中国木薯生产水足迹时空特征及水影响研究——以两广地区为例

SPATIAL-TEMPORAL CHARACTERISTICS OF WATER FOOTPRINT AND IMPACT ON WATER RESOURCES OF CHINA'S CASSAVA PRODUCTION——A CASE STUDY ON GUANGXI AND GUANGDONG

关键词:  水足迹  木薯  时空特征  水压力程度  两广地区

Key words:  water footprint  cassava  spatial-temporal characteristics  water pressure degree  Guangxi and Guangdong

摘要:

目的 木薯是我国重要的生物燃料原料作物，研究我国木薯主产区的生产耗水特征对木薯产业发展、水资源管理和政策制定具有重要意义。方法 文章基于水足迹理论及应用探索性空间数据分析（ESDA）方法，选取2004—2020年广东和广西（简称“两广地区”）木薯主产区 45个气象站点气象数据和相关农业数据，对两广地区木薯水足迹时空演变规律及其对当地水资源的影响进行研究。结果 （1）研究期间，两广地区木薯生产水足迹总体呈现下降趋势。其中，广西木薯水足迹高于广东，绿水足迹占比大于蓝水足迹。（2） 两广地区木薯水足迹在平水年2004年、枯水年2011年和丰水年2019年空间分布略有差异，整体有从广东东南方向至广西西北方向递增的趋势。（3）两广地区木薯水足迹具有很高的空间相关性和强空间聚集性。水足迹高高聚集区（H—H）主要分布在广西北部和中部，低低聚集区（L—L）主要分布在广东经济发达地区。（4）枯水年2011年有着相对较高的水压力程度。广西木薯生产对当地水资源产生对影响更大。结论 两广地区木薯生产及其需水量随年份发生了明显的变化，用水效率及水消耗量空间差异较大，具有明显的空间聚集特征。因此，应调整两广地区木薯种植结构，制定区域内合理灌溉制度，提升水资源和种植结构的匹配度，从而达到促进木薯产业可持续发展和缓解当地水资源压力的目的。

Abstract:

Cassava is an important biofuel feedstock crop in China. It is significant to study the impact of cassava production on water resources in major cassava-producing areas (Guangxi and Guangdong) in China for cassava industry development, water resources management, and policymaking. The meteorological data from 45 meteorological stations and agricultural data in Guangxi and Guangdong from 2004 to 2020 were selected as specific samples, this paper investigated the evolving temporal-spatial water footprint (WF) of cassava production and the impact on local water resources by using water footprint theory and the exploratory spatial data analysis (ESDA) method. The results were listed as follows. During the investigation, there was a downward trend of the WF of cassava production in Guangxi and Guangdong from 2004 to 2020. There was higher cassava WFs in Guangxi than in Guangdong. The proportion of green WF was larger than that of blue WF. (2) The spatial distribution of the cassava WF in those two areas differed slightly in the normal year (2004), the dry year (2011), and the wet year (2019), with an upward trend from the southeast of Guangdong to the northwest of Guangxi. (3) The cassava WF in Guangxi and Guangdong possessed characteristics of strong spatial correlation and solid spatial aggregation. The high-high agglomeration areas (H—H) were mainly distributed in northern and central Guangxi, while the low-low agglomeration areas (L—L) were distributed primarily in the economically developed regions of Guangdong. (4) The dry year (2011) faced a relatively high water presure degree, thus Guangxi's cassava production posed a more significant impact on local water resources. Overall, cassava production and water demand in Guangxi and Guangdong changes notably over the years. The spatial difference of water-use efficiency and water consumption is significant, with prominent spatial aggregation characteristics. Therefore, it is necessary to adjust the cassava planting structure in Guangxi and Guangdong based on water resources, formulate a reasonable irrigation system in the region, and improve the matching degree between water resources and planting structure, so as to achieve the goal of promoting sustainable development of the cassava industry and alleviating local water resource pressure.