Journal of Geo-information Science >
Study on Rainfall Index Selection for Hazard Analysis of Mountain Torrents Disaster of Small Watersheds
Received date: 2016-06-13
Request revised date: 2016-08-26
Online published: 2017-03-20
Copyright
Mountain torrents are one of the most dangerous weather-related natural disasters in the world. As the direct driving force and inducing factor of mountain torrent disasters, rainfall can be used as an indispensable index in the hazard analysis of flash flood. In different study areas, the rainfall with different return periods and durations may affect mountain torrent disasters differently and would be therefore selected disparately for the hazard analysis. However, there is little quantitative research on the principles of rainfall index selection in the previous literatures. Based on the small watershed map (1:50,000 scale), the rainstorm atlas and the spatial distribution of mountain torrent disasters, this paper focused on the small watersheds in Wuyuan County in Jangxi Province and used GIS (Geographic Information System), Correlational Analysis, Spatial Cluster and Geographical Detector to obtain the rainfall indices which had great impact on the mountain torrent disasters of the small watersheds. The selected rainfall indices will take part in the hazard analysis of mountain torrent disasters in the study area. The conclusion is drawn as follows: (1) Seven uncorrelated rainfall indices have been obtained from the original 24 rainfall indices by the correlational analysis method. This means that in order to avoid the information overlap, we need to analyze the correlation between pairs of the rainfall indices before the hazard analysis of mountain torrent disaster. (2) By using the Optimized Hot Spot Analysis tool based on Local Getis-Ord Gi* Algorithm to get the estimated hazard values of the mountain torrent disasters of small watersheds, the calculation results are in line with the spatial distribution of mountain torrent disasters in this study area. (3)It’s better to introduce geographical detector to quantify the relevance between rainfall indices and mountain torrent disasters of small watersheds. Through the comprehensive analysis, the final rainfall factors, which cause mountain torrent disasters of the small watersheds with a great probability, will be derived and will participate in the hazard analysis of flash flood. The finally selected rainfall factors of small watersheds in Wuyuan County are the maximum rainfall with 100-year return period and 6-hour duration and the maximum rainfall with 100-year return period and 24-hour duration. The technical method in this paper possesses an important reference value and guidance to the quantitative selection of rainfall indices in the hazard analysis of flash flood of small watersheds.
Key words: GIS; rainfall index; correlational analysis; spatial cluster; geographical detector
LI Huawei , WAN Qing . Study on Rainfall Index Selection for Hazard Analysis of Mountain Torrents Disaster of Small Watersheds[J]. Journal of Geo-information Science, 2017 , 19(3) : 425 -435 . DOI: 10.3724/SP.J.1047.2017.00425
