higher elevation that gradually becomes coarse at the valley. The discharge was greatest in rainy season and smallest in summer. Sediment concentration of 325 mg/i WAS recorded during rainy season a: the watershed outlet. Overland flow was greatest in open agricultural (cropped) area (9.6% of the precipitation) and smallest in cardamom agroforcstry (2.17%). Soil loss of 477 kg/ha was recorded in open agricultural area, while it was very low (6 kg/ha) in dense mixed temperate natural forest. Large quantities of nutrients were lost through soil erosion from the open agricultural area in comparison to agroforestry systems. Agroforestry systems should be promoted in most of the areas where open agricultural practices are followed. The overland flow, soil and nutrient loss, and precipitation partitioning in different pathways in natural forest and agroforestry systems suggests that these land uses promote conservation of soil water, and nutrients.