Abstract

The repository of soil by water at a national and basin scale was estimated using the RUSLE empirical model which is the first of its kind in Bhutan. The annual soil loss is estimated and categorized into five categories; very low (<200 t/yr), low (200-400 t/yr), moderate (400-600 t/yr), high (600-800 t/yr), and very high (>800 t/yr). Sakteng and Jaldakha basins contributed the highest soil loss rate of 0.04 t/ha/yr and 0.039 t/ha/yr, while considering on landuse pattern, non-built-up and landslide category encountered the highest soil loss of 4.09 t/ha/yr and 0.7 t/ha/yr among others. Similarly, Tsirang, Samtse, and Haa contributed the major soil loss of 0.03 t/ha/yr, 0.0298 t/ha/yr, and 0.02 t/ha/yr respectively. The research can be used as an authentic instrument enabling the soil conservationist and the policymakers to evaluate the adverse impacts, prioritize the conservation efforts and investigate further to narrow down the causes of soil erosion.

摘要

使用不丹首创的 RUSLE 经验模型估算了全国和流域范围内的土壤水库。估计每年的土壤流失并分为五类：非常低 (<200 吨/年)、低 (200-400 吨/年)、中等 (400-600 吨/年)、高 (600-800 吨/年) 和非常高 (>800 吨/年) . Sakteng 和 Jaldakha 流域的土壤流失率最高，分别为 0.04 t/ha/yr 和 0.039 t/ha/yr，同时考虑土地利用模式，非建筑和滑坡类别的土壤流失率最高，为 4.09 t/ha/年和 0.7 吨/公顷/年等。同样，Tsirang，Samtse和Haa造成的主要土壤流失分别为0.03吨/公顷/年，0.0298吨/公顷/年和0.02吨/公顷/年。