为了探索河套灌区玉米的节水灌溉制度,采用沟灌对玉米的灌溉制度进行研究。以田间试验数据为基础,利用ISAREG模型对玉米沟灌的实际灌溉制度进行评价,并模拟了多种灌水方案。研究表明:灌溉水源为黄河水时,玉米生育期内灌水4次,总灌水量约...为了探索河套灌区玉米的节水灌溉制度,采用沟灌对玉米的灌溉制度进行研究。以田间试验数据为基础,利用ISAREG模型对玉米沟灌的实际灌溉制度进行评价,并模拟了多种灌水方案。研究表明:灌溉水源为黄河水时,玉米生育期内灌水4次,总灌水量约为257 m m,产量下降率为8.1%;灌溉水源为井水时,玉米全生育期灌水4次,灌溉定额为240 m m,产量下降率为7.8%。因此,制定合理的玉米沟灌灌溉制度,为当地合理节约水资源提供参考。展开更多
This study assesses vulnerability of agriculture to drought, using WINISAREG model and seasonal SPI2-index for eight climate regions （1951-2004）. Results relative to Plovdiv show that in soils of large TAW （total a...This study assesses vulnerability of agriculture to drought, using WINISAREG model and seasonal SPI2-index for eight climate regions （1951-2004）. Results relative to Plovdiv show that in soils of large TAW （total available water） net irrigation requirements NIRs range from 0 to 380 mm. In soils of small TAW, NIRs reach 440 mm in the very dry year. NIRs in Sofia/Silistra are about 100 mm smaller than in Plovdiv while in Sandanski they are 30-110 mm larger. Rainfed maize is associated with great yield variability （29% 〈 Cv 〈 72%）. Considering an economical RYD （relative yield decrease） threshold, 32% of years are risky when TA Wis large in Plovdiv that is double than in Sofia and half than in Sandanski. In North Bulgaria the risky years are 10% in Pleven/Silistra that is half than in Lom. In Plovdiv region reliable relationships （R2 〉 91%） were found relating the SPI2 ＂July-Aug.＂ with simulated RYD of rainfed maize while remaining relationships were less accurate （73% 〈 R2 〈 86%）. Economical losses are produced when High Peak Season SPI2 〈 ＋ 0.20 in Sandanski, SPI2 〈 - 0.50 in Plovdiv and SPI2 〈 - 0.90 in Sofia. In North Bulgaria the SPI2 threshold ranges from - 0.75 to - 1.50. Derived reliable relationships and SPl-thresholds are used for drought vulnerability mapping.展开更多
文摘为了探索河套灌区玉米的节水灌溉制度,采用沟灌对玉米的灌溉制度进行研究。以田间试验数据为基础,利用ISAREG模型对玉米沟灌的实际灌溉制度进行评价,并模拟了多种灌水方案。研究表明:灌溉水源为黄河水时,玉米生育期内灌水4次,总灌水量约为257 m m,产量下降率为8.1%;灌溉水源为井水时,玉米全生育期灌水4次,灌溉定额为240 m m,产量下降率为7.8%。因此,制定合理的玉米沟灌灌溉制度,为当地合理节约水资源提供参考。
文摘This study assesses vulnerability of agriculture to drought, using WINISAREG model and seasonal SPI2-index for eight climate regions （1951-2004）. Results relative to Plovdiv show that in soils of large TAW （total available water） net irrigation requirements NIRs range from 0 to 380 mm. In soils of small TAW, NIRs reach 440 mm in the very dry year. NIRs in Sofia/Silistra are about 100 mm smaller than in Plovdiv while in Sandanski they are 30-110 mm larger. Rainfed maize is associated with great yield variability （29% 〈 Cv 〈 72%）. Considering an economical RYD （relative yield decrease） threshold, 32% of years are risky when TA Wis large in Plovdiv that is double than in Sofia and half than in Sandanski. In North Bulgaria the risky years are 10% in Pleven/Silistra that is half than in Lom. In Plovdiv region reliable relationships （R2 〉 91%） were found relating the SPI2 ＂July-Aug.＂ with simulated RYD of rainfed maize while remaining relationships were less accurate （73% 〈 R2 〈 86%）. Economical losses are produced when High Peak Season SPI2 〈 ＋ 0.20 in Sandanski, SPI2 〈 - 0.50 in Plovdiv and SPI2 〈 - 0.90 in Sofia. In North Bulgaria the SPI2 threshold ranges from - 0.75 to - 1.50. Derived reliable relationships and SPl-thresholds are used for drought vulnerability mapping.
