MAPPING AND GIS ANALYSIS OF HOUSEHOLD PONDS IN THE HALDA RIVER WATERSHED

Earth Science Malaysia

article

Shubha Sarker¹  Razat Suvra Das²  Sayedur Rahman Chowdhury¹  M. Shahadat Hossain¹  Milan Kumar Shiuli¹ 

[1] Institute of Marine Sciences, University of Chittagong;Department of Oceanography, Noakhali Science and Technology University

关键词: Digitization;    Pond Map;    Halda river watershed;    Relative Neighbourhood Graph (RNG).;   

DOI  :  10.26480/esmy.02.2021.65.70

学科分类：地球科学(综合)

来源: Zibeline International

【 摘 要 】

A project was undertaken to create an inventory and generate relevant baseline information on household ponds in the Halda river watershed. This research is mostly belongs to Mapping and GIS analysis. At first all ponds are divided into two groups, large ponds (above 1000 m2 area) and small ponds (below 1000 m2 area). Then some important geometric and geographic parameters of large ponds are calculated. They are area, elevation and elevation wise distribution, neighbourhood distances, length, width, aspect ratio. Descriptive statistics are generated on these parameters and their mean, median, mode, sum, standard deviation, count, minimum, maximum etc. were calculated. Some informative charts are included in the result showing the findings. To calculate the area and total number of small ponds, intentional sampling is used. The average area of large ponds is about 2670 m2. The average elevation of these ponds is found 11.75 m. The mean neighbouring distance among these ponds is about 237 m and these ponds are rectangular shape in average because their average aspect ratio is 1.46 where aspect ratio 1.00 means the perfect square shape. The total area occupied by all ponds (both large and small) is estimated as 44.2 km2 and it is 2.63% of whole watershed area and 7.38 % of the valley area (here <20 m elevation and relatively plain). The total number of pond is estimated 43745 (large pond 6730 and small pond 37015) and almost all of them are in the valley area of Halda river watershed.

【 授权许可】

CC BY