摘要
以宁夏中部干旱带盐池县为研究对象,对区域植被生态需水的内涵及类型划分进行了分析,并结合彭曼—蒙特斯模型逐月估算了区域林草植被潜在蒸散量,采用Jensen公式结合实测的区域土壤特征曲线确定了土壤水分修正系数,为植被生态需水量的确定奠定了基础。通过对不同类型林草植被生态需水占比分析,可知当前盐池县草地的生态需水量远高于林地,是盐池县生态需水的主体。通过对植被生态需水与降雨平衡的时间变化规律分析可知,除7、8、9月份以外,盐池县各类林草植被生态需水均处于严重亏缺状态,其中缺水量最为严重的是4月份;从植被类型上分析,可知林地中无论是生态需水亏缺量还是盈余水量均以灌木林地为最,而草地中以天然草地为最。进一步对盐池县各生态分区需水特征进行分析,可知一级生态分区中,风沙区的生态需水比例远大于黄土丘陵区;二级生态分区生态需水比例由大到小依次为花马池镇、王乐井乡、大水坑镇、高沙窝镇、惠安堡镇、冯记沟乡、青山乡、麻黄山乡。一级生态分区中风沙区的生态需水系数及生态需水模数均大于黄土丘陵区;二级各生态分区中生态需水系数及模数由大到小依次为花马池镇、王乐井乡、大水坑镇、惠安堡镇、高沙窝镇、青山乡、冯记沟乡,最小为麻黄山乡。盐池县降雨消耗性生态需水量最小值占蒸发总量的比例为30. 51%,适宜值占蒸发总量的比例为72. 91%,比例都比较高,其余的的蒸发量属于无效蒸发水量,仍然占有一定的比重,这依然为区域植被建设留有一定的空间,但要通过合理的水资源调控手段进行调配。
The paper chose Yanchi County which is located in the arid area of central Ningxia Province, China, as the research object. The connotation and classification of ecological water requirement are analyzed firstly. Then the regional vegetation potential evaporation and ecological water requirement were estimated from month to month using the Penman-Monteith model. The soil moisture correction coefficient was determined using the Jensen formula combined with the measured regional soil characteristics curve at last. Through the proportion analysis of different types of ecological water requirement from vegetation, it showed that the current existing grassland ecological water re- quirement was far higher than that of woodland. For the three kinds of forest ecological water requirement, shrub proportion was the largest, and the descending order list of grassland ecological water requirement from large to small was as follows： natural grassland, perennial artificial grassland, and annual artificial grassland. Secondly the temporal variation of balance law between rainfall and ecological water requirement for vegetation was analyzed, and it showed that the ecological water requirement from each kind of existing vegetation was in serious deficit except in the months of July,August and September with the situation in April being the worst. It also showed that whether there is water deficit or water surplus in terms of meeting ecological water requirement from the woodland, the shrub land was outstanding, and from the grass land, the natural grass land was outstanding. The analysis of ecological wa- ter requirement characteristics based on ecological zoning indicated that the proportion of ecological water require- ment from the windy and sandy area was much greater than that in loess hilly region in the primary ecological divi- sion. For the secondary ecological division, the list in descending order based on the proportion of ecological water requirement from big to small was as follows： Huamachi town, Wanglejing town, Dashuikeng town, Gaoshawo town, Hui ＇anpu town, Fengjigou town and Qingshan town. The minimum value of existing rainfall consumptive ecological water requirement accounted for 30.51% of total evaporation and the suitable value accounted for 72.91% of total evaporation. The proportion was high and the rest of the evaporation part may be consumed in non-forest land soil evaporation, which belongs to ineffective evaporation of water consumption yet occupies a large proportion.
作者
李金燕
LI Jin-yan(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,Ningxia,China;Engineering Technique Research Center for Water Saving Irrigation and Water Resources in Ningxia,Yinehuan 750021,Ningxia,China;Engineering Research Center for Efficient Utilization of Water Resources in Modern Agriculture in Arid Regions,Yinehuan 750021,Ningxia,China)
出处
《干旱区地理》
CSCD
北大核心
2018年第5期1064-1072,共9页
Arid Land Geography
基金
国家自然科学基金项目(51569024)资助
宁夏高等学校一流学科建设(水利工程NXYLXK2017A03)资助
关键词
宁夏盐池县
植被生态需水占比
降水资源平衡
生态需水
Yanchi County of Ningxia
proportion of ecological water requirement of vegetation
balance between rainfall resource and ecological water requirement
ecological water requirement
