Comprehensive Assessment of Natural Disaster Risk for Agricultural Production in Guanzhong Region Based on GIS
Received date: 2012-04-22
Request revised date: 2012-07-03
Online published: 2012-12-20
Copyright
China is one of the few countries severely affected by natural hazards. Since 1990s, the economic losses caused by natural disasters have been an obvious upward trend. According to the statistics, the farmland area which affected by various natural disasters each year reaches to 34 × 106hm2, natural disasters caused great economic losses which take up 3%~6% of the Gross Domestic Product (GDP). Guanzhong region locates in the Loess Plateau and belongs to the arid and semiarid area, Because of the vulnerable ecological environment and complex topography of the region, soil erosion, debris flow and other disasters happened frequently. Meanwhile, drought, flood and other natural disasters have great impact on the agricultural production. Therefore, assessment, especially comprehensive assessment of natural disaster for agricultural production is very significant. The main influence factors of each disaster were selected based on the analysis of the type and character of natural disaster in the present paper. Furthermore, comprehensive assessment model is developed to analyze and evaluate the natural disaster risk which the agricultural production of Guanzhong region may suffer. The results show that agricultural production natural disaster risk in Guanzhong region is generally high. The corresponding area of different risk grade for higher-grade, medium-grade and lower-grade is 28.2%, 46.6%and 25.2% , respectively. The higher-grade risk area is mainly located in Fengxian County, Taibai Country, Linyou County and the northern part of Longxian Country, medium-grade risk area is mainly distributed in the tableland edge of the area and low mountain areas, while lower-grade risk area is mainly distributed in the Guanzhong basin. The main type of disaster in higher-grade risk area is geological disaster and water and soil erosion, the main type of disaster in medium-grade risk area is water and soil erosion and ecological environment, while the main type of disaster in lower-grade risk area is drought and flood.
Key words: natural disasters; risk assessment; GIS; Guanzhong region
ZHOU Yin-kang , JIN Xiao-bin , WANG Qian , DU Xin-dong . Comprehensive Assessment of Natural Disaster Risk for Agricultural Production in Guanzhong Region Based on GIS[J]. SCIENTIA GEOGRAPHICA SINICA, 2012 , 32(12) : 1465 -1472 . DOI: 10.13249/j.cnki.sgs.2012.012.1465
Fig.1 Location of the study area图1 研究区示意图 |
Table 1 Assessment indices of drought hazard degree表1 干旱灾害危险度评价指标 |
评价指标 | 等级 | 分值 | 范围 |
---|---|---|---|
春旱频率 | 1 | 1.0 | < 10.0% |
2 | 1.2 | 10.1% ~ 20.0% | |
3 | 1.5 | 20.1% ~30.0% | |
4 | 1.7 | 30.1% ~40.0% | |
