**2. Estimation of physiochemical and biological index, a case study of Soan River**

### **2.1 Study site**

Sampling sites have been selected that vary in their physiochemical characteristics of the Soan River, Pakistan, at the time of spring 2015. These sites were named A (N 33°43.120, E 073°20.44), B (N 33°37.133, E 073°17.88), C (N 33°33.174, E 073°08.547), and D (N 33°32.906, E073°05.844) which was starts from site A and end at D site as mentioned in [26]. Their positions are shown on the map (**Figure 1**). The starting point was Simply dam, and the sampling sites were selected thereafter. Photos for Site A (**Figure 2**), Site B (**Figure 3**), Site C (**Figure 4**), and Site D (**Figure 5**) are presented. In addition, the site descriptions are listed in **Table 1**. Site A was considered upstream, site B and C considered mid-stream, while all the sites were categorized

### **Figure 1.**

*Map of study area and location of sampling sites at Soan River, Pakistan.* 

**Figure 2.** *Site A.*

with respect to major water pollution entry in the river. i.e., site A has no major pollution activities; site B receives poultry farms wastage; site C receives industry pollution wastage without treatment; site D is a dumping point of sewage from Rawalpindi and Islamabad. After that, no major pollution point was spotted.
