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2006年四川发生了百年一遇的特大干旱。按照自然地理条件相近、森林覆盖率有较大差异的原则;同时,在同一行政区内按森林覆盖率的高低分成对照组。在县层面上,共3对对比县,在乡层面上共7对对比乡。对比县中,森林覆盖率高的一组森森覆盖率为34.20%～52.29%,平均为43.16%,森林覆盖率低的一组为16.60%～27.28%,平均为20.84%;对比乡镇中,森林覆盖率高的一组森林覆盖率为28.50%～56.23%,平均为41.29%,森林覆盖率低的一组为10.70%～19.12%,平均为14.61%。在干旱后期,调查了四川盆地丘陵区9个县14个乡镇主要农作物(水稻、玉米和红薯)的受灾率、成灾率和绝收率。调研结果表明,森林对农业的旱情具有一定的缓解作用。在县层次上,与森林覆盖率低的相比,森林覆盖率高的主要农作物(水稻、玉米和红薯)的平均受灾率、成灾率、绝收率分别降低16.6%、16.2%、4.0%;在乡镇层次上,与森林覆盖率低的相比,森林覆盖率高的主要农作物(水稻、玉米和红薯)的平均受灾率、成灾率、绝收率分别降低20.3%、19.7%、12.7%;与无农田防护林网相比,有农田防护林网的水稻平均受灾率、成灾率分别降低5.8%、22.8%,没有绝收现象,而无防护林的水稻平均绝收率为6.5%。
In 2006 there was a serious drought once in a century in Sichuan. In accordance with the principle of similar natural and geographical conditions, there is a big difference between the forest coverage; the same time, in the same administrative region according to the level of forest coverage into control group. In the county level, a total of 3 pairs of counties, at the township level a total of 7 pairs of rural areas. In contrast with the county, the forest coverage of a group of high forest cover 34.20% ~ 52.29%, with an average of 43.16%, a group of low forest cover 16.60% ~ 27.28%, an average of 20.84%; contrast towns, forests The highest coverage of a group of forest cover 28.50% ~ 56.23%, an average of 41.29%, a group of low forest cover 10.70% ~ 19.12%, with an average of 14.61%. In the later drought period, the investigation of the disaster-hit rate, disaster-hit rate and rate of waste of major crops (rice, corn and sweet potato) in 14 townships in 9 counties in the hilly area of Sichuan Basin. The survey results show that forests have some relief to the drought in agriculture. At the county level, the average disaster reduction rate, disaster recovery rate and total reject rate of major crops with high forest cover (rice, corn and sweet potato) decreased by 16.6%, 16.2% and 4.0% respectively as compared with those with low forest cover. At the township level, the average disaster reduction rate, disaster recovery rate and total waste recovery rate of main crops with high forest coverage (rice, corn and sweet potato) decreased by 20.3%, 19.7% and 12.7% respectively compared with those with low forest coverage. Compared with the non-farmland shelterbelt network, the average disaster-affected rate and the disaster-incidence rate of paddy field shelterbelts were reduced by 5.8% and 22.8% respectively, with no yield loss, while the shelter-free rice average yield was 6.5%.