ho33 gɣ33 lo21, and South, 
i33 tʂʼɪ33 mɯ21, when combined, form the character for water, 
dʑi21. Li Jingsheng 李静生 speculates that the reason for this is that the Naxi were living in an area where a river flowed from north to south at the time of the creation of the north/south pictographs. We know that the Naxi are descendants of the ancient Qiang tribes of Northwest China, who migrated south and finally settled in Lijiang. During this migration, the only time that they were settled in an area with a river flowing north-south was during the late Shang (1600-1046 BC) and early Zhou (1045 BC-256 AD) dynasties, when the Naxi settled by the upper reaches of the Min River 岷江 in Sichuan, a tributary of the upper Yangtze. If the pictographs originated during this period, then that would make them of similar age to the oracle bones (most of which date to the last few centuries of the Shang dynasty).
Li adds to this theory by looking at the pictographs for the four seasons, which depict the climatic conditions associated with the particular season. The pictograph for Spring, 
ŋy21, clearly indicates that this is the windy season (the character is composed of sky + wind). Likewise, the character for Summer, 
ʐu21, shows the rainy season (sky + rain). Autumn, 
tʂʼɣ55, depicts a flower in bloom (sky + flower) and Winter , 
tsʼɪ33, is of course snow (sky + snow). The problem here is with Autumn 
. Flowers do not bloom in the Autumn months in the Lijiang basin, so why should the pictograph depict the flower? Li suggests that the pictograph originates from a time when the Naxi people were settled in an area with autumn flowering plants. The History of the Qiang People 《羌族史》 notes:“羌族分布在青藏高原东部边缘,山脉重重，地势陡峭，地面有岷江，黑水河。。。初秋时节，河谷正是紫罗兰盛开，而高山却是白雪皑皑”
“The Qiang were spread across the Eastern edge of the Tibetan plateau, a steep mountainous area through which the Min and Heishui Rivers flow…in early autumn, violas bloom across the river valley, and yet the mountaintops reveal an expanse of white snow.”
This shows the reasoning behind the flower in bloom as a symbol for autumn. From this Li backs up his claim that the Naxi were living by the Min River at the time of the character’s creation, dating some pictographs (at their very earliest) to the Shang/Zhou dynasties.
I’m an independent scholar of all hieroglyphic writing systems, and I also take the minority position that Dongba Proto-Writing is as old as Oracle Bone Script. I also think that both of them go back to Sumerian. My positions are based on my experience working with the hieroglyphic writing systems of the world, comparing their mechanics and forms.
I think what throws people off is two-fold : 1st Opposition to mono-genesis in writing systems and languages (Greenberg and Ruhlen) is political. Because political de-centralization is the song of the day, ideology in academia takes up the tune. 2nd What traveled from Sumer was not writing systems in toto but rather the idea of how they worked. Their appearances are mostly based on local pre-existing iconographic traditions. 3rd It takes a lot of experience and scholarly sense to really form reliable ideas on ancient hieroglyphic writing systems. I am trained professionally in linguistics and anthropology, and self-trained in art history and other necessary disciplines. However, another modern taboo in linguistics is against the study of writing systems. And so ignorance not only continues, it increases.
But this is what Academia is for, now-a-days, folks, retarding understanding and dooping the populace out of insight, knowledge, and especially money.
If someone studies hieroglyphic writing systems seriously enough, they will come to the same conclusions I have. Dongba Proto-Writing is not some 7th century invention, it’s a much more important part of history.
It’s also more than Oracle Bone Script or Bronze Script : I think it probably preserved a tradition of glyph coloration (polychrome glyph coloring) of which we have no evidence for Oracle Bone Script or Bronze Script. It might be like Egyptian is to Sumerian in that the Naxi People preserved the pictoral forms and coloration longer, and like Aztec to Mayan in that the Naxi People did not form the “new ideas” into writing but what is called “proto-writing”, textually-mneumonic iconography.
But even if I’m wrong, it holds an important place in the area between iconography, mneumonic and symbolic proto-writing, hieroglyphic writing, and non-hieroglyphic writing.
I would also like to add what a shame it is that the Chinese destroyed most of the manuscripts in the Cultural Revolution. If you read my previous post, you would understand. But if certain things from the pre-CR period have survived, it is not such a big loss for scholarship, at least my own studies.
A word on this. I have been to China and taught Chinese some months, and met many people, Chinese and non-Chinese and talked with them. The Chinese learned the concept of writing from the Sumerians (eventually, probably through the Indians and Elamites first), but then forgot or lied all about it, maybe claiming it was “from the gods” as so many peoples do. The Chinese in general do not believe in non-writing system etymology : They believe that Chinese has borrowed no words from any other language, only the other way around. This is part of their culture and world-view and there is little interest outside of traditional though-lines even today. I don’t want to step on the author’s or anyone’s toes who hasn’t been to China and met the Chinese. Their cultures (in the sense as used in anthropology) are very different from Western cultures, perhaps as different as they could be.
But in Egypt-Babylon-based civilizations we have also found reason to destroy old things. But it turns out this is not the same as China destroying Dongba codices. It would be the same if we obliterated all the ancient writings and art of the Middle East, for these shed similar light on the origin and function and etymology of modern Western writing systems and literatures as do the Dongba codices.
It’s a shame, but it’s not surprising, and it would have eventually happened. Perhaps in 100 years, the people of the world will destroy all old writings, their thoughts completely different from all of ours. What we find in old writings is that thinking changes and has changed, and probably will change again.