CAJ | 학술논문

目的探索湖沼地区水位变化对钉螺消长的影响及其规律.方法选择湖南省岳阳市长江村典型钉螺孳生地为现场,收集2001-2009年间的水位资料和螺情资料,包括平均水位、最高水位和最低水位及活螺密度、阳性螺密度、有螺框出现率和阳性螺框出现率等.描述水位指标和螺情指标的时间分布情况,用广义相加模型(GAM)拟合分析水位变化与钉螺消长之间的关系.结果 2001-2009年度中当年的平均水位和现场水淹天数对活螺密度的影响均有统计学意义(P＜0.01),表现为二次曲线关系,活螺密度在平均水位为25.0m,水淹天数为120 d时最低.当年的平均水位和上一年的现场水淹天数对阳性螺密度和阳性螺框出现率的影响均有统计学意义(P＜0.05),表现为二次曲线或三次及更复杂分段样曲线关系;对有螺框出现率的影响均有统计学意义(P值接近0.05),表现为二次曲线关系.阳性螺密度和阳性螺框出现率在平均水位为25.0 m,上一年水淹天数为110 d时最低;而有螺框出现率在平均水位为25.0 m,上一年水淹天数为160 d时最低.结论水位变化对钉螺消长的影响主要表现为非线性的光滑函数关系.水淹天数对有螺框出现率、阳性螺密度和阳性螺框出现率的影响存在滞后效应.用GAM拟合水位变化对钉螺消长的影响可能更贴近实际而便于解释,容易发现两者之间的潜在关系和规律.
목적 탐색호소지구수위변화대정라소장적영향급기규률.방법 선택호남성악양시장강촌전형정라자생지위현장,수집2001-2009년간적수위자료화라정자료,포괄평균수위、최고수위화최저수위급활라밀도、양성라밀도、유라광출현솔화양성라광출현솔등.묘술수위지표화라정지표적시간분포정황,용엄의상가모형(GAM)의합분석수위변화여정라소장지간적관계.결과 2001-2009년도중당년적평균수위화현장수엄천수대활라밀도적영향균유통계학의의(P＜0.01),표현위이차곡선관계,활라밀도재평균수위위25.0m,수엄천수위120 d시최저.당년적평균수위화상일년적현장수엄천수대양성라밀도화양성라광출현솔적영향균유통계학의의(P＜0.05),표현위이차곡선혹삼차급경복잡분단양곡선관계;대유라광출현솔적영향균유통계학의의(P치접근0.05),표현위이차곡선관계.양성라밀도화양성라광출현솔재평균수위위25.0 m,상일년수엄천수위110 d시최저;이유라광출현솔재평균수위위25.0 m,상일년수엄천수위160 d시최저.결론 수위변화대정라소장적영향주요표현위비선성적광활함수관계.수엄천수대유라광출현솔、양성라밀도화양성라광출현솔적영향존재체후효응.용GAM의합수위변화대정라소장적영향가능경첩근실제이편우해석,용역발현량자지간적잠재관계화규률.
Objective To explore the impact and regularity of snail population after changing of water level and to develop effective control and prediction programs. Methods A typical snail habitat closed to Changjiang county in Yueyang city, Hunan province was selected as the survey field.Data on water level and the changing trend of snail population during 2001-2009 including the average water level, maximum and minimum water levels, snail and infected snail densities,proportion of sampling frames with living and infected snails etc. were collected. The distribution of water level and snail indexes were described and a general additive model(GAM)for the relationships between these indexes were also fitted. Results Impacts of the average water level and the watered-out days in current year in the surveyed field on the snail density were statistically significant(P＜0.01), showing a quadratic curve association. The snail density remained at the lowest level when the average water level was at 25.0 m and the surveyed field watered-out days was 120. The average water level in current year and the field watered-out days in the past year showed statistically significant impacts on the infected snail density(P＜0.001), the proportion of sampling frames with infected snails(P＜0.05)and living snails(P value neared 0.05), presented a quadratic curve, a cubic curve or even a more complicated piecewise curve association. Both the infected snail density and the proportion of sampling frames with infected snails remained at the lowest level when the average water level was at 25.0 m and the watered-out days in the past year was 110, while the proportion of sampling frames with living snails kept the lowest level when the average water level was at 25.0 m and the watered-out days in the past year was 160. Conclusion The water level and the field watered-out days affected the development of snail population directly. The changing water level had an impact on snail population change, which mainly presented as nonlinear smooth function relation. Impact of the field watered out days on the infected snail density and the proportion of sampling frames with living snails and infected snails showed a hysteresis effect. The snail density was predicted to be retaining a high level when the water level was 24.0 m and the field watered-out days was 3 months. It had obvious advantages to fit the relationship of the changing water level and the snail indexes with a GAM which could get closer to the reality as well as easier to find and explain the potential associations and regulations.