Уменьшение норматива длины учетного маршрута с помощью двойного расслоения выборки

Abstract

On 2 territories, different in areas and levels of linear density populations of moose, the number of wild animals by the trails on the route was counted. Census data were recorded and processed by two methods: traditional - winter route census (WRC) with grouping of sample by category of land (forest, field, swamp), and the new one with grouping of segments of the route according to the level of linear density (trace / 1 km of route), separately for each stratum. Stratification and lamination of the sample within the strata on sections of the rout with different linear density function as a two-fold lamination of the sample route by the tracks. The processing of data using the new methodology was performed on a special PC that calculates, among other things, evaluation of the number according to the layers, strata, territories in total and the value of the standard error (SE) of the number estimate N. On site No. 1 the linear density of moose population was 0.774 trace/ 1 km of the route, the original standard of route length was 1.82 km/1 thousand ha, SE (WrC) - 17.2%; SE (new method) - 6.0 %, the rate of decline SE =2.87 times. When the reduction ratio in the minimum density stratum equals 75%, total ratio 1.22 km, SE = 8.4%. When cut across all strata of 50% (total ratio 0.92 km) the result is negative (SE = 11.3%). The optimal total ratio is 1.0 km/ 1 thousand hectares, while the norm in the minimum density strata is 0.6 km / 1 thousand ha. Expected value of SE = 8.5 - 9.9 %. On site No. 2 the linear density of moose population is 2.03 trace /1 km of the route, the original standard of path length is 1.09 km/1 thousand ha, SE (WRC) = 11.2%; SE (new method) = 4.4%, and the rate of decline SE=2.55 times. When the ratio in the minimum density stratum reduced by 75%, reduced ratio was 0.94 km, SE = 7.0%. When cut across all strata of 50% - total ratio = 0,56 km, SE = 9.5%. Optimal planning standard in the sample is 0.6 km / 1 thousand hectares, while the norm in the strata with a minimum density is 0.3 km / thousand ha. Expected value SE < 9.5 % N. Percentage of reduction of the route length standard in both areas is the same and equals to 45%.