5 | 2.0 | > 40.0% | |
夏旱频率 | 1 | 1.0 | < 10.0% |
2 | 1.2 | 10.1% ~20.0% | |
3 | 1.5 | 20.1% ~30.0% | |
4 | 1.7 | 30.1% ~40.0% | |
5 | 2.0 | > 40.0% | |
秋旱频率 | 1 | 1.0 | < 10.0% |
2 | 1.2 | 10.1% ~20.0% | |
3 | 1.5 | 20.1% ~30.0% | |
4 | 1.7 | 30.1% ~40.0% | |
5 | 2.0 | > 40.0% | |
地表湿润指数 | 1 | 1.0 | > 1.30 |
2 | 1.2 | 1.11~1.30 | |
3 | 1.5 | 0.91~1.10 | |
4 | 1.7 | 0.71~0.90 | |
5 | 2.0 | < 0.70 |
注:表中分值1.0表示不易引起干旱,2.0表示易引起干旱。 |
Fig. 2 Comprehensive assessment of nature disaster risk for agriculture production in Guangzhong region图2 关中地区农业生产综合风险评价结果 |
Table 2 Assessment indices of geological disaster表2 地质灾害危险度评价指标 |
影响因素 | 等级 | 分值 | 范围/类型 |
---|---|---|---|
地貌类型 | 1 | 1.0 | 河流阶地 |
2 | 1.2 | 洪积扇 | |
3 | 1.5 | 丘陵 | |
4 | 1.7 | 苔塬 | |
5 | 2.0 | 梁峁 | |
坡度 | 1 | 1.0 | < 5.0° |
2 | 1.2 | 5.1° ~10.0° | |
3 | 1.5 | 10.1° ~15.0° | |
4 | 1.7 | 15.1° ~20.0° | |
5 | 2 | > 20.0° | |
地质条件 | 1 | 1.0 | 硬质岩石 |
2 | 1.2 | 软质岩石 | |
3 | 1.5 | 砂/粉类土 | |
4 | 1.7 | 粘类土 | |
5 | 2 | 黄土 | |
距地质隐患点距离 | 1 | 1.0 | > 3000 m |
2 | 1.5 | 1000 ~3000 m | |
3 | 2.0 | < 1000 m | |
降水量 | 1 | 1.0 | < 500 mm |
2 | 1.5 | 500 ~600 mm | |
3 | 2.0 | > 600 mm |
Table 3 Assessment indices of flood hazard degree表3 洪涝灾害危险度评价指标 |
影响因素 | 等级 | 分值 | 范围 |
---|---|---|---|
历史洪灾频率 | 1 | 1.0 | 0.5% ~2.5% |
2 | 1.2 | 2.6%~5.0% | |
3 | 1.5 | 5.1% ~7.5% | |
4 | 1.7 | 7.6% ~10.0% | |
5 | 2.0 | > 10.0% | |
高程标准差 | 1 | 1.0 | > 70.0 m |
2 | 1.2 | 50.1 ~70.0 m | |
3 | 1.5 | 30.1 ~50.0 m | |
4 | 1.7 | 10.0 ~30.0 m | |
5 | 2.0 | < 10.0 m | |
日降暴雨 | 1 | 1.0 | < 100 mm |
2 | 1.2 | 101~120 mm | |
3 | 1.5 | 121~140 mm | |
4 | 1.7 | 141~160 mm | |
5 | 2.0 | > 160 mm | |
距河流距离 | 1 | 1.0 | < 500 m |
2 | 1.5 | 500 ~2000 m | |
3 | 2.0 | > 2000 m |
Table 4 Assessment indices of environment deterioration表4 生态环境恶化危险度评价指标 |
影响因素 | 等级 | 分值 | 范围 |
---|---|---|---|
化肥投入 强度 | 1 | 1 | < 1500.0 kg/hm2 |
2 | 2 | 1500.0 ~2250.0 kg/hm2 | |
3 | 3 | > 2250.0 kg/hm2 | |
农药投入 强度 | 1 | 1 | < 3.0 kg/hm2 |
2 | 2 | 3.0~7.5 kg/ hm2 | |
3 | 3 | > 7.5 kg/ hm2 | |
COD 排放量 | 1 | 1 | < 2000.0 t |
2 | 2 | 2000.0~4000.0 t | |
3 | 3 | > 4000.0 t | |
二氧化硫 排放量 | 1 | 1 | < 1000.0 t |
2 | 2 | 1000.0 ~2000.0 t | |
3 | 3 | > 2000.0 t | |
固体废弃物排放量 | 1 | 1 | < 20000.0 t |
2 | 2 | 20000.0 ~40000.0 t | |
3 | 3 | > 40000.0 t |
Table 5 Assessment indices of agriculture production vulnerability表5 农业生产脆弱度评价指标 |
影响因素 | 等级 | 分值 | 范围 |
---|---|---|---|
第一产业GDP | 1 | 1.0 | > 40 亿元 |
2 | 1.5 | 20 ~40 亿元 | |
3 | 2.0 | < 20 亿元 | |
农民人均收入 | 1 | 1.0 | > 6000.0元 |
2 | 1.5 | 4000.0~6000.0元 | |
3 | 2.0 | < 4000.0元 | |
坡度 | 1 | 1.0 | < 5.0° |
2 | 1.2 | 5.1°~10.0° | |
3 | 1.5 | 10.1°~15.0° | |
4 | 1.7 | 15.1°~20.0° | |
5 | 2.0 | > 20.0° | |
水资源量 | 1 | 1.0 | > 5.0×104m3 |
2 | 1.5 | 1.0~5.0×104m3 | |
3 | 2.0 | < 1.0×104m3 |
The authors have declared that no competing interests exist.
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