贵州毕节石桥小流域喀斯特石漠化耕地治理研究

Rehabilitation of Arable Land with Karst Rocky Desertification in Shiqiao Sub-watershed of Bijie City,Guizhou

贵州毕节石桥小流域是喀斯特石漠化典型区域,人口密度大,农民基本口粮短缺,经济收入极低,生态环境日趋恶化。利用3S技术得出小流域耕地面积456.57 hm2,其中48.7%发生石漠化,引用人—地关系平衡模型对研究区人口进行3年的粮食需求预测,确定出在其人口数量的所需耕地量为281.91 hm2,发现需保有的耕地中仍有47.79 hm2存在不同程度的石漠化。在此基础上根据流域不同游段环境特征与社会经济发展情况,对流域耕地石漠化的区域实施林农间作、粮草间作、坡改梯等间作和增产措施后,耕地的石漠化得到有效控制,土壤侵蚀深度总体呈下降趋势(由2007年的0.76 mm下降到2009年的0.64 mm),直接经济收入人均增加288元,有效地保障耕地的石漠化治理与农民生计。

Shiqiao sub-watershed of Bijie city is a typical Karst rocky desertification mountainous area with high population density,shortage of essential provisions,very low income and gradual deteriorative eco-environment in Guizhou.There is 456.57 hm2 arable land,48.7% of which is being rocky-deserted.The grain demand forecasted by the human-land balance model for population in the area during next three years shows that 281.91hm2 arable land can support the population and there is 47.79hm2 arable lands with different rocky desertification degree.The rocky desertification of arable land is effectively controlled,the soil erosion depth decrease from 0.76mm in 2007 to 0.64mm in 2009 and the direct economic income per capita increased by 288 Yuan after implementing measures of forest and crops intercropping,crops and grass intercropping,terraced plowing and so on according to environmental characteristics and social economic development status of different areas in Shiqiao sub-watershed,which effectively ensures rocky desertification control of arable land and farmers＇ livelihood.