CAJ | 학술논문

为解决地形复杂区域因无法及时获取数据而影响旱灾监测的问题，该研究以湖北省清江流域中上游为例，基于具有较强物理机制的分布式水文模型（soil and water assessment tool，SWAT），建立作物水分亏缺指数进行农业旱情监测，其中，利用该流域的土地覆被、土壤、地形、气象以及2003-2005年和2007-2010年水文观测数据构建了流域SWAT模型，模拟作物水分亏缺指数的有关参量，包括潜在蒸散量和降水量。研究结果表明：1）SWAT模型模拟的潜在蒸散量与气象数据计算得到的潜在蒸散量拟合相关度达到97%以上；2）与标准化降水指数监测结果进行对比，基于SWAT模型建立的作物水分亏缺指数能够从机理方面客观反映监测区域作物生长期的受旱程度，有效实现了流域尺度的旱灾监测，克服了复杂地形区利用少数气象站点建立气象干旱指标评价旱情的局限性。该研究可为复杂地形区旱灾评估提供可行途径。
위해결지형복잡구역인무법급시획취수거이영향한재감측적문제，해연구이호북성청강류역중상유위례，기우구유교강물리궤제적분포식수문모형（soil and water assessment tool，SWAT），건립작물수분우결지수진행농업한정감측，기중，이용해류역적토지복피、토양、지형、기상이급2003-2005년화2007-2010년수문관측수거구건료류역SWAT모형，모의작물수분우결지수적유관삼량，포괄잠재증산량화강수량。연구결과표명：1）SWAT모형모의적잠재증산량여기상수거계산득도적잠재증산량의합상관도체도97%이상；2）여표준화강수지수감측결과진행대비，기우SWAT모형건립적작물수분우결지수능구종궤리방면객관반영감측구역작물생장기적수한정도，유효실현료류역척도적한재감측，극복료복잡지형구이용소수기상참점건립기상간한지표평개한정적국한성。해연구가위복잡지형구한재평고제공가행도경。
In recent years droughts occurred frequently in western, southwestern remote mountainous areas of China, affecting the local agricultural production and farmers' life. Drought monitoring and prediction is one of the main tasks of crop condition monitoring. Remote sensing data and ground survey data are used to monitor drought in current crop condition monitoring system, while high-resolution Remote sensing data and enough ground survey data for effective monitoring are often unable to access timely in those remote mountainous areas due to complex topography and broken plots. The aim of the study was to develop drought monitoring method to meet the complex terrain area and then to provide reliable scientific information to guide agricultural production. Crop water deficit index (CWDI) as an index characterizing agricultural drought has been widely used, which includes parameters of potential evapotranspiration (PET) and precipitation. Soil and water assessment tool (SWAT) as a distributed hydrological model with strong mechanism has been used to simulate crop’s potential evapotranspiration in those areas with complex topography. Those tools provide a feasible way of this study. The upper and middle reaches of Qingjiang River Basin, as the study area, from which drought conditions were monitored by the combination of CWDI and SWAT. Land use/cover data, soil data, topography data, meteorology data and hydrological data from 2003 to 2005 and 2007 to 2010 were used for calibration and validation of SWAT model. The PET simulated by SWAT had a high correlation fit with the PET calculated with meteorological data. Comparison of the statistical indexes included relative bias, root mean square error and multiple correlation coefficients. Standard precipitation index (SPI) was used for two times of drought monitoring tests to compare with the crop water deficit index (CWDI) based on the SWAT model. In July 2009, heavy drought happened in upper and middle reaches of Qingjiang River Basin. From the result of SPI, most part of the area had severe drought including Lichuan, Jianshi and Hefeng. Based on statistics of GIS software, severe drought area was about 86,830 ha. There was a different range of severe drought in Lichuan, Enshi, Jianshi, Badong and Xuanen from the result of CWDI. The area of severe drought was 23,059 ha. However, based on the regional survey, due to continuous high temperatures and less precipitation, crop growth was affected and about 25,440 ha of farmland was heavily affected. In April 2010, light drought was taken place in upper and middle reaches of Qingjiang River Basin. From the result of SPI, only mild drought happened in Enshi, Badong and Jianshi and there was no other level of drought for the same time period. The monitoring result of CWDI showed that moderate drought occurred in part of Enshi region and mild drought in north-central of Jianshi, north of Badong. There was about 7,448 ha of moderate drought from the statistical survey result. According to the statistical survey data,the affected area of crop reached 8,000 ha. Compared with the monitoring results of SPI, the disaster degree and scope were closer between CWDI and actual survey results. The difference existed in these two kinds of monitoring results, which mainly because SPI consisted of precipitation without other elements, which can not objectively reflect the degree of water demand of land surface. CWDI was composed by PET and precipitation and PET was a function of many meteorological elements and crop factor, which can reflect different situation under the same precipitation. The results proved that the combination of CWDI and SWAT can reflect the regional drought condition objectively at the period of crop growth in mountainous areas and overcome the limitations of meteorological drought index calculated by few meteorological stations’ data.