CAJ | 학술논문

通过研究滇池蓝藻水华在可见光、红外谱段的光谱特征,并利用假彩色合成法以及归一化植被指数(NDVI)法进行了滇池蓝藻水华信息的遥感识别和提取,进而对提取结果进行了对比分析.结果表明:假彩色合成图的绿色区域和NDVI值大于-0.1的区域,为蓝藻水华区域.-0.1≤NDVI≤0.2时,轻度水华,像元内水华覆盖度为0-30%;0.2<NDVI≤0.4时,中度水华,像元内蓝藻水华覆盖度为31%-80%;NDVI>0.4时,重度水华,水华浓厚,像元内蓝藻水华覆盖度为81%-100%同时研究了激励滇池蓝藻水华暴发的关键气象因子和指标.滇池蓝藻水华暴发的关键时期是6-9月份,影响滇池蓝藻暴发的关键因子是日照和风速.6-9月份连续4-5h的光照,且风速≤2m/s的气象条件组合极易引起蓝藻水华暴发.
통과연구전지람조수화재가견광、홍외보단적광보특정,병이용가채색합성법이급귀일화식피지수(NDVI)법진행료전지람조수화신식적요감식별화제취,진이대제취결과진행료대비분석.결과표명:가채색합성도적록색구역화NDVI치대우-0.1적구역,위람조수화구역.-0.1≤NDVI≤0.2시,경도수화,상원내수화복개도위0-30%;0.2<NDVI≤0.4시,중도수화,상원내람조수화복개도위31%-80%;NDVI>0.4시,중도수화,수화농후,상원내람조수화복개도위81%-100%동시연구료격려전지람조수화폭발적관건기상인자화지표.전지람조수화폭발적관건시기시6-9월빈,영향전지람조폭발적관건인자시일조화풍속.6-9월빈련속4-5h적광조,차풍속≤2m/s적기상조건조합겁역인기람조수화폭발.
Based on high spectral reflectivity features of Blue-green Algal Bloom (BAB) in Lake Dianchi, by MODIS satellite re mote sensing data, RGB:621 combined false color synthesis and Normalized Difference Vegetation Index(NDVI)method, we found that green region in false color synthesis image and the region with NDVI value > - 0.1 were just the BAB area. When - 0. 1 ≤ NDVI≤0. 2, slight BAB occurred, and bloom coverage in a pixel reaches 0-30%; when 0.2 <NDVI≤0.4, moderate bloom hap pened, bloom coverage in a pixel reached 31% -80%; dense bloom corned forth while NDVI >0.4,and bloom coverage in a pixel can be 81% -100%. From June to September is the key period for BAB breaking-out in Lake Dianchi, and the key factors to affect BAB breaking-out maybe sunshine and wind velocity. During this period, if the sunshine can last for only 4-5 hours and the wind velocity ≤2m/s, it's quite easy for BAB breaking-out.