Fig. 1 Map of the study area图1 研究区概况图 |
Tab. 1 Main data type, format, coordinate system and source表1 研究区主要数据类型、格式、坐标系及来源 |
数据类型 | 格式 | 空间坐标系 | 来源 |
---|---|---|---|
江西省暴雨图集 | SHAPEFILE | GCS_China_Geodetic_Coordinate_System_2000 | 全国山洪灾害调查评价数据 |
DEM(90 m)数据 | TIF | GCS_WGS_1984 | SRTM |
1:5万小流域数据 | SHAPEFILE | GCS_WGS_1984 | 全国山洪灾害调查评价数据 |
1955-2014年婺源县 历史山洪灾害数据 | SHAPEFILE | Beijing_1954_3_Degree_GK_CM_117E | 全国山洪灾害调查评价数据 |
Tab. 2 The preliminarily constructed rainfall index system表2 初步构建的降雨指标体系 |
历时 | 编号 | 指标/mm |
---|---|---|
10 min | S11 | 年均最大10 min降雨量 |
S12 | 5年一遇最大10 min降雨量 | |
S13 | 10年一遇最大10 min降雨量 | |
S14 | 20年一遇最大10 min降雨量 | |
S15 | 50年一遇最大10 min降雨量 | |
S16 | 100年一遇最大10 min降雨量 | |
1 h | S21 | 年均最大1 h降雨量 |
S22 | 5年一遇最大1 h降雨量 | |
S23 | 10年一遇最大1 h降雨量 | |
S24 | 20年一遇最大1 h降雨量 | |
S25 | 50年一遇最大1 h降雨量 | |
S26 | 100年一遇最大1 h降雨量 | |
6 h | S31 | 年均最大6 h降雨量 |
S32 | 5年一遇最大6 h降雨量 | |
S33 | 10年一遇最大6 h降雨量 | |
S34 | 20年一遇最大6 h降雨量 | |
S35 | 50年一遇最大6 h降雨量 | |
S36 | 100年一遇最大6 h降雨量 | |
24 h | S41 | 年均最大24 h降雨量 |
S42 | 5年一遇最大24 h降雨量 | |
S43 | 10年一遇最大24 h降雨量 | |
S44 | 20年一遇最大24 h降雨量 | |
S45 | 50年一遇最大24 h降雨量 | |
S46 | 100年一遇最大24 h降雨量 |
Fig. 2 The correlation coefficient matrix of initially selected rainfall indices图2 初步选取降雨指标的相关系数矩阵图 |
Fig. 3 Spatial distributions of the preliminarily screened rainfall indices of small watersheds in Wuyuan County图3 初步筛选的婺源县小流域降雨指标空间分布图 |
Fig. 4 Spatial distribution of the hazard of mountain torrent disaster in Wuyuan County图4 婺源县山洪灾害危险性空间分布图 |
Tab. 3 The preliminarily screened rainfall indices表3 初步筛选的降雨指标 |
历时 | 编号 | 指标/mm |
---|---|---|
10 min | S13 | 10年一遇最大10 min降雨量 |
S14 | 20年一遇最大10 min降雨量 | |
1 h | S26 | 100年一遇最大1 h降雨量 |
6 h | S34 | 20年一遇最大6 h降雨量 |
S36 | 100年一遇最大6 h降雨量 | |
24 h | S41 | 年均最大24 h降雨量 |
S46 | 100年一遇最大24 h降雨量 |
Fig. 5 Scatter plots and linear fits of rainfall indices and estimated hazard value of small watersheds in Wuyuan County图5 婺源县小流域降雨指标和危险度估值的散点图及线性拟合图 |
Tab. 4 Detected result of the preliminarily screened rainfall indices表4 初步筛选降雨指标的探测结果 |
历时 | 编号 | 指标/mm | 排序(从大到小) | P | |
---|---|---|---|---|---|
10 min | S13 | 10年一遇最大10 min降雨量 | 0.1676 | 4 | 0.00 |
S14 | 20年一遇最大10 min降雨量 | 0.1008 | 6 | 0.00 | |
1 h | S26 | 100年一遇最大1 h降雨量 | 0.0414 | 7 | 0.08 |
6 h | S34 | 20年一遇最大6 h降雨量 | 0.4276 | 1 | 0.00 |
S36 | 100年一遇最大6 h降雨量 | 0.3923 | 2 | 0.00 | |
24 h | S41 | 年均最大24 h降雨量 | 0.2546 | 3 | 0.00 |
S46 | 100年一遇最大24 h降雨量 | 0.1570 | 5 | 0.00 |
Tab. 5 Interaction between pairs of the four rainfall indices表5 4种降雨指标之间的交互作用 |
交互指标(C) | 解释力() | 结果 | 影响模式 |
---|---|---|---|
10年一遇最大10 min降雨20年一遇最大6 h降雨 | 0.4820 | 双线性增强 | |
10年一遇最大10 min降雨100年一遇最大6 h降雨 | 0.4808 | 双线性增强 | |
10年一遇最大10 min降雨100年一遇最大24 h降雨 | 0.5281 | 非线性增强 | |
20年一遇最大6 h降雨100年一遇最大6 h降雨 | 0.6430 | 双线性增强 | |
20年一遇最大6 h降雨100年一遇最大24 h降雨 | 0.6660 | 非线性增强 | |
100年一遇最大6 h降雨100年一遇最大24 h降雨 | 0.7211 | 非线性增强 |
注:、、、是相应降雨指标的编号,具体见表4 |
The authors have declared that no competing interests exist.